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author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 15:45:04 +0200 |
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committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-07-27 15:45:04 +0200 |
commit | 85538b1ad145c67198cb55d02de14ba269cc323d (patch) | |
tree | 409fca93b357839b8c89b7099f2888c087694b64 /Documentation/media/uapi/v4l/vidioc-enumaudioout.rst | |
parent | Merge tag 'media/v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mch... (diff) | |
parent | [media] cx23885-cardlist.rst: add a new card (diff) | |
download | linux-85538b1ad145c67198cb55d02de14ba269cc323d.tar.xz linux-85538b1ad145c67198cb55d02de14ba269cc323d.zip |
Merge branch 'topic/docs-next' into v4l_for_linus
* topic/docs-next: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
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..cde1db55834f --- /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. |