diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
---|---|---|
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-std.rst | |
parent | Initial commit. (diff) | |
download | linux-430c2fc249ea5c0536abd21c23382884005c9093.tar.xz linux-430c2fc249ea5c0536abd21c23382884005c9093.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/userspace-api/media/v4l/vidioc-g-std.rst')
-rw-r--r-- | Documentation/userspace-api/media/v4l/vidioc-g-std.rst | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-std.rst b/Documentation/userspace-api/media/v4l/vidioc-g-std.rst new file mode 100644 index 000000000..da91fe07d --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-g-std.rst @@ -0,0 +1,82 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_G_STD: + +************************************************************************** +ioctl VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_SUBDEV_G_STD, VIDIOC_SUBDEV_S_STD +************************************************************************** + +Name +==== + +VIDIOC_G_STD - VIDIOC_S_STD - VIDIOC_SUBDEV_G_STD - VIDIOC_SUBDEV_S_STD - Query or select the video standard of the current input + +Synopsis +======== + +.. c:macro:: VIDIOC_G_STD + +``int ioctl(int fd, VIDIOC_G_STD, v4l2_std_id *argp)`` + +.. c:macro:: VIDIOC_S_STD + +``int ioctl(int fd, VIDIOC_S_STD, const v4l2_std_id *argp)`` + +.. c:macro:: VIDIOC_SUBDEV_G_STD + +``int ioctl(int fd, VIDIOC_SUBDEV_G_STD, v4l2_std_id *argp)`` + +.. c:macro:: VIDIOC_SUBDEV_S_STD + +``int ioctl(int fd, VIDIOC_SUBDEV_S_STD, const v4l2_std_id *argp)`` + +Arguments +========= + +``fd`` + File descriptor returned by :c:func:`open()`. + +``argp`` + Pointer to :c:type:`v4l2_std_id`. + +Description +=========== + +To query and select the current video standard applications use the +:ref:`VIDIOC_G_STD <VIDIOC_G_STD>` and :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` ioctls which take a pointer to a +:ref:`v4l2_std_id <v4l2-std-id>` type as argument. :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` +can return a single flag or a set of flags as in struct +:c:type:`v4l2_standard` field ``id``. The flags must be +unambiguous such that they appear in only one enumerated +struct :c:type:`v4l2_standard` structure. + +:ref:`VIDIOC_S_STD <VIDIOC_G_STD>` accepts one or more flags, being a write-only ioctl it +does not return the actual new standard as :ref:`VIDIOC_G_STD <VIDIOC_G_STD>` does. When +no flags are given or the current input does not support the requested +standard the driver returns an ``EINVAL`` error code. When the standard set +is ambiguous drivers may return ``EINVAL`` or choose any of the requested +standards. If the current input or output does not support standard +video timings (e.g. if :ref:`VIDIOC_ENUMINPUT` +does not set the ``V4L2_IN_CAP_STD`` flag), then ``ENODATA`` error code is +returned. + +Calling ``VIDIOC_SUBDEV_S_STD`` on a subdev device node that has been registered +in read-only mode is not allowed. An error is returned and the errno variable is +set to ``-EPERM``. + +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 :ref:`VIDIOC_S_STD <VIDIOC_G_STD>` parameter was unsuitable. + +ENODATA + Standard video timings are not supported for this input or output. + +EPERM + ``VIDIOC_SUBDEV_S_STD`` has been called on a read-only subdevice. |