[vorbis-dev] True surround sound for Ogg -- a proposal

[David Carter]

On Fri, Jul 27, 2001 at 10:15:32PM -0500, David Carter wrote:
> On Fri, Jul 27, 2001 at 07:53:23PM -0700, Michael Paine wrote:
> > Has this sblive/ambisonic idea gone anywhere?  I would love if it did..
[snip]
> It would be a good idea to determine how many of these things already exist,
> and how many would need to be found/created/modified.  As for the sound HW,
> users will probably just have to bite the bullet and buy one of the existing
> cards.  The software side is a lot more open.

One update -- it seems that the software to do all the manipulation of the
uncompressed sound files (ambisonic or otherwise) is available (GPLd, even)
in the Computer Music Toolkit (http://www.ladspa.org/cmt/).  Thus, we'd just
need to add support to oggenc for reading .wxyz files (the standard Ambisonic
uncompressed format), as this package can be used to do any other needed
conversions.  Obviously, this makes things much simpler, as we just need to
check into sound driver support (for 4-channel output), defining the metadata
info for the ogg representation, and patching oggenc/ogg123 to do the Right
Thing with all this.

[snipped test disc ramblings]
> On the software side, surround support has not been added yet, beyond the
> generic multichannel encoding that oggenc supports (if you feed it a 4-channel
> WAV, it'll make a 4-channel ogg file, but AFAIK there's no support for mapping
> the channels to Ambisonic signals).  Someone should still e-mail Richard
> Furse about possibly relicensing his software Ambisonic decoder under GPL-
> compatible terms (or looser, if he was amenable) so we wouldn't have to write
> one from scratch.  I think he also has software to mix discrete channels into
> an Ambisonic stream, positioning them arbitrarily.  That would also be useful.
> His software page is at http://www.muse.demon.co.uk/mn_index.html.

All the stuff about asking Richard is moot -- see above. :)


-- 
David Carter ** dcarter at sigfs.org ** dcarter at visi.com
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