media/drivers/aspeed-video.rst

1 .. SPDX-License-Identifier: GPL-2.0
5 ASPEED video driver
8 ASPEED Video Engine found on AST2400/2500/2600 SoC supports high performance
9 video compressions with a wide range of video quality and compression ratio
14 * JPEG JFIF standard mode: for single frame and management compression
15 * ASPEED proprietary mode: for multi-frame and differential compression.
16   Support 2-pass (high quality) video compression scheme (Patent pending by
17   ASPEED). Provide visually lossless video compression quality or to reduce
21 stands for JPEG JFIF standard mode; V4L2_PIX_FMT_AJPG stands for ASPEED
22 proprietary mode.
24 More details on the ASPEED video hardware operations can be found in
25 *chapter 6.2.16 KVM Video Driver* of SDK_User_Guide which available on
26 `github <https://github.com/AspeedTech-BMC/openbmc/releases/>`__.
28 The ASPEED video driver implements the following driver-specific control:
31 ---------------------------
32     Enable/Disable ASPEED's High quality mode. This is a private control
33     that can be used to enable high quality for aspeed proprietary mode.
35 .. flat-table::
36     :header-rows:  0
37     :stub-columns: 0
40     * - ``(0)``
41       - ASPEED HQ mode is disabled.
42     * - ``(1)``
43       - ASPEED HQ mode is enabled.
46 -----------------------------------
47     Define the quality of ASPEED's High quality mode. This is a private control
48     that can be used to decide compression quality if High quality mode enabled
51 .. flat-table::
52     :header-rows:  0
53     :stub-columns: 0
56     * - ``(1)``
57       - minimum
58     * - ``(12)``
59       - maximum
60     * - ``(1)``
61       - step
62     * - ``(1)``
63       - default