From 76cb841cb886eef6b3bee341a2266c76578724ad Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 6 May 2024 03:02:30 +0200 Subject: Adding upstream version 4.19.249. Signed-off-by: Daniel Baumann --- Documentation/media/uapi/v4l/vidioc-g-output.rst | 66 ++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 Documentation/media/uapi/v4l/vidioc-g-output.rst (limited to 'Documentation/media/uapi/v4l/vidioc-g-output.rst') 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 000000000..3e0093f66 --- /dev/null +++ b/Documentation/media/uapi/v4l/vidioc-g-output.rst @@ -0,0 +1,66 @@ +.. -*- 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 +======== + +.. c:function:: int ioctl( int fd, VIDIOC_G_OUTPUT, int *argp ) + :name: VIDIOC_G_OUTPUT + +.. c:function:: int ioctl( int fd, VIDIOC_S_OUTPUT, int *argp ) + :name: VIDIOC_S_OUTPUT + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() `. + +``argp`` + Pointer to an integer with output index. + + +Description +=========== + +To query the current video output applications call the +:ref:`VIDIOC_G_OUTPUT ` ioctl with a pointer to an integer where the driver +stores the number of the output, as in the struct +:c:type:`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 ` 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 ` chapter. + +EINVAL + The number of the video output is out of bounds, or there are no + video outputs at all. -- cgit v1.2.3