On Mon, Feb 21, 2022 at 02:12:01PM -0500, Nicolas Dufresne wrote: > MM21 has been documented through two software implementation [0] in libyuv and > [2] GStreamer. This format is similar to other tiled format, though it uses > uneven tile sizes. The luma tiles are 16x32 while the chroma tile have a > subsampled size of 16x16. This is the uncompressed cousin of V4L2_PIX_FMT_MT21C > and shares its tiling pattern and alignment. > > [0] https://chromium.googlesource.com/libyuv/libyuv/+/b4ddbaf549a1bf5572bf703fd2862d1eb7380c6a > [1] https://gitlab.freedesktop.org/gstreamer/gstreamer/-/commit/c9b127dae3af4b3fe78468e697cb491902425254 > > Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx> Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx> > --- > .../userspace-api/media/v4l/pixfmt-reserved.rst | 15 ++++----------- > .../userspace-api/media/v4l/pixfmt-yuv-planar.rst | 6 ++++++ > 2 files changed, 10 insertions(+), 11 deletions(-) > > diff --git a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst > index 2f2133b4cd9ce..cabfa34b7db5a 100644 > --- a/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst > +++ b/Documentation/userspace-api/media/v4l/pixfmt-reserved.rst > @@ -233,19 +233,12 @@ please make a proposal on the linux-media mailing list. > > - ``V4L2_PIX_FMT_MT21C`` > - 'MT21' > - - Compressed two-planar YVU420 format used by Mediatek MT8173. > - The compression is lossless. > - It is an opaque intermediate format and the MDP hardware must be > + - Compressed two-planar YVU420 format used by Mediatek MT8173, MT8192, > + MT8195 and more. The compression is lossless. This format have > + similitude with ``V4L2_PIX_FMT_MM21`` in term of alignment and tiling. > + It remains an opaque intermediate format and the MDP hardware must be > used to convert ``V4L2_PIX_FMT_MT21C`` to ``V4L2_PIX_FMT_NV12M``, > ``V4L2_PIX_FMT_YUV420M`` or ``V4L2_PIX_FMT_YVU420``. > - * .. _V4L2-PIX-FMT-MM21: > - > - - ``V4L2_PIX_FMT_MM21`` > - - 'MM21' > - - Non-compressed, tiled two-planar format used by Mediatek MT8183. > - This is an opaque intermediate format and the MDP3 hardware can be > - used to convert it to other formats. > - > .. raw:: latex > > \normalsize > diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst > index 3a09d93d405b2..570791fbc5c8b 100644 > --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst > +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst > @@ -296,6 +296,12 @@ tiles linearly in memory. The line stride and image height must be > aligned to a multiple of 32. The layouts of the luma and chroma planes are > identical. > > +``V4L2_PIX_FMT_MM21`` store luma pixel in 16x32 tiles, and chroma pixels > +in 16x16 tiles. The line stride must be aligned to a multiple of 16 and the > +image height must be aligned to a multiple of 32. The number of luma and chroma > +tiles are identical, even though the tile size differ. The image is formed of > +two non-contiguous planes. > + > .. _nv12mt: > > .. kernel-figure:: nv12mt.svg > -- > 2.35.1 >
