[FFmpeg-devel] [PATCH] compute chapters end

[Aurelien Jacobs]

On Sat, 24 May 2008 17:21:20 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> On Sat, May 24, 2008 at 04:13:17PM +0200, Aurelien Jacobs wrote:
> > On Sat, 24 May 2008 16:01:21 +0200
> > Aurelien Jacobs <aurel at gnuage.org> wrote:
> > 
> > > Hi,
> > > 
> > > Attached patch will compute the end of all chapters when end
> > > is not specified in the container.
> > 
> > Oh, and here is a version which won't segfault when no chapters
> > are present.
> > 
> > Aurel
> 
> > Index: libavformat/utils.c
> > ===================================================================
> > --- libavformat/utils.c	(revision 13280)
> > +++ libavformat/utils.c	(working copy)
> > @@ -1805,6 +1805,20 @@
> >      return CODEC_ID_NONE;
> >  }
> >  
> > +static void compute_chapters_end(AVFormatContext *s)
> > +{
> > +    unsigned int i;
> > +
> > +    for (i=0; i+1<s->nb_chapters; i++)
> > +        if (s->chapters[i]->end == AV_NOPTS_VALUE)
> > +            s->chapters[i]->end = s->chapters[i+1]->start;
> > +
> > +    if (s->nb_chapters && s->chapters[i]->end == AV_NOPTS_VALUE)
> > +        s->chapters[i]->end = av_rescale_q(s->start_time + s->duration,
> > +                                           AV_TIME_BASE_Q,
> > +                                           s->chapters[i]->time_base);
> > +}
> 
> This needs a few asserts
> s->chapters[i]->start <= s->chapters[i+1]->start
> s->chapters[i]->time_base == s->chapters[i+1]->time_base
> s->start_time != AV_NOPTS_VALUE
> s->duration>0
> 
> I assume these are guranteed to be true whenever end == AV_NOPTS_VALUE 
> currently, the asserts() would ensure that future changes dont lead to
> hard to debug issues.

Good idea indeed.
Patch applied with asserts.

Aurel