RM10 Multichannel Channel Separation

[LiFe]

Just doing some testing to see that multichannel was working, and I came up with some interesting channel separation issues.

See demo files (http://www.zipworld.com.au/~qcvp/dom/6chan/).

The surround channels in the wav file are completely separated, yet after encoding in rm10, particulalry at the lowwer bitrates, there was a reasonable amount of the surround channels crossing.

96kbit/s seems to be fairly useless?

LiFe.

[karl_lillevold]

If you look in the RA5.1 info thread (http://forum.doom9.org/showthread.php?s=&threadid=56684), you fill find the following table:

flavor bitrate #ch bitrate allocations
30 : 96 kbps (5 ch) 32s + 32s + 32m
31 : 128 kbps (6 ch) 44s + 44s + 32m + 8m
32 : 180 kbps (6 ch) 64s + 64s + 44m + 8m
33 : 264 kbps (6 ch) 96s + 64s + 96m + 8m
The bitrate allocation notation is:
Front(Right/Left) + Rear(Right/Left) + Center + Sub : s=stereo, m=mono
The front and rear pairs are encoded using cook stereo, the center using cook mono, and the sub using a custom cook mono codec.

As you can see, at 96 kbps for 5.1, only 32 kbps is used for each stereo pair. This is coded as joint stereo, and at such low bitrate, there will be a certain loss in channel separation. I would suggest minimum 128 kbps, and 180 kbps high quality, with 264 kbps for 5.1 Music only.