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+.. Permission is granted to copy, distribute and/or modify this
+.. document under the terms of the GNU Free Documentation License,
+.. Version 1.1 or any later version published by the Free Software
+.. Foundation, with no Invariant Sections, no Front-Cover Texts
+.. and no Back-Cover Texts. A copy of the license is included at
+.. Documentation/userspace-api/media/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _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
+========
+
+.. c:function:: int ioctl( int fd, VIDIOC_G_INPUT, int *argp )
+    :name: VIDIOC_G_INPUT
+
+.. c:function:: int ioctl( int fd, VIDIOC_S_INPUT, int *argp )
+    :name: VIDIOC_S_INPUT
+
+
+Arguments
+=========
+
+``fd``
+    File descriptor returned by :ref:`open() <func-open>`.
+
+``argp``
+    Pointer an integer with input index.
+
+
+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
+:c:type:`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.