[Vorbis-dev] several questions

[Ralph Giles]

On Wed, Aug 24, 2005 at 08:47:31AM +0800, fangchao_dlut at sina.com wrote:

>  Any help is appriatiate.
>  I download the libvorbis-1.1.1 and find it support 2 channels only,is it 
>  the truth or i just made a mistake?

Vorbis supports up to 255 channels. Just tell it how many you want to encode
and it should handle it fine.

However, the channel coupling in libvorbis-1.1.1 only works with 2 channels;
more complex coupling is supported by the specification and handled by the
decoder, but the encoder needs to be updated to take full advantage of this
for surround applications, and so the bitrate there will be higher than it
needs to be. For discrete tracks it doesn't make much difference.

>  i think the psychology model is model??,why not use model ??? is it because 
>  the patent question?

I don't know much about the psychoacoustic model. It started out based on published
research old enough to be safe from patents, but I understand it has been much
tuned based on listening experiments by Monty, aoTuV and others.

Hope that helps,
 -r