Synopsis
========
-.. cpp:function:: int ioctl( int fd, int request, struct v4l2_modulator *argp )
+.. c:function:: int ioctl( int fd, VIDIOC_G_MODULATOR, struct v4l2_modulator *argp )
+ :name: VIDIOC_G_MODULATOR
-.. cpp:function:: int ioctl( int fd, int request, const struct v4l2_modulator *argp )
+.. c:function:: int ioctl( int fd, VIDIOC_S_MODULATOR, const struct v4l2_modulator *argp )
+ :name: VIDIOC_S_MODULATOR
Arguments
``fd``
File descriptor returned by :ref:`open() <func-open>`.
-``request``
- VIDIOC_G_MODULATOR, VIDIOC_S_MODULATOR
-
``argp``
To query the attributes of a modulator applications initialize the
``index`` field and zero out the ``reserved`` array of a struct
-:ref:`v4l2_modulator <v4l2-modulator>` and call the
+:c:type:`v4l2_modulator` and call the
:ref:`VIDIOC_G_MODULATOR <VIDIOC_G_MODULATOR>` ioctl with a pointer to this structure. Drivers
fill the rest of the structure or return an ``EINVAL`` error code when the
index is out of bounds. To enumerate all modulators applications shall
:ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl is available.
-.. _v4l2-modulator:
+.. tabularcolumns:: |p{2.9cm}|p{2.9cm}|p{5.8cm}|p{2.9cm}|p{3.0cm}|
+
+.. c:type:: v4l2_modulator
.. flat-table:: struct v4l2_modulator
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2 1 1
-
- - .. row 1
-
- - __u32
-
- - ``index``
-
- - Identifies the modulator, set by the application.
-
- - .. row 2
-
- - __u8
-
- - ``name``\ [32]
-
- - Name of the modulator, a NUL-terminated ASCII string. This
- information is intended for the user.
-
- - .. row 3
-
- - __u32
-
- - ``capability``
-
- - Modulator capability flags. No flags are defined for this field,
- the tuner flags in struct :ref:`v4l2_tuner <v4l2-tuner>` are
- used accordingly. The audio flags indicate the ability to encode
- audio subprograms. They will *not* change for example with the
- current video standard.
-
- - .. row 4
-
- - __u32
-
- - ``rangelow``
-
- - The lowest tunable frequency in units of 62.5 KHz, or if the
- ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
- 62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
- set, in units of 1 Hz.
-
- - .. row 5
-
- - __u32
-
- - ``rangehigh``
-
- - The highest tunable frequency in units of 62.5 KHz, or if the
- ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
- 62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
- set, in units of 1 Hz.
-
- - .. row 6
-
- - __u32
-
- - ``txsubchans``
-
- - With this field applications can determine how audio sub-carriers
- shall be modulated. It contains a set of flags as defined in
- :ref:`modulator-txsubchans`.
-
- .. note:: The tuner ``rxsubchans`` flags are reused, but the
- semantics are different. Video output devices
- are assumed to have an analog or PCM audio input with 1-3
- channels. The ``txsubchans`` flags select one or more channels
- for modulation, together with some audio subprogram indicator,
- for example, a stereo pilot tone.
-
- - .. row 7
-
- - __u32
-
- - ``type``
-
- - :cspan:`2` Type of the modulator, see :ref:`v4l2-tuner-type`.
-
- - .. row 8
-
- - __u32
-
- - ``reserved``\ [3]
-
- - Reserved for future extensions. Drivers and applications must set
- the array to zero.
-
-
+ * - __u32
+ - ``index``
+ - Identifies the modulator, set by the application.
+ * - __u8
+ - ``name``\ [32]
+ - Name of the modulator, a NUL-terminated ASCII string.
+
+ This information is intended for the user.
+ * - __u32
+ - ``capability``
+ - Modulator capability flags. No flags are defined for this field,
+ the tuner flags in struct :c:type:`v4l2_tuner` are
+ used accordingly. The audio flags indicate the ability to encode
+ audio subprograms. They will *not* change for example with the
+ current video standard.
+ * - __u32
+ - ``rangelow``
+ - The lowest tunable frequency in units of 62.5 KHz, or if the
+ ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
+ 62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
+ set, in units of 1 Hz.
+ * - __u32
+ - ``rangehigh``
+ - The highest tunable frequency in units of 62.5 KHz, or if the
+ ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units of
+ 62.5 Hz, or if the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is
+ set, in units of 1 Hz.
+ * - __u32
+ - ``txsubchans``
+ - With this field applications can determine how audio sub-carriers
+ shall be modulated. It contains a set of flags as defined in
+ :ref:`modulator-txsubchans`.
+
+ .. note::
+
+ The tuner ``rxsubchans`` flags are reused, but the
+ semantics are different. Video output devices
+ are assumed to have an analog or PCM audio input with 1-3
+ channels. The ``txsubchans`` flags select one or more channels
+ for modulation, together with some audio subprogram indicator,
+ for example, a stereo pilot tone.
+ * - __u32
+ - ``type``
+ - :cspan:`2` Type of the modulator, see :c:type:`v4l2_tuner_type`.
+ * - __u32
+ - ``reserved``\ [3]
+ - Reserved for future extensions.
+
+ Drivers and applications must set the array to zero.
+
+
+
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
.. _modulator-txsubchans:
:stub-columns: 0
:widths: 3 1 4
-
- - .. row 1
-
- - ``V4L2_TUNER_SUB_MONO``
-
- - 0x0001
-
- - Modulate channel 1 as mono audio, when the input has more
- channels, a down-mix of channel 1 and 2. This flag does not
- combine with ``V4L2_TUNER_SUB_STEREO`` or
- ``V4L2_TUNER_SUB_LANG1``.
-
- - .. row 2
-
- - ``V4L2_TUNER_SUB_STEREO``
-
- - 0x0002
-
- - Modulate channel 1 and 2 as left and right channel of a stereo
- audio signal. When the input has only one channel or two channels
- and ``V4L2_TUNER_SUB_SAP`` is also set, channel 1 is encoded as
- left and right channel. This flag does not combine with
- ``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_LANG1``. When the
- driver does not support stereo audio it shall fall back to mono.
-
- - .. row 3
-
- - ``V4L2_TUNER_SUB_LANG1``
-
- - 0x0008
-
- - Modulate channel 1 and 2 as primary and secondary language of a
- bilingual audio signal. When the input has only one channel it is
- used for both languages. It is not possible to encode the primary
- or secondary language only. This flag does not combine with
- ``V4L2_TUNER_SUB_MONO``, ``V4L2_TUNER_SUB_STEREO`` or
- ``V4L2_TUNER_SUB_SAP``. If the hardware does not support the
- respective audio matrix, or the current video standard does not
- permit bilingual audio the :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall
- return an ``EINVAL`` error code and the driver shall fall back to mono
- or stereo mode.
-
- - .. row 4
-
- - ``V4L2_TUNER_SUB_LANG2``
-
- - 0x0004
-
- - Same effect as ``V4L2_TUNER_SUB_SAP``.
-
- - .. row 5
-
- - ``V4L2_TUNER_SUB_SAP``
-
- - 0x0004
-
- - When combined with ``V4L2_TUNER_SUB_MONO`` the first channel is
- encoded as mono audio, the last channel as Second Audio Program.
- When the input has only one channel it is used for both audio
- tracks. When the input has three channels the mono track is a
- down-mix of channel 1 and 2. When combined with
- ``V4L2_TUNER_SUB_STEREO`` channel 1 and 2 are encoded as left and
- right stereo audio, channel 3 as Second Audio Program. When the
- input has only two channels, the first is encoded as left and
- right channel and the second as SAP. When the input has only one
- channel it is used for all audio tracks. It is not possible to
- encode a Second Audio Program only. This flag must combine with
- ``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_STEREO``. If the
- hardware does not support the respective audio matrix, or the
- current video standard does not permit SAP the
- :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall return an ``EINVAL`` error code and
- driver shall fall back to mono or stereo mode.
-
- - .. row 6
-
- - ``V4L2_TUNER_SUB_RDS``
-
- - 0x0010
-
- - Enable the RDS encoder for a radio FM transmitter.
+ * - ``V4L2_TUNER_SUB_MONO``
+ - 0x0001
+ - Modulate channel 1 as mono audio, when the input has more
+ channels, a down-mix of channel 1 and 2. This flag does not
+ combine with ``V4L2_TUNER_SUB_STEREO`` or
+ ``V4L2_TUNER_SUB_LANG1``.
+ * - ``V4L2_TUNER_SUB_STEREO``
+ - 0x0002
+ - Modulate channel 1 and 2 as left and right channel of a stereo
+ audio signal. When the input has only one channel or two channels
+ and ``V4L2_TUNER_SUB_SAP`` is also set, channel 1 is encoded as
+ left and right channel. This flag does not combine with
+ ``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_LANG1``. When the
+ driver does not support stereo audio it shall fall back to mono.
+ * - ``V4L2_TUNER_SUB_LANG1``
+ - 0x0008
+ - Modulate channel 1 and 2 as primary and secondary language of a
+ bilingual audio signal. When the input has only one channel it is
+ used for both languages. It is not possible to encode the primary
+ or secondary language only. This flag does not combine with
+ ``V4L2_TUNER_SUB_MONO``, ``V4L2_TUNER_SUB_STEREO`` or
+ ``V4L2_TUNER_SUB_SAP``. If the hardware does not support the
+ respective audio matrix, or the current video standard does not
+ permit bilingual audio the :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall
+ return an ``EINVAL`` error code and the driver shall fall back to mono
+ or stereo mode.
+ * - ``V4L2_TUNER_SUB_LANG2``
+ - 0x0004
+ - Same effect as ``V4L2_TUNER_SUB_SAP``.
+ * - ``V4L2_TUNER_SUB_SAP``
+ - 0x0004
+ - When combined with ``V4L2_TUNER_SUB_MONO`` the first channel is
+ encoded as mono audio, the last channel as Second Audio Program.
+ When the input has only one channel it is used for both audio
+ tracks. When the input has three channels the mono track is a
+ down-mix of channel 1 and 2. When combined with
+ ``V4L2_TUNER_SUB_STEREO`` channel 1 and 2 are encoded as left and
+ right stereo audio, channel 3 as Second Audio Program. When the
+ input has only two channels, the first is encoded as left and
+ right channel and the second as SAP. When the input has only one
+ channel it is used for all audio tracks. It is not possible to
+ encode a Second Audio Program only. This flag must combine with
+ ``V4L2_TUNER_SUB_MONO`` or ``V4L2_TUNER_SUB_STEREO``. If the
+ hardware does not support the respective audio matrix, or the
+ current video standard does not permit SAP the
+ :ref:`VIDIOC_S_MODULATOR <VIDIOC_G_MODULATOR>` ioctl shall return an ``EINVAL`` error code and
+ driver shall fall back to mono or stereo mode.
+ * - ``V4L2_TUNER_SUB_RDS``
+ - 0x0010
+ - Enable the RDS encoder for a radio FM transmitter.
Return Value
:ref:`Generic Error Codes <gen-errors>` chapter.
EINVAL
- The struct :ref:`v4l2_modulator <v4l2-modulator>` ``index`` is
+ The struct :c:type:`v4l2_modulator` ``index`` is
out of bounds.
projects / cascardo / linux.git / blobdiff