[FFmpeg-devel] [PATCH 2/3] lavf/aiffdec: don't stop parsing after SSND chunk

[Michael Niedermayer]

On Sun, Jul 01, 2012 at 10:37:24PM +0200, Matthieu Bouron wrote:
> On Sun, Jul 01, 2012 at 08:59:04PM +0200, Michael Niedermayer wrote:
> > On Sun, Jul 01, 2012 at 08:10:45PM +0200, Matthieu Bouron wrote:
> > > On Sun, Jul 01, 2012 at 04:18:58PM +0200, Michael Niedermayer wrote:
> > > > On Sun, Jul 01, 2012 at 11:16:42AM +0200, Matthieu Bouron wrote:
> > > > > Some file has ID3 chunk placed after SSND.
> > > > > ---
> > > > >  libavformat/aiffdec.c | 2 --
> > > > >  1 file changed, 2 deletions(-)
> > > > > 
> > > > > diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c
> > > > > index 4083316..9764f82 100644
> > > > > --- a/libavformat/aiffdec.c
> > > > > +++ b/libavformat/aiffdec.c
> > > > > @@ -251,8 +251,6 @@ static int aiff_read_header(AVFormatContext *s)
> > > > >              offset = avio_rb32(pb);      /* Offset of sound data */
> > > > >              avio_rb32(pb);               /* BlockSize... don't care */
> > > > >              offset += avio_tell(pb);    /* Compute absolute data offset */
> > > > > -            if (st->codec->block_align)    /* Assume COMM already parsed */
> > > > > -                goto got_sound;
> > > > >              if (!pb->seekable) {
> > > > >                  av_log(s, AV_LOG_ERROR, "file is not seekable\n");
> > > > >                  return -1;
> > > > 
> > > > this will probably cause the whole file to be read in
> > > > aiff_read_header() in some cases
> > > > 
> > > Yes, this will cause ffmpeg to seek at the start of every chunks.
> > > This is required for some file (for example aiff files purchased from
> > > beatport.com) which has their ID3 chunk after the SSND chunk.
> > > 
> > > Maybe a better solution would be to add an option which tell the demuxer to
> > > look for other chunks after SSND ?
> > 
> > where is the id3 chunk exactly in relation to the audio data and
> > other chunks as well as offset ?
> > 
> 
> In my case, the ID3 chunk is placed after the entire SSND chunk (including
> audio data). Anyway i didn't find any documentations which specify that
> the ID3 chunk should be before or after the SSND chunk (or another type of
> chunk).

hmm, well thats a unfortunate layout.
at least a check shoudl be added if the underlaying protocol is
seekable, because it not we cannot move to the end of the ssnd
chunk because we would never be able to seek back and play anything
(unless it all fits in our small buffer)


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

When the tyrant has disposed of foreign enemies by conquest or treaty, and
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