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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-output.rst | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-g-output.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-g-output.rst | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-output.rst b/Documentation/userspace-api/media/v4l/vidioc-g-output.rst new file mode 100644 index 000000000..3138c4cc8 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-g-output.rst @@ -0,0 +1,65 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _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:macro:: VIDIOC_G_OUTPUT + +``int ioctl(int fd, VIDIOC_G_OUTPUT, int *argp)`` + +.. c:macro:: VIDIOC_S_OUTPUT + +``int ioctl(int fd, VIDIOC_S_OUTPUT, int *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to an integer with output index. + +Description +=========== + +To query the current video output applications call the +:ref:`VIDIOC_G_OUTPUT <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 <VIDIOC_G_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 <gen-errors>` chapter. + +EINVAL + The number of the video output is out of bounds, or there are no + video outputs at all. |