On 24/12/2021 02:27, 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. It 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@xxxxxxxxxxxxxx> > --- > v8: > - Add decoder information for aspeed-jpeg > v7: > - Add more information for aspeed-jpeg > v6: > - Update description for new format, aspeed-jpeg, in Documentation. > v5: > - no update > v4: > - new > --- > .../media/uapi/v4l/pixfmt-reserved.rst | 17 +++++++++++++++++ > drivers/media/v4l2-core/v4l2-ioctl.c | 1 + > include/uapi/linux/videodev2.h | 1 + > 3 files changed, 19 insertions(+) > > diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst This is the wrong file! It should be: Documentation/userspace-api/media/v4l/pixfmt-reserved.rst Regards, Hans > index b2cd155e691b..1d0dc8d86ed7 100644 > --- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst > +++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst > @@ -264,6 +264,23 @@ 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. > + > + The implementation is based on AST2600 A3 datasheet, revision 0.9, which > + is not publicly available. Or you can reference Video stream data format > + – ASPEED mode compression of SDK_User_Guide which available on > + AspeedTech-BMC/openbmc/releases. > + > + Decoder's implementation can be found here, > + `https://github.com/AspeedTech-BMC/aspeed_codec/ <https://github.com/AspeedTech-BMC/aspeed_codec/>`__ > > .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| > > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index 24db33f803c0..00dde01d2f97 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1378,6 +1378,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt) > case V4L2_PIX_FMT_S5C_UYVY_JPG: descr = "S5C73MX interleaved UYVY/JPEG"; break; > case V4L2_PIX_FMT_MT21C: descr = "Mediatek Compressed Format"; break; > case V4L2_PIX_FMT_SUNXI_TILED_NV12: descr = "Sunxi Tiled NV12 Format"; break; > + case V4L2_PIX_FMT_AJPG: descr = "Aspeed JPEG"; break; > default: > if (fmt->description[0]) > return; > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 3210b3c82a4a..994eb6155ea9 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -726,6 +726,7 @@ struct v4l2_pix_format { > #define V4L2_PIX_FMT_INZI v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth 16-bit */ > #define V4L2_PIX_FMT_SUNXI_TILED_NV12 v4l2_fourcc('S', 'T', '1', '2') /* Sunxi Tiled NV12 Format */ > #define V4L2_PIX_FMT_CNF4 v4l2_fourcc('C', 'N', 'F', '4') /* Intel 4-bit packed depth confidence information */ > +#define V4L2_PIX_FMT_AJPG v4l2_fourcc('A', 'J', 'P', 'G') /* Aspeed JPEG */ > > /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits unused */ > #define V4L2_PIX_FMT_IPU3_SBGGR10 v4l2_fourcc('i', 'p', '3', 'b') /* IPU3 packed 10-bit BGGR bayer */
