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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-g-input.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_G_INPUT:
+
+************************************
+ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT
+************************************
+
+Name
+====
+
+VIDIOC_G_INPUT - VIDIOC_S_INPUT - Query or select the current video input
+
+
+Synopsis
+========
+
+.. cpp:function:: int ioctl( int fd, int request, int *argp )
+
+
+Arguments
+=========
+
+``fd``
+ File descriptor returned by :ref:`open() <func-open>`.
+
+``request``
+ VIDIOC_G_INPUT, VIDIOC_S_INPUT
+
+``argp``
+
+
+Description
+===========
+
+To query the current video input applications call the
+:ref:`VIDIOC_G_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer to an integer where the driver
+stores the number of the input, as in the struct
+:ref:`v4l2_input <v4l2-input>` ``index`` field. This ioctl will fail
+only when there are no video inputs, returning ``EINVAL``.
+
+To select a video input applications store the number of the desired
+input in an integer and call the :ref:`VIDIOC_S_INPUT <VIDIOC_G_INPUT>` ioctl with a pointer
+to this integer. Side effects are possible. For example inputs may
+support different video standards, so the driver may implicitly switch
+the current standard. Because of these possible side effects
+applications must select an input before querying or negotiating any
+other parameters.
+
+Information about video inputs is available using the
+:ref:`VIDIOC_ENUMINPUT` 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 input is out of bounds.