Messages in this thread | | | Date | Fri, 19 Nov 2021 10:02:40 +0800 | Subject | Re: [PATCH v5 05/10] media: v4l: Add definition for the Aspeed JPEG format | From | Jammy Huang <> |
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Hi Sakari,
On 2021/11/18 下午 08:33, Sakari Ailus wrote: > Hi Jammy, > > On Thu, Nov 18, 2021 at 03:40:26PM +0800, Jammy Huang wrote: >> This introduces support for the Aspeed JPEG format, where the new frame >> can refer to previous frame to reduce the amount of compressed data. The >> concept is similar to I/P frame of video compression. I will compare the >> new frame with previous one to decide which macroblock's data is >> changed, and only the changed macroblocks will be compressed. >> >> This Aspeed JPEG format is used by the video engine on Aspeed platforms, >> which is generally adapted for remote KVM. >> >> Signed-off-by: Jammy Huang <jammy_huang@aspeedtech.com> >> --- >> v5: >> - no update >> v4: >> - new >> --- >> Documentation/media/uapi/v4l/pixfmt-reserved.rst | 12 ++++++++++++ >> drivers/media/v4l2-core/v4l2-ioctl.c | 1 + >> include/uapi/linux/videodev2.h | 1 + >> 3 files changed, 14 insertions(+) >> >> diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst >> index b2cd155e691b..23c05063133d 100644 >> --- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst >> +++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst >> @@ -264,6 +264,18 @@ please make a proposal on the linux-media mailing list. >> of tiles, resulting in 32-aligned resolutions for the luminance plane >> and 16-aligned resolutions for the chrominance plane (with 2x2 >> subsampling). >> + * .. _V4L2-PIX-FMT-AJPG: >> + >> + - ``V4L2_PIX_FMT_AJPG`` >> + - 'AJPG' >> + - ASPEED JPEG format used by the aspeed-video driver on Aspeed platforms, >> + which is generally adapted for remote KVM. >> + On each frame compression, I will compare the new frame with previous >> + one to decide which macroblock's data is changed, and only the changed >> + macroblocks will be compressed. >> + >> + You could reference to chapter 36, Video Engine, of AST2600's datasheet >> + for more information. > Is this datasheet publicly available? Do you have a URL?
Sorry, this datasheet is not publicly available. Hans mentioned this as well in the discussion below:
https://lkml.org/lkml/2021/11/10/101
-- Best Regards Jammy
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