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authorMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-08 17:40:06 +0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2016-07-08 17:59:40 +0300
commit60c2820d0f6d3497975b6488e2599f8f611d8b95 (patch)
treeb3b03707c6438ea9b99cc57e847ebf517f968ab1 /Documentation/media/uapi/v4l/vidioc-enumaudioout.rst
parenta97369b5e21ea9b8b5fef7c0f4f48bbe60c07ca3 (diff)
downloadlinux-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>
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+.. -*- 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.