xref: /kernel/linux/linux-5.10/Documentation/userspace-api/media/dvb/video-command.rst (revision 8c2ecf20)

.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.video

.. _VIDEO_COMMAND:

=============
VIDEO_COMMAND
=============

Name
----

VIDEO_COMMAND

.. attention:: This ioctl is deprecated.

Synopsis
--------

.. c:macro:: VIDEO_COMMAND

``int ioctl(int fd, VIDEO_COMMAND, struct video_command *cmd)``

Arguments
---------

.. flat-table::
    :header-rows:  0
    :stub-columns: 0

    -  .. row 1

       -  int fd

       -  File descriptor returned by a previous call to open().

    -  .. row 2

       -  int request

       -  Equals VIDEO_COMMAND for this command.

    -  .. row 3

       -  struct video_command \*cmd

       -  Commands the decoder.

Description
-----------

This ioctl is obsolete. Do not use in new drivers. For V4L2 decoders
this ioctl has been replaced by the
:ref:`VIDIOC_DECODER_CMD` ioctl.

This ioctl commands the decoder. The ``video_command`` struct is a
subset of the ``v4l2_decoder_cmd`` struct, so refer to the
:ref:`VIDIOC_DECODER_CMD` documentation for
more information.

.. c:type:: video_command

.. code-block:: c

	/* The structure must be zeroed before use by the application
	This ensures it can be extended safely in the future. */
	struct video_command {
		__u32 cmd;
		__u32 flags;
		union {
			struct {
				__u64 pts;
			} stop;

			struct {
				/* 0 or 1000 specifies normal speed,
				1 specifies forward single stepping,
				-1 specifies backward single stepping,
				>1: playback at speed/1000 of the normal speed,
				<-1: reverse playback at (-speed/1000) of the normal speed. */
				__s32 speed;
				__u32 format;
			} play;

			struct {
				__u32 data[16];
			} raw;
		};
	};

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.