[Ffmpeg-devel] support for hddvd .evo files (mpg ps variant) in ffmpeg

[Ian Caulfield]

On 1/17/07, Michael Niedermayer <michaelni at gmx.at> wrote:

>
> [...]
> > @@ -1539,6 +1578,54 @@
> >              header_len -= 10;
> >              len -= 10;
> >          }
> > +        if ((flags & 0x01) == 0x01) { /* PES extension */
>
> if(flags & 0x01) is more readable IMHO


fair enough

[...]
> > +            if ((pes_ext & 0x80) == 0x80) { /* PES private data */
> > +                if (header_len < 16)
> > +                    goto redo;
> > +                url_fskip(&s->pb, 16);
> > +                header_len -= 16;
> > +                len -= 16;
> > +            }
> > +            if ((pes_ext & 0x40) == 0x40) { /* pack header - should be
> zero in PS */
> > +                goto redo;
> > +            }
> > +            if ((pes_ext & 0x20) == 0x20) { /* program packet sequence
> counter */
> > +                if (header_len < 2)
> > +                    goto redo;
> > +                url_fskip(&s->pb, 2);
> > +                header_len -= 2;
> > +                len -= 2;
> > +            }
> > +            if ((pes_ext & 0x10) == 0x10) { /* P-STD buffer */
> > +                if (header_len < 2)
> > +                    goto redo;
> > +                url_fskip(&s->pb, 2);
> > +                header_len -= 2;
> > +                len -= 2;
> > +            }
>
> skip= (pes_ext>>4) & 0xB;
> skip+= skip & 0x9;
> if (header_len < skip)
>     goto redo;
> url_fskip(&s->pb, skip);
> header_len -= skip;
> len -= skip;


That's certainly shorter :)


[...]
> > @@ -1553,7 +1640,7 @@
> >              goto redo;
> >          startcode = get_byte(&s->pb);
> >          len--;
> > -        if (startcode >= 0x80 && startcode <= 0xbf) {
> > +        if (startcode >= 0x80 && startcode <= 0xcf) {
> >              /* audio: skip header */
> >              if (len < 3)
> >                  goto redo;
> > @@ -1641,15 +1728,22 @@
> >      } else if (startcode >= 0x80 && startcode <= 0x87) {
> >          type = CODEC_TYPE_AUDIO;
> >          codec_id = CODEC_ID_AC3;
> > -    } else if (startcode >= 0x88 && startcode <= 0x9f) {
> > +    } else if ((startcode >= 0x88 && startcode <= 0x8f)
> > +               || (startcode >= 0x98 && startcode <= 0x9f)) {
>
> and what is 0x90 .. 0x97 ?


The documents I've seen say it's reserved for SDDS - I believe the original
0x9f may have been a typo for 0x8f.

Ian