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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-08 17:40:06 +0300 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-08 17:59:40 +0300 |
commit | 60c2820d0f6d3497975b6488e2599f8f611d8b95 (patch) | |
tree | b3b03707c6438ea9b99cc57e847ebf517f968ab1 /Documentation/media/uapi/v4l/vidioc-enumaudioout.rst | |
parent | a97369b5e21ea9b8b5fef7c0f4f48bbe60c07ca3 (diff) | |
download | linux-60c2820d0f6d3497975b6488e2599f8f611d8b95.tar.xz |
doc_rst: rename the media Sphinx suff to Documentation/media
The name of the subsystem is "media", and not "linux_tv". Also,
as we plan to add other stuff there in the future, let's
rename also the media uAPI book to media_uapi, to make it
clearer.
No functional changes.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-enumaudioout.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/vidioc-enumaudioout.rst | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-enumaudioout.rst b/Documentation/media/uapi/v4l/vidioc-enumaudioout.rst new file mode 100644 index 000000000000..15bc5a40f4a6 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-enumaudioout.rst @@ -0,0 +1,59 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_ENUMAUDOUT: + +*********************** +ioctl VIDIOC_ENUMAUDOUT +*********************** + +Name +==== + +VIDIOC_ENUMAUDOUT - Enumerate audio outputs + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, struct v4l2_audioout *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_ENUMAUDOUT + +``argp`` + + +Description +=========== + +To query the attributes of an audio output applications initialize the +``index`` field and zero out the ``reserved`` array of a struct +:ref:`v4l2_audioout <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 +:ref:`v4l2_audioout <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. |