On Tue, Oct 30, 2012 at 9:01 AM, Michael Chapman <s...@mchapman.com> wrote: > 'Native' CAF also has the possibility for 'W,X,Y,Z' so (again without > acknowledgment) I suspect that could be counted as a *.amb > variant.
Has anyone had any success with this? It's in the Core Audio header files, but a couple of years ago, I tried writing out some B-format files and got an 'unimplemented' error. (I forget the exact error, but could recreate it if anyone is interested). Also, I've encoded 4-channel B-format files with Ogg Vorbis and MPEG-4 AAC at rates around 160-256 kbps, and wavpack lossy (which is around 350kbps, iirc) and they decoded correctly without spatial artifacts, so at moderate bit rates these codecs preserve phase information. At very low bit rates, Ogg Vorbis switches to "square polar mapping" mode which will corrupt the phase relationships in stereo signals. I don't know how they handle multichannel files. See http://xiph.org/vorbis/doc/stereo.html -- Aaron (hel...@ai.sri.com) Menlo Park, CA US _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
