[vorbis] RC2 artifacts

Bacchus 13 bacchus13 at zdnetonebox.com
Thu Aug 16 15:21:13 PDT 2001



---- "Gian-Carlo Pascutto" <gcp at sjeng.org> wrote:

B>Actually, I expected even worse results by the added channel coupling.

G> Worse? If anything, channel coupling should drastically improve
G> quality at equal bitrates. Channel coupling removes more redundant
G> information that can be used to improve the hard to encode parts
G> of the music.

Sorry if it caused misunderstanding, but I meant the possibility of bugs.
 For MP3's joint stereo had problems and Ogg's Channel Coupling seems
to be more complex technology.

G> The only problem that it has now is that a piece of normalisation
G> code is missing that can add a hissyness at bitrates 256kbps if
G> point/phase stereo is used.

Just like this.  However, it was a good surprise that it hasn't got many
of these kinds of problems.
 
B>I don't know why they bother comparing WMA at 64 with MP3 at 128 in r3mix
B>forum (http://r3mix.net/forum).  Obviously, Ogg sounds much better
B>and is smaller than WMA.

G> What are you talking about? The listening test going on in r3mix is
G> comparing WMA,OGG,LAME,Xing,AAC and MPC, all at 128kbps (or VBR G>
setting which averages that)

Wrong thread...I meant a thread 'MP3 vs WMA.'  However, yours seem to
be much more interesting.  Thanx.
 
G> I did not like some aspects of the RC2 encoder and have my own tuned
G> mode.
G> It fixes the problems that were most annoying to me. 
G> I tested it with your sample and it seems to fix the problem to me.

Good.  I'll wait till the next release.  However, just from curiosity,
why didn't hackers fix the problem while an individual can fix it single-handedly?

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