[FFmpeg-devel] [PATCH] avcodec/hevcdec: constrained intra predict, do not check top left IS_INTRA if it's not available

[Linjie Fu]

On Mon, Oct 26, 2020 at 10:29 PM Guangxin Xu <oddstone at gmail.com> wrote:

> The bug reporter confirmed the fix.
> https://trac.ffmpeg.org/ticket/8932
>
> ping for review and merge.
> thanks
>
> On Fri, Oct 16, 2020 at 9:57 PM Xu Guangxin <oddstone at gmail.com> wrote:
>
> > fix ticket: 8932
> >
> > For poc 2, we have tile boundary at x = 640.
> > When we predict cu(640,912),the top left pixel is not avaliable to the
> cu.
> > So, we can not check it's intra or not. We need set top[-1] = top[0]
> > directly.
> > see 8.4.4.2.1 for details
> > ---
> >  libavcodec/hevcpred_template.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/hevcpred_template.c
> > b/libavcodec/hevcpred_template.c
> > index 6fe33546b1..e550707874 100644
> > --- a/libavcodec/hevcpred_template.c
> > +++ b/libavcodec/hevcpred_template.c
> > @@ -213,7 +213,7 @@ do {                                  \
> >                  while (j < size_max_x && !IS_INTRA(j, -1))
> >                      j++;
> >                  if (j > 0)
> > -                    if (x0 > 0) {
> > +                    if (cand_up_left) {
> >                          EXTEND_LEFT_CIP(top, j, j + 1);
> >                      } else {
> >                          EXTEND_LEFT_CIP(top, j, j);
> > --
> > 2.17.1
> >
> >


Looks reasonable, also verified there is no garbage anymore.
Prefer to apply soon if no objections.

- Linjie