[Ffmpeg-devel] Re: [Ffmpeg-cvslog] CVS: ffmpeg/libavcodec dv.c, 1.72, 1.73

[Michael Niedermayer]

Hi

On Thu, Feb 23, 2006 at 06:03:19PM -0800, Roman Shaposhnick wrote:
[...]
> >                         } else {
> > +                           if(b->next[k] >= mb_area_start[a+1] && b->next[k]<64){
> > +                                for(a2=a+1; b->next[k] >= mb_area_start[a2+1]; a2++);
> > +                                assert(a2<4);
> > +                                assert(b->mb[b->next[k]]);
> 
>   Why these particular asserts ? 

no special reason ...


[...]
> > -    } while ((vs_total_ac_bits < size[0] + size[1] + size[2] + size[3] + size[4]) &&
> > -             (qnos[0]|qnos[1]|qnos[2]|qnos[3]|qnos[4]));
> > +       if(vs_total_ac_bits >= size[0] + size[1] + size[2] + size[3] + size[4])
> > +            return;
> > +    } while (qnos[0]|qnos[1]|qnos[2]|qnos[3]|qnos[4]);
> > +
> > +
> > +    for(a=2; a==2 || vs_total_ac_bits < size[0]; a+=a){
> > +        b = blks;
> > +        size[0] = 0;
> > +        for (j=0; j<6*5; j++, b++) {
> > +            prev= b->prev[0];
> > +            for (k= b->next[prev]; k<64; k= b->next[k]) {
> > +                if(b->mb[k] < a && b->mb[k] > -a){
> > +                    b->next[prev] = b->next[k];
> > +                }else{
> > +                    size[0] += dv_rl2vlc_size(k - prev - 1, b->mb[k]);
> > +                    prev= k;
> > +                }
> > +            }
> > +        }
> > +    }
> 
>    
>    Are you sure that we need this chunk of code ? My concern is -- in case
>    where encoder maxes out on all QNOs being 0s -- there's very little we
>    can to do salvage the situation anyway. Or did you have another idea 
>    when creating this chunk of code ?

well, IMHO its better to remove the smallest coefficients instead of
removing random ones _and_ generating an invalid bittream without EOBs

[...]
-- 
Michael