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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/v4l/vidioc-enumaudioout.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-enumaudioout.rst | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-enumaudioout.rst b/Documentation/userspace-api/media/v4l/vidioc-enumaudioout.rst new file mode 100644 index 000000000..d4c3ba320 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-enumaudioout.rst @@ -0,0 +1,58 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_ENUMAUDOUT: + +*********************** +ioctl VIDIOC_ENUMAUDOUT +*********************** + +Name +==== + +VIDIOC_ENUMAUDOUT - Enumerate audio outputs + +Synopsis +======== + +.. c:macro:: VIDIOC_ENUMAUDOUT + +``int ioctl(int fd, VIDIOC_ENUMAUDOUT, struct v4l2_audioout *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to struct :c:type:`v4l2_audioout`. + +Description +=========== + +To query the attributes of an audio output applications initialize the +``index`` field and zero out the ``reserved`` array of a struct +:c:type:`v4l2_audioout` and call the ``VIDIOC_G_AUDOUT`` +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 outputs applications shall begin at index +zero, incrementing by one until the driver returns ``EINVAL``. + +.. note:: + + Connectors on a TV card to loop back the received audio signal + to a sound card are not audio outputs in this sense. + +See :ref:`VIDIOC_G_AUDIOout <VIDIOC_G_AUDOUT>` for a description of struct +:c:type:`v4l2_audioout`. + +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 output is out of bounds. |