Documentation/DocBook/media/v4l/controls.xml

   1   <section id="control">
   2     <title>User Controls</title>
   3
   4     <para>Devices typically have a number of user-settable controls
   5 such as brightness, saturation and so on, which would be presented to
   6 the user on a graphical user interface. But, different devices
   7 will have different controls available, and furthermore, the range of
   8 possible values, and the default value will vary from device to
   9 device. The control ioctls provide the information and a mechanism to
  10 create a nice user interface for these controls that will work
  11 correctly with any device.</para>
  12
  13     <para>All controls are accessed using an ID value. V4L2 defines
  14 several IDs for specific purposes. Drivers can also implement their
  15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
  16 and higher values. The pre-defined control IDs have the prefix
  17 <constant>V4L2_CID_</constant>, and are listed in <xref
  18 linkend="control-id" />. The ID is used when querying the attributes of
  19 a control, and when getting or setting the current value.</para>
  20
  21     <para>Generally applications should present controls to the user
  22 without assumptions about their purpose. Each control comes with a
  23 name string the user is supposed to understand. When the purpose is
  24 non-intuitive the driver writer should provide a user manual, a user
  25 interface plug-in or a driver specific panel application. Predefined
  26 IDs were introduced to change a few controls programmatically, for
  27 example to mute a device during a channel switch.</para>
  28
  29     <para>Drivers may enumerate different controls after switching
  30 the current video input or output, tuner or modulator, or audio input
  31 or output. Different in the sense of other bounds, another default and
  32 current value, step size or other menu items. A control with a certain
  33 <emphasis>custom</emphasis> ID can also change name and
  34 type.<footnote>
  35         <para>It will be more convenient for applications if drivers
  36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
  37 that was never required.</para>
  38       </footnote> Control values are stored globally, they do not
  39 change when switching except to stay within the reported bounds. They
  40 also do not change &eg; when the device is opened or closed, when the
  41 tuner radio frequency is changed or generally never without
  42 application request. Since V4L2 specifies no event mechanism, panel
  43 applications intended to cooperate with other panel applications (be
  44 they built into a larger application, as a TV viewer) may need to
  45 regularly poll control values to update their user
  46 interface.<footnote>
  47         <para>Applications could call an ioctl to request events.
  48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
  49 shared properties the &func-select; function would indicate
  50 readability until any ioctl (querying the properties) is
  51 called.</para>
  52       </footnote></para>
  53
  54     <para>
  55       All controls use machine endianness.
  56     </para>
  57
  58     <table pgwide="1" frame="none" id="control-id">
  59       <title>Control IDs</title>
  60       <tgroup cols="3">
  61         &cs-def;
  62         <thead>
  63           <row>
  64             <entry>ID</entry>
  65             <entry>Type</entry>
  66             <entry>Description</entry>
  67           </row>
  68         </thead>
  69         <tbody valign="top">
  70           <row>
  71             <entry><constant>V4L2_CID_BASE</constant></entry>
  72             <entry></entry>
  73             <entry>First predefined ID, equal to
  74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
  75           </row>
  76           <row>
  77             <entry><constant>V4L2_CID_USER_BASE</constant></entry>
  78             <entry></entry>
  79             <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
  80           </row>
  81           <row>
  82             <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
  83             <entry>integer</entry>
  84             <entry>Picture brightness, or more precisely, the black
  85 level.</entry>
  86           </row>
  87           <row>
  88             <entry><constant>V4L2_CID_CONTRAST</constant></entry>
  89             <entry>integer</entry>
  90             <entry>Picture contrast or luma gain.</entry>
  91           </row>
  92           <row>
  93             <entry><constant>V4L2_CID_SATURATION</constant></entry>
  94             <entry>integer</entry>
  95             <entry>Picture color saturation or chroma gain.</entry>
  96           </row>
  97           <row>
  98             <entry><constant>V4L2_CID_HUE</constant></entry>
  99             <entry>integer</entry>
 100             <entry>Hue or color balance.</entry>
 101           </row>
 102           <row>
 103             <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
 104             <entry>integer</entry>
 105             <entry>Overall audio volume. Note some drivers also
 106 provide an OSS or ALSA mixer interface.</entry>
 107           </row>
 108           <row>
 109             <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
 110             <entry>integer</entry>
 111             <entry>Audio stereo balance. Minimum corresponds to all
 112 the way left, maximum to right.</entry>
 113           </row>
 114           <row>
 115             <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
 116             <entry>integer</entry>
 117             <entry>Audio bass adjustment.</entry>
 118           </row>
 119           <row>
 120             <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
 121             <entry>integer</entry>
 122             <entry>Audio treble adjustment.</entry>
 123           </row>
 124           <row>
 125             <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
 126             <entry>boolean</entry>
 127             <entry>Mute audio, &ie; set the volume to zero, however
 128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
 129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
 130 noise. Actually the entire device should be reset to a low power
 131 consumption state.</entry>
 132           </row>
 133           <row>
 134             <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
 135             <entry>boolean</entry>
 136             <entry>Loudness mode (bass boost).</entry>
 137           </row>
 138           <row>
 139             <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
 140             <entry>integer</entry>
 141             <entry>Another name for brightness (not a synonym of
 142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
 143 and should not be used in new drivers and applications.</entry>
 144           </row>
 145           <row>
 146             <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
 147             <entry>boolean</entry>
 148             <entry>Automatic white balance (cameras).</entry>
 149           </row>
 150           <row>
 151             <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
 152             <entry>button</entry>
 153             <entry>This is an action control. When set (the value is
 154 ignored), the device will do a white balance and then hold the current
 155 setting. Contrast this with the boolean
 156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
 157 activated, keeps adjusting the white balance.</entry>
 158           </row>
 159           <row>
 160             <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
 161             <entry>integer</entry>
 162             <entry>Red chroma balance.</entry>
 163           </row>
 164           <row>
 165             <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
 166             <entry>integer</entry>
 167             <entry>Blue chroma balance.</entry>
 168           </row>
 169           <row>
 170             <entry><constant>V4L2_CID_GAMMA</constant></entry>
 171             <entry>integer</entry>
 172             <entry>Gamma adjust.</entry>
 173           </row>
 174           <row>
 175             <entry><constant>V4L2_CID_WHITENESS</constant></entry>
 176             <entry>integer</entry>
 177             <entry>Whiteness for grey-scale devices. This is a synonym
 178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
 179 and should not be used in new drivers and applications.</entry>
 180           </row>
 181           <row>
 182             <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
 183             <entry>integer</entry>
 184             <entry>Exposure (cameras). [Unit?]</entry>
 185           </row>
 186           <row>
 187             <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
 188             <entry>boolean</entry>
 189             <entry>Automatic gain/exposure control.</entry>
 190           </row>
 191           <row>
 192             <entry><constant>V4L2_CID_GAIN</constant></entry>
 193             <entry>integer</entry>
 194             <entry>Gain control.</entry>
 195           </row>
 196           <row>
 197             <entry><constant>V4L2_CID_HFLIP</constant></entry>
 198             <entry>boolean</entry>
 199             <entry>Mirror the picture horizontally.</entry>
 200           </row>
 201           <row>
 202             <entry><constant>V4L2_CID_VFLIP</constant></entry>
 203             <entry>boolean</entry>
 204             <entry>Mirror the picture vertically.</entry>
 205           </row>
 206         <row>
 207           <entry><constant>V4L2_CID_HCENTER_DEPRECATED</constant> (formerly <constant>V4L2_CID_HCENTER</constant>)</entry>
 208             <entry>integer</entry>
 209             <entry>Horizontal image centering. This control is
 210 deprecated. New drivers and applications should use the <link
 211 linkend="camera-controls">Camera class controls</link>
 212 <constant>V4L2_CID_PAN_ABSOLUTE</constant>,
 213 <constant>V4L2_CID_PAN_RELATIVE</constant> and
 214 <constant>V4L2_CID_PAN_RESET</constant> instead.</entry>
 215           </row>
 216           <row>
 217             <entry><constant>V4L2_CID_VCENTER_DEPRECATED</constant>
 218             (formerly <constant>V4L2_CID_VCENTER</constant>)</entry>
 219             <entry>integer</entry>
 220             <entry>Vertical image centering. Centering is intended to
 221 <emphasis>physically</emphasis> adjust cameras. For image cropping see
 222 <xref linkend="crop" />, for clipping <xref linkend="overlay" />. This
 223 control is deprecated. New drivers and applications should use the
 224 <link linkend="camera-controls">Camera class controls</link>
 225 <constant>V4L2_CID_TILT_ABSOLUTE</constant>,
 226 <constant>V4L2_CID_TILT_RELATIVE</constant> and
 227 <constant>V4L2_CID_TILT_RESET</constant> instead.</entry>
 228           </row>
 229           <row id="v4l2-power-line-frequency">
 230             <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
 231             <entry>enum</entry>
 232             <entry>Enables a power line frequency filter to avoid
 233 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
 234 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
 235 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
 236 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
 237 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
 238           </row>
 239           <row>
 240             <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
 241             <entry>boolean</entry>
 242             <entry>Enables automatic hue control by the device. The
 243 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
 244 hue control is enabled is undefined, drivers should ignore such
 245 request.</entry>
 246           </row>
 247           <row>
 248             <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
 249             <entry>integer</entry>
 250             <entry>This control specifies the white balance settings
 251 as a color temperature in Kelvin. A driver should have a minimum of
 252 2800 (incandescent) to 6500 (daylight). For more information about
 253 color temperature see <ulink
 254 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
 255           </row>
 256           <row>
 257             <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
 258             <entry>integer</entry>
 259             <entry>Adjusts the sharpness filters in a camera. The
 260 minimum value disables the filters, higher values give a sharper
 261 picture.</entry>
 262           </row>
 263           <row>
 264             <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
 265             <entry>integer</entry>
 266             <entry>Adjusts the backlight compensation in a camera. The
 267 minimum value disables backlight compensation.</entry>
 268           </row>
 269           <row>
 270             <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
 271             <entry>boolean</entry>
 272             <entry>Chroma automatic gain control.</entry>
 273           </row>
 274           <row>
 275             <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
 276             <entry>integer</entry>
 277             <entry>Adjusts the Chroma gain control (for use when chroma AGC
 278             is disabled).</entry>
 279           </row>
 280           <row>
 281             <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
 282             <entry>boolean</entry>
 283             <entry>Enable the color killer (&ie; force a black &amp; white image in case of a weak video signal).</entry>
 284           </row>
 285           <row id="v4l2-colorfx">
 286             <entry><constant>V4L2_CID_COLORFX</constant></entry>
 287             <entry>enum</entry>
 288             <entry>Selects a color effect. The following values are defined:
 289             </entry>
 290           </row><row>
 291           <entry></entry>
 292           <entry></entry>
 293             <entrytbl spanname="descr" cols="2">
 294               <tbody valign="top">
 295                 <row>
 296                   <entry><constant>V4L2_COLORFX_NONE</constant>&nbsp;</entry>
 297                   <entry>Color effect is disabled.</entry>
 298                 </row>
 299                 <row>
 300                   <entry><constant>V4L2_COLORFX_ANTIQUE</constant>&nbsp;</entry>
 301                   <entry>An aging (old photo) effect.</entry>
 302                 </row>
 303                 <row>
 304                   <entry><constant>V4L2_COLORFX_ART_FREEZE</constant>&nbsp;</entry>
 305                   <entry>Frost color effect.</entry>
 306                 </row>
 307                 <row>
 308                   <entry><constant>V4L2_COLORFX_AQUA</constant>&nbsp;</entry>
 309                   <entry>Water color, cool tone.</entry>
 310                 </row>
 311                 <row>
 312                   <entry><constant>V4L2_COLORFX_BW</constant>&nbsp;</entry>
 313                   <entry>Black and white.</entry>
 314                 </row>
 315                 <row>
 316                   <entry><constant>V4L2_COLORFX_EMBOSS</constant>&nbsp;</entry>
 317                   <entry>Emboss, the highlights and shadows replace light/dark boundaries
 318                   and low contrast areas are set to a gray background.</entry>
 319                 </row>
 320                 <row>
 321                   <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant>&nbsp;</entry>
 322                   <entry>Grass green.</entry>
 323                 </row>
 324                 <row>
 325                   <entry><constant>V4L2_COLORFX_NEGATIVE</constant>&nbsp;</entry>
 326                   <entry>Negative.</entry>
 327                 </row>
 328                 <row>
 329                   <entry><constant>V4L2_COLORFX_SEPIA</constant>&nbsp;</entry>
 330                   <entry>Sepia tone.</entry>
 331                 </row>
 332                 <row>
 333                   <entry><constant>V4L2_COLORFX_SKETCH</constant>&nbsp;</entry>
 334                   <entry>Sketch.</entry>
 335                 </row>
 336                 <row>
 337                   <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant>&nbsp;</entry>
 338                   <entry>Skin whiten.</entry>
 339                 </row>
 340                 <row>
 341                   <entry><constant>V4L2_COLORFX_SKY_BLUE</constant>&nbsp;</entry>
 342                   <entry>Sky blue.</entry>
 343                 </row>
 344                 <row>
 345                   <entry><constant>V4L2_COLORFX_SOLARIZATION</constant>&nbsp;</entry>
 346                   <entry>Solarization, the image is partially reversed in tone,
 347                   only color values above or below a certain threshold are inverted.
 348                   </entry>
 349                 </row>
 350                 <row>
 351                   <entry><constant>V4L2_COLORFX_SILHOUETTE</constant>&nbsp;</entry>
 352                   <entry>Silhouette (outline).</entry>
 353                 </row>
 354                 <row>
 355                   <entry><constant>V4L2_COLORFX_VIVID</constant>&nbsp;</entry>
 356                   <entry>Vivid colors.</entry>
 357                 </row>
 358                 <row>
 359                   <entry><constant>V4L2_COLORFX_SET_CBCR</constant>&nbsp;</entry>
 360                   <entry>The Cb and Cr chroma components are replaced by fixed
 361                   coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
 362                   control.</entry>
 363                 </row>
 364               </tbody>
 365             </entrytbl>
 366           </row>
 367           <row>
 368             <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
 369             <entry>integer</entry>
 370             <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
 371             color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
 372             Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
 373           </entry>
 374           </row>
 375           <row>
 376             <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
 377             <entry>boolean</entry>
 378             <entry>Enable Automatic Brightness.</entry>
 379           </row>
 380           <row>
 381             <entry><constant>V4L2_CID_ROTATE</constant></entry>
 382             <entry>integer</entry>
 383             <entry>Rotates the image by specified angle. Common angles are 90,
 384             270 and 180. Rotating the image to 90 and 270 will reverse the height
 385             and width of the display window. It is necessary to set the new height and
 386             width of the picture using the &VIDIOC-S-FMT; ioctl according to
 387             the rotation angle selected.</entry>
 388           </row>
 389           <row>
 390             <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
 391             <entry>integer</entry>
 392             <entry>Sets the background color on the current output device.
 393             Background color needs to be specified in the RGB24 format. The
 394             supplied 32 bit value is interpreted as bits 0-7 Red color information,
 395             bits 8-15 Green color information, bits 16-23 Blue color
 396             information and bits 24-31 must be zero.</entry>
 397           </row>
 398           <row>
 399             <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
 400                 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
 401             <entry>boolean</entry>
 402             <entry>Switch on or off the illuminator 1 or 2 of the device
 403                 (usually a microscope).</entry>
 404           </row>
 405           <row>
 406             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
 407             <entry>integer</entry>
 408             <entry>This is a read-only control that can be read by the application
 409 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
 410 The value is the minimum number of CAPTURE buffers that is necessary for hardware
 411 to work.</entry>
 412           </row>
 413           <row>
 414             <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
 415             <entry>integer</entry>
 416             <entry>This is a read-only control that can be read by the application
 417 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
 418 The value is the minimum number of OUTPUT buffers that is necessary for hardware
 419 to work.</entry>
 420           </row>
 421           <row id="v4l2-alpha-component">
 422             <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
 423             <entry>integer</entry>
 424             <entry> Sets the alpha color component on the capture device or on
 425             the capture buffer queue of a mem-to-mem device. When a mem-to-mem
 426             device produces frame format that includes an alpha component
 427             (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
 428             and the alpha value is not defined by the mem-to-mem input data
 429             this control lets you select the alpha component value of all
 430             pixels. It is applicable to any pixel format that contains an alpha
 431             component.
 432             </entry>
 433           </row>
 434           <row>
 435             <entry><constant>V4L2_CID_LASTP1</constant></entry>
 436             <entry></entry>
 437             <entry>End of the predefined control IDs (currently
 438               <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
 439           </row>
 440           <row>
 441             <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
 442             <entry></entry>
 443             <entry>ID of the first custom (driver specific) control.
 444 Applications depending on particular custom controls should check the
 445 driver name and version, see <xref linkend="querycap" />.</entry>
 446           </row>
 447         </tbody>
 448       </tgroup>
 449     </table>
 450
 451     <para>Applications can enumerate the available controls with the
 452 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
 453 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
 454 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
 455 <constant>VIDIOC_G_CTRL</constant> and
 456 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
 457 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
 458 more menu type controls.</para>
 459
 460     <example>
 461       <title>Enumerating all controls</title>
 462
 463       <programlisting>
 464 &v4l2-queryctrl; queryctrl;
 465 &v4l2-querymenu; querymenu;
 466
 467 static void
 468 enumerate_menu (void)
 469 {
 470         printf ("  Menu items:\n");
 471
 472         memset (&amp;querymenu, 0, sizeof (querymenu));
 473         querymenu.id = queryctrl.id;
 474
 475         for (querymenu.index = queryctrl.minimum;
 476              querymenu.index &lt;= queryctrl.maximum;
 477               querymenu.index++) {
 478                 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &amp;querymenu)) {
 479                         printf ("  %s\n", querymenu.name);
 480                 }
 481         }
 482 }
 483
 484 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 485
 486 for (queryctrl.id = V4L2_CID_BASE;
 487      queryctrl.id &lt; V4L2_CID_LASTP1;
 488      queryctrl.id++) {
 489         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 490                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 491                         continue;
 492
 493                 printf ("Control %s\n", queryctrl.name);
 494
 495                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 496                         enumerate_menu ();
 497         } else {
 498                 if (errno == EINVAL)
 499                         continue;
 500
 501                 perror ("VIDIOC_QUERYCTRL");
 502                 exit (EXIT_FAILURE);
 503         }
 504 }
 505
 506 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
 507      queryctrl.id++) {
 508         if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 509                 if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED)
 510                         continue;
 511
 512                 printf ("Control %s\n", queryctrl.name);
 513
 514                 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
 515                         enumerate_menu ();
 516         } else {
 517                 if (errno == EINVAL)
 518                         break;
 519
 520                 perror ("VIDIOC_QUERYCTRL");
 521                 exit (EXIT_FAILURE);
 522         }
 523 }
 524 </programlisting>
 525     </example>
 526
 527     <example>
 528       <title>Changing controls</title>
 529
 530       <programlisting>
 531 &v4l2-queryctrl; queryctrl;
 532 &v4l2-control; control;
 533
 534 memset (&amp;queryctrl, 0, sizeof (queryctrl));
 535 queryctrl.id = V4L2_CID_BRIGHTNESS;
 536
 537 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;queryctrl)) {
 538         if (errno != EINVAL) {
 539                 perror ("VIDIOC_QUERYCTRL");
 540                 exit (EXIT_FAILURE);
 541         } else {
 542                 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 543         }
 544 } else if (queryctrl.flags &amp; V4L2_CTRL_FLAG_DISABLED) {
 545         printf ("V4L2_CID_BRIGHTNESS is not supported\n");
 546 } else {
 547         memset (&amp;control, 0, sizeof (control));
 548         control.id = V4L2_CID_BRIGHTNESS;
 549         control.value = queryctrl.default_value;
 550
 551         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)) {
 552                 perror ("VIDIOC_S_CTRL");
 553                 exit (EXIT_FAILURE);
 554         }
 555 }
 556
 557 memset (&amp;control, 0, sizeof (control));
 558 control.id = V4L2_CID_CONTRAST;
 559
 560 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &amp;control)) {
 561         control.value += 1;
 562
 563         /* The driver may clamp the value or return ERANGE, ignored here */
 564
 565         if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &amp;control)
 566             &amp;&amp; errno != ERANGE) {
 567                 perror ("VIDIOC_S_CTRL");
 568                 exit (EXIT_FAILURE);
 569         }
 570 /* Ignore if V4L2_CID_CONTRAST is unsupported */
 571 } else if (errno != EINVAL) {
 572         perror ("VIDIOC_G_CTRL");
 573         exit (EXIT_FAILURE);
 574 }
 575
 576 control.id = V4L2_CID_AUDIO_MUTE;
 577 control.value = TRUE; /* silence */
 578
 579 /* Errors ignored */
 580 ioctl (fd, VIDIOC_S_CTRL, &amp;control);
 581 </programlisting>
 582     </example>
 583   </section>
 584
 585   <section id="extended-controls">
 586     <title>Extended Controls</title>
 587
 588     <section>
 589       <title>Introduction</title>
 590
 591       <para>The control mechanism as originally designed was meant
 592 to be used for user settings (brightness, saturation, etc). However,
 593 it turned out to be a very useful model for implementing more
 594 complicated driver APIs where each driver implements only a subset of
 595 a larger API.</para>
 596
 597       <para>The MPEG encoding API was the driving force behind
 598 designing and implementing this extended control mechanism: the MPEG
 599 standard is quite large and the currently supported hardware MPEG
 600 encoders each only implement a subset of this standard. Further more,
 601 many parameters relating to how the video is encoded into an MPEG
 602 stream are specific to the MPEG encoding chip since the MPEG standard
 603 only defines the format of the resulting MPEG stream, not how the
 604 video is actually encoded into that format.</para>
 605
 606       <para>Unfortunately, the original control API lacked some
 607 features needed for these new uses and so it was extended into the
 608 (not terribly originally named) extended control API.</para>
 609
 610       <para>Even though the MPEG encoding API was the first effort
 611 to use the Extended Control API, nowadays there are also other classes
 612 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
 613 The Extended Controls API as well as all Extended Controls classes are
 614 described in the following text.</para>
 615     </section>
 616
 617     <section>
 618       <title>The Extended Control API</title>
 619
 620       <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
 621 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
 622 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
 623 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
 624 since it is often required to atomically change several controls at
 625 once.</para>
 626
 627       <para>Each of the new ioctls expects a pointer to a
 628 &v4l2-ext-controls;. This structure contains a pointer to the control
 629 array, a count of the number of controls in that array and a control
 630 class. Control classes are used to group similar controls into a
 631 single class. For example, control class
 632 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
 633 (&ie; all controls that can also be set using the old
 634 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
 635 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
 636 relating to MPEG encoding, etc.</para>
 637
 638       <para>All controls in the control array must belong to the
 639 specified control class. An error is returned if this is not the
 640 case.</para>
 641
 642       <para>It is also possible to use an empty control array (count
 643 == 0) to check whether the specified control class is
 644 supported.</para>
 645
 646       <para>The control array is a &v4l2-ext-control; array. The
 647 <structname>v4l2_ext_control</structname> structure is very similar to
 648 &v4l2-control;, except for the fact that it also allows for 64-bit
 649 values and pointers to be passed.</para>
 650
 651       <para>It is important to realize that due to the flexibility of
 652 controls it is necessary to check whether the control you want to set
 653 actually is supported in the driver and what the valid range of values
 654 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
 655 check this. Also note that it is possible that some of the menu
 656 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
 657 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
 658 return an error). A good example is the list of supported MPEG audio
 659 bitrates. Some drivers only support one or two bitrates, others
 660 support a wider range.</para>
 661
 662       <para>
 663         All controls use machine endianness.
 664       </para>
 665     </section>
 666
 667     <section>
 668       <title>Enumerating Extended Controls</title>
 669
 670       <para>The recommended way to enumerate over the extended
 671 controls is by using &VIDIOC-QUERYCTRL; in combination with the
 672 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
 673
 674       <informalexample>
 675         <programlisting>
 676 &v4l2-queryctrl; qctrl;
 677
 678 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
 679 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 680         /* ... */
 681         qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 682 }
 683 </programlisting>
 684       </informalexample>
 685
 686       <para>The initial control ID is set to 0 ORed with the
 687 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
 688 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
 689 control with a higher ID than the specified one. When no such controls
 690 are found an error is returned.</para>
 691
 692       <para>If you want to get all controls within a specific control
 693 class, then you can set the initial
 694 <structfield>qctrl.id</structfield> value to the control class and add
 695 an extra check to break out of the loop when a control of another
 696 control class is found:</para>
 697
 698       <informalexample>
 699         <programlisting>
 700 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
 701 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &amp;qctrl)) {
 702         if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
 703                 break;
 704                 /* ... */
 705                 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
 706         }
 707 </programlisting>
 708       </informalexample>
 709
 710       <para>The 32-bit <structfield>qctrl.id</structfield> value is
 711 subdivided into three bit ranges: the top 4 bits are reserved for
 712 flags (&eg; <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
 713 actually part of the ID. The remaining 28 bits form the control ID, of
 714 which the most significant 12 bits define the control class and the
 715 least significant 16 bits identify the control within the control
 716 class. It is guaranteed that these last 16 bits are always non-zero
 717 for controls. The range of 0x1000 and up are reserved for
 718 driver-specific controls. The macro
 719 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
 720 ID based on a control ID.</para>
 721
 722       <para>If the driver does not support extended controls, then
 723 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
 724 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
 725 that case the old method of enumerating control should be used (see
 726 1.8). But if it is supported, then it is guaranteed to enumerate over
 727 all controls, including driver-private controls.</para>
 728     </section>
 729
 730     <section>
 731       <title>Creating Control Panels</title>
 732
 733       <para>It is possible to create control panels for a graphical
 734 user interface where the user can select the various controls.
 735 Basically you will have to iterate over all controls using the method
 736 described above. Each control class starts with a control of type
 737 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
 738 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
 739 control class which can be used as the title of a tab page within a
 740 control panel.</para>
 741
 742       <para>The flags field of &v4l2-queryctrl; also contains hints on
 743 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
 744 for more details.</para>
 745     </section>
 746
 747     <section id="mpeg-controls">
 748       <title>MPEG Control Reference</title>
 749
 750       <para>Below all controls within the MPEG control class are
 751 described. First the generic controls, then controls specific for
 752 certain hardware.</para>
 753
 754       <section>
 755         <title>Generic MPEG Controls</title>
 756
 757         <table pgwide="1" frame="none" id="mpeg-control-id">
 758           <title>MPEG Control IDs</title>
 759           <tgroup cols="4">
 760             <colspec colname="c1" colwidth="1*" />
 761             <colspec colname="c2" colwidth="6*" />
 762             <colspec colname="c3" colwidth="2*" />
 763             <colspec colname="c4" colwidth="6*" />
 764             <spanspec namest="c1" nameend="c2" spanname="id" />
 765             <spanspec namest="c2" nameend="c4" spanname="descr" />
 766             <thead>
 767               <row>
 768                 <entry spanname="id" align="left">ID</entry>
 769                 <entry align="left">Type</entry>
 770               </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
 771               </row>
 772             </thead>
 773             <tbody valign="top">
 774               <row><entry></entry></row>
 775               <row>
 776                 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant>&nbsp;</entry>
 777                 <entry>class</entry>
 778               </row><row><entry spanname="descr">The MPEG class
 779 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
 780 description of this control class. This description can be used as the
 781 caption of a Tab page in a GUI, for example.</entry>
 782               </row>
 783               <row><entry></entry></row>
 784               <row id="v4l2-mpeg-stream-type">
 785                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant>&nbsp;</entry>
 786                 <entry>enum&nbsp;v4l2_mpeg_stream_type</entry>
 787               </row><row><entry spanname="descr">The MPEG-1, -2 or -4
 788 output stream type. One cannot assume anything here. Each hardware
 789 MPEG encoder tends to support different subsets of the available MPEG
 790 stream types. This control is specific to multiplexed MPEG streams.
 791 The currently defined stream types are:</entry>
 792               </row>
 793               <row>
 794                 <entrytbl spanname="descr" cols="2">
 795                   <tbody valign="top">
 796                     <row>
 797                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant>&nbsp;</entry>
 798                       <entry>MPEG-2 program stream</entry>
 799                     </row>
 800                     <row>
 801                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant>&nbsp;</entry>
 802                       <entry>MPEG-2 transport stream</entry>
 803                     </row>
 804                     <row>
 805                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant>&nbsp;</entry>
 806                       <entry>MPEG-1 system stream</entry>
 807                     </row>
 808                     <row>
 809                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant>&nbsp;</entry>
 810                       <entry>MPEG-2 DVD-compatible stream</entry>
 811                     </row>
 812                     <row>
 813                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant>&nbsp;</entry>
 814                       <entry>MPEG-1 VCD-compatible stream</entry>
 815                     </row>
 816                     <row>
 817                       <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant>&nbsp;</entry>
 818                       <entry>MPEG-2 SVCD-compatible stream</entry>
 819                     </row>
 820                   </tbody>
 821                 </entrytbl>
 822               </row>
 823               <row><entry></entry></row>
 824               <row>
 825                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant>&nbsp;</entry>
 826                 <entry>integer</entry>
 827               </row><row><entry spanname="descr">Program Map Table
 828 Packet ID for the MPEG transport stream (default 16)</entry>
 829               </row>
 830               <row><entry></entry></row>
 831               <row>
 832                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant>&nbsp;</entry>
 833                 <entry>integer</entry>
 834               </row><row><entry spanname="descr">Audio Packet ID for
 835 the MPEG transport stream (default 256)</entry>
 836               </row>
 837               <row><entry></entry></row>
 838               <row>
 839                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant>&nbsp;</entry>
 840                 <entry>integer</entry>
 841               </row><row><entry spanname="descr">Video Packet ID for
 842 the MPEG transport stream (default 260)</entry>
 843               </row>
 844               <row><entry></entry></row>
 845               <row>
 846                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant>&nbsp;</entry>
 847                 <entry>integer</entry>
 848               </row><row><entry spanname="descr">Packet ID for the
 849 MPEG transport stream carrying PCR fields (default 259)</entry>
 850               </row>
 851               <row><entry></entry></row>
 852               <row>
 853                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant>&nbsp;</entry>
 854                 <entry>integer</entry>
 855               </row><row><entry spanname="descr">Audio ID for MPEG
 856 PES</entry>
 857               </row>
 858               <row><entry></entry></row>
 859               <row>
 860                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant>&nbsp;</entry>
 861                 <entry>integer</entry>
 862               </row><row><entry spanname="descr">Video ID for MPEG
 863 PES</entry>
 864               </row>
 865               <row><entry></entry></row>
 866               <row id="v4l2-mpeg-stream-vbi-fmt">
 867                 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant>&nbsp;</entry>
 868                 <entry>enum&nbsp;v4l2_mpeg_stream_vbi_fmt</entry>
 869               </row><row><entry spanname="descr">Some cards can embed
 870 VBI data (&eg; Closed Caption, Teletext) into the MPEG stream. This
 871 control selects whether VBI data should be embedded, and if so, what
 872 embedding method should be used. The list of possible VBI formats
 873 depends on the driver. The currently defined VBI format types
 874 are:</entry>
 875               </row>
 876               <row>
 877                 <entrytbl spanname="descr" cols="2">
 878                   <tbody valign="top">
 879                     <row>
 880                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant>&nbsp;</entry>
 881                       <entry>No VBI in the MPEG stream</entry>
 882                     </row>
 883                     <row>
 884                       <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant>&nbsp;</entry>
 885                       <entry>VBI in private packets, IVTV format (documented
 886 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
 887                     </row>
 888                   </tbody>
 889                 </entrytbl>
 890               </row>
 891               <row><entry></entry></row>
 892               <row id="v4l2-mpeg-audio-sampling-freq">
 893                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant>&nbsp;</entry>
 894                 <entry>enum&nbsp;v4l2_mpeg_audio_sampling_freq</entry>
 895               </row><row><entry spanname="descr">MPEG Audio sampling
 896 frequency. Possible values are:</entry>
 897               </row>
 898               <row>
 899                 <entrytbl spanname="descr" cols="2">
 900                   <tbody valign="top">
 901                     <row>
 902                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant>&nbsp;</entry>
 903                       <entry>44.1 kHz</entry>
 904                     </row>
 905                     <row>
 906                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant>&nbsp;</entry>
 907                       <entry>48 kHz</entry>
 908                     </row>
 909                     <row>
 910                       <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant>&nbsp;</entry>
 911                       <entry>32 kHz</entry>
 912                     </row>
 913                   </tbody>
 914                 </entrytbl>
 915               </row>
 916               <row><entry></entry></row>
 917               <row id="v4l2-mpeg-audio-encoding">
 918                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant>&nbsp;</entry>
 919                 <entry>enum&nbsp;v4l2_mpeg_audio_encoding</entry>
 920               </row><row><entry spanname="descr">MPEG Audio encoding.
 921 This control is specific to multiplexed MPEG streams.
 922 Possible values are:</entry>
 923               </row>
 924               <row>
 925                 <entrytbl spanname="descr" cols="2">
 926                   <tbody valign="top">
 927                     <row>
 928                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant>&nbsp;</entry>
 929                       <entry>MPEG-1/2 Layer I encoding</entry>
 930                     </row>
 931                     <row>
 932                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant>&nbsp;</entry>
 933                       <entry>MPEG-1/2 Layer II encoding</entry>
 934                     </row>
 935                     <row>
 936                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant>&nbsp;</entry>
 937                       <entry>MPEG-1/2 Layer III encoding</entry>
 938                     </row>
 939                     <row>
 940                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant>&nbsp;</entry>
 941                       <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
 942                     </row>
 943                     <row>
 944                       <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant>&nbsp;</entry>
 945                       <entry>AC-3 aka ATSC A/52 encoding</entry>
 946                     </row>
 947                   </tbody>
 948                 </entrytbl>
 949               </row>
 950               <row><entry></entry></row>
 951               <row id="v4l2-mpeg-audio-l1-bitrate">
 952                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant>&nbsp;</entry>
 953                 <entry>enum&nbsp;v4l2_mpeg_audio_l1_bitrate</entry>
 954               </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
 955 Possible values are:</entry>
 956               </row>
 957               <row>
 958                 <entrytbl spanname="descr" cols="2">
 959                   <tbody valign="top">
 960                     <row>
 961                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant>&nbsp;</entry>
 962                       <entry>32 kbit/s</entry></row>
 963                     <row>
 964                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant>&nbsp;</entry>
 965                       <entry>64 kbit/s</entry>
 966                     </row>
 967                     <row>
 968                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant>&nbsp;</entry>
 969                       <entry>96 kbit/s</entry>
 970                     </row>
 971                     <row>
 972                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant>&nbsp;</entry>
 973                       <entry>128 kbit/s</entry>
 974                     </row>
 975                     <row>
 976                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant>&nbsp;</entry>
 977                       <entry>160 kbit/s</entry>
 978                     </row>
 979                     <row>
 980                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant>&nbsp;</entry>
 981                       <entry>192 kbit/s</entry>
 982                     </row>
 983                     <row>
 984                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant>&nbsp;</entry>
 985                       <entry>224 kbit/s</entry>
 986                     </row>
 987                     <row>
 988                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant>&nbsp;</entry>
 989                       <entry>256 kbit/s</entry>
 990                     </row>
 991                     <row>
 992                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant>&nbsp;</entry>
 993                       <entry>288 kbit/s</entry>
 994                     </row>
 995                     <row>
 996                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant>&nbsp;</entry>
 997                       <entry>320 kbit/s</entry>
 998                     </row>
 999                     <row>
1000                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant>&nbsp;</entry>
1001                       <entry>352 kbit/s</entry>
1002                     </row>
1003                     <row>
1004                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant>&nbsp;</entry>
1005                       <entry>384 kbit/s</entry>
1006                     </row>
1007                     <row>
1008                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant>&nbsp;</entry>
1009                       <entry>416 kbit/s</entry>
1010                     </row>
1011                     <row>
1012                       <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant>&nbsp;</entry>
1013                       <entry>448 kbit/s</entry>
1014                     </row>
1015                   </tbody>
1016                 </entrytbl>
1017               </row>
1018               <row><entry></entry></row>
1019               <row id="v4l2-mpeg-audio-l2-bitrate">
1020                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant>&nbsp;</entry>
1021                 <entry>enum&nbsp;v4l2_mpeg_audio_l2_bitrate</entry>
1022               </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1023 Possible values are:</entry>
1024               </row>
1025               <row>
1026                 <entrytbl spanname="descr" cols="2">
1027                   <tbody valign="top">
1028                     <row>
1029                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant>&nbsp;</entry>
1030                       <entry>32 kbit/s</entry>
1031                     </row>
1032                     <row>
1033                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant>&nbsp;</entry>
1034                       <entry>48 kbit/s</entry>
1035                     </row>
1036                     <row>
1037                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant>&nbsp;</entry>
1038                       <entry>56 kbit/s</entry>
1039                     </row>
1040                     <row>
1041                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant>&nbsp;</entry>
1042                       <entry>64 kbit/s</entry>
1043                     </row>
1044                     <row>
1045                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant>&nbsp;</entry>
1046                       <entry>80 kbit/s</entry>
1047                     </row>
1048                     <row>
1049                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant>&nbsp;</entry>
1050                       <entry>96 kbit/s</entry>
1051                     </row>
1052                     <row>
1053                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant>&nbsp;</entry>
1054                       <entry>112 kbit/s</entry>
1055                     </row>
1056                     <row>
1057                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant>&nbsp;</entry>
1058                       <entry>128 kbit/s</entry>
1059                     </row>
1060                     <row>
1061                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant>&nbsp;</entry>
1062                       <entry>160 kbit/s</entry>
1063                     </row>
1064                     <row>
1065                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant>&nbsp;</entry>
1066                       <entry>192 kbit/s</entry>
1067                     </row>
1068                     <row>
1069                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant>&nbsp;</entry>
1070                       <entry>224 kbit/s</entry>
1071                     </row>
1072                     <row>
1073                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant>&nbsp;</entry>
1074                       <entry>256 kbit/s</entry>
1075                     </row>
1076                     <row>
1077                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant>&nbsp;</entry>
1078                       <entry>320 kbit/s</entry>
1079                     </row>
1080                     <row>
1081                       <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant>&nbsp;</entry>
1082                       <entry>384 kbit/s</entry>
1083                     </row>
1084                   </tbody>
1085                 </entrytbl>
1086               </row>
1087               <row><entry></entry></row>
1088               <row id="v4l2-mpeg-audio-l3-bitrate">
1089                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant>&nbsp;</entry>
1090                 <entry>enum&nbsp;v4l2_mpeg_audio_l3_bitrate</entry>
1091               </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1092 Possible values are:</entry>
1093               </row>
1094               <row>
1095                 <entrytbl spanname="descr" cols="2">
1096                   <tbody valign="top">
1097                     <row>
1098                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant>&nbsp;</entry>
1099                       <entry>32 kbit/s</entry>
1100                     </row>
1101                     <row>
1102                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant>&nbsp;</entry>
1103                       <entry>40 kbit/s</entry>
1104                     </row>
1105                     <row>
1106                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant>&nbsp;</entry>
1107                       <entry>48 kbit/s</entry>
1108                     </row>
1109                     <row>
1110                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant>&nbsp;</entry>
1111                       <entry>56 kbit/s</entry>
1112                     </row>
1113                     <row>
1114                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant>&nbsp;</entry>
1115                       <entry>64 kbit/s</entry>
1116                     </row>
1117                     <row>
1118                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant>&nbsp;</entry>
1119                       <entry>80 kbit/s</entry>
1120                     </row>
1121                     <row>
1122                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant>&nbsp;</entry>
1123                       <entry>96 kbit/s</entry>
1124                     </row>
1125                     <row>
1126                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant>&nbsp;</entry>
1127                       <entry>112 kbit/s</entry>
1128                     </row>
1129                     <row>
1130                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant>&nbsp;</entry>
1131                       <entry>128 kbit/s</entry>
1132                     </row>
1133                     <row>
1134                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant>&nbsp;</entry>
1135                       <entry>160 kbit/s</entry>
1136                     </row>
1137                     <row>
1138                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant>&nbsp;</entry>
1139                       <entry>192 kbit/s</entry>
1140                     </row>
1141                     <row>
1142                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant>&nbsp;</entry>
1143                       <entry>224 kbit/s</entry>
1144                     </row>
1145                     <row>
1146                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant>&nbsp;</entry>
1147                       <entry>256 kbit/s</entry>
1148                     </row>
1149                     <row>
1150                       <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant>&nbsp;</entry>
1151                       <entry>320 kbit/s</entry>
1152                     </row>
1153                   </tbody>
1154                 </entrytbl>
1155               </row>
1156               <row><entry></entry></row>
1157               <row>
1158                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant>&nbsp;</entry>
1159                 <entry>integer</entry>
1160               </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1161               </row>
1162               <row><entry></entry></row>
1163               <row id="v4l2-mpeg-audio-ac3-bitrate">
1164                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant>&nbsp;</entry>
1165                 <entry>enum&nbsp;v4l2_mpeg_audio_ac3_bitrate</entry>
1166               </row><row><entry spanname="descr">AC-3 bitrate.
1167 Possible values are:</entry>
1168               </row>
1169               <row>
1170                 <entrytbl spanname="descr" cols="2">
1171                   <tbody valign="top">
1172                     <row>
1173                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant>&nbsp;</entry>
1174                       <entry>32 kbit/s</entry>
1175                     </row>
1176                     <row>
1177                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant>&nbsp;</entry>
1178                       <entry>40 kbit/s</entry>
1179                     </row>
1180                     <row>
1181                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant>&nbsp;</entry>
1182                       <entry>48 kbit/s</entry>
1183                     </row>
1184                     <row>
1185                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant>&nbsp;</entry>
1186                       <entry>56 kbit/s</entry>
1187                     </row>
1188                     <row>
1189                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant>&nbsp;</entry>
1190                       <entry>64 kbit/s</entry>
1191                     </row>
1192                     <row>
1193                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant>&nbsp;</entry>
1194                       <entry>80 kbit/s</entry>
1195                     </row>
1196                     <row>
1197                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant>&nbsp;</entry>
1198                       <entry>96 kbit/s</entry>
1199                     </row>
1200                     <row>
1201                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant>&nbsp;</entry>
1202                       <entry>112 kbit/s</entry>
1203                     </row>
1204                     <row>
1205                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant>&nbsp;</entry>
1206                       <entry>128 kbit/s</entry>
1207                     </row>
1208                     <row>
1209                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant>&nbsp;</entry>
1210                       <entry>160 kbit/s</entry>
1211                     </row>
1212                     <row>
1213                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant>&nbsp;</entry>
1214                       <entry>192 kbit/s</entry>
1215                     </row>
1216                     <row>
1217                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant>&nbsp;</entry>
1218                       <entry>224 kbit/s</entry>
1219                     </row>
1220                     <row>
1221                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant>&nbsp;</entry>
1222                       <entry>256 kbit/s</entry>
1223                     </row>
1224                     <row>
1225                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant>&nbsp;</entry>
1226                       <entry>320 kbit/s</entry>
1227                     </row>
1228                     <row>
1229                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant>&nbsp;</entry>
1230                       <entry>384 kbit/s</entry>
1231                     </row>
1232                     <row>
1233                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant>&nbsp;</entry>
1234                       <entry>448 kbit/s</entry>
1235                     </row>
1236                     <row>
1237                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant>&nbsp;</entry>
1238                       <entry>512 kbit/s</entry>
1239                     </row>
1240                     <row>
1241                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant>&nbsp;</entry>
1242                       <entry>576 kbit/s</entry>
1243                     </row>
1244                     <row>
1245                       <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant>&nbsp;</entry>
1246                       <entry>640 kbit/s</entry>
1247                     </row>
1248                   </tbody>
1249                 </entrytbl>
1250               </row>
1251               <row><entry></entry></row>
1252               <row id="v4l2-mpeg-audio-mode">
1253                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant>&nbsp;</entry>
1254                 <entry>enum&nbsp;v4l2_mpeg_audio_mode</entry>
1255               </row><row><entry spanname="descr">MPEG Audio mode.
1256 Possible values are:</entry>
1257               </row>
1258               <row>
1259                 <entrytbl spanname="descr" cols="2">
1260                   <tbody valign="top">
1261                     <row>
1262                       <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant>&nbsp;</entry>
1263                       <entry>Stereo</entry>
1264                     </row>
1265                     <row>
1266                       <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant>&nbsp;</entry>
1267                       <entry>Joint Stereo</entry>
1268                     </row>
1269                     <row>
1270                       <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant>&nbsp;</entry>
1271                       <entry>Bilingual</entry>
1272                     </row>
1273                     <row>
1274                       <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant>&nbsp;</entry>
1275                       <entry>Mono</entry>
1276                     </row>
1277                   </tbody>
1278                 </entrytbl>
1279               </row>
1280               <row><entry></entry></row>
1281               <row id="v4l2-mpeg-audio-mode-extension">
1282                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant>&nbsp;</entry>
1283                 <entry>enum&nbsp;v4l2_mpeg_audio_mode_extension</entry>
1284               </row><row><entry spanname="descr">Joint Stereo
1285 audio mode extension. In Layer I and II they indicate which subbands
1286 are in intensity stereo. All other subbands are coded in stereo. Layer
1287 III is not (yet) supported. Possible values
1288 are:</entry>
1289               </row>
1290               <row>
1291                 <entrytbl spanname="descr" cols="2">
1292                   <tbody valign="top">
1293                     <row>
1294                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant>&nbsp;</entry>
1295                       <entry>Subbands 4-31 in intensity stereo</entry>
1296                     </row>
1297                     <row>
1298                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant>&nbsp;</entry>
1299                       <entry>Subbands 8-31 in intensity stereo</entry>
1300                     </row>
1301                     <row>
1302                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant>&nbsp;</entry>
1303                       <entry>Subbands 12-31 in intensity stereo</entry>
1304                     </row>
1305                     <row>
1306                       <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant>&nbsp;</entry>
1307                       <entry>Subbands 16-31 in intensity stereo</entry>
1308                     </row>
1309                   </tbody>
1310                 </entrytbl>
1311               </row>
1312               <row><entry></entry></row>
1313               <row id="v4l2-mpeg-audio-emphasis">
1314                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant>&nbsp;</entry>
1315                 <entry>enum&nbsp;v4l2_mpeg_audio_emphasis</entry>
1316               </row><row><entry spanname="descr">Audio Emphasis.
1317 Possible values are:</entry>
1318               </row>
1319               <row>
1320                 <entrytbl spanname="descr" cols="2">
1321                   <tbody valign="top">
1322                     <row>
1323                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant>&nbsp;</entry>
1324                       <entry>None</entry>
1325                     </row>
1326                     <row>
1327                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant>&nbsp;</entry>
1328                       <entry>50/15 microsecond emphasis</entry>
1329                     </row>
1330                     <row>
1331                       <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant>&nbsp;</entry>
1332                       <entry>CCITT J.17</entry>
1333                     </row>
1334                   </tbody>
1335                 </entrytbl>
1336               </row>
1337               <row><entry></entry></row>
1338               <row id="v4l2-mpeg-audio-crc">
1339                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant>&nbsp;</entry>
1340                 <entry>enum&nbsp;v4l2_mpeg_audio_crc</entry>
1341               </row><row><entry spanname="descr">CRC method. Possible
1342 values are:</entry>
1343               </row>
1344               <row>
1345                 <entrytbl spanname="descr" cols="2">
1346                   <tbody valign="top">
1347                     <row>
1348                       <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant>&nbsp;</entry>
1349                       <entry>None</entry>
1350                     </row>
1351                     <row>
1352                       <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant>&nbsp;</entry>
1353                       <entry>16 bit parity check</entry>
1354                     </row>
1355                   </tbody>
1356                 </entrytbl>
1357               </row>
1358               <row><entry></entry></row>
1359               <row>
1360                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant>&nbsp;</entry>
1361                 <entry>boolean</entry>
1362               </row><row><entry spanname="descr">Mutes the audio when
1363 capturing. This is not done by muting audio hardware, which can still
1364 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1365 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1366               </row>
1367               <row><entry></entry></row>
1368               <row id="v4l2-mpeg-audio-dec-playback">
1369                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant>&nbsp;</entry>
1370                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1371               </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1372 Possible values are:</entry>
1373               </row>
1374               <row>
1375                 <entrytbl spanname="descr" cols="2">
1376                   <tbody valign="top">
1377                     <row>
1378                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant>&nbsp;</entry>
1379                       <entry>Automatically determines the best playback mode.</entry>
1380                     </row>
1381                     <row>
1382                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant>&nbsp;</entry>
1383                       <entry>Stereo playback.</entry>
1384                     </row>
1385                     <row>
1386                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant>&nbsp;</entry>
1387                       <entry>Left channel playback.</entry>
1388                     </row>
1389                     <row>
1390                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant>&nbsp;</entry>
1391                       <entry>Right channel playback.</entry>
1392                     </row>
1393                     <row>
1394                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant>&nbsp;</entry>
1395                       <entry>Mono playback.</entry>
1396                     </row>
1397                     <row>
1398                       <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant>&nbsp;</entry>
1399                       <entry>Stereo playback with swapped left and right channels.</entry>
1400                     </row>
1401                   </tbody>
1402                 </entrytbl>
1403               </row>
1404               <row><entry></entry></row>
1405               <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1406                 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant>&nbsp;</entry>
1407                 <entry>enum&nbsp;v4l2_mpeg_audio_dec_playback</entry>
1408               </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1409               </row>
1410               <row><entry></entry></row>
1411               <row id="v4l2-mpeg-video-encoding">
1412                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant>&nbsp;</entry>
1413                 <entry>enum&nbsp;v4l2_mpeg_video_encoding</entry>
1414               </row><row><entry spanname="descr">MPEG Video encoding
1415 method. This control is specific to multiplexed MPEG streams.
1416 Possible values are:</entry>
1417               </row>
1418               <row>
1419                 <entrytbl spanname="descr" cols="2">
1420                   <tbody valign="top">
1421                     <row>
1422                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant>&nbsp;</entry>
1423                       <entry>MPEG-1 Video encoding</entry>
1424                     </row>
1425                     <row>
1426                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant>&nbsp;</entry>
1427                       <entry>MPEG-2 Video encoding</entry>
1428                     </row>
1429                     <row>
1430                       <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant>&nbsp;</entry>
1431                       <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1432                     </row>
1433                   </tbody>
1434                 </entrytbl>
1435               </row>
1436               <row><entry></entry></row>
1437               <row id="v4l2-mpeg-video-aspect">
1438                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant>&nbsp;</entry>
1439                 <entry>enum&nbsp;v4l2_mpeg_video_aspect</entry>
1440               </row><row><entry spanname="descr">Video aspect.
1441 Possible values are:</entry>
1442               </row>
1443               <row>
1444                 <entrytbl spanname="descr" cols="2">
1445                   <tbody valign="top">
1446                     <row>
1447                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant>&nbsp;</entry>
1448                     </row>
1449                     <row>
1450                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant>&nbsp;</entry>
1451                     </row>
1452                     <row>
1453                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant>&nbsp;</entry>
1454                     </row>
1455                     <row>
1456                       <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant>&nbsp;</entry>
1457                     </row>
1458                   </tbody>
1459                 </entrytbl>
1460               </row>
1461               <row><entry></entry></row>
1462               <row>
1463                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant>&nbsp;</entry>
1464                 <entry>integer</entry>
1465               </row><row><entry spanname="descr">Number of B-Frames
1466 (default 2)</entry>
1467               </row>
1468               <row><entry></entry></row>
1469               <row>
1470                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant>&nbsp;</entry>
1471                 <entry>integer</entry>
1472               </row><row><entry spanname="descr">GOP size (default
1473 12)</entry>
1474               </row>
1475               <row><entry></entry></row>
1476               <row>
1477                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant>&nbsp;</entry>
1478                 <entry>boolean</entry>
1479               </row><row><entry spanname="descr">GOP closure (default
1480 1)</entry>
1481               </row>
1482               <row><entry></entry></row>
1483               <row>
1484                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant>&nbsp;</entry>
1485                 <entry>boolean</entry>
1486               </row><row><entry spanname="descr">Enable 3:2 pulldown
1487 (default 0)</entry>
1488               </row>
1489               <row><entry></entry></row>
1490               <row id="v4l2-mpeg-video-bitrate-mode">
1491                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant>&nbsp;</entry>
1492                 <entry>enum&nbsp;v4l2_mpeg_video_bitrate_mode</entry>
1493               </row><row><entry spanname="descr">Video bitrate mode.
1494 Possible values are:</entry>
1495               </row>
1496               <row>
1497                 <entrytbl spanname="descr" cols="2">
1498                   <tbody valign="top">
1499                     <row>
1500                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant>&nbsp;</entry>
1501                       <entry>Variable bitrate</entry>
1502                     </row>
1503                     <row>
1504                       <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant>&nbsp;</entry>
1505                       <entry>Constant bitrate</entry>
1506                     </row>
1507                   </tbody>
1508                 </entrytbl>
1509               </row>
1510               <row><entry></entry></row>
1511               <row>
1512                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant>&nbsp;</entry>
1513                 <entry>integer</entry>
1514               </row><row><entry spanname="descr">Video bitrate in bits
1515 per second.</entry>
1516               </row>
1517               <row><entry></entry></row>
1518               <row>
1519                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant>&nbsp;</entry>
1520                 <entry>integer</entry>
1521               </row><row><entry spanname="descr">Peak video bitrate in
1522 bits per second. Must be larger or equal to the average video bitrate.
1523 It is ignored if the video bitrate mode is set to constant
1524 bitrate.</entry>
1525               </row>
1526               <row><entry></entry></row>
1527               <row>
1528                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant>&nbsp;</entry>
1529                 <entry>integer</entry>
1530               </row><row><entry spanname="descr">For every captured
1531 frame, skip this many subsequent frames (default 0).</entry>
1532               </row>
1533               <row><entry></entry></row>
1534               <row>
1535                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant>&nbsp;</entry>
1536                 <entry>boolean</entry>
1537               </row>
1538               <row><entry spanname="descr">"Mutes" the video to a
1539 fixed color when capturing. This is useful for testing, to produce a
1540 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1541               </row>
1542               <row><entry></entry></row>
1543               <row>
1544                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant>&nbsp;</entry>
1545                 <entry>integer</entry>
1546               </row><row><entry spanname="descr">Sets the "mute" color
1547 of the video. The supplied 32-bit integer is interpreted as follows (bit
1548 0 = least significant bit):</entry>
1549               </row>
1550               <row>
1551                 <entrytbl spanname="descr" cols="2">
1552                   <tbody valign="top">
1553                     <row>
1554                       <entry>Bit 0:7</entry>
1555                       <entry>V chrominance information</entry>
1556                     </row>
1557                     <row>
1558                       <entry>Bit 8:15</entry>
1559                       <entry>U chrominance information</entry>
1560                     </row>
1561                     <row>
1562                       <entry>Bit 16:23</entry>
1563                       <entry>Y luminance information</entry>
1564                     </row>
1565                     <row>
1566                       <entry>Bit 24:31</entry>
1567                       <entry>Must be zero.</entry>
1568                     </row>
1569                   </tbody>
1570                 </entrytbl>
1571               </row>
1572               <row><entry></entry></row>
1573               <row id="v4l2-mpeg-video-dec-pts">
1574                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant>&nbsp;</entry>
1575                 <entry>integer64</entry>
1576               </row><row><entry spanname="descr">This read-only control returns the
1577 33-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1578 the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1579               </row>
1580               <row><entry></entry></row>
1581               <row id="v4l2-mpeg-video-dec-frame">
1582                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant>&nbsp;</entry>
1583                 <entry>integer64</entry>
1584               </row><row><entry spanname="descr">This read-only control returns the
1585 frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1586 the decoder is started.</entry>
1587               </row>
1588
1589               <row><entry></entry></row>
1590               <row>
1591                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant>&nbsp;</entry>
1592                 <entry>boolean</entry>
1593               </row>
1594               <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1595 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1596 </entry>
1597               </row>
1598
1599               <row><entry></entry></row>
1600               <row>
1601                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant>&nbsp;</entry>
1602                 <entry>boolean</entry>
1603               </row>
1604               <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1605 Applicable to the H264 encoder.</entry>
1606               </row>
1607
1608               <row><entry></entry></row>
1609               <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1610                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant>&nbsp;</entry>
1611                 <entry>enum&nbsp;v4l2_mpeg_video_h264_vui_sar_idc</entry>
1612               </row>
1613               <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1614 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1615               </row>
1616               <row>
1617                 <entrytbl spanname="descr" cols="2">
1618                   <tbody valign="top">
1619
1620                         <row>
1621                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant>&nbsp;</entry>
1622                           <entry>Unspecified</entry>
1623                         </row>
1624                         <row>
1625                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant>&nbsp;</entry>
1626                           <entry>1x1</entry>
1627                         </row>
1628                         <row>
1629                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant>&nbsp;</entry>
1630                           <entry>12x11</entry>
1631                         </row>
1632                         <row>
1633                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant>&nbsp;</entry>
1634                           <entry>10x11</entry>
1635                         </row>
1636                         <row>
1637                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant>&nbsp;</entry>
1638                           <entry>16x11</entry>
1639                         </row>
1640                         <row>
1641                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant>&nbsp;</entry>
1642                           <entry>40x33</entry>
1643                         </row>
1644                         <row>
1645                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant>&nbsp;</entry>
1646                           <entry>24x11</entry>
1647                         </row>
1648                         <row>
1649                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant>&nbsp;</entry>
1650                           <entry>20x11</entry>
1651                         </row>
1652                         <row>
1653                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant>&nbsp;</entry>
1654                           <entry>32x11</entry>
1655                         </row>
1656                         <row>
1657                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant>&nbsp;</entry>
1658                           <entry>80x33</entry>
1659                         </row>
1660                         <row>
1661                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant>&nbsp;</entry>
1662                           <entry>18x11</entry>
1663                         </row>
1664                         <row>
1665                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant>&nbsp;</entry>
1666                           <entry>15x11</entry>
1667                         </row>
1668                         <row>
1669                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant>&nbsp;</entry>
1670                           <entry>64x33</entry>
1671                         </row>
1672                         <row>
1673                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant>&nbsp;</entry>
1674                           <entry>160x99</entry>
1675                         </row>
1676                         <row>
1677                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant>&nbsp;</entry>
1678                           <entry>4x3</entry>
1679                         </row>
1680                         <row>
1681                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant>&nbsp;</entry>
1682                           <entry>3x2</entry>
1683                         </row>
1684                         <row>
1685                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant>&nbsp;</entry>
1686                           <entry>2x1</entry>
1687                         </row>
1688                         <row>
1689                           <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant>&nbsp;</entry>
1690                           <entry>Extended SAR</entry>
1691                         </row>
1692                   </tbody>
1693                 </entrytbl>
1694               </row>
1695
1696               <row><entry></entry></row>
1697               <row>
1698                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant>&nbsp;</entry>
1699                 <entry>integer</entry>
1700               </row>
1701               <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1702 Applicable to the H264 encoder.</entry>
1703               </row>
1704
1705               <row><entry></entry></row>
1706               <row>
1707                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant>&nbsp;</entry>
1708                 <entry>integer</entry>
1709               </row>
1710               <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1711 Applicable to the H264 encoder.</entry>
1712               </row>
1713
1714               <row><entry></entry></row>
1715               <row id="v4l2-mpeg-video-h264-level">
1716                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant>&nbsp;</entry>
1717                 <entry>enum&nbsp;v4l2_mpeg_video_h264_level</entry>
1718               </row>
1719               <row><entry spanname="descr">The level information for the H264 video elementary stream.
1720 Applicable to the H264 encoder.
1721 Possible values are:</entry>
1722               </row>
1723               <row>
1724                 <entrytbl spanname="descr" cols="2">
1725                   <tbody valign="top">
1726                     <row>
1727                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant>&nbsp;</entry>
1728                       <entry>Level 1.0</entry>
1729                     </row>
1730                     <row>
1731                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant>&nbsp;</entry>
1732                       <entry>Level 1B</entry>
1733                     </row>
1734                     <row>
1735                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant>&nbsp;</entry>
1736                       <entry>Level 1.1</entry>
1737                     </row>
1738                     <row>
1739                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant>&nbsp;</entry>
1740                       <entry>Level 1.2</entry>
1741                     </row>
1742                     <row>
1743                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant>&nbsp;</entry>
1744                       <entry>Level 1.3</entry>
1745                     </row>
1746                     <row>
1747                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant>&nbsp;</entry>
1748                       <entry>Level 2.0</entry>
1749                     </row>
1750                     <row>
1751                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant>&nbsp;</entry>
1752                       <entry>Level 2.1</entry>
1753                     </row>
1754                     <row>
1755                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant>&nbsp;</entry>
1756                       <entry>Level 2.2</entry>
1757                     </row>
1758                     <row>
1759                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant>&nbsp;</entry>
1760                       <entry>Level 3.0</entry>
1761                     </row>
1762                     <row>
1763                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant>&nbsp;</entry>
1764                       <entry>Level 3.1</entry>
1765                     </row>
1766                     <row>
1767                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant>&nbsp;</entry>
1768                       <entry>Level 3.2</entry>
1769                     </row>
1770                     <row>
1771                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant>&nbsp;</entry>
1772                       <entry>Level 4.0</entry>
1773                     </row>
1774                     <row>
1775                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant>&nbsp;</entry>
1776                       <entry>Level 4.1</entry>
1777                     </row>
1778                     <row>
1779                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant>&nbsp;</entry>
1780                       <entry>Level 4.2</entry>
1781                     </row>
1782                     <row>
1783                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant>&nbsp;</entry>
1784                       <entry>Level 5.0</entry>
1785                     </row>
1786                     <row>
1787                       <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant>&nbsp;</entry>
1788                       <entry>Level 5.1</entry>
1789                     </row>
1790                   </tbody>
1791                 </entrytbl>
1792               </row>
1793
1794               <row><entry></entry></row>
1795               <row id="v4l2-mpeg-video-mpeg4-level">
1796                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant>&nbsp;</entry>
1797                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_level</entry>
1798               </row>
1799               <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1800 Applicable to the MPEG4 encoder.
1801 Possible values are:</entry>
1802               </row>
1803               <row>
1804                 <entrytbl spanname="descr" cols="2">
1805                   <tbody valign="top">
1806                     <row>
1807                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant>&nbsp;</entry>
1808                       <entry>Level 0</entry>
1809                     </row>
1810                     <row>
1811                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant>&nbsp;</entry>
1812                       <entry>Level 0b</entry>
1813                     </row>
1814                     <row>
1815                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant>&nbsp;</entry>
1816                       <entry>Level 1</entry>
1817                     </row>
1818                     <row>
1819                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant>&nbsp;</entry>
1820                       <entry>Level 2</entry>
1821                     </row>
1822                     <row>
1823                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant>&nbsp;</entry>
1824                       <entry>Level 3</entry>
1825                     </row>
1826                     <row>
1827                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant>&nbsp;</entry>
1828                       <entry>Level 3b</entry>
1829                     </row>
1830                     <row>
1831                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant>&nbsp;</entry>
1832                       <entry>Level 4</entry>
1833                     </row>
1834                     <row>
1835                       <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant>&nbsp;</entry>
1836                       <entry>Level 5</entry>
1837                     </row>
1838                   </tbody>
1839                 </entrytbl>
1840               </row>
1841
1842               <row><entry></entry></row>
1843               <row id="v4l2-mpeg-video-h264-profile">
1844                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant>&nbsp;</entry>
1845                 <entry>enum&nbsp;v4l2_mpeg_video_h264_profile</entry>
1846               </row>
1847               <row><entry spanname="descr">The profile information for H264.
1848 Applicable to the H264 encoder.
1849 Possible values are:</entry>
1850               </row>
1851               <row>
1852                 <entrytbl spanname="descr" cols="2">
1853                   <tbody valign="top">
1854                     <row>
1855                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant>&nbsp;</entry>
1856                       <entry>Baseline profile</entry>
1857                     </row>
1858                     <row>
1859                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant>&nbsp;</entry>
1860                       <entry>Constrained Baseline profile</entry>
1861                     </row>
1862                     <row>
1863                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant>&nbsp;</entry>
1864                       <entry>Main profile</entry>
1865                     </row>
1866                     <row>
1867                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant>&nbsp;</entry>
1868                       <entry>Extended profile</entry>
1869                     </row>
1870                     <row>
1871                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant>&nbsp;</entry>
1872                       <entry>High profile</entry>
1873                     </row>
1874                     <row>
1875                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant>&nbsp;</entry>
1876                       <entry>High 10 profile</entry>
1877                     </row>
1878                     <row>
1879                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant>&nbsp;</entry>
1880                       <entry>High 422 profile</entry>
1881                     </row>
1882                     <row>
1883                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant>&nbsp;</entry>
1884                       <entry>High 444 Predictive profile</entry>
1885                     </row>
1886                     <row>
1887                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant>&nbsp;</entry>
1888                       <entry>High 10 Intra profile</entry>
1889                     </row>
1890                     <row>
1891                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant>&nbsp;</entry>
1892                       <entry>High 422 Intra profile</entry>
1893                     </row>
1894                     <row>
1895                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant>&nbsp;</entry>
1896                       <entry>High 444 Intra profile</entry>
1897                     </row>
1898                     <row>
1899                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant>&nbsp;</entry>
1900                       <entry>CAVLC 444 Intra profile</entry>
1901                     </row>
1902                     <row>
1903                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant>&nbsp;</entry>
1904                       <entry>Scalable Baseline profile</entry>
1905                     </row>
1906                     <row>
1907                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant>&nbsp;</entry>
1908                       <entry>Scalable High profile</entry>
1909                     </row>
1910                     <row>
1911                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant>&nbsp;</entry>
1912                       <entry>Scalable High Intra profile</entry>
1913                     </row>
1914                     <row>
1915                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant>&nbsp;</entry>
1916                       <entry>Stereo High profile</entry>
1917                     </row>
1918                     <row>
1919                       <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant>&nbsp;</entry>
1920                       <entry>Multiview High profile</entry>
1921                     </row>
1922
1923                   </tbody>
1924                 </entrytbl>
1925               </row>
1926
1927               <row><entry></entry></row>
1928               <row id="v4l2-mpeg-video-mpeg4-profile">
1929                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant>&nbsp;</entry>
1930                 <entry>enum&nbsp;v4l2_mpeg_video_mpeg4_profile</entry>
1931               </row>
1932               <row><entry spanname="descr">The profile information for MPEG4.
1933 Applicable to the MPEG4 encoder.
1934 Possible values are:</entry>
1935               </row>
1936               <row>
1937                 <entrytbl spanname="descr" cols="2">
1938                   <tbody valign="top">
1939                     <row>
1940                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant>&nbsp;</entry>
1941                       <entry>Simple profile</entry>
1942                     </row>
1943                     <row>
1944                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant>&nbsp;</entry>
1945                       <entry>Advanced Simple profile</entry>
1946                     </row>
1947                     <row>
1948                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant>&nbsp;</entry>
1949                       <entry>Core profile</entry>
1950                     </row>
1951                     <row>
1952                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant>&nbsp;</entry>
1953                       <entry>Simple Scalable profile</entry>
1954                     </row>
1955                     <row>
1956                       <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant>&nbsp;</entry>
1957                       <entry></entry>
1958                     </row>
1959                   </tbody>
1960                 </entrytbl>
1961               </row>
1962
1963               <row><entry></entry></row>
1964               <row>
1965                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant>&nbsp;</entry>
1966                 <entry>integer</entry>
1967               </row>
1968               <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1969 Applicable to the encoder.
1970 </entry>
1971               </row>
1972
1973               <row><entry></entry></row>
1974               <row id="v4l2-mpeg-video-multi-slice-mode">
1975                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant>&nbsp;</entry>
1976                 <entry>enum&nbsp;v4l2_mpeg_video_multi_slice_mode</entry>
1977               </row>
1978               <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1979 Applicable to the encoder.
1980 Possible values are:</entry>
1981               </row>
1982               <row>
1983                 <entrytbl spanname="descr" cols="2">
1984                   <tbody valign="top">
1985                     <row>
1986                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant>&nbsp;</entry>
1987                       <entry>Single slice per frame.</entry>
1988                     </row>
1989                     <row>
1990                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>&nbsp;</entry>
1991                       <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1992                     </row>
1993                     <row>
1994                       <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>&nbsp;</entry>
1995                       <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1996                     </row>
1997                   </tbody>
1998                 </entrytbl>
1999               </row>
2000
2001               <row><entry></entry></row>
2002               <row>
2003                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant>&nbsp;</entry>
2004                 <entry>integer</entry>
2005               </row>
2006               <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
2007 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
2008 Applicable to the encoder.</entry>
2009               </row>
2010
2011               <row><entry></entry></row>
2012               <row>
2013                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant>&nbsp;</entry>
2014                 <entry>integer</entry>
2015               </row>
2016               <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
2017 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
2018 Applicable to the encoder.</entry>
2019               </row>
2020
2021               <row><entry></entry></row>
2022               <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2023                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant>&nbsp;</entry>
2024                 <entry>enum&nbsp;v4l2_mpeg_video_h264_loop_filter_mode</entry>
2025               </row>
2026               <row><entry spanname="descr">Loop filter mode for H264 encoder.
2027 Possible values are:</entry>
2028               </row>
2029               <row>
2030                 <entrytbl spanname="descr" cols="2">
2031                   <tbody valign="top">
2032                     <row>
2033                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant>&nbsp;</entry>
2034                       <entry>Loop filter is enabled.</entry>
2035                     </row>
2036                     <row>
2037                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant>&nbsp;</entry>
2038                       <entry>Loop filter is disabled.</entry>
2039                     </row>
2040                     <row>
2041                       <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant>&nbsp;</entry>
2042                       <entry>Loop filter is disabled at the slice boundary.</entry>
2043                     </row>
2044                   </tbody>
2045                 </entrytbl>
2046               </row>
2047
2048               <row><entry></entry></row>
2049               <row>
2050                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant>&nbsp;</entry>
2051                 <entry>integer</entry>
2052               </row>
2053               <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2054 Applicable to the H264 encoder.</entry>
2055               </row>
2056
2057               <row><entry></entry></row>
2058               <row>
2059                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant>&nbsp;</entry>
2060                 <entry>integer</entry>
2061               </row>
2062               <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2063 Applicable to the H264 encoder.</entry>
2064               </row>
2065
2066               <row><entry></entry></row>
2067               <row id="v4l2-mpeg-video-h264-entropy-mode">
2068                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant>&nbsp;</entry>
2069                 <entry>enum&nbsp;v4l2_mpeg_video_h264_entropy_mode</entry>
2070               </row>
2071               <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2072 Applicable to the H264 encoder.
2073 Possible values are:</entry>
2074               </row>
2075               <row>
2076                 <entrytbl spanname="descr" cols="2">
2077                   <tbody valign="top">
2078                     <row>
2079                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant>&nbsp;</entry>
2080                       <entry>Use CAVLC entropy coding.</entry>
2081                     </row>
2082                     <row>
2083                       <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant>&nbsp;</entry>
2084                       <entry>Use CABAC entropy coding.</entry>
2085                     </row>
2086                   </tbody>
2087                 </entrytbl>
2088               </row>
2089
2090               <row><entry></entry></row>
2091               <row>
2092                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant>&nbsp;</entry>
2093                 <entry>boolean</entry>
2094               </row>
2095               <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2096               </row>
2097
2098               <row><entry></entry></row>
2099               <row>
2100                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant>&nbsp;</entry>
2101                 <entry>integer</entry>
2102               </row>
2103               <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2104 refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2105 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2106               </row>
2107
2108               <row><entry></entry></row>
2109               <row>
2110                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant>&nbsp;</entry>
2111                 <entry>boolean</entry>
2112               </row>
2113               <row><entry spanname="descr">Frame level rate control enable.
2114 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2115 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2116 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2117 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2118 Applicable to encoders.</entry>
2119               </row>
2120
2121               <row><entry></entry></row>
2122               <row>
2123                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>&nbsp;</entry>
2124                 <entry>boolean</entry>
2125               </row>
2126               <row><entry spanname="descr">Macroblock level rate control enable.
2127 Applicable to the MPEG4 and H264 encoders.</entry>
2128               </row>
2129
2130               <row><entry></entry></row>
2131               <row>
2132                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant>&nbsp;</entry>
2133                 <entry>boolean</entry>
2134               </row>
2135               <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2136               </row>
2137
2138               <row><entry></entry></row>
2139               <row>
2140                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>&nbsp;</entry>
2141                 <entry>integer</entry>
2142               </row>
2143               <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2144               </row>
2145
2146               <row><entry></entry></row>
2147               <row>
2148                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>&nbsp;</entry>
2149                 <entry>integer</entry>
2150               </row>
2151               <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2152               </row>
2153
2154               <row><entry></entry></row>
2155               <row>
2156                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant>&nbsp;</entry>
2157                 <entry>integer</entry>
2158               </row>
2159               <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2160               </row>
2161
2162               <row><entry></entry></row>
2163               <row>
2164                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant>&nbsp;</entry>
2165                 <entry>integer</entry>
2166               </row>
2167               <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2168               </row>
2169
2170               <row><entry></entry></row>
2171               <row>
2172                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant>&nbsp;</entry>
2173                 <entry>integer</entry>
2174               </row>
2175               <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2176               </row>
2177
2178               <row><entry></entry></row>
2179               <row>
2180                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant>&nbsp;</entry>
2181                 <entry>integer</entry>
2182               </row>
2183               <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2184               </row>
2185
2186               <row><entry></entry></row>
2187               <row>
2188                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant>&nbsp;</entry>
2189                 <entry>integer</entry>
2190               </row>
2191               <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2192               </row>
2193
2194               <row><entry></entry></row>
2195               <row>
2196                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant>&nbsp;</entry>
2197                 <entry>integer</entry>
2198               </row>
2199               <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2200               </row>
2201
2202               <row><entry></entry></row>
2203               <row>
2204                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant>&nbsp;</entry>
2205                 <entry>integer</entry>
2206               </row>
2207               <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2208               </row>
2209
2210               <row><entry></entry></row>
2211               <row>
2212                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant>&nbsp;</entry>
2213                 <entry>integer</entry>
2214               </row>
2215               <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2216               </row>
2217
2218               <row><entry></entry></row>
2219               <row>
2220                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant>&nbsp;</entry>
2221                 <entry>integer</entry>
2222               </row>
2223               <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2224               </row>
2225
2226               <row><entry></entry></row>
2227               <row>
2228                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant>&nbsp;</entry>
2229                 <entry>integer</entry>
2230               </row>
2231               <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2232               </row>
2233
2234               <row><entry></entry></row>
2235               <row>
2236                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant>&nbsp;</entry>
2237                 <entry>integer</entry>
2238               </row>
2239               <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2240               </row>
2241
2242               <row><entry></entry></row>
2243               <row>
2244                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant>&nbsp;</entry>
2245                 <entry>integer</entry>
2246               </row>
2247               <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2248               </row>
2249
2250               <row><entry></entry></row>
2251               <row>
2252                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant>&nbsp;</entry>
2253                 <entry>integer</entry>
2254               </row>
2255               <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2256               </row>
2257
2258               <row><entry></entry></row>
2259               <row>
2260                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant>&nbsp;</entry>
2261                 <entry>integer</entry>
2262               </row>
2263               <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2264 The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2265 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2266 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2267 encoder or editing process may produce.".
2268 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2269               </row>
2270
2271               <row><entry></entry></row>
2272               <row id="v4l2-mpeg-video-vbv-delay">
2273                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant>&nbsp;</entry>
2274                 <entry>integer</entry>
2275               </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2276 VBV buffer control.</entry>
2277               </row>
2278
2279               <row><entry></entry></row>
2280               <row>
2281                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant>&nbsp;</entry>
2282                 <entry>integer</entry>
2283               </row>
2284               <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2285 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2286 Applicable to the H264 encoder.</entry>
2287               </row>
2288
2289               <row><entry></entry></row>
2290               <row>
2291                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant>&nbsp;</entry>
2292                 <entry>integer</entry>
2293               </row>
2294               <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2295 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2296 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2297 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2298 previous frames. Applicable to the H264 encoder.</entry>
2299               </row>
2300
2301               <row><entry></entry></row>
2302               <row id="v4l2-mpeg-video-header-mode">
2303                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant>&nbsp;</entry>
2304                 <entry>enum&nbsp;v4l2_mpeg_video_header_mode</entry>
2305               </row>
2306               <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2307 it returned together with the first frame. Applicable to encoders.
2308 Possible values are:</entry>
2309               </row>
2310               <row>
2311                 <entrytbl spanname="descr" cols="2">
2312                   <tbody valign="top">
2313                     <row>
2314                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant>&nbsp;</entry>
2315                       <entry>The stream header is returned separately in the first buffer.</entry>
2316                     </row>
2317                     <row>
2318                       <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant>&nbsp;</entry>
2319                       <entry>The stream header is returned together with the first encoded frame.</entry>
2320                     </row>
2321                   </tbody>
2322                 </entrytbl>
2323               </row>
2324               <row><entry></entry></row>
2325               <row>
2326                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant>&nbsp;</entry>
2327                 <entry>boolean</entry>
2328               </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2329 Applicable to the MPEG4 decoder.</entry>
2330               </row>
2331               <row><entry></entry></row>
2332               <row>
2333                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant>&nbsp;</entry>
2334                 <entry>integer</entry>
2335               </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2336               </row>
2337               <row><entry></entry></row>
2338               <row>
2339                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant>&nbsp;</entry>
2340                 <entry>integer</entry>
2341               </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2342               </row>
2343
2344               <row><entry></entry></row>
2345               <row>
2346                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant>&nbsp;</entry>
2347                 <entry>boolean</entry>
2348               </row>
2349               <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2350 The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2351               </row>
2352
2353               <row><entry></entry></row>
2354               <row>
2355                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant>&nbsp;</entry>
2356                 <entry>boolean</entry>
2357               </row>
2358               <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2359 Applicable to the H264 encoder.</entry>
2360               </row>
2361
2362               <row><entry></entry></row>
2363               <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2364                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant>&nbsp;</entry>
2365                 <entry>enum&nbsp;v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2366               </row>
2367               <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2368 Applicable to the H264 encoder.
2369 Possible values are:</entry>
2370               </row>
2371               <row>
2372                 <entrytbl spanname="descr" cols="2">
2373                   <tbody valign="top">
2374                     <row>
2375                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant>&nbsp;</entry>
2376                       <entry>Pixels are alternatively from L and R.</entry>
2377                     </row>
2378                     <row>
2379                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant>&nbsp;</entry>
2380                       <entry>L and R are interlaced by column.</entry>
2381                     </row>
2382                     <row>
2383                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant>&nbsp;</entry>
2384                       <entry>L and R are interlaced by row.</entry>
2385                     </row>
2386                     <row>
2387                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant>&nbsp;</entry>
2388                       <entry>L is on the left, R on the right.</entry>
2389                     </row>
2390                     <row>
2391                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant>&nbsp;</entry>
2392                       <entry>L is on top, R on bottom.</entry>
2393                     </row>
2394                     <row>
2395                       <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant>&nbsp;</entry>
2396                       <entry>One view per frame.</entry>
2397                     </row>
2398                   </tbody>
2399                 </entrytbl>
2400               </row>
2401
2402               <row><entry></entry></row>
2403               <row>
2404                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant>&nbsp;</entry>
2405                 <entry>boolean</entry>
2406               </row>
2407               <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2408 used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2409               </row>
2410
2411               <row><entry></entry></row>
2412               <row id="v4l2-mpeg-video-h264-fmo-map-type">
2413                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant>&nbsp;</entry>
2414                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_map_type</entry>
2415               </row>
2416               <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2417 Applicable to the H264 encoder.
2418 Possible values are:</entry>
2419               </row>
2420               <row>
2421                 <entrytbl spanname="descr" cols="2">
2422                   <tbody valign="top">
2423                     <row>
2424                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant>&nbsp;</entry>
2425                       <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2426                     </row>
2427                     <row>
2428                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant>&nbsp;</entry>
2429                       <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2430                     </row>
2431                     <row>
2432                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant>&nbsp;</entry>
2433                       <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2434                     </row>
2435                     <row>
2436                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant>&nbsp;</entry>
2437                       <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2438                     </row>
2439                     <row>
2440                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant>&nbsp;</entry>
2441                       <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2442                     </row>
2443                     <row>
2444                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant>&nbsp;</entry>
2445                       <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2446                     </row>
2447                     <row>
2448                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant>&nbsp;</entry>
2449                       <entry>User defined map type.</entry>
2450                     </row>
2451                   </tbody>
2452                 </entrytbl>
2453               </row>
2454
2455               <row><entry></entry></row>
2456               <row>
2457                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant>&nbsp;</entry>
2458                 <entry>integer</entry>
2459               </row>
2460               <row><entry spanname="descr">Number of slice groups in FMO.
2461 Applicable to the H264 encoder.</entry>
2462               </row>
2463
2464               <row><entry></entry></row>
2465               <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2466                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant>&nbsp;</entry>
2467                 <entry>enum&nbsp;v4l2_mpeg_video_h264_fmo_change_dir</entry>
2468               </row>
2469               <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2470 Applicable to the H264 encoder.
2471 Possible values are:</entry>
2472               </row>
2473               <row>
2474                 <entrytbl spanname="descr" cols="2">
2475                   <tbody valign="top">
2476                     <row>
2477                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant>&nbsp;</entry>
2478                       <entry>Raster scan or wipe right.</entry>
2479                     </row>
2480                     <row>
2481                       <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant>&nbsp;</entry>
2482                       <entry>Reverse raster scan or wipe left.</entry>
2483                     </row>
2484                   </tbody>
2485                 </entrytbl>
2486               </row>
2487
2488               <row><entry></entry></row>
2489               <row>
2490                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant>&nbsp;</entry>
2491                 <entry>integer</entry>
2492               </row>
2493               <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2494 Applicable to the H264 encoder.</entry>
2495               </row>
2496
2497               <row><entry></entry></row>
2498               <row>
2499                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant>&nbsp;</entry>
2500                 <entry>integer</entry>
2501               </row>
2502               <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2503 Applicable to the H264 encoder.</entry>
2504               </row>
2505
2506               <row><entry></entry></row>
2507               <row>
2508                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant>&nbsp;</entry>
2509                 <entry>boolean</entry>
2510               </row>
2511               <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2512 Applicable to the H264 encoder.</entry>
2513               </row>
2514
2515               <row><entry></entry></row>
2516               <row>
2517                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant>&nbsp;</entry>
2518                 <entry>integer</entry>
2519               </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2520 The supplied 32-bit integer is interpreted as follows (bit
2521 0 = least significant bit):</entry>
2522               </row>
2523               <row>
2524                 <entrytbl spanname="descr" cols="2">
2525                   <tbody valign="top">
2526                     <row>
2527                       <entry>Bit 0:15</entry>
2528                       <entry>Slice ID</entry>
2529                     </row>
2530                     <row>
2531                       <entry>Bit 16:32</entry>
2532                       <entry>Slice position or order</entry>
2533                     </row>
2534                   </tbody>
2535                 </entrytbl>
2536               </row>
2537
2538               <row><entry></entry></row>
2539               <row>
2540                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant>&nbsp;</entry>
2541                 <entry>boolean</entry>
2542               </row>
2543               <row><entry spanname="descr">Enables H264 hierarchical coding.
2544 Applicable to the H264 encoder.</entry>
2545               </row>
2546
2547               <row><entry></entry></row>
2548               <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2549                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant>&nbsp;</entry>
2550                 <entry>enum&nbsp;v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2551               </row>
2552               <row><entry spanname="descr">Specifies the hierarchical coding type.
2553 Applicable to the H264 encoder.
2554 Possible values are:</entry>
2555               </row>
2556               <row>
2557                 <entrytbl spanname="descr" cols="2">
2558                   <tbody valign="top">
2559                     <row>
2560                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant>&nbsp;</entry>
2561                       <entry>Hierarchical B coding.</entry>
2562                     </row>
2563                     <row>
2564                       <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant>&nbsp;</entry>
2565                       <entry>Hierarchical P coding.</entry>
2566                     </row>
2567                   </tbody>
2568                 </entrytbl>
2569               </row>
2570
2571               <row><entry></entry></row>
2572               <row>
2573                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant>&nbsp;</entry>
2574                 <entry>integer</entry>
2575               </row>
2576               <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2577 Applicable to the H264 encoder.</entry>
2578               </row>
2579
2580               <row><entry></entry></row>
2581               <row>
2582                 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant>&nbsp;</entry>
2583                 <entry>integer</entry>
2584               </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2585 The supplied 32-bit integer is interpreted as follows (bit
2586 0 = least significant bit):</entry>
2587               </row>
2588               <row>
2589                 <entrytbl spanname="descr" cols="2">
2590                   <tbody valign="top">
2591                     <row>
2592                       <entry>Bit 0:15</entry>
2593                       <entry>QP value</entry>
2594                     </row>
2595                     <row>
2596                       <entry>Bit 16:32</entry>
2597                       <entry>Layer number</entry>
2598                     </row>
2599                   </tbody>
2600                 </entrytbl>
2601               </row>
2602
2603             </tbody>
2604           </tgroup>
2605         </table>
2606       </section>
2607
2608       <section>
2609         <title>MFC 5.1 MPEG Controls</title>
2610
2611         <para>The following MPEG class controls deal with MPEG
2612 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2613 in the S5P family of SoCs by Samsung.
2614 </para>
2615
2616         <table pgwide="1" frame="none" id="mfc51-control-id">
2617           <title>MFC 5.1 Control IDs</title>
2618           <tgroup cols="4">
2619             <colspec colname="c1" colwidth="1*" />
2620             <colspec colname="c2" colwidth="6*" />
2621             <colspec colname="c3" colwidth="2*" />
2622             <colspec colname="c4" colwidth="6*" />
2623             <spanspec namest="c1" nameend="c2" spanname="id" />
2624             <spanspec namest="c2" nameend="c4" spanname="descr" />
2625             <thead>
2626               <row>
2627                 <entry spanname="id" align="left">ID</entry>
2628                 <entry align="left">Type</entry>
2629               </row><row><entry spanname="descr" align="left">Description</entry>
2630               </row>
2631             </thead>
2632             <tbody valign="top">
2633               <row><entry></entry></row>
2634               <row>
2635                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant>&nbsp;</entry>
2636                 <entry>integer</entry>
2637               </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2638 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2639 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2640 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2641 Applicable to the H264 decoder.
2642               </entry>
2643               </row>
2644               <row><entry></entry></row>
2645               <row>
2646                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant>&nbsp;</entry>
2647                 <entry>integer</entry>
2648               </row><row><entry spanname="descr">Display delay value for H264 decoder.
2649 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2650 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2651 as a reference picture for subsequent frames.
2652 </entry>
2653               </row>
2654               <row><entry></entry></row>
2655               <row>
2656                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant>&nbsp;</entry>
2657                 <entry>integer</entry>
2658               </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2659 Applicable to the H264 encoder.</entry>
2660               </row>
2661               <row><entry></entry></row>
2662               <row>
2663                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant>&nbsp;</entry>
2664                 <entry>boolean</entry>
2665               </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2666 Applicable to encoders.</entry>
2667               </row>
2668               <row><entry></entry></row>
2669               <row>
2670                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant>&nbsp;</entry>
2671                 <entry>integer</entry>
2672               </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2673 0 = least significant bit):</entry>
2674               </row>
2675               <row>
2676                 <entrytbl spanname="descr" cols="2">
2677                   <tbody valign="top">
2678                     <row>
2679                       <entry>Bit 0:7</entry>
2680                       <entry>V chrominance information</entry>
2681                     </row>
2682                     <row>
2683                       <entry>Bit 8:15</entry>
2684                       <entry>U chrominance information</entry>
2685                     </row>
2686                     <row>
2687                       <entry>Bit 16:23</entry>
2688                       <entry>Y luminance information</entry>
2689                     </row>
2690                     <row>
2691                       <entry>Bit 24:31</entry>
2692                       <entry>Must be zero.</entry>
2693                     </row>
2694                   </tbody>
2695                 </entrytbl>
2696               </row>
2697               <row><entry></entry></row>
2698               <row>
2699                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant>&nbsp;</entry>
2700                 <entry>integer</entry>
2701               </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2702 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2703 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2704 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2705 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2706 </entry>
2707               </row>
2708               <row><entry></entry></row>
2709               <row>
2710                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant>&nbsp;</entry>
2711                 <entry>boolean</entry>
2712               </row><row><entry spanname="descr">Adaptive rate control for dark region.
2713 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2714 Applicable to the H264 encoder.</entry>
2715               </row>
2716               <row><entry></entry></row>
2717               <row>
2718                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant>&nbsp;</entry>
2719                 <entry>boolean</entry>
2720               </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2721 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2722 Applicable to the H264 encoder.</entry>
2723               </row>
2724               <row><entry></entry></row>
2725               <row>
2726                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant>&nbsp;</entry>
2727                 <entry>boolean</entry>
2728               </row><row><entry spanname="descr">Adaptive rate control for static region.
2729 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2730 Applicable to the H264 encoder.</entry>
2731               </row>
2732               <row><entry></entry></row>
2733               <row>
2734                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant>&nbsp;</entry>
2735                 <entry>boolean</entry>
2736               </row><row><entry spanname="descr">Adaptive rate control for activity region.
2737 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2738 Applicable to the H264 encoder.</entry>
2739               </row>
2740               <row><entry></entry></row>
2741               <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2742                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant>&nbsp;</entry>
2743                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2744               </row>
2745               <row><entry spanname="descr">
2746 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2747 a chosen data limit then the frame will be skipped.
2748 Possible values are:</entry>
2749               </row>
2750               <row>
2751                 <entrytbl spanname="descr" cols="2">
2752                   <tbody valign="top">
2753                     <row>
2754                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant>&nbsp;</entry>
2755                       <entry>Frame skip mode is disabled.</entry>
2756                     </row>
2757                     <row>
2758                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant>&nbsp;</entry>
2759                       <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2760                     </row>
2761                     <row>
2762                       <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant>&nbsp;</entry>
2763                       <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2764                     </row>
2765                   </tbody>
2766                 </entrytbl>
2767               </row>
2768               <row><entry></entry></row>
2769               <row>
2770                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant>&nbsp;</entry>
2771                 <entry>integer</entry>
2772               </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2773 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2774 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2775 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2776 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2777 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2778 the stream will meet tight bandwidth contraints. Applicable to encoders.
2779 </entry>
2780               </row>
2781               <row><entry></entry></row>
2782               <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2783                 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant>&nbsp;</entry>
2784                 <entry>enum&nbsp;v4l2_mpeg_mfc51_video_force_frame_type</entry>
2785               </row>
2786               <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2787 Possible values are:</entry>
2788               </row>
2789               <row>
2790                 <entrytbl spanname="descr" cols="2">
2791                   <tbody valign="top">
2792                     <row>
2793                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant>&nbsp;</entry>
2794                       <entry>Forcing a specific frame type disabled.</entry>
2795                     </row>
2796                     <row>
2797                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant>&nbsp;</entry>
2798                       <entry>Force an I-frame.</entry>
2799                     </row>
2800                     <row>
2801                       <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant>&nbsp;</entry>
2802                       <entry>Force a non-coded frame.</entry>
2803                     </row>
2804                   </tbody>
2805                 </entrytbl>
2806               </row>
2807             </tbody>
2808           </tgroup>
2809         </table>
2810       </section>
2811
2812       <section>
2813         <title>CX2341x MPEG Controls</title>
2814
2815         <para>The following MPEG class controls deal with MPEG
2816 encoding settings that are specific to the Conexant CX23415 and
2817 CX23416 MPEG encoding chips.</para>
2818
2819         <table pgwide="1" frame="none" id="cx2341x-control-id">
2820           <title>CX2341x Control IDs</title>
2821           <tgroup cols="4">
2822             <colspec colname="c1" colwidth="1*" />
2823             <colspec colname="c2" colwidth="6*" />
2824             <colspec colname="c3" colwidth="2*" />
2825             <colspec colname="c4" colwidth="6*" />
2826             <spanspec namest="c1" nameend="c2" spanname="id" />
2827             <spanspec namest="c2" nameend="c4" spanname="descr" />
2828             <thead>
2829               <row>
2830                 <entry spanname="id" align="left">ID</entry>
2831                 <entry align="left">Type</entry>
2832               </row><row><entry spanname="descr" align="left">Description</entry>
2833               </row>
2834             </thead>
2835             <tbody valign="top">
2836               <row><entry></entry></row>
2837               <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2838                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant>&nbsp;</entry>
2839                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2840               </row><row><entry spanname="descr">Sets the Spatial
2841 Filter mode (default <constant>MANUAL</constant>). Possible values
2842 are:</entry>
2843               </row>
2844               <row>
2845                 <entrytbl spanname="descr" cols="2">
2846                   <tbody valign="top">
2847                     <row>
2848                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2849                       <entry>Choose the filter manually</entry>
2850                     </row>
2851                     <row>
2852                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2853                       <entry>Choose the filter automatically</entry>
2854                     </row>
2855                   </tbody>
2856                 </entrytbl>
2857               </row>
2858               <row><entry></entry></row>
2859               <row>
2860                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant>&nbsp;</entry>
2861                 <entry>integer&nbsp;(0-15)</entry>
2862               </row><row><entry spanname="descr">The setting for the
2863 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2864               </row>
2865               <row><entry></entry></row>
2866               <row id="luma-spatial-filter-type">
2867                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2868                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2869               </row><row><entry spanname="descr">Select the algorithm
2870 to use for the Luma Spatial Filter (default
2871 <constant>1D_HOR</constant>). Possible values:</entry>
2872               </row>
2873               <row>
2874                 <entrytbl spanname="descr" cols="2">
2875                   <tbody valign="top">
2876                     <row>
2877                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2878                       <entry>No filter</entry>
2879                     </row>
2880                     <row>
2881                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2882                       <entry>One-dimensional horizontal</entry>
2883                     </row>
2884                     <row>
2885                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant>&nbsp;</entry>
2886                       <entry>One-dimensional vertical</entry>
2887                     </row>
2888                     <row>
2889                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant>&nbsp;</entry>
2890                       <entry>Two-dimensional separable</entry>
2891                     </row>
2892                     <row>
2893                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant>&nbsp;</entry>
2894                       <entry>Two-dimensional symmetrical
2895 non-separable</entry>
2896                     </row>
2897                   </tbody>
2898                 </entrytbl>
2899               </row>
2900               <row><entry></entry></row>
2901               <row id="chroma-spatial-filter-type">
2902                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant>&nbsp;</entry>
2903                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2904               </row><row><entry spanname="descr">Select the algorithm
2905 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2906 Possible values are:</entry>
2907               </row>
2908               <row>
2909                 <entrytbl spanname="descr" cols="2">
2910                   <tbody valign="top">
2911                     <row>
2912                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2913                       <entry>No filter</entry>
2914                     </row>
2915                     <row>
2916                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant>&nbsp;</entry>
2917                       <entry>One-dimensional horizontal</entry>
2918                     </row>
2919                   </tbody>
2920                 </entrytbl>
2921               </row>
2922               <row><entry></entry></row>
2923               <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2924                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant>&nbsp;</entry>
2925                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2926               </row><row><entry spanname="descr">Sets the Temporal
2927 Filter mode (default <constant>MANUAL</constant>). Possible values
2928 are:</entry>
2929               </row>
2930               <row>
2931                 <entrytbl spanname="descr" cols="2">
2932                   <tbody valign="top">
2933                     <row>
2934                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant>&nbsp;</entry>
2935                       <entry>Choose the filter manually</entry>
2936                     </row>
2937                     <row>
2938                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant>&nbsp;</entry>
2939                       <entry>Choose the filter automatically</entry>
2940                     </row>
2941                   </tbody>
2942                 </entrytbl>
2943               </row>
2944               <row><entry></entry></row>
2945               <row>
2946                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant>&nbsp;</entry>
2947                 <entry>integer&nbsp;(0-31)</entry>
2948               </row><row><entry spanname="descr">The setting for the
2949 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2950 capturing and 0 for scaled capturing.)</entry>
2951               </row>
2952               <row><entry></entry></row>
2953               <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2954                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant>&nbsp;</entry>
2955                 <entry>enum&nbsp;v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2956               </row><row><entry spanname="descr">Median Filter Type
2957 (default <constant>OFF</constant>). Possible values are:</entry>
2958               </row>
2959               <row>
2960                 <entrytbl spanname="descr" cols="2">
2961                   <tbody valign="top">
2962                     <row>
2963                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant>&nbsp;</entry>
2964                       <entry>No filter</entry>
2965                     </row>
2966                     <row>
2967                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant>&nbsp;</entry>
2968                       <entry>Horizontal filter</entry>
2969                     </row>
2970                     <row>
2971                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant>&nbsp;</entry>
2972                       <entry>Vertical filter</entry>
2973                     </row>
2974                     <row>
2975                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant>&nbsp;</entry>
2976                       <entry>Horizontal and vertical filter</entry>
2977                     </row>
2978                     <row>
2979                       <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant>&nbsp;</entry>
2980                       <entry>Diagonal filter</entry>
2981                     </row>
2982                   </tbody>
2983                 </entrytbl>
2984               </row>
2985               <row><entry></entry></row>
2986               <row>
2987                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
2988                 <entry>integer&nbsp;(0-255)</entry>
2989               </row><row><entry spanname="descr">Threshold above which
2990 the luminance median filter is enabled (default 0)</entry>
2991               </row>
2992               <row><entry></entry></row>
2993               <row>
2994                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
2995                 <entry>integer&nbsp;(0-255)</entry>
2996               </row><row><entry spanname="descr">Threshold below which
2997 the luminance median filter is enabled (default 255)</entry>
2998               </row>
2999               <row><entry></entry></row>
3000               <row>
3001                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant>&nbsp;</entry>
3002                 <entry>integer&nbsp;(0-255)</entry>
3003               </row><row><entry spanname="descr">Threshold above which
3004 the chroma median filter is enabled (default 0)</entry>
3005               </row>
3006               <row><entry></entry></row>
3007               <row>
3008                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant>&nbsp;</entry>
3009                 <entry>integer&nbsp;(0-255)</entry>
3010               </row><row><entry spanname="descr">Threshold below which
3011 the chroma median filter is enabled (default 255)</entry>
3012               </row>
3013               <row><entry></entry></row>
3014               <row>
3015                 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant>&nbsp;</entry>
3016                 <entry>boolean</entry>
3017               </row>
3018               <row><entry spanname="descr">The CX2341X MPEG encoder
3019 can insert one empty MPEG-2 PES packet into the stream between every
3020 four video frames. The packet size is 2048 bytes, including the
3021 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
3022 (private stream 2). The payload consists of 0x00 bytes, to be filled
3023 in by the application. 0 = do not insert, 1 = insert packets.</entry>
3024               </row>
3025             </tbody>
3026           </tgroup>
3027         </table>
3028       </section>
3029     </section>
3030
3031     <section id="camera-controls">
3032       <title>Camera Control Reference</title>
3033
3034       <para>The Camera class includes controls for mechanical (or
3035 equivalent digital) features of a device such as controllable lenses
3036 or sensors.</para>
3037
3038     <table pgwide="1" frame="none" id="camera-control-id">
3039       <title>Camera Control IDs</title>
3040       <tgroup cols="4">
3041         <colspec colname="c1" colwidth="1*" />
3042         <colspec colname="c2" colwidth="6*" />
3043         <colspec colname="c3" colwidth="2*" />
3044         <colspec colname="c4" colwidth="6*" />
3045         <spanspec namest="c1" nameend="c2" spanname="id" />
3046         <spanspec namest="c2" nameend="c4" spanname="descr" />
3047         <thead>
3048           <row>
3049             <entry spanname="id" align="left">ID</entry>
3050             <entry align="left">Type</entry>
3051           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3052           </row>
3053         </thead>
3054         <tbody valign="top">
3055           <row><entry></entry></row>
3056           <row>
3057             <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant>&nbsp;</entry>
3058             <entry>class</entry>
3059           </row><row><entry spanname="descr">The Camera class
3060 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3061 description of this control class.</entry>
3062           </row>
3063           <row><entry></entry></row>
3064
3065           <row id="v4l2-exposure-auto-type">
3066             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant>&nbsp;</entry>
3067             <entry>enum&nbsp;v4l2_exposure_auto_type</entry>
3068           </row><row><entry spanname="descr">Enables automatic
3069 adjustments of the exposure time and/or iris aperture. The effect of
3070 manual changes of the exposure time or iris aperture while these
3071 features are enabled is undefined, drivers should ignore such
3072 requests. Possible values are:</entry>
3073           </row>
3074           <row>
3075             <entrytbl spanname="descr" cols="2">
3076               <tbody valign="top">
3077                 <row>
3078                   <entry><constant>V4L2_EXPOSURE_AUTO</constant>&nbsp;</entry>
3079                       <entry>Automatic exposure time, automatic iris
3080 aperture.</entry>
3081                 </row>
3082                 <row>
3083                   <entry><constant>V4L2_EXPOSURE_MANUAL</constant>&nbsp;</entry>
3084                   <entry>Manual exposure time, manual iris.</entry>
3085                 </row>
3086                 <row>
3087                   <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant>&nbsp;</entry>
3088                   <entry>Manual exposure time, auto iris.</entry>
3089                 </row>
3090                 <row>
3091                   <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant>&nbsp;</entry>
3092                   <entry>Auto exposure time, manual iris.</entry>
3093                 </row>
3094               </tbody>
3095             </entrytbl>
3096           </row>
3097           <row><entry></entry></row>
3098
3099           <row>
3100             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant>&nbsp;</entry>
3101             <entry>integer</entry>
3102           </row><row><entry spanname="descr">Determines the exposure
3103 time of the camera sensor. The exposure time is limited by the frame
3104 interval. Drivers should interpret the values as 100 &micro;s units,
3105 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3106 and 100000 for 10 seconds.</entry>
3107           </row>
3108           <row><entry></entry></row>
3109
3110           <row>
3111             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant>&nbsp;</entry>
3112             <entry>boolean</entry>
3113           </row><row><entry spanname="descr">When
3114 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3115 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3116 this control determines if the device may dynamically vary the frame
3117 rate. By default this feature is disabled (0) and the frame rate must
3118 remain constant.</entry>
3119           </row>
3120           <row><entry></entry></row>
3121
3122           <row>
3123             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant>&nbsp;</entry>
3124             <entry>integer menu</entry>
3125           </row><row><entry spanname="descr"> Determines the automatic
3126 exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3127 control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3128 or <constant>APERTURE_PRIORITY</constant>.
3129 It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3130 units, where the value 1000 stands for +1 EV.
3131 <para>Increasing the exposure compensation value is equivalent to decreasing
3132 the exposure value (EV) and will increase the amount of light at the image
3133 sensor. The camera performs the exposure compensation by adjusting absolute
3134 exposure time and/or aperture.</para></entry>
3135           </row>
3136           <row><entry></entry></row>
3137
3138           <row id="v4l2-exposure-metering">
3139             <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant>&nbsp;</entry>
3140             <entry>enum&nbsp;v4l2_exposure_metering</entry>
3141           </row><row><entry spanname="descr">Determines how the camera measures
3142 the amount of light available for the frame exposure. Possible values are:</entry>
3143           </row>
3144           <row>
3145             <entrytbl spanname="descr" cols="2">
3146               <tbody valign="top">
3147                 <row>
3148                   <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant>&nbsp;</entry>
3149                   <entry>Use the light information coming from the entire frame
3150 and average giving no weighting to any particular portion of the metered area.
3151                   </entry>
3152                 </row>
3153                 <row>
3154                   <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant>&nbsp;</entry>
3155                   <entry>Average the light information coming from the entire frame
3156 giving priority to the center of the metered area.</entry>
3157                 </row>
3158                 <row>
3159                   <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant>&nbsp;</entry>
3160                   <entry>Measure only very small area at the center of the frame.</entry>
3161                 </row>
3162               </tbody>
3163             </entrytbl>
3164           </row>
3165           <row><entry></entry></row>
3166
3167           <row>
3168             <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant>&nbsp;</entry>
3169             <entry>integer</entry>
3170           </row><row><entry spanname="descr">This control turns the
3171 camera horizontally by the specified amount. The unit is undefined. A
3172 positive value moves the camera to the right (clockwise when viewed
3173 from above), a negative value to the left. A value of zero does not
3174 cause motion. This is a write-only control.</entry>
3175           </row>
3176           <row><entry></entry></row>
3177
3178           <row>
3179             <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant>&nbsp;</entry>
3180             <entry>integer</entry>
3181           </row><row><entry spanname="descr">This control turns the
3182 camera vertically by the specified amount. The unit is undefined. A
3183 positive value moves the camera up, a negative value down. A value of
3184 zero does not cause motion. This is a write-only control.</entry>
3185           </row>
3186           <row><entry></entry></row>
3187
3188           <row>
3189             <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant>&nbsp;</entry>
3190             <entry>button</entry>
3191           </row><row><entry spanname="descr">When this control is set,
3192 the camera moves horizontally to the default position.</entry>
3193           </row>
3194           <row><entry></entry></row>
3195
3196           <row>
3197             <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant>&nbsp;</entry>
3198             <entry>button</entry>
3199           </row><row><entry spanname="descr">When this control is set,
3200 the camera moves vertically to the default position.</entry>
3201           </row>
3202           <row><entry></entry></row>
3203
3204           <row>
3205             <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant>&nbsp;</entry>
3206             <entry>integer</entry>
3207           </row><row><entry spanname="descr">This control
3208 turns the camera horizontally to the specified position. Positive
3209 values move the camera to the right (clockwise when viewed from above),
3210 negative values to the left. Drivers should interpret the values as arc
3211 seconds, with valid values between -180 * 3600 and +180 * 3600
3212 inclusive.</entry>
3213           </row>
3214           <row><entry></entry></row>
3215
3216           <row>
3217             <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant>&nbsp;</entry>
3218             <entry>integer</entry>
3219           </row><row><entry spanname="descr">This control
3220 turns the camera vertically to the specified position. Positive values
3221 move the camera up, negative values down. Drivers should interpret the
3222 values as arc seconds, with valid values between -180 * 3600 and +180
3223 * 3600 inclusive.</entry>
3224           </row>
3225           <row><entry></entry></row>
3226
3227           <row>
3228             <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant>&nbsp;</entry>
3229             <entry>integer</entry>
3230           </row><row><entry spanname="descr">This control sets the
3231 focal point of the camera to the specified position. The unit is
3232 undefined. Positive values set the focus closer to the camera,
3233 negative values towards infinity.</entry>
3234           </row>
3235           <row><entry></entry></row>
3236
3237           <row>
3238             <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant>&nbsp;</entry>
3239             <entry>integer</entry>
3240           </row><row><entry spanname="descr">This control moves the
3241 focal point of the camera by the specified amount. The unit is
3242 undefined. Positive values move the focus closer to the camera,
3243 negative values towards infinity. This is a write-only control.</entry>
3244           </row>
3245           <row><entry></entry></row>
3246
3247           <row>
3248             <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant>&nbsp;</entry>
3249             <entry>boolean</entry>
3250           </row><row><entry spanname="descr">Enables continuous automatic
3251 focus adjustments. The effect of manual focus adjustments while this feature
3252 is enabled is undefined, drivers should ignore such requests.</entry>
3253           </row>
3254           <row><entry></entry></row>
3255
3256           <row>
3257             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant>&nbsp;</entry>
3258             <entry>button</entry>
3259           </row><row><entry spanname="descr">Starts single auto focus process.
3260 The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3261 is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3262 such requests.</entry>
3263           </row>
3264           <row><entry></entry></row>
3265
3266           <row>
3267             <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant>&nbsp;</entry>
3268             <entry>button</entry>
3269           </row><row><entry spanname="descr">Aborts automatic focusing
3270 started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3271 effective only when the continuous autofocus is disabled, that is when
3272 <constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3273 </constant> (0).</entry>
3274           </row>
3275           <row><entry></entry></row>
3276
3277           <row id="v4l2-auto-focus-status">
3278             <entry spanname="id">
3279               <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>&nbsp;</entry>
3280             <entry>bitmask</entry>
3281           </row>
3282           <row><entry spanname="descr">The automatic focus status. This is a read-only
3283           control.</entry>
3284           </row>
3285           <row>
3286             <entrytbl spanname="descr" cols="2">
3287               <tbody valign="top">
3288                 <row>
3289                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant>&nbsp;</entry>
3290                   <entry>Automatic focus is not active.</entry>
3291                 </row>
3292                 <row>
3293                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant>&nbsp;</entry>
3294                   <entry>Automatic focusing is in progress.</entry>
3295                 </row>
3296                 <row>
3297                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant>&nbsp;</entry>
3298                   <entry>Focus has been reached.</entry>
3299                 </row>
3300                 <row>
3301                   <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant>&nbsp;</entry>
3302                   <entry>Automatic focus has failed, the driver will not
3303                   transition from this state until another action is
3304                   performed by an application.</entry>
3305                 </row>
3306               </tbody>
3307             </entrytbl>
3308           </row>
3309           <row><entry spanname="descr">
3310 Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3311 </constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3312 control value.</entry>
3313           </row>
3314           <row><entry></entry></row>
3315
3316           <row id="v4l2-auto-focus-range">
3317             <entry spanname="id">
3318               <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant>&nbsp;</entry>
3319             <entry>enum&nbsp;v4l2_auto_focus_range</entry>
3320           </row>
3321           <row><entry spanname="descr">Determines auto focus distance range
3322 for which lens may be adjusted. </entry>
3323           </row>
3324           <row>
3325             <entrytbl spanname="descr" cols="2">
3326               <tbody valign="top">
3327                 <row>
3328                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant>&nbsp;</entry>
3329                   <entry>The camera automatically selects the focus range.</entry>
3330                 </row>
3331                 <row>
3332                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant>&nbsp;</entry>
3333                   <entry>Normal distance range, limited for best automatic focus
3334 performance.</entry>
3335                 </row>
3336                 <row>
3337                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant>&nbsp;</entry>
3338                   <entry>Macro (close-up) auto focus. The camera will
3339 use its minimum possible distance for auto focus.</entry>
3340                 </row>
3341                 <row>
3342                   <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant>&nbsp;</entry>
3343                   <entry>The lens is set to focus on an object at infinite distance.</entry>
3344                 </row>
3345               </tbody>
3346             </entrytbl>
3347           </row>
3348           <row><entry></entry></row>
3349
3350           <row>
3351             <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant>&nbsp;</entry>
3352             <entry>integer</entry>
3353           </row><row><entry spanname="descr">Specify the objective lens
3354 focal length as an absolute value. The zoom unit is driver-specific and its
3355 value should be a positive integer.</entry>
3356           </row>
3357           <row><entry></entry></row>
3358
3359           <row>
3360             <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant>&nbsp;</entry>
3361             <entry>integer</entry>
3362           </row><row><entry spanname="descr">Specify the objective lens
3363 focal length relatively to the current value. Positive values move the zoom
3364 lens group towards the telephoto direction, negative values towards the
3365 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3366           </row>
3367           <row><entry></entry></row>
3368
3369           <row>
3370             <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant>&nbsp;</entry>
3371             <entry>integer</entry>
3372           </row><row><entry spanname="descr">Move the objective lens group
3373 at the specified speed until it reaches physical device limits or until an
3374 explicit request to stop the movement. A positive value moves the zoom lens
3375 group towards the telephoto direction. A value of zero stops the zoom lens
3376 group movement. A negative value moves the zoom lens group towards the
3377 wide-angle direction. The zoom speed unit is driver-specific.</entry>
3378           </row>
3379           <row><entry></entry></row>
3380
3381           <row>
3382             <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant>&nbsp;</entry>
3383             <entry>integer</entry>
3384           </row><row><entry spanname="descr">This control sets the
3385 camera's aperture to the specified value. The unit is undefined.
3386 Larger values open the iris wider, smaller values close it.</entry>
3387           </row>
3388           <row><entry></entry></row>
3389
3390           <row>
3391             <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant>&nbsp;</entry>
3392             <entry>integer</entry>
3393           </row><row><entry spanname="descr">This control modifies the
3394 camera's aperture by the specified amount. The unit is undefined.
3395 Positive values open the iris one step further, negative values close
3396 it one step further. This is a write-only control.</entry>
3397           </row>
3398           <row><entry></entry></row>
3399
3400           <row>
3401             <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant>&nbsp;</entry>
3402             <entry>boolean</entry>
3403           </row><row><entry spanname="descr">Prevent video from being acquired
3404 by the camera. When this control is set to <constant>TRUE</constant> (1), no
3405 image can be captured by the camera. Common means to enforce privacy are
3406 mechanical obturation of the sensor and firmware image processing, but the
3407 device is not restricted to these methods. Devices that implement the privacy
3408 control must support read access and may support write access.</entry>
3409           </row>
3410
3411           <row>
3412             <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant>&nbsp;</entry>
3413             <entry>integer</entry>
3414           </row><row><entry spanname="descr">Switch the band-stop filter of a
3415 camera sensor on or off, or specify its strength. Such band-stop filters can
3416 be used, for example, to filter out the fluorescent light component.</entry>
3417           </row>
3418           <row><entry></entry></row>
3419
3420           <row id="v4l2-auto-n-preset-white-balance">
3421             <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant>&nbsp;</entry>
3422             <entry>enum&nbsp;v4l2_auto_n_preset_white_balance</entry>
3423           </row><row><entry spanname="descr">Sets white balance to automatic,
3424 manual or a preset. The presets determine color temperature of the light as
3425 a hint to the camera for white balance adjustments resulting in most accurate
3426 color representation. The following white balance presets are listed in order
3427 of increasing color temperature.</entry>
3428           </row>
3429           <row>
3430             <entrytbl spanname="descr" cols="2">
3431               <tbody valign="top">
3432                 <row>
3433                   <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant>&nbsp;</entry>
3434                   <entry>Manual white balance.</entry>
3435                 </row>
3436                 <row>
3437                   <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant>&nbsp;</entry>
3438                   <entry>Automatic white balance adjustments.</entry>
3439                 </row>
3440                 <row>
3441                   <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant>&nbsp;</entry>
3442                   <entry>White balance setting for incandescent (tungsten) lighting.
3443 It generally cools down the colors and corresponds approximately to 2500...3500 K
3444 color temperature range.</entry>
3445                 </row>
3446                 <row>
3447                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant>&nbsp;</entry>
3448                   <entry>White balance preset for fluorescent lighting.
3449 It corresponds approximately to 4000...5000 K color temperature.</entry>
3450                 </row>
3451                 <row>
3452                   <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant>&nbsp;</entry>
3453                   <entry>With this setting the camera will compensate for
3454 fluorescent H lighting.</entry>
3455                 </row>
3456                 <row>
3457                   <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant>&nbsp;</entry>
3458                   <entry>White balance setting for horizon daylight.
3459 It corresponds approximately to 5000 K color temperature.</entry>
3460                 </row>
3461                 <row>
3462                   <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant>&nbsp;</entry>
3463                   <entry>White balance preset for daylight (with clear sky).
3464 It corresponds approximately to 5000...6500 K color temperature.</entry>
3465                 </row>
3466                 <row>
3467                   <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant>&nbsp;</entry>
3468                   <entry>With this setting the camera will compensate for the flash
3469 light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3470 color temperature.</entry>
3471                 </row>
3472                 <row>
3473                   <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant>&nbsp;</entry>
3474                   <entry>White balance preset for moderately overcast sky.
3475 This option corresponds approximately to 6500...8000 K color temperature
3476 range.</entry>
3477                 </row>
3478                 <row>
3479                   <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant>&nbsp;</entry>
3480                   <entry>White balance preset for shade or heavily overcast
3481 sky. It corresponds approximately to 9000...10000 K color temperature.
3482 </entry>
3483                 </row>
3484               </tbody>
3485             </entrytbl>
3486           </row>
3487           <row><entry></entry></row>
3488
3489           <row id="v4l2-wide-dynamic-range">
3490             <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3491             <entry>boolean</entry>
3492           </row>
3493           <row>
3494             <entry spanname="descr">Enables or disables the camera's wide dynamic
3495 range feature. This feature allows to obtain clear images in situations where
3496 intensity of the illumination varies significantly throughout the scene, i.e.
3497 there are simultaneously very dark and very bright areas. It is most commonly
3498 realized in cameras by combining two subsequent frames with different exposure
3499 times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3500 control in the future, if more options are required.</para></footnote></entry>
3501           </row>
3502           <row><entry></entry></row>
3503
3504           <row id="v4l2-image-stabilization">
3505             <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3506             <entry>boolean</entry>
3507           </row>
3508           <row>
3509             <entry spanname="descr">Enables or disables image stabilization.
3510               <footnoteref linkend="ctypeconv"/></entry>
3511           </row>
3512           <row><entry></entry></row>
3513
3514           <row>
3515             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant>&nbsp;</entry>
3516             <entry>integer menu</entry>
3517           </row><row><entry spanname="descr">Determines ISO equivalent of an
3518 image sensor indicating the sensor's sensitivity to light. The numbers are
3519 expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3520 where doubling the sensor sensitivity is represented by doubling the numerical
3521 ISO value. Applications should interpret the values as standard ISO values
3522 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3523 usually support only a subset of standard ISO values. The effect of setting
3524 this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3525 control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3526 </constant> is undefined, drivers should ignore such requests.</entry>
3527           </row>
3528           <row><entry></entry></row>
3529
3530           <row id="v4l2-iso-sensitivity-auto-type">
3531             <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3532             <entry>enum&nbsp;v4l2_iso_sensitivity_type</entry>
3533           </row><row><entry spanname="descr">Enables or disables automatic ISO
3534 sensitivity adjustments.</entry>
3535           </row>
3536           <row>
3537             <entrytbl spanname="descr" cols="2">
3538               <tbody valign="top">
3539                 <row>
3540                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant>&nbsp;</entry>
3541                   <entry>Manual ISO sensitivity.</entry>
3542                 </row>
3543                 <row>
3544                   <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>&nbsp;</entry>
3545                   <entry>Automatic ISO sensitivity adjustments.</entry>
3546                 </row>
3547               </tbody>
3548             </entrytbl>
3549           </row>
3550           <row><entry></entry></row>
3551
3552           <row id="v4l2-scene-mode">
3553             <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant>&nbsp;</entry>
3554             <entry>enum&nbsp;v4l2_scene_mode</entry>
3555           </row><row><entry spanname="descr">This control allows to select
3556 scene programs as the camera automatic modes optimized for common shooting
3557 scenes. Within these modes the camera determines best exposure, aperture,
3558 focusing, light metering, white balance and equivalent sensitivity. The
3559 controls of those parameters are influenced by the scene mode control.
3560 An exact behavior in each mode is subject to the camera specification.
3561
3562 <para>When the scene mode feature is not used, this control should be set to
3563 <constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3564 related controls are accessible. The following scene programs are defined:
3565 </para>
3566 </entry>
3567           </row>
3568           <row>
3569             <entrytbl spanname="descr" cols="2">
3570               <tbody valign="top">
3571                 <row>
3572                   <entry><constant>V4L2_SCENE_MODE_NONE</constant>&nbsp;</entry>
3573                   <entry>The scene mode feature is disabled.</entry>
3574                 </row>
3575                 <row>
3576                   <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant>&nbsp;</entry>
3577                   <entry>Backlight. Compensates for dark shadows when light is
3578                   coming from behind a subject, also by automatically turning
3579                   on the flash.</entry>
3580                 </row>
3581                 <row>
3582                   <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant>&nbsp;</entry>
3583                   <entry>Beach and snow. This mode compensates for all-white or
3584 bright scenes, which tend to look gray and low contrast, when camera's automatic
3585 exposure is based on an average scene brightness. To compensate, this mode
3586 automatically slightly overexposes the frames. The white balance may also be
3587 adjusted to compensate for the fact that reflected snow looks bluish rather
3588 than white.</entry>
3589                 </row>
3590                 <row>
3591                   <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant>&nbsp;</entry>
3592                   <entry>Candle light. The camera generally raises the ISO
3593 sensitivity and lowers the shutter speed. This mode compensates for relatively
3594 close subject in the scene. The flash is disabled in order to preserve the
3595 ambiance of the light.</entry>
3596                 </row>
3597                 <row>
3598                   <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant>&nbsp;</entry>
3599                   <entry>Dawn and dusk. Preserves the colors seen in low
3600 natural light before dusk and after down. The camera may turn off the flash,
3601 and automatically focus at infinity. It will usually boost saturation and
3602 lower the shutter speed.</entry>
3603                 </row>
3604                 <row>
3605                   <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant>&nbsp;</entry>
3606                   <entry>Fall colors. Increases saturation and adjusts white
3607 balance for color enhancement. Pictures of autumn leaves get saturated reds
3608 and yellows.</entry>
3609                 </row>
3610                 <row>
3611                   <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant>&nbsp;</entry>
3612                   <entry>Fireworks. Long exposure times are used to capture
3613 the expanding burst of light from a firework. The camera may invoke image
3614 stabilization.</entry>
3615                 </row>
3616                 <row>
3617                   <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant>&nbsp;</entry>
3618                   <entry>Landscape. The camera may choose a small aperture to
3619 provide deep depth of field and long exposure duration to help capture detail
3620 in dim light conditions. The focus is fixed at infinity. Suitable for distant
3621 and wide scenery.</entry>
3622                 </row>
3623                 <row>
3624                   <entry><constant>V4L2_SCENE_MODE_NIGHT</constant>&nbsp;</entry>
3625                   <entry>Night, also known as Night Landscape. Designed for low
3626 light conditions, it preserves detail in the dark areas without blowing out bright
3627 objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3628 with a relatively long exposure time, and turns flash off. As such, there will be
3629 increased image noise and the possibility of blurred image.</entry>
3630                 </row>
3631                 <row>
3632                   <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant>&nbsp;</entry>
3633                   <entry>Party and indoor. Designed to capture indoor scenes
3634 that are lit by indoor background lighting as well as the flash. The camera
3635 usually increases ISO sensitivity, and adjusts exposure for the low light
3636 conditions.</entry>
3637                 </row>
3638                 <row>
3639                   <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant>&nbsp;</entry>
3640                   <entry>Portrait. The camera adjusts the aperture so that the
3641 depth of field is reduced, which helps to isolate the subject against a smooth
3642 background. Most cameras recognize the presence of faces in the scene and focus
3643 on them. The color hue is adjusted to enhance skin tones. The intensity of the
3644 flash is often reduced.</entry>
3645                 </row>
3646                 <row>
3647                   <entry><constant>V4L2_SCENE_MODE_SPORTS</constant>&nbsp;</entry>
3648                   <entry>Sports. Significantly increases ISO and uses a fast
3649 shutter speed to freeze motion of rapidly-moving subjects. Increased image
3650 noise may be seen in this mode.</entry>
3651                 </row>
3652                 <row>
3653                   <entry><constant>V4L2_SCENE_MODE_SUNSET</constant>&nbsp;</entry>
3654                   <entry>Sunset. Preserves deep hues seen in sunsets and
3655 sunrises. It bumps up the saturation.</entry>
3656                 </row>
3657                 <row>
3658                   <entry><constant>V4L2_SCENE_MODE_TEXT</constant>&nbsp;</entry>
3659                   <entry>Text. It applies extra contrast and sharpness, it is
3660 typically a black-and-white mode optimized for readability. Automatic focus
3661 may be switched to close-up mode and this setting may also involve some
3662 lens-distortion correction.</entry>
3663                 </row>
3664               </tbody>
3665             </entrytbl>
3666           </row>
3667           <row><entry></entry></row>
3668
3669           <row>
3670             <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3671             <entry>bitmask</entry>
3672           </row>
3673           <row>
3674             <entry spanname="descr">This control locks or unlocks the automatic
3675 focus, exposure and white balance. The automatic adjustments can be paused
3676 independently by setting the corresponding lock bit to 1. The camera then retains
3677 the settings until the lock bit is cleared. The following lock bits are defined:
3678 </entry>
3679           </row>
3680           <row>
3681             <entrytbl spanname="descr" cols="2">
3682               <tbody valign="top">
3683                 <row>
3684                   <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3685                   <entry>Automatic exposure adjustments lock.</entry>
3686                 </row>
3687                 <row>
3688                   <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3689                   <entry>Automatic white balance adjustments lock.</entry>
3690                 </row>
3691                 <row>
3692                   <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3693                   <entry>Automatic focus lock.</entry>
3694                 </row>
3695               </tbody>
3696             </entrytbl>
3697           </row>
3698           <row><entry spanname="descr">
3699 When a given algorithm is not enabled, drivers should ignore requests
3700 to lock it and should return no error. An example might be an application
3701 setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3702 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3703 <constant>FALSE</constant>. The value of this control may be changed
3704 by exposure, white balance or focus controls.</entry>
3705           </row>
3706           <row><entry></entry></row>
3707
3708         </tbody>
3709       </tgroup>
3710     </table>
3711   </section>
3712
3713     <section id="fm-tx-controls">
3714       <title>FM Transmitter Control Reference</title>
3715
3716       <para>The FM Transmitter (FM_TX) class includes controls for common features of
3717 FM transmissions capable devices. Currently this class includes parameters for audio
3718 compression, pilot tone generation, audio deviation limiter, RDS transmission and
3719 tuning power features.</para>
3720
3721       <table pgwide="1" frame="none" id="fm-tx-control-id">
3722       <title>FM_TX Control IDs</title>
3723
3724       <tgroup cols="4">
3725         <colspec colname="c1" colwidth="1*" />
3726         <colspec colname="c2" colwidth="6*" />
3727         <colspec colname="c3" colwidth="2*" />
3728         <colspec colname="c4" colwidth="6*" />
3729         <spanspec namest="c1" nameend="c2" spanname="id" />
3730         <spanspec namest="c2" nameend="c4" spanname="descr" />
3731         <thead>
3732           <row>
3733             <entry spanname="id" align="left">ID</entry>
3734             <entry align="left">Type</entry>
3735           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3736           </row>
3737         </thead>
3738         <tbody valign="top">
3739           <row><entry></entry></row>
3740           <row>
3741             <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant>&nbsp;</entry>
3742             <entry>class</entry>
3743           </row><row><entry spanname="descr">The FM_TX class
3744 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3745 description of this control class.</entry>
3746           </row>
3747           <row>
3748             <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant>&nbsp;</entry>
3749             <entry>integer</entry>
3750           </row>
3751           <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3752 The range and step are driver-specific.</entry>
3753           </row>
3754           <row>
3755             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant>&nbsp;</entry>
3756             <entry>integer</entry>
3757           </row>
3758           <row><entry spanname="descr">Sets the RDS Programme Identification field
3759 for transmission.</entry>
3760           </row>
3761           <row>
3762             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant>&nbsp;</entry>
3763             <entry>integer</entry>
3764           </row>
3765           <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3766 This encodes up to 31 pre-defined programme types.</entry>
3767           </row>
3768           <row>
3769             <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant>&nbsp;</entry>
3770             <entry>string</entry>
3771           </row>
3772           <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
3773 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
3774 identification and selection.  In Annex E of <xref linkend="iec62106" />, the RDS specification,
3775 there is a full description of the correct character encoding for Programme Service name strings.
3776 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
3777 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
3778 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
3779           </row>
3780           <row>
3781             <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant>&nbsp;</entry>
3782             <entry>string</entry>
3783           </row>
3784           <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
3785 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
3786 programme-related information or any other text. In these cases, RadioText should be used in addition to
3787 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
3788 in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
3789 used to transmit it, either 32 (2A block) or 64 (2B block).  However, it is also possible
3790 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
3791 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
3792           </row>
3793           <row>
3794             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant>&nbsp;</entry>
3795             <entry>boolean</entry>
3796           </row>
3797           <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
3798 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
3799 distortion and prevent overmodulation.
3800 </entry>
3801           </row>
3802           <row>
3803             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant>&nbsp;</entry>
3804             <entry>integer</entry>
3805           </row>
3806           <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
3807 Unit is in useconds. Step and range are driver-specific.</entry>
3808           </row>
3809           <row>
3810             <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant>&nbsp;</entry>
3811             <entry>integer</entry>
3812           </row>
3813           <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
3814 The range and step are driver-specific.</entry>
3815           </row>
3816           <row>
3817             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant>&nbsp;</entry>
3818             <entry>boolean</entry>
3819           </row>
3820           <row><entry spanname="descr">Enables or disables the audio compression feature.
3821 This feature amplifies signals below the threshold by a fixed gain and compresses audio
3822 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
3823           </row>
3824           <row>
3825             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant>&nbsp;</entry>
3826             <entry>integer</entry>
3827           </row>
3828           <row><entry spanname="descr">Sets the gain for audio compression feature. It is
3829 a dB value. The range and step are driver-specific.</entry>
3830           </row>
3831           <row>
3832             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant>&nbsp;</entry>
3833             <entry>integer</entry>
3834           </row>
3835           <row><entry spanname="descr">Sets the threshold level for audio compression freature.
3836 It is a dB value. The range and step are driver-specific.</entry>
3837           </row>
3838           <row>
3839             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant>&nbsp;</entry>
3840             <entry>integer</entry>
3841           </row>
3842           <row><entry spanname="descr">Sets the attack time for audio compression feature.
3843 It is a useconds value. The range and step are driver-specific.</entry>
3844           </row>
3845           <row>
3846             <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant>&nbsp;</entry>
3847             <entry>integer</entry>
3848           </row>
3849           <row><entry spanname="descr">Sets the release time for audio compression feature.
3850 It is a useconds value. The range and step are driver-specific.</entry>
3851           </row>
3852           <row>
3853             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant>&nbsp;</entry>
3854             <entry>boolean</entry>
3855           </row>
3856           <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
3857           </row>
3858           <row>
3859             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant>&nbsp;</entry>
3860             <entry>integer</entry>
3861           </row>
3862           <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
3863 in Hz. The range and step are driver-specific.</entry>
3864           </row>
3865           <row>
3866             <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant>&nbsp;</entry>
3867             <entry>integer</entry>
3868           </row>
3869           <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
3870 in Hz. The range and step are driver-specific.</entry>
3871           </row>
3872           <row>
3873             <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant>&nbsp;</entry>
3874             <entry>integer</entry>
3875           </row>
3876           <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
3877 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
3878 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum&nbsp;v4l2_preemphasis
3879 defines possible values for pre-emphasis. Here they are:</entry>
3880         </row><row>
3881         <entrytbl spanname="descr" cols="2">
3882                   <tbody valign="top">
3883                     <row>
3884                       <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant>&nbsp;</entry>
3885                       <entry>No pre-emphasis is applied.</entry>
3886                     </row>
3887                     <row>
3888                       <entry><constant>V4L2_PREEMPHASIS_50_uS</constant>&nbsp;</entry>
3889                       <entry>A pre-emphasis of 50 uS is used.</entry>
3890                     </row>
3891                     <row>
3892                       <entry><constant>V4L2_PREEMPHASIS_75_uS</constant>&nbsp;</entry>
3893                       <entry>A pre-emphasis of 75 uS is used.</entry>
3894                     </row>
3895                   </tbody>
3896                 </entrytbl>
3897
3898           </row>
3899           <row>
3900             <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant>&nbsp;</entry>
3901             <entry>integer</entry>
3902           </row>
3903           <row><entry spanname="descr">Sets the output power level for signal transmission.
3904 Unit is in dBuV. Range and step are driver-specific.</entry>
3905           </row>
3906           <row>
3907             <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant>&nbsp;</entry>
3908             <entry>integer</entry>
3909           </row>
3910           <row><entry spanname="descr">This selects the value of antenna tuning capacitor
3911 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
3912           </row>
3913           <row><entry></entry></row>
3914         </tbody>
3915       </tgroup>
3916       </table>
3917
3918 <para>For more details about RDS specification, refer to
3919 <xref linkend="iec62106" /> document, from CENELEC.</para>
3920     </section>
3921
3922     <section id="flash-controls">
3923       <title>Flash Control Reference</title>
3924
3925       <note>
3926         <title>Experimental</title>
3927
3928         <para>This is an <link linkend="experimental">experimental</link>
3929 interface and may change in the future.</para>
3930       </note>
3931
3932       <para>
3933         The V4L2 flash controls are intended to provide generic access
3934         to flash controller devices. Flash controller devices are
3935         typically used in digital cameras.
3936       </para>
3937
3938       <para>
3939         The interface can support both LED and xenon flash devices. As
3940         of writing this, there is no xenon flash driver using this
3941         interface.
3942       </para>
3943
3944       <section id="flash-controls-use-cases">
3945         <title>Supported use cases</title>
3946
3947         <section>
3948           <title>Unsynchronised LED flash (software strobe)</title>
3949
3950           <para>
3951             Unsynchronised LED flash is controlled directly by the
3952             host as the sensor. The flash must be enabled by the host
3953             before the exposure of the image starts and disabled once
3954             it ends. The host is fully responsible for the timing of
3955             the flash.
3956           </para>
3957
3958           <para>Example of such device: Nokia N900.</para>
3959         </section>
3960
3961         <section>
3962           <title>Synchronised LED flash (hardware strobe)</title>
3963
3964           <para>
3965             The synchronised LED flash is pre-programmed by the host
3966             (power and timeout) but controlled by the sensor through a
3967             strobe signal from the sensor to the flash.
3968           </para>
3969
3970           <para>
3971             The sensor controls the flash duration and timing. This
3972             information typically must be made available to the
3973             sensor.
3974           </para>
3975
3976         </section>
3977
3978         <section>
3979           <title>LED flash as torch</title>
3980
3981           <para>
3982             LED flash may be used as torch in conjunction with another
3983             use case involving camera or individually.
3984           </para>
3985
3986
3987           <table pgwide="1" frame="none" id="flash-control-id">
3988           <title>Flash Control IDs</title>
3989
3990           <tgroup cols="4">
3991         <colspec colname="c1" colwidth="1*" />
3992         <colspec colname="c2" colwidth="6*" />
3993         <colspec colname="c3" colwidth="2*" />
3994         <colspec colname="c4" colwidth="6*" />
3995         <spanspec namest="c1" nameend="c2" spanname="id" />
3996         <spanspec namest="c2" nameend="c4" spanname="descr" />
3997         <thead>
3998           <row>
3999             <entry spanname="id" align="left">ID</entry>
4000             <entry align="left">Type</entry>
4001           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4002           </row>
4003         </thead>
4004         <tbody valign="top">
4005           <row><entry></entry></row>
4006           <row>
4007             <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4008             <entry>class</entry>
4009           </row>
4010           <row>
4011             <entry spanname="descr">The FLASH class descriptor.</entry>
4012           </row>
4013           <row>
4014             <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
4015             <entry>menu</entry>
4016           </row>
4017           <row id="v4l2-flash-led-mode">
4018             <entry spanname="descr">Defines the mode of the flash LED,
4019             the high-power white LED attached to the flash controller.
4020             Setting this control may not be possible in presence of
4021             some faults. See V4L2_CID_FLASH_FAULT.</entry>
4022           </row>
4023           <row>
4024             <entrytbl spanname="descr" cols="2">
4025               <tbody valign="top">
4026                 <row>
4027                   <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4028                   <entry>Off.</entry>
4029                 </row>
4030                 <row>
4031                   <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4032                   <entry>Flash mode.</entry>
4033                 </row>
4034                 <row>
4035                   <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4036                   <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4037                 </row>
4038               </tbody>
4039             </entrytbl>
4040           </row>
4041           <row>
4042             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4043             <entry>menu</entry>
4044           </row>
4045           <row id="v4l2-flash-strobe-source"><entry
4046           spanname="descr">Defines the source of the flash LED
4047           strobe.</entry>
4048           </row>
4049           <row>
4050             <entrytbl spanname="descr" cols="2">
4051               <tbody valign="top">
4052                 <row>
4053                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4054                   <entry>The flash strobe is triggered by using
4055                   the V4L2_CID_FLASH_STROBE control.</entry>
4056                 </row>
4057                 <row>
4058                   <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4059                   <entry>The flash strobe is triggered by an
4060                   external source. Typically this is a sensor,
4061                   which makes it possible to synchronises the
4062                   flash strobe start to exposure start.</entry>
4063                 </row>
4064               </tbody>
4065             </entrytbl>
4066           </row>
4067           <row>
4068             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4069             <entry>button</entry>
4070           </row>
4071           <row>
4072             <entry spanname="descr">Strobe flash. Valid when
4073             V4L2_CID_FLASH_LED_MODE is set to
4074             V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4075             is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4076             control may not be possible in presence of some faults.
4077             See V4L2_CID_FLASH_FAULT.</entry>
4078           </row>
4079           <row>
4080             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4081             <entry>button</entry>
4082           </row>
4083           <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4084           </row>
4085           <row>
4086             <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4087             <entry>boolean</entry>
4088           </row>
4089           <row>
4090             <entry spanname="descr">Strobe status: whether the flash
4091             is strobing at the moment or not. This is a read-only
4092             control.</entry>
4093           </row>
4094           <row>
4095             <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4096             <entry>integer</entry>
4097           </row>
4098           <row>
4099             <entry spanname="descr">Hardware timeout for flash. The
4100             flash strobe is stopped after this period of time has
4101             passed from the start of the strobe.</entry>
4102           </row>
4103           <row>
4104             <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4105             <entry>integer</entry>
4106           </row>
4107           <row>
4108             <entry spanname="descr">Intensity of the flash strobe when
4109             the flash LED is in flash mode
4110             (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4111             (mA) if possible.</entry>
4112           </row>
4113           <row>
4114             <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4115             <entry>integer</entry>
4116           </row>
4117           <row>
4118             <entry spanname="descr">Intensity of the flash LED in
4119             torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4120             milliamps (mA) if possible. Setting this control may not
4121             be possible in presence of some faults. See
4122             V4L2_CID_FLASH_FAULT.</entry>
4123           </row>
4124           <row>
4125             <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4126             <entry>integer</entry>
4127           </row>
4128           <row>
4129             <entry spanname="descr">Intensity of the indicator LED.
4130             The indicator LED may be fully independent of the flash
4131             LED. The unit should be microamps (uA) if possible.</entry>
4132           </row>
4133           <row>
4134             <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4135             <entry>bitmask</entry>
4136           </row>
4137           <row>
4138             <entry spanname="descr">Faults related to the flash. The
4139             faults tell about specific problems in the flash chip
4140             itself or the LEDs attached to it. Faults may prevent
4141             further use of some of the flash controls. In particular,
4142             V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4143             if the fault affects the flash LED. Exactly which faults
4144             have such an effect is chip dependent. Reading the faults
4145             resets the control and returns the chip to a usable state
4146             if possible.</entry>
4147           </row>
4148           <row>
4149             <entrytbl spanname="descr" cols="2">
4150               <tbody valign="top">
4151                 <row>
4152                   <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4153                   <entry>Flash controller voltage to the flash LED
4154                   has exceeded the limit specific to the flash
4155                   controller.</entry>
4156                 </row>
4157                 <row>
4158                   <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4159                   <entry>The flash strobe was still on when
4160                   the timeout set by the user ---
4161                   V4L2_CID_FLASH_TIMEOUT control --- has expired.
4162                   Not all flash controllers may set this in all
4163                   such conditions.</entry>
4164                 </row>
4165                 <row>
4166                   <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4167                   <entry>The flash controller has overheated.</entry>
4168                 </row>
4169                 <row>
4170                   <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4171                   <entry>The short circuit protection of the flash
4172                   controller has been triggered.</entry>
4173                 </row>
4174                 <row>
4175                   <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4176                   <entry>Current in the LED power supply has exceeded the limit
4177                   specific to the flash controller.</entry>
4178                 </row>
4179                 <row>
4180                   <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4181                   <entry>The flash controller has detected a short or open
4182                   circuit condition on the indicator LED.</entry>
4183                 </row>
4184               </tbody>
4185             </entrytbl>
4186           </row>
4187           <row>
4188             <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4189             <entry>boolean</entry>
4190           </row>
4191           <row><entry spanname="descr">Enable or disable charging of the xenon
4192           flash capacitor.</entry>
4193           </row>
4194           <row>
4195             <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4196             <entry>boolean</entry>
4197           </row>
4198           <row>
4199             <entry spanname="descr">Is the flash ready to strobe?
4200             Xenon flashes require their capacitors charged before
4201             strobing. LED flashes often require a cooldown period
4202             after strobe during which another strobe will not be
4203             possible. This is a read-only control.</entry>
4204           </row>
4205           <row><entry></entry></row>
4206         </tbody>
4207           </tgroup>
4208           </table>
4209         </section>
4210       </section>
4211     </section>
4212
4213     <section id="jpeg-controls">
4214       <title>JPEG Control Reference</title>
4215       <para>The JPEG class includes controls for common features of JPEG
4216       encoders and decoders. Currently it includes features for codecs
4217       implementing progressive baseline DCT compression process with
4218       Huffman entrophy coding.</para>
4219       <table pgwide="1" frame="none" id="jpeg-control-id">
4220       <title>JPEG Control IDs</title>
4221
4222       <tgroup cols="4">
4223         <colspec colname="c1" colwidth="1*" />
4224         <colspec colname="c2" colwidth="6*" />
4225         <colspec colname="c3" colwidth="2*" />
4226         <colspec colname="c4" colwidth="6*" />
4227         <spanspec namest="c1" nameend="c2" spanname="id" />
4228         <spanspec namest="c2" nameend="c4" spanname="descr" />
4229         <thead>
4230           <row>
4231             <entry spanname="id" align="left">ID</entry>
4232             <entry align="left">Type</entry>
4233           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4234           </row>
4235         </thead>
4236         <tbody valign="top">
4237           <row><entry></entry></row>
4238           <row>
4239             <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant>&nbsp;</entry>
4240             <entry>class</entry>
4241           </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4242           &VIDIOC-QUERYCTRL; for this control will return a description of this
4243           control class.
4244
4245         </entry>
4246           </row>
4247           <row>
4248             <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4249             <entry>menu</entry>
4250           </row>
4251           <row id="v4l2-jpeg-chroma-subsampling">
4252             <entry spanname="descr">The chroma subsampling factors describe how
4253             each component of an input image is sampled, in respect to maximum
4254             sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4255             clause A.1.1. for more details. The <constant>
4256             V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4257             Cb and Cr components are downsampled after coverting an input image
4258             from RGB to Y'CbCr color space.
4259             </entry>
4260           </row>
4261           <row>
4262             <entrytbl spanname="descr" cols="2">
4263               <tbody valign="top">
4264                 <row>
4265                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4266                   </entry><entry>No chroma subsampling, each pixel has
4267                   Y, Cr and Cb values.</entry>
4268                 </row>
4269                 <row>
4270                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4271                   </entry><entry>Horizontally subsample Cr, Cb components
4272                   by a factor of 2.</entry>
4273                 </row>
4274                 <row>
4275                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4276                   </entry><entry>Subsample Cr, Cb components horizontally
4277                   and vertically by 2.</entry>
4278                 </row>
4279                 <row>
4280                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4281                   </entry><entry>Horizontally subsample Cr, Cb components
4282                   by a factor of 4.</entry>
4283                 </row>
4284                 <row>
4285                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4286                   </entry><entry>Subsample Cr, Cb components horizontally
4287                   by 4 and vertically by 2.</entry>
4288                 </row>
4289                 <row>
4290                   <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4291                   </entry><entry>Use only luminance component.</entry>
4292                 </row>
4293               </tbody>
4294             </entrytbl>
4295           </row>
4296           <row>
4297             <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4298             </entry><entry>integer</entry>
4299           </row>
4300           <row><entry spanname="descr">
4301               The restart interval determines an interval of inserting RSTm
4302               markers (m = 0..7). The purpose of these markers is to additionally
4303               reinitialize the encoder process, in order to process blocks of
4304               an image independently.
4305               For the lossy compression processes the restart interval unit is
4306               MCU (Minimum Coded Unit) and its value is contained in DRI
4307               (Define Restart Interval) marker. If <constant>
4308               V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4309               DRI and RSTm markers will not be inserted.
4310             </entry>
4311           </row>
4312           <row id="jpeg-quality-control">
4313             <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4314             <entry>integer</entry>
4315           </row>
4316           <row>
4317             <entry spanname="descr">
4318               <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4319               determines trade-off between image quality and size.
4320               It provides simpler method for applications to control image quality,
4321               without a need for direct reconfiguration of luminance and chrominance
4322               quantization tables.
4323
4324               In cases where a driver uses quantization tables configured directly
4325               by an application, using interfaces defined elsewhere, <constant>
4326               V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4327               by driver to 0.
4328
4329               <para>The value range of this control is driver-specific. Only
4330               positive, non-zero values are meaningful. The recommended range
4331               is 1 - 100, where larger values correspond to better image quality.
4332               </para>
4333             </entry>
4334             </row>
4335           <row id="jpeg-active-marker-control">
4336             <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4337             <entry>bitmask</entry>
4338           </row>
4339           <row>
4340             <entry spanname="descr">Specify which JPEG markers are included
4341             in compressed stream. This control is valid only for encoders.
4342             </entry>
4343           </row>
4344           <row>
4345             <entrytbl spanname="descr" cols="2">
4346               <tbody valign="top">
4347                 <row>
4348                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4349                   <entry>Application data segment APP<subscript>0</subscript>.</entry>
4350                 </row><row>
4351                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4352                   <entry>Application data segment APP<subscript>1</subscript>.</entry>
4353                 </row><row>
4354                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4355                   <entry>Comment segment.</entry>
4356                 </row><row>
4357                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4358                   <entry>Quantization tables segment.</entry>
4359                 </row><row>
4360                   <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4361                   <entry>Huffman tables segment.</entry>
4362                 </row>
4363               </tbody>
4364             </entrytbl>
4365           </row>
4366           <row><entry></entry></row>
4367         </tbody>
4368       </tgroup>
4369       </table>
4370       <para>For more details about JPEG specification, refer
4371       to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4372       <xref linkend="w3c-jpeg-jfif"/>.</para>
4373     </section>
4374
4375     <section id="image-source-controls">
4376       <title>Image Source Control Reference</title>
4377
4378       <note>
4379         <title>Experimental</title>
4380
4381         <para>This is an <link
4382         linkend="experimental">experimental</link> interface and may
4383         change in the future.</para>
4384       </note>
4385
4386       <para>
4387         The Image Source control class is intended for low-level
4388         control of image source devices such as image sensors. The
4389         devices feature an analogue to digital converter and a bus
4390         transmitter to transmit the image data out of the device.
4391       </para>
4392
4393       <table pgwide="1" frame="none" id="image-source-control-id">
4394       <title>Image Source Control IDs</title>
4395
4396       <tgroup cols="4">
4397         <colspec colname="c1" colwidth="1*" />
4398         <colspec colname="c2" colwidth="6*" />
4399         <colspec colname="c3" colwidth="2*" />
4400         <colspec colname="c4" colwidth="6*" />
4401         <spanspec namest="c1" nameend="c2" spanname="id" />
4402         <spanspec namest="c2" nameend="c4" spanname="descr" />
4403         <thead>
4404           <row>
4405             <entry spanname="id" align="left">ID</entry>
4406             <entry align="left">Type</entry>
4407           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4408           </row>
4409         </thead>
4410         <tbody valign="top">
4411           <row><entry></entry></row>
4412           <row>
4413             <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4414             <entry>class</entry>
4415           </row>
4416           <row>
4417             <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4418           </row>
4419           <row>
4420             <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4421             <entry>integer</entry>
4422           </row>
4423           <row>
4424             <entry spanname="descr">Vertical blanking. The idle period
4425             after every frame during which no image data is produced.
4426             The unit of vertical blanking is a line. Every line has
4427             length of the image width plus horizontal blanking at the
4428             pixel rate defined by
4429             <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4430             same sub-device.</entry>
4431           </row>
4432           <row>
4433             <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4434             <entry>integer</entry>
4435           </row>
4436           <row>
4437             <entry spanname="descr">Horizontal blanking. The idle
4438             period after every line of image data during which no
4439             image data is produced. The unit of horizontal blanking is
4440             pixels.</entry>
4441           </row>
4442           <row>
4443             <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4444             <entry>integer</entry>
4445           </row>
4446           <row>
4447             <entry spanname="descr">Analogue gain is gain affecting
4448             all colour components in the pixel matrix. The gain
4449             operation is performed in the analogue domain before A/D
4450             conversion.
4451             </entry>
4452           </row>
4453           <row><entry></entry></row>
4454         </tbody>
4455       </tgroup>
4456       </table>
4457
4458     </section>
4459
4460     <section id="image-process-controls">
4461       <title>Image Process Control Reference</title>
4462
4463       <note>
4464         <title>Experimental</title>
4465
4466         <para>This is an <link
4467         linkend="experimental">experimental</link> interface and may
4468         change in the future.</para>
4469       </note>
4470
4471       <para>
4472         The Image Source control class is intended for low-level control of
4473         image processing functions. Unlike
4474         <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4475         this class affect processing the image, and do not control capturing
4476         of it.
4477       </para>
4478
4479       <table pgwide="1" frame="none" id="image-process-control-id">
4480       <title>Image Source Control IDs</title>
4481
4482       <tgroup cols="4">
4483         <colspec colname="c1" colwidth="1*" />
4484         <colspec colname="c2" colwidth="6*" />
4485         <colspec colname="c3" colwidth="2*" />
4486         <colspec colname="c4" colwidth="6*" />
4487         <spanspec namest="c1" nameend="c2" spanname="id" />
4488         <spanspec namest="c2" nameend="c4" spanname="descr" />
4489         <thead>
4490           <row>
4491             <entry spanname="id" align="left">ID</entry>
4492             <entry align="left">Type</entry>
4493           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4494           </row>
4495         </thead>
4496         <tbody valign="top">
4497           <row><entry></entry></row>
4498           <row>
4499             <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4500             <entry>class</entry>
4501           </row>
4502           <row>
4503             <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4504           </row>
4505           <row>
4506             <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4507             <entry>integer menu</entry>
4508           </row>
4509           <row>
4510             <entry spanname="descr">Data bus frequency. Together with the
4511             media bus pixel code, bus type (clock cycles per sample), the
4512             data bus frequency defines the pixel rate
4513             (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4514             pixel array (or possibly elsewhere, if the device is not an
4515             image sensor). The frame rate can be calculated from the pixel
4516             clock, image width and height and horizontal and vertical
4517             blanking. While the pixel rate control may be defined elsewhere
4518             than in the subdev containing the pixel array, the frame rate
4519             cannot be obtained from that information. This is because only
4520             on the pixel array it can be assumed that the vertical and
4521             horizontal blanking information is exact: no other blanking is
4522             allowed in the pixel array. The selection of frame rate is
4523             performed by selecting the desired horizontal and vertical
4524             blanking. The unit of this control is Hz. </entry>
4525           </row>
4526           <row>
4527             <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4528             <entry>64-bit integer</entry>
4529           </row>
4530           <row>
4531             <entry spanname="descr">Pixel rate in the source pads of
4532             the subdev. This control is read-only and its unit is
4533             pixels / second.
4534             </entry>
4535           </row>
4536           <row>
4537             <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4538             <entry>menu</entry>
4539           </row>
4540           <row id="v4l2-test-pattern">
4541             <entry spanname="descr"> Some capture/display/sensor devices have
4542             the capability to generate test pattern images. These hardware
4543             specific test patterns can be used to test if a device is working
4544             properly.</entry>
4545           </row>
4546           <row><entry></entry></row>
4547         </tbody>
4548       </tgroup>
4549       </table>
4550
4551     </section>
4552
4553     <section id="dv-controls">
4554       <title>Digital Video Control Reference</title>
4555
4556       <note>
4557         <title>Experimental</title>
4558
4559         <para>This is an <link
4560         linkend="experimental">experimental</link> interface and may
4561         change in the future.</para>
4562       </note>
4563
4564       <para>
4565         The Digital Video control class is intended to control receivers
4566         and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4567         <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4568         (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4569         These controls are generally expected to be private to the receiver or transmitter
4570         subdevice that implements them, so they are only exposed on the
4571         <filename>/dev/v4l-subdev*</filename> device node.
4572       </para>
4573
4574       <para>Note that these devices can have multiple input or output pads which are
4575       hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4576       transmit video from/to only one of those pads, the other pads can still be
4577       active when it comes to EDID (Extended Display Identification Data,
4578       <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4579       Protection System, <xref linkend="hdcp" />) processing, allowing the device
4580       to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4581       switching between connectors.</para>
4582
4583       <para>These pads appear in several of the controls in this section as
4584       bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4585       etc. The maximum value of the control is the set of valid pads.</para>
4586
4587       <table pgwide="1" frame="none" id="dv-control-id">
4588       <title>Digital Video Control IDs</title>
4589
4590       <tgroup cols="4">
4591         <colspec colname="c1" colwidth="1*" />
4592         <colspec colname="c2" colwidth="6*" />
4593         <colspec colname="c3" colwidth="2*" />
4594         <colspec colname="c4" colwidth="6*" />
4595         <spanspec namest="c1" nameend="c2" spanname="id" />
4596         <spanspec namest="c2" nameend="c4" spanname="descr" />
4597         <thead>
4598           <row>
4599             <entry spanname="id" align="left">ID</entry>
4600             <entry align="left">Type</entry>
4601           </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4602           </row>
4603         </thead>
4604         <tbody valign="top">
4605           <row><entry></entry></row>
4606           <row>
4607             <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4608             <entry>class</entry>
4609           </row>
4610           <row>
4611             <entry spanname="descr">The Digital Video class descriptor.</entry>
4612           </row>
4613           <row>
4614             <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4615             <entry>bitmask</entry>
4616           </row>
4617           <row>
4618             <entry spanname="descr">Many connectors have a hotplug pin which is high
4619             if EDID information is available from the source. This control shows the
4620             state of the hotplug pin as seen by the transmitter.
4621             Each bit corresponds to an output pad on the transmitter. If an output pad
4622             does not have an associated hotplug pin, then the bit for that pad will be 0.
4623             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4624             </entry>
4625           </row>
4626           <row>
4627             <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4628             <entry>bitmask</entry>
4629           </row>
4630           <row>
4631             <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
4632             clock lines. This normally means that the sink has left/entered standby (i.e.
4633             the transmitter can sense that the receiver is ready to receive video).
4634             Each bit corresponds to an output pad on the transmitter. If an output pad
4635             does not have an associated Rx Sense, then the bit for that pad will be 0.
4636             This read-only control is applicable to DVI-D and HDMI devices.
4637             </entry>
4638           </row>
4639           <row>
4640             <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4641             <entry>bitmask</entry>
4642           </row>
4643           <row>
4644             <entry spanname="descr">When the transmitter sees the hotplug signal from the
4645             receiver it will attempt to read the EDID. If set, then the transmitter has read
4646             at least the first block (= 128 bytes).
4647             Each bit corresponds to an output pad on the transmitter. If an output pad
4648             does not support EDIDs, then the bit for that pad will be 0.
4649             This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4650             </entry>
4651           </row>
4652           <row>
4653             <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
4654             <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
4655           </row>
4656           <row>
4657             <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
4658             or in HDMI mode (video + audio + auxiliary data). This control selects which mode
4659             to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
4660             This control is applicable to HDMI connectors.
4661             </entry>
4662           </row>
4663           <row>
4664             <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
4665             <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
4666           </row>
4667           <row>
4668             <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
4669             follows the RGB quantization range specified in the standard for the video interface
4670             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4671             to be compatible with sinks that have not implemented the standard correctly
4672             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4673             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4674             where N is the number of bits per component.
4675             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4676             </entry>
4677           </row>
4678           <row>
4679             <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4680             <entry>bitmask</entry>
4681           </row>
4682           <row>
4683             <entry spanname="descr">Detects whether the receiver receives power from the source
4684             (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
4685             which contains EDID information, such that the source can read the EDID even if
4686             the sink is in standby/power off.
4687             Each bit corresponds to an input pad on the transmitter. If an input pad
4688             cannot detect whether power is present, then the bit for that pad will be 0.
4689             This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4690             </entry>
4691           </row>
4692           <row>
4693             <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4694             <entry>enum v4l2_dv_rgb_range</entry>
4695           </row>
4696           <row>
4697             <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
4698             follows the RGB quantization range specified in the standard for the video interface
4699             (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4700             to be compatible with sources that have not implemented the standard correctly
4701             (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4702             used whereas limited range sets the range to (16 &lt;&lt; (N-8)) - (235 &lt;&lt; (N-8))
4703             where N is the number of bits per component.
4704             This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4705             </entry>
4706           </row>
4707           <row><entry></entry></row>
4708         </tbody>
4709       </tgroup>
4710       </table>
4711
4712     </section>
4713 </section>