[FFmpeg-devel] Patch to WAV to accurately report duration

[Michael Niedermayer]

On Wed, Jan 12, 2011 at 01:59:09PM -0800, Frank Barchard wrote:
> On Wed, Jan 12, 2011 at 8:04 AM, Michael Niedermayer <michaelni at gmx.at>wrote:
> 
> > On Mon, Jan 10, 2011 at 06:51:18PM -0800, Frank Barchard wrote:
> > > Patch to accurately report duration of a WAV.
> >
> > -    } else
> > > +    } else {
> > >          wav->data_end= url_ftell(pb) + size;
> > > +        st->nb_frames = size /
> > > +            (st->codec->channels * (st->codec->bits_per_coded_sample >>
> > 3));
> > > +        st->duration = st->codec->frame_size ?
> > > +            st->nb_frames * st->codec->frame_size : st->nb_frames;
> > > +    }
> >
> > this is wrong, iam not even sure its guranteed to work with PCM
> >
> 
> The patch has certainly worked for 8-bit, 16-bit, and 24-bit wav files that
> we've tested.  With the patch, the number of frames is reported as exactly
> right (as compared with the results returned by Apple's 'afinfo' tool).
>  Without the patch it is not accurate.

try it with any VBR codec

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

It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
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