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

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

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Linux kernel
Corpus path
Documentation/userspace-api/media/v4l/ext-ctrls-codec-stateless.rst
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.rst
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138268 bytes
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Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
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atlas-only

Why This File Exists

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

Dependency Surface

Detected Declarations

Annotated Snippet

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

.. _codec-stateless-controls:

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

The Stateless Codec control class is intended to support
stateless decoder and encoders (i.e. hardware accelerators).

These drivers are typically supported by the :ref:`stateless_decoder`,
and deal with parsed pixel formats such as V4L2_PIX_FMT_H264_SLICE.

Stateless Codec Control ID
==========================

.. _codec-stateless-control-id:

``V4L2_CID_CODEC_STATELESS_CLASS (class)``
    The Stateless Codec class descriptor.

.. _v4l2-codec-stateless-h264:

``V4L2_CID_STATELESS_H264_SPS (struct)``
    Specifies the sequence parameter set (as extracted from the
    bitstream) for the associated H264 slice data. This includes the
    necessary parameters for configuring a stateless hardware decoding
    pipeline for H264. The bitstream parameters are defined according
    to :ref:`h264`, section 7.4.2.1.1 "Sequence Parameter Set Data
    Semantics". For further documentation, refer to the above
    specification, unless there is an explicit comment stating
    otherwise.

.. c:type:: v4l2_ctrl_h264_sps

.. raw:: latex

    \small

.. tabularcolumns:: |p{1.2cm}|p{8.6cm}|p{7.5cm}|

.. flat-table:: struct v4l2_ctrl_h264_sps
    :header-rows:  0
    :stub-columns: 0
    :widths:       1 1 2

    * - __u8
      - ``profile_idc``
      -
    * - __u8
      - ``constraint_set_flags``
      - See :ref:`Sequence Parameter Set Constraints Set Flags <h264_sps_constraints_set_flags>`
    * - __u8
      - ``level_idc``
      -
    * - __u8
      - ``seq_parameter_set_id``
      -
    * - __u8
      - ``chroma_format_idc``
      -
    * - __u8
      - ``bit_depth_luma_minus8``
      -
    * - __u8
      - ``bit_depth_chroma_minus8``
      -
    * - __u8

Annotation

Implementation Notes