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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/userspace-api/media/v4l/vidioc-g-input.rst | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-g-input.rst | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-input.rst b/Documentation/userspace-api/media/v4l/vidioc-g-input.rst new file mode 100644 index 000000000..eee9ce51c --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-g-input.rst @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _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:macro:: VIDIOC_G_INPUT + +``int ioctl(int fd, VIDIOC_G_INPUT, int *argp)`` + +.. c:macro:: VIDIOC_S_INPUT + +``int ioctl(int fd, VIDIOC_S_INPUT, int *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c: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. |