Could someone explain me one thing?
I have two Wagner records in OGG Vorbis and Mpegplus formats. Both formats use VBR and were both used on classical music, which is often hard to encode. But if MPC files' bitrate varies in a very high diapason, the bitrate of OGG files (as Winamp shows it) changes slowly, even though musical fragments are very different.
Isn't OGG just wasting space this way? It looks much closer to ABR, than to VBR. Please, correct me if I'm wrong.

P.S.: Ogg files were encoded by Oggdrop by using a quality scale.

it's the way Winamp displays Vorbis bitrate.

You can change the way the mpc-bitrate is displayed by changing UpdateBitrate in musepack.ini in winamps plugin folder.
Try changing it to around 60 (just a guess) - this will make it look more like vorbis.
By changing it to 1 you will get a very accurate display...

Is there a way to get the vorbis decoder to update the bitrate more often? I think the current appearance of ABR is damaging to people opinion of vorbis.

Eh.. I kind of doubt it's "damaging". How many people have you really seen complain about this? I'd venture to guess that there are just as many people that prefer a slow update vs a fast one. Besides, if people are using the winamp display to gauge quality, it'd be better to educate them and explain how the codec actually works in regards to VBR than to create the illusion of an actual difference in behavior by simply changing the winamp display.

people who make pseudo-scientific conclusions based on bitrate display variations are dumb anyway, at least in my opinion. also, VBR display is always ahead of actual sound, since it shows bitrate of currently decoded sound (being usually about 2 seconds ahead of playback due to buffering in output); averaging it over some time before displaying actually reduces the lag.

Actually, some of us already knew that. I'm guilty of watching the bitrate field and noting it takes upward jumps about 2 seconds before a HF burst. Why I would study the has something to do with listening to one song 20+ times in a row and how my attention starts to wander.

As for the VBR field for Vorbis I've read somewhere else (in HA) that frequent updates annoy some people because they are too used to CBR and freak out when another part of their display is animated. Guess you can see this debate is about preference.

I've changed the buffering in WinAMP to 500ms (from 2000ms) so that the bitrate is closely correlated to the music being played. No skipping either.

famous "skipping" is hardly related to buffer size / buffer underruns anyway, you might get stuttering if buffer is too low and system load is too high (but 500ms is usually enough on not-so-old machines).

You've probably had to deal with hundreds of posters on various forums who write huge, flawed analyses on codecs and audio players based on bitrate displays, but I think SacRat simply wasn't aware of the inner workings of Winamp. I used to stare at the bitrate display when comparing MP3 VBR implementations, which I now know is a fallacy. So I think the question was prompted by a lack of education on the subject, rather than being "dumb".

But I know you were just making a general observation based on your experience, and not pointing to any particular case or making an absolute statement. I just don't want to discourage new forum members from asking reasonable questions. By the way, cute cat! Is it yours?

So now that we know the Winamp bitrate display isn't a good tool for measuring bitrate fluctuation, is there a better way to see how different codecs allocate bits, like an EncSpot-like bitrate graph that can analyze Vorbis or MPC files? Or, since these formats are "true" VBR (as opposed to MP3, which must use pre-defined frame sizes), does this kind of analysis not really work?

Naturally, this kind of analysis isn't useful for quality comparison (that's what ears are for!), but it does satisfy a sort of geek fascination.

Well, it seems, that here was some misunderstanding.

I'm not going to judge Vorbis just because of the bitrate Winamp displays, I'm only trying to make some things clear for myself.

So, as zZzZzZz says, it's all because of bitrate indicator updates. Looks like that.

Then another question... How are Vorbis VBR model borders defined for different quality settings?

I agree with SometimesWarrior: a bitrate allocation graph tool for OGG Vorbis could be useful.

2 SometimesWarrior: no offence. All I wanted to know is the kind of variate model used for OGG files (ABR or VBR) and is Winamp's display of it's bitrate correct.

Parameters in the psychoacoustic model.

Edit musepack.ini in the Plugin directory.

Replace the line

UpdateBitrate=38

by

UpdateBitrate=380

and you have a smoother display.

I myself prefer UpdateBitrate=1
It looks more....."living"