[FFmpeg-devel] [PATCH] Stream parsing

[Reimar Döffinger]

On Sun, Oct 03, 2010 at 02:40:52PM -0400, Justin Ruggles wrote:
> Benjamin Larsson wrote:
> 
> > $topic, previously discussed in [RFC] Stream parsing
> > 
> > MvH
> > Benjamin Larsson
> > 
> 
> > +/**
> > + * Codec should fill in channel configuration and samplerate instead of container
> > + */
> > +#define CODEC_CAP_CHANNEL_CONF     0x0400
> [...]
> > @@ -2191,9 +2192,17 @@
> >              }
> >          }
> >          assert(!st->codec->codec);
> > +        codec = avcodec_find_decoder(st->codec->codec_id);
> > +
> > +        /* Force decoding of at least one frame of codec data
> > +         * this makes sure the codec initializes the channel configuration
> > +         * and does not trust the values from the container.
> > +         */
> > +        if (codec && codec->capabilities & CODEC_CAP_CHANNEL_CONF)
> > +            st->codec->channels = 0;
> 
> Your documentation says channel configuration and samplerate.  Why is
> sample_rate not also set to 0 here?

I think the documentation should say:
Will override container channel configuration (i.e. even if it was
specified by the container) and fill in sample rate (i.e. usually only
when it was not set by the container).
I do not know 100% this is what will happen (e.g. SBR actually might
double the container-specified value I think), but in principle that
would be the ideal behaviour.