[vorbis] 6 channel encoding

Adam Williams broadcast at earthling.net
Mon Nov 18 05:52:31 PST 2002



It appears that either Vorbis was never intended to support more than 2 
channels
or the algorithm doesn't work for low sound levels.  In trying to encode
Beauty and the Beast and Starwars II using 6 channels, the Vorbis 
encoder produced
noise in all the scenes were audio dropped below -25 dB.  Unfortunately 
since most
dialog is below -25 dB, the Vorbis encodings are unintelligable for most 
of the movies.  Not
a single dialog scene in Starwars which could be understood using Vorbis 
encoding while the
end credits in Starwars and the Ballroom scene in Beauty and the Beast were
completely destroyed by the Vorbis encoding.  Seems long string passages 
in 6 channels
have beating added by Vorbis while most of the frequencies in dialog are 
removed.  
These encodings were done at 768000bits/second variable bitrate.

<p><p><p>--- >8 ----
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