[vorbis] AC-3 Decoding

[Marco Al]

On Wednesday 08 August 2001 13:57, you wrote:

> 1. It is only 2D, space is 3D , remember ? :-)
> 2. It is "hardwired" to a particular speaker setup -> lack of flexibility
> and scalability 3. Has less direction precision as Ambisonic ( the "thing"
> that will be used by ogg/vorbis for spatial sound ) , but I am not 100%
> sure about this, some of the gurus should confirm ( or deny )

When I hear 3D support I tend to think about allowing the protocol to specify 
an exact 3D position for each channel in the file, which can then be 
_optimally_ mapped to a given setup client side.

Ambisonics is a way to pre-encode positions into a 4 channel format, but it 
will allways loose some precision. Ambisonics could simply be supported by 4 
channel support and seperate post processing, the only thing vorbis would 
really need in this respect is a flag in the header to indicate its an 
ambisonic recording and perhaps a special mode to make best use of the 
correlation between the channels ala the proposed joint stereo encoding.

Marco

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