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Diffstat (limited to 'Documentation/linux_tv/media/v4l/vidioc-g-input.rst')
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diff --git a/Documentation/linux_tv/media/v4l/vidioc-g-input.rst b/Documentation/linux_tv/media/v4l/vidioc-g-input.rst new file mode 100644 index 0000000..fffba83 --- /dev/null +++ b/Documentation/linux_tv/media/v4l/vidioc-g-input.rst @@ -0,0 +1,70 @@ +.. -*- coding: utf-8; mode: rst -*- + +.. _vidioc-g-input: + +************************************ +ioctl VIDIOC_G_INPUT, VIDIOC_S_INPUT +************************************ + +*man VIDIOC_G_INPUT(2)* + +VIDIOC_S_INPUT +Query or select the current video input + + +Synopsis +======== + +.. c: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 +``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 ``VIDIOC_S_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 <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. + + +.. ------------------------------------------------------------------------------ +.. This file was automatically converted from DocBook-XML with the dbxml +.. library (https://github.com/return42/sphkerneldoc). The origin XML comes +.. from the linux kernel, refer to: +.. +.. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook +.. ------------------------------------------------------------------------------ |
