[FFmpeg-devel] [PATCH] avcodec/ffv1enc: choose 1.2 by default for higher resolutions to ensure multi-threaded decodability

[Michael Niedermayer]

On Mon, Dec 09, 2013 at 12:46:37AM +0100, Peter B. wrote:
> On 12/08/2013 06:25 PM, Michael Niedermayer wrote:
> > Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> > ---
> >  libavcodec/ffv1enc.c |    4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/libavcodec/ffv1enc.c b/libavcodec/ffv1enc.c
> > index 2c87d7a..4856be5 100644
> > --- a/libavcodec/ffv1enc.c
> > +++ b/libavcodec/ffv1enc.c
> > @@ -672,6 +672,10 @@ static av_cold int encode_init(AVCodecContext *avctx)
> >      if ((avctx->flags & (CODEC_FLAG_PASS1|CODEC_FLAG_PASS2)) || avctx->slices>1)
> >          s->version = FFMAX(s->version, 2);
> >  
> > +    // Unspecified level & slices, we choose version 1.2+ to ensure multithreaded decodability
> > +    if (avctx->slices == 0 && avctx->level < 0 && avctx->width * avctx->height > 720*576)
> > +        s->version = FFMAX(s->version, 2);
> > +
> >      if (avctx->level == 3 || (avctx->level <= 0 && s->version == 2)) {
> >          s->version = 3;
> >      }
> 
> Do I understand this correctly to set the bitstream version to "2" if
> the resolution is greater than SD?
> 
> If so, I wanted to ask why not set the version to 1.3 directly?

there is no reason, its equivalent, the next line will change it to
3

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
some war or other, in order that the people may require a leader. -- Plato
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