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diff --git a/Documentation/media/uapi/v4l/vidioc-querystd.rst b/Documentation/media/uapi/v4l/vidioc-querystd.rst deleted file mode 100644 index d8cf28274cfc..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-querystd.rst +++ /dev/null @@ -1,77 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_QUERYSTD: - -********************************************* -ioctl VIDIOC_QUERYSTD, VIDIOC_SUBDEV_QUERYSTD -********************************************* - -Name -==== - -VIDIOC_QUERYSTD - VIDIOC_SUBDEV_QUERYSTD - Sense the video standard received by the current input - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_QUERYSTD, v4l2_std_id *argp ) - :name: VIDIOC_QUERYSTD - -.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_QUERYSTD, v4l2_std_id *argp ) - :name: VIDIOC_SUBDEV_QUERYSTD - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to :c:type:`v4l2_std_id`. - - -Description -=========== - -The hardware may be able to detect the current video standard -automatically. To do so, applications call :ref:`VIDIOC_QUERYSTD` with a -pointer to a :ref:`v4l2_std_id <v4l2-std-id>` type. The driver -stores here a set of candidates, this can be a single flag or a set of -supported standards if for example the hardware can only distinguish -between 50 and 60 Hz systems. If no signal was detected, then the driver -will return V4L2_STD_UNKNOWN. When detection is not possible or fails, -the set must contain all standards supported by the current video input -or output. - -.. note:: - - Drivers shall *not* switch the video standard - automatically if a new video standard is detected. Instead, drivers - should send the ``V4L2_EVENT_SOURCE_CHANGE`` event (if they support - this) and expect that userspace will take action by calling - :ref:`VIDIOC_QUERYSTD`. The reason is that a new video standard can mean - different buffer sizes as well, and you cannot change buffer sizes on - the fly. In general, applications that receive the Source Change event - will have to call :ref:`VIDIOC_QUERYSTD`, and if the detected video - standard is valid they will have to stop streaming, set the new - standard, allocate new buffers and start streaming again. - - -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. - -ENODATA - Standard video timings are not supported for this input or output. |