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diff --git a/Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst b/Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst new file mode 100644 index 000000000..06ee8386a --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-enumoutput.rst @@ -0,0 +1,153 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_ENUMOUTPUT: + +*********************** +ioctl VIDIOC_ENUMOUTPUT +*********************** + +Name +==== + +VIDIOC_ENUMOUTPUT - Enumerate video outputs + +Synopsis +======== + +.. c:macro:: VIDIOC_ENUMOUTPUT + +``int ioctl(int fd, VIDIOC_ENUMOUTPUT, struct v4l2_output *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_output`. + +Description +=========== + +To query the attributes of a video outputs applications initialize the +``index`` field of struct :c:type:`v4l2_output` and call +the :ref:`VIDIOC_ENUMOUTPUT` 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``. + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}| + +.. c:type:: v4l2_output + +.. flat-table:: struct v4l2_output + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``index`` + - Identifies the output, set by the application. + * - __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. + * - __u32 + - ``type`` + - Type of the output, see :ref:`output-type`. + * - __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`. + * - __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 + :c:type:`v4l2_modulator` field ``index``. For + details on modulators see :ref:`tuner`. + * - :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`. + * - __u32 + - ``capabilities`` + - This field provides capabilities for the output. See + :ref:`output-capabilities` for flags. + * - __u32 + - ``reserved``\ [3] + - Reserved for future extensions. Drivers must set the array to + zero. + + +.. tabularcolumns:: |p{7.5cm}|p{0.6cm}|p{9.2cm}| + +.. _output-type: + +.. flat-table:: Output Type + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - ``V4L2_OUTPUT_TYPE_MODULATOR`` + - 1 + - This output is an analog TV modulator. + * - ``V4L2_OUTPUT_TYPE_ANALOG`` + - 2 + - Any non-modulator video output, for example Composite Video, + S-Video, HDMI. The naming as ``_TYPE_ANALOG`` is historical, + today we would have called it ``_TYPE_VIDEO``. + * - ``V4L2_OUTPUT_TYPE_ANALOGVGAOVERLAY`` + - 3 + - The video output will be copied to a :ref:`video overlay <overlay>`. + + +.. tabularcolumns:: |p{6.4cm}|p{2.4cm}|p{8.5cm}| + +.. _output-capabilities: + +.. flat-table:: Output capabilities + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - ``V4L2_OUT_CAP_DV_TIMINGS`` + - 0x00000002 + - This output supports setting video timings by using + ``VIDIOC_S_DV_TIMINGS``. + * - ``V4L2_OUT_CAP_STD`` + - 0x00000004 + - This output supports setting the TV standard by using + ``VIDIOC_S_STD``. + * - ``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 :c:type:`v4l2_output` ``index`` is out of + bounds. |