AC3 Decode / Dynamic Range Compression & Dialog Normalization

[Tim Müller]

On Fri, 2014-07-18 at 20:02 +0000, David Weldon wrote:

> I was wondering if anyone familiar with the AC3 decoders can tell me
> if any decoders support both Dynamic Range Compression, and/or Dialog
> Normalization.
> From what I can tell, avdec_ac3 does not support either of these…  It
> looks like a54dec possibly supports dynamic range compression; I’m not
> sure about dialog normalization however…  Could it possibly be there
> and always on?  

I believe faad supports both of these, the Dialog Normalization is
applied when downmixing to stereo, but the problem is often that the
audio sink doesn't correctly announce that the output is only stereo and
then downmixing happens in the sink's libraries somewhere and then
normalization can't be applied. But faad can certainly do this, and if
it doesn't when forced to stereo output then that can be fixed.

For avdec_ac3 also see https://bugzilla.gnome.org/show_bug.cgi?id=608892

Cheers
 -Tim

-- 
Tim Müller, Centricular Ltd - http://www.centricular.com