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View Full Version : AC3 to Vorbis; a natural match or not?


mdoubledragon
18th September 2007, 10:49
I recently encoded a DVD with stereo AC3 stream to Vorbis. The original AC3 was 192kbps and the target vorbis stream had average bitrate of 64kbps (96max). The resulting audio was clearly very degraded than the original stream. When I encoded the AC3 stream to AAC at 64k, the audio quality was much better. I was using the latest version of libvorbis and besweet (with belite) for vorbis encoding.
Now my question would vorbis sound better than AAC when the original source is an uncompressed original stream for both and not AC3? I mean for AC3 encoding, is AAC a more natural option?
I read somewhere that different audio codecs keep and truncate different portions of audio spectrum, so some transcodes are more natural than others if the two formats share more in what they tend to keep and discard. Does the same rule apply here?

obieobieobie
18th September 2007, 13:50
Yes, the rule applies, but I would try Vorbis at 80 kbps average before you make any conclusions. Also, try mp3 at 128 kbps average just to see if there is something special with the source.