is it really so great as it was said?
and how is it compared with mp3 vbr & wma9 vbr? just with the same file size which one sounds better?

Depends what people told you. If they told you it sucks big time, than they are probably right
So you can say that it isn't really great.



mp3 and wma9 will sound better (except maybe some very rare cases (unlikely)).

Menno

In it's time it sounded good for it's bitrate IMHO. They were typically 80 and 96 kbs (using half for each channel).
But it's really obsolete by now, these days you would take ogg, aac, wma or even mp3pro to achieve comparable or better results. It is probably not fair to compare with vbr encoders though.
Oh yeah, it was also proprietary, closed encoder (libraries) and such, which made a lot of people look elsewhere.
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Ge Someone

Don't do drugs and don't use vqf. Those two seem to be related somehow.

hehe, thx i see

Actually, VQF is very good (compared to other encoders) at very low bitrates (around 8-16kbps). That's why it's part of the MPEG4 audio codec portfolio for this bitrate range.

You are probably right, MPEG wouldn't choose it for nothing. Although I never heard an optimised MPEG-4 TwinVQ encoder, so it's hard to tell.

Note should be taken though, that the TwinVQ in MPEG-4 is a bit different from Yamaha's VQF. For example it uses (or can use) all the MPEG-4 GA coding tools (MS, IS, TNS, Prediction) and it uses some sort of entropy coding, which VQF doesn't seem to use (all static sized parameters for a frame).

Menno

Isn't wma some how related to vqf?

Not really. Both use vector quantization, but that's about it regarding similarities.

Edit: I'm talking about WMA standard, not WMA pro. Maybe WMA pro also uses VQ, but I don't know.