Hi, On Wed 03 Jul 19, 14:28, Boris Brezillon wrote: > Looks like some stateless decoders expect slices to be prefixed with > ANNEX B start codes (they most likely do some kind of bitstream parsing > and/or need that to delimit slices when doing per frame decoding). > Since skipping those start codes for dummy stateless decoders (those > expecting all params to be passed through controls) should be pretty > easy, let's mandate that all slices be prepended with ANNEX B start > codes. > > If we ever need to support AVC headers, we can add a new menu control > to select the type of NAL header to use. After thinking a bit about this, I'd rather be in favor of having offsets in the control structures rather than forcing the start code type or having a dedicated control for that, as I've mentionned on the other patch. What do you think? Cheers, Paul > Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > Reviewed-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> > --- > Changes in v3: > * Add Paul's R-b > > Changes in v2: > * None > --- > Documentation/media/uapi/v4l/ext-ctrls-codec.rst | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > index 7a1947f5be96..3ae1367806cf 100644 > --- a/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > +++ b/Documentation/media/uapi/v4l/ext-ctrls-codec.rst > @@ -1726,6 +1726,7 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > :ref:`h264`, section 7.4.3 "Slice Header Semantics". For further > documentation, refer to the above specification, unless there is > an explicit comment stating otherwise. > + All slices should be prepended with an ANNEX B start code. > > .. note:: > > -- > 2.21.0 > -- Paul Kocialkowski, Bootlin Embedded Linux and kernel engineering https://bootlin.com
