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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-g-output.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-g-output.rst')
-rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-output.rst | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-output.rst b/Documentation/media/uapi/v4l/vidioc-g-output.rst new file mode 100644 index 000000000000..ae0ad577ba97 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-g-output.rst @@ -0,0 +1,64 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _VIDIOC_G_OUTPUT: + +************************************** +ioctl VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT +************************************** + +Name +==== + +VIDIOC_G_OUTPUT - VIDIOC_S_OUTPUT - Query or select the current video output + + +Synopsis +======== + +.. cpp:function:: int ioctl( int fd, int request, int *argp ) + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``request`` + VIDIOC_G_OUTPUT, VIDIOC_S_OUTPUT + +``argp`` + + +Description +=========== + +To query the current video output applications call the +:ref:`VIDIOC_G_OUTPUT <VIDIOC_G_OUTPUT>` ioctl with a pointer to an integer where the driver +stores the number of the output, as in the struct +:ref:`v4l2_output <v4l2-output>` ``index`` field. This ioctl will +fail only when there are no video outputs, returning the ``EINVAL`` error +code. + +To select a video output applications store the number of the desired +output in an integer and call the :ref:`VIDIOC_S_OUTPUT <VIDIOC_G_OUTPUT>` ioctl with a +pointer to this integer. Side effects are possible. For example outputs +may support different video standards, so the driver may implicitly +switch the current standard. standard. Because of these possible side +effects applications must select an output before querying or +negotiating any other parameters. + +Information about video outputs is available using the +:ref:`VIDIOC_ENUMOUTPUT` ioctl. + + +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 video output is out of bounds, or there are no + video outputs at all. |