Synopsis
========
-.. cpp:function:: int ioctl( int fd, int request, struct v4l2_frequency_band *argp )
+.. c:function:: int ioctl( int fd, VIDIOC_ENUM_FREQ_BANDS, struct v4l2_frequency_band *argp )
+ :name: VIDIOC_ENUM_FREQ_BANDS
Arguments
``fd``
File descriptor returned by :ref:`open() <func-open>`.
-``request``
- VIDIOC_ENUM_FREQ_BANDS
-
``argp``
Enumerates the frequency bands that a tuner or modulator supports. To do
this applications initialize the ``tuner``, ``type`` and ``index``
fields, and zero out the ``reserved`` array of a struct
-:ref:`v4l2_frequency_band <v4l2-frequency-band>` and call the
+:c:type:`v4l2_frequency_band` and call the
:ref:`VIDIOC_ENUM_FREQ_BANDS` ioctl with a pointer to this structure.
This ioctl is supported if the ``V4L2_TUNER_CAP_FREQ_BANDS`` capability
of the corresponding tuner/modulator is set.
-.. _v4l2-frequency-band:
+.. tabularcolumns:: |p{2.9cm}|p{2.9cm}|p{5.8cm}|p{2.9cm}|p{3.0cm}|
+
+.. c:type:: v4l2_frequency_band
.. flat-table:: struct v4l2_frequency_band
:header-rows: 0
:stub-columns: 0
:widths: 1 1 2 1 1
-
- - .. row 1
-
- - __u32
-
- - ``tuner``
-
- - The tuner or modulator index number. This is the same value as in
- the struct :ref:`v4l2_input <v4l2-input>` ``tuner`` field and
- the struct :ref:`v4l2_tuner <v4l2-tuner>` ``index`` field, or
- the struct :ref:`v4l2_output <v4l2-output>` ``modulator`` field
- and the struct :ref:`v4l2_modulator <v4l2-modulator>` ``index``
- field.
-
- - .. row 2
-
- - __u32
-
- - ``type``
-
- - The tuner type. This is the same value as in the struct
- :ref:`v4l2_tuner <v4l2-tuner>` ``type`` field. The type must be
- set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and
- to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to
- ``V4L2_TUNER_RADIO`` for modulators (currently only radio
- modulators are supported). See :ref:`v4l2-tuner-type`
-
- - .. row 3
-
- - __u32
-
- - ``index``
-
- - Identifies the frequency band, set by the application.
-
- - .. row 4
-
- - __u32
-
- - ``capability``
-
- - :cspan:`2` The tuner/modulator capability flags for this
- frequency band, see :ref:`tuner-capability`. The
- ``V4L2_TUNER_CAP_LOW`` or ``V4L2_TUNER_CAP_1HZ`` capability must
- be the same for all frequency bands of the selected
- tuner/modulator. So either all bands have that capability set, or
- none of them have that capability.
-
- - .. row 5
-
- - __u32
-
- - ``rangelow``
-
- - :cspan:`2` 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, for this frequency band. A 1 Hz unit is used when the
- ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
-
- - .. row 6
-
- - __u32
-
- - ``rangehigh``
-
- - :cspan:`2` 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, for this frequency band. A 1 Hz unit is used
- when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
-
- - .. row 7
-
- - __u32
-
- - ``modulation``
-
- - :cspan:`2` The supported modulation systems of this frequency
- band. See :ref:`band-modulation`.
-
- .. note::
-
- Currently only one modulation system per frequency band
- is supported. More work will need to be done if multiple
- modulation systems are possible. Contact the linux-media
- mailing list
- (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__)
- if you need such functionality.
-
- - .. row 8
-
- - __u32
-
- - ``reserved``\ [9]
-
- - Reserved for future extensions. Applications and drivers must set
- the array to zero.
-
-
+ * - __u32
+ - ``tuner``
+ - The tuner or modulator index number. This is the same value as in
+ the struct :c:type:`v4l2_input` ``tuner`` field and
+ the struct :c:type:`v4l2_tuner` ``index`` field, or
+ the struct :c:type:`v4l2_output` ``modulator`` field
+ and the struct :c:type:`v4l2_modulator` ``index``
+ field.
+ * - __u32
+ - ``type``
+ - The tuner type. This is the same value as in the struct
+ :c:type:`v4l2_tuner` ``type`` field. The type must be
+ set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and
+ to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to
+ ``V4L2_TUNER_RADIO`` for modulators (currently only radio
+ modulators are supported). See :c:type:`v4l2_tuner_type`
+ * - __u32
+ - ``index``
+ - Identifies the frequency band, set by the application.
+ * - __u32
+ - ``capability``
+ - :cspan:`2` The tuner/modulator capability flags for this
+ frequency band, see :ref:`tuner-capability`. The
+ ``V4L2_TUNER_CAP_LOW`` or ``V4L2_TUNER_CAP_1HZ`` capability must
+ be the same for all frequency bands of the selected
+ tuner/modulator. So either all bands have that capability set, or
+ none of them have that capability.
+ * - __u32
+ - ``rangelow``
+ - :cspan:`2` 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, for this frequency band. A 1 Hz unit is used when the
+ ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
+ * - __u32
+ - ``rangehigh``
+ - :cspan:`2` 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, for this frequency band. A 1 Hz unit is used
+ when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set.
+ * - __u32
+ - ``modulation``
+ - :cspan:`2` The supported modulation systems of this frequency
+ band. See :ref:`band-modulation`.
+
+ .. note::
+
+ Currently only one modulation system per frequency band
+ is supported. More work will need to be done if multiple
+ modulation systems are possible. Contact the linux-media
+ mailing list
+ (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__)
+ if you need such functionality.
+ * - __u32
+ - ``reserved``\ [9]
+ - Reserved for future extensions.
+
+ Applications and drivers must set the array to zero.
+
+
+
+.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
.. _band-modulation:
:stub-columns: 0
:widths: 3 1 4
-
- - .. row 1
-
- - ``V4L2_BAND_MODULATION_VSB``
-
- - 0x02
-
- - Vestigial Sideband modulation, used for analog TV.
-
- - .. row 2
-
- - ``V4L2_BAND_MODULATION_FM``
-
- - 0x04
-
- - Frequency Modulation, commonly used for analog radio.
-
- - .. row 3
-
- - ``V4L2_BAND_MODULATION_AM``
-
- - 0x08
-
- - Amplitude Modulation, commonly used for analog radio.
+ * - ``V4L2_BAND_MODULATION_VSB``
+ - 0x02
+ - Vestigial Sideband modulation, used for analog TV.
+ * - ``V4L2_BAND_MODULATION_FM``
+ - 0x04
+ - Frequency Modulation, commonly used for analog radio.
+ * - ``V4L2_BAND_MODULATION_AM``
+ - 0x08
+ - Amplitude Modulation, commonly used for analog radio.
Return Value
projects / cascardo / linux.git / blobdiff