unpredictable corruption in multichannel Ogg vorbis files
Has anyone else created Vorbis files with more than 6 channels? I'm a game developer trying to use multichannel Ogg Vorbis files for a PS3 and XBOX 360 title. Using the latest release libs and tools, I've created a Mac application that weaves up to 8 stereo AIFF files into one 16 channel Ogg file. What I'm finding is that if anything more than 3 stereo files (corresponding to a 5.1 audio file) are encoded, then the encoded output becomes unstable. I hear vocoder like artifacts and garbled output on some of the stereo pairs. It should be noted that I'm using a linear permutation matrix, so that the output file maintains the original stereo pairs, ie 16 channels in -> 16 channels out.
I've built Universal Binary versions of the latest Ogg and Vorbis libs available for download, and meticulously tested my sample_read callback, and everything is doing the right thing. I've even built raw and AIFF versions of a 16 track file, verified the integrity of the data, and run them through the readily available command line encoders for PC and Unix. The output corruption is identical to what I experience on my own encoder.
Its incredibly frustrating, and seems to be content dependent. In some file groupings, it performs brilliantly (I love the sound of Vorbis much more than MP3) for 3 minutes, and then goes to crap. In others, the corruption is evident much earlier. It always appears at the same place for each file group, no matter what the encoding settings.