[FFmpeg-devel] [PATCH 1/2] avcodec/jpeg2000dec: Set sample aspect ratio before getting buffer

[Tomas Härdin]

fre 2022-09-23 klockan 20:48 +0200 skrev Andreas Rheinhardt:
> Tomas Härdin:
> > fre 2022-09-23 klockan 17:40 +0200 skrev Andreas Rheinhardt:
> > > That way the SAR will be automatically set on the AVFrame.
> > > 
> > > Signed-off-by: Andreas Rheinhardt
> > > <andreas.rheinhardt at outlook.com>
> > > ---
> > > If I am not mistaken, then the earlier code would set the sar
> > > with a delay of one frame on the returned frames in case
> > > there is a sar change mid-stream. But I don't have a sample
> > > for this.
> > > 
> > >  libavcodec/jpeg2000dec.c | 7 ++++---
> > >  1 file changed, 4 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
> > > index 7d9661f29f..c3f2a7aa03 100644
> > > --- a/libavcodec/jpeg2000dec.c
> > > +++ b/libavcodec/jpeg2000dec.c
> > > @@ -2519,6 +2519,10 @@ static int
> > > jpeg2000_decode_frame(AVCodecContext *avctx, AVFrame *picture,
> > >      if (ret = jpeg2000_read_main_headers(s))
> > >          goto end;
> > >  
> > > +    if (s->sar.num && s->sar.den)
> > > +        avctx->sample_aspect_ratio = s->sar;
> > > +    s->sar.num = s->sar.den = 0;
> > > +
> > >      /* get picture buffer */
> > >      if ((ret = ff_thread_get_buffer(avctx, picture, 0)) < 0)
> > >          goto end;
> > > @@ -2547,9 +2551,6 @@ static int
> > > jpeg2000_decode_frame(AVCodecContext
> > > *avctx, AVFrame *picture,
> > >  
> > >      if (s->avctx->pix_fmt == AV_PIX_FMT_PAL8)
> > >          memcpy(picture->data[1], s->palette, 256 *
> > > sizeof(uint32_t));
> > > -    if (s->sar.num && s->sar.den)
> > > -        avctx->sample_aspect_ratio = s->sar;
> > > -    s->sar.num = s->sar.den = 0;
> > 
> > I suspect not doing this is what caused my simple hack to not work
> > when
> > ff_thread_get_buffer() was skipped. Looks OK, passes FATE.
> > 
> 
> FYI: Patch two passes FATE even without patch one. In what way did
> your
> simple hack not work when ff_thread_get_buffer() is skipped?

I had it like patch attached. I suspect the reason it didn't work is
because it sets *got_frame. If I run it then I get

  Assertion frame->buf[0] failed at libavcodec/decode.c:502
  Avbruten (SIGABRT)

/Tomas
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