[FFmpeg-devel] MPEG TS encoding problem on change from stereo to mono, pay for fix

[Reimar Döffinger]

On Sun, Nov 21, 2010 at 11:11:30PM +0100, Stefano Sabatini wrote:
> On date Friday 2010-11-19 23:05:34 +0100, Reimar D?ffinger encoded:
> > On Fri, Nov 19, 2010 at 03:26:57PM +0100, Stefano Sabatini wrote:
> > > diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
> > > index bff9477..22e3615 100644
> > > --- a/libavcodec/avcodec.h
> > > +++ b/libavcodec/avcodec.h
> > > @@ -3076,6 +3076,14 @@ ReSampleContext *av_audio_resample_init(int output_channels, int input_channels,
> > >                                          int filter_length, int log2_phase_count,
> > >                                          int linear, double cutoff);
> > >  
> > > +int av_audio_resample_reinit(ReSampleContext **ctx,
> > > +                             int output_channels, int input_channels,
> > > +                             int output_rate, int input_rate,
> > > +                             enum AVSampleFormat sample_fmt_out,
> > > +                             enum AVSampleFormat sample_fmt_in,
> > > +                             int filter_length, int log2_phase_count,
> > > +                             int linear, double cutoff);
> > 
> > I'm not convinced this should be public API, since it only
> > checks for changes to the first arguments but not filter_length
> > etc. I'd consider it too confusing/hackish to make it public...
> 
> The problem is that those values cannot be checked in the
> ReSampleContext, as are defined in AVResampleContext, which is opaque
> in resample.c where the function is defined.
> 
> If we want to quickly fix the problem we could simply state in the
> docs that those values are supposed to be the same, or make
> AVResampleContext definition visible in resample.c, which doesn't look
> a good idea.

Or we could (for now) leave it completely up to the application to
keep track of which values they created the context with.
Would also be simpler in this case, since within FFmpeg we don't
have to check if any of the output stuff changed since that is
always the same.