[Vorbis-dev] 5.1 surround channel coupling

[Sebastian Olter]

2007/2/26, Richard Lee <ricardo at justnet.com.au>:
> Does this mean there is a logical and tested path for a *.AMB file (the Ambisonic studio B-format file) to be encoded into a Vorbis stream ?

The most logical way (i.e. involving the simplest logic :P) is to map
B-Format channels 1:1. Vorbis is a rare case of a codec that allows up
to 255 discrete channels to be encoded, and its official encoder,
oggenc, needed just 2 lines of code to be tweaked in order to handle
this. My patch includes this simple modification as well.

> What I was asking is if there is a logical and tested path for a Vorbis Ambisonic stream to recover the original B-format signals.

The official Vorbis-to-wav decoder is called oggdec and it can handle
multichannel files. Wav can be converted into .amb format with
mctools.