diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-enumoutput.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-enumoutput.rst | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-enumoutput.rst b/Documentation/media/uapi/v4l/vidioc-enumoutput.rst new file mode 100644 index 000000000000..82fc9d3b237f --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-enumoutput.rst @@ -0,0 +1,222 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_ENUMOUTPUT: + +*********************** +ioctl VIDIOC_ENUMOUTPUT +*********************** + +Name +==== + +VIDIOC_ENUMOUTPUT - Enumerate video outputs + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, struct v4l2_output *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_ENUMOUTPUT + +``argp`` + + +Description +=========== + +To query the attributes of a video outputs applications initialize the +``index`` field of struct :ref:`v4l2_output <v4l2-output>` and call +the :ref:`VIDIOC_ENUMOUTPUT` 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 outputs applications +shall begin at index zero, incrementing by one until the driver returns +EINVAL. + + +.. _v4l2-output: + +.. flat-table:: struct v4l2_output + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + + - .. row 1 + + - __u32 + + - ``index`` + + - Identifies the output, set by the application. + + - .. row 2 + + - __u8 + + - ``name``\ [32] + + - Name of the video output, a NUL-terminated ASCII string, for + example: "Vout". This information is intended for the user, + preferably the connector label on the device itself. + + - .. row 3 + + - __u32 + + - ``type`` + + - Type of the output, see :ref:`output-type`. + + - .. row 4 + + - __u32 + + - ``audioset`` + + - Drivers can enumerate up to 32 video and audio outputs. This field + shows which audio outputs were selectable as the current output if + this was the currently selected video output. It is a bit mask. + The LSB corresponds to audio output 0, the MSB to output 31. Any + number of bits can be set, or none. + + When the driver does not enumerate audio outputs no bits must be + set. Applications shall not interpret this as lack of audio + support. Drivers may automatically select audio outputs without + enumerating them. + + For details on audio outputs and how to select the current output + see :ref:`audio`. + + - .. row 5 + + - __u32 + + - ``modulator`` + + - Output devices can have zero or more RF modulators. When the + ``type`` is ``V4L2_OUTPUT_TYPE_MODULATOR`` this is an RF connector + and this field identifies the modulator. It corresponds to struct + :ref:`v4l2_modulator <v4l2-modulator>` field ``index``. For + details on modulators see :ref:`tuner`. + + - .. row 6 + + - :ref:`v4l2_std_id <v4l2-std-id>` + + - ``std`` + + - Every video output supports one or more different video standards. + This field is a set of all supported standards. For details on + video standards and how to switch see :ref:`standard`. + + - .. row 7 + + - __u32 + + - ``capabilities`` + + - This field provides capabilities for the output. See + :ref:`output-capabilities` for flags. + + - .. row 8 + + - __u32 + + - ``reserved``\ [3] + + - Reserved for future extensions. Drivers must set the array to + zero. + + + +.. _output-type: + +.. flat-table:: Output Type + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + + - .. row 1 + + - ``V4L2_OUTPUT_TYPE_MODULATOR`` + + - 1 + + - This output is an analog TV modulator. + + - .. row 2 + + - ``V4L2_OUTPUT_TYPE_ANALOG`` + + - 2 + + - Analog baseband output, for example Composite / CVBS, S-Video, + RGB. + + - .. row 3 + + - ``V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY`` + + - 3 + + - [?] + + + +.. _output-capabilities: + +.. flat-table:: Output capabilities + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + + - .. row 1 + + - ``V4L2_OUT_CAP_DV_TIMINGS`` + + - 0x00000002 + + - This output supports setting video timings by using + VIDIOC_S_DV_TIMINGS. + + - .. row 2 + + - ``V4L2_OUT_CAP_STD`` + + - 0x00000004 + + - This output supports setting the TV standard by using + VIDIOC_S_STD. + + - .. row 3 + + - ``V4L2_OUT_CAP_NATIVE_SIZE`` + + - 0x00000008 + + - This output supports setting the native size using the + ``V4L2_SEL_TGT_NATIVE_SIZE`` selection target, see + :ref:`v4l2-selections-common`. + + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +EINVAL + The struct :ref:`v4l2_output <v4l2-output>` ``index`` is out of + bounds. |