[Speex-dev] [Vorbis-dev] Vorbis-/Speex-Audio for Movie-Archiving

Hannes Hauswedell lists at soulrebel.in-berlin.de
Wed Apr 15 14:49:22 PDT 2009

On Tuesday, 14. April 2009 03:16:48 you wrote:
> > I) Multi-channel
> >
> > Up until now I mostly encoded to stereo; now I am thinking of encoding
> > more movies to 4.0 or 5.1. I heard that vorbis does not optimize for
> > channels > 2, i.e. that 6 channels is just stereo*3. AAC is supposed to
> > do this better... Now I really digg vorbis, because its patent-free and
> > grass-roots-developed ;) so this doesnt mean I am switching to aac, but
> > I'd like to know whether this true or if its just FUD.
> Vorbis the format is able to efficiently encode multichannel.  The
> current encoder does not-- mainly because we've never had access to
> high quality surround source to do the tuning.  Starting from another
> compressed source, especially a source that's not particularly high
> quality to start with like a consumer DVD, is better than nothing, but
> not a great solution.
> Monty

Hm, thanks for your reply. Good to here that its not a format-problem and 
/just/ related to the implementation. I think right now with the "movie-
archiving-community" switching to HD we have a good oppurtunity of introducing 
new codecs to them. Use of audio codecs in Movies-Files greatly impacts their 
reception and overall-use, therefor we shouldn't miss the chance. Once 
everyone starts seeing aac as *the* new audio codec a switch will hard.
Matroska got widespread adoption very fast for example...
Concerning audio a couple of people in the community currently say "I'll take 
vorbis for all stereo tracks and aac for all 5.1/7.1-audio", with many people 
probably just sticking with aac all along. But this shows that people do 
realise that vorbis is better for stereo, so one be might able to convince 
them that it is *the* audio codec, if one could improve the encoder for multi-

I know everyone is limited in time and that I can't contribute, but maybe it 
would help to put it on some TODO or make a Google-SoC-Proposal of it (I don't 
know if / how many slots Xiph got).


More information about the Speex-dev mailing list