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Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst')
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diff --git a/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst b/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst new file mode 100644 index 000000000..7873e5434 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-enumaudio.rst @@ -0,0 +1,53 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_ENUMAUDIO: + +********************** +ioctl VIDIOC_ENUMAUDIO +********************** + +Name +==== + +VIDIOC_ENUMAUDIO - Enumerate audio inputs + +Synopsis +======== + +.. c:macro:: VIDIOC_ENUMAUDIO + +``int ioctl(int fd, VIDIOC_ENUMAUDIO, struct v4l2_audio *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_audio`. + +Description +=========== + +To query the attributes of an audio input applications initialize the +``index`` field and zero out the ``reserved`` array of a struct +:c:type:`v4l2_audio` and call the :ref:`VIDIOC_ENUMAUDIO` +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 audio inputs applications shall begin at index +zero, incrementing by one until the driver returns ``EINVAL``. + +See :ref:`VIDIOC_G_AUDIO <VIDIOC_G_AUDIO>` for a description of struct +:c:type:`v4l2_audio`. + +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 number of the audio input is out of bounds. |