Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

Source file repositories/reference/linux-study-clean/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst

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Linux kernel
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Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
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.rst
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Support Tooling And Documentation
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Documentation
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Support Tooling And Documentation: documentation
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Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L

.. _codec-controls:

***********************
Codec Control Reference
***********************

Below all controls within the Codec control class are described. First
the generic controls, then controls specific for certain hardware.

.. note::

   These controls are applicable to all codecs and not just MPEG. The
   defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG as the controls
   were originally made for MPEG codecs and later extended to cover all
   encoding formats.


Generic Codec Controls
======================


.. _mpeg-control-id:

Codec Control IDs
-----------------

``V4L2_CID_CODEC_CLASS (class)``
    The Codec class descriptor. Calling
    :ref:`VIDIOC_QUERYCTRL` for this control will
    return a description of this control class. This description can be
    used as the caption of a Tab page in a GUI, for example.

.. _v4l2-mpeg-stream-type:

``V4L2_CID_MPEG_STREAM_TYPE``
    (enum)

enum v4l2_mpeg_stream_type -
    The MPEG-1, -2 or -4 output stream type. One cannot assume anything
    here. Each hardware MPEG encoder tends to support different subsets
    of the available MPEG stream types. This control is specific to
    multiplexed MPEG streams. The currently defined stream types are:



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

    * - ``V4L2_MPEG_STREAM_TYPE_MPEG2_PS``
      - MPEG-2 program stream
    * - ``V4L2_MPEG_STREAM_TYPE_MPEG2_TS``
      - MPEG-2 transport stream
    * - ``V4L2_MPEG_STREAM_TYPE_MPEG1_SS``
      - MPEG-1 system stream
    * - ``V4L2_MPEG_STREAM_TYPE_MPEG2_DVD``
      - MPEG-2 DVD-compatible stream
    * - ``V4L2_MPEG_STREAM_TYPE_MPEG1_VCD``
      - MPEG-1 VCD-compatible stream
    * - ``V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD``
      - MPEG-2 SVCD-compatible stream



``V4L2_CID_MPEG_STREAM_PID_PMT (integer)``
    Program Map Table Packet ID for the MPEG transport stream (default
    16)

Annotation

Implementation Notes