[vorbis] Meaningful encoder testing

[Ross Levis]

A large number of these test WAV files are the result of years of MP3 encoding
with the LAME project.  The files are portions of songs that people have found
and submitted which show up problems in the LAME encoder.  I thought
Velvet.wav was on the list but I just checked and couldn't find it so I
presume LAME has fixed the problem.  I guess Monty has gone through the list
checking the files with his encoder.  The list is at
http://lame.sourceforge.net/gpsycho/quality.html

Ross.

Craig Duncan wrote:

> I'm very _glad_ you're a perfectionist!  With respect to particular
> "bugs" being revealed by certain test wav files, i'm curious as to how
> this works.  Does Monty have a "suite" of files that stress certain
> aspects of the encoding?  Are they developed on the fly?  Do they
> produce discernable differences (to a listener) or just "noise" as
> recognized in a waveform analysis?
>
> I've been nowhere near jumping onto the ogg/vorbis bandwagon . . .
> mostly because i like Lame so much.  I'm just a "private" user and the
> legal issues are not much of a factor to me with respect to archiving my
> own personal recordings.  Quality is _always_ an issue, though, and i'm
> wondering what the Lame team uses, in terms of wave files, to "stress"
> their encoder and reveal bugs and deficiencies in it and whether it is
> ever done (or whether there is any possibility) to use the same wave
> files that Lame or Monty use (maybe even gathering a suite of test
> files?) to see how one encoder handles limitations recognized in
> another?
>
> I've read stuff on analysis of particular encoders using the testers own
> specific tools and methods but always wonder about the validity of all
> of this, which bears on the idea of the possibility of people working in
> the field agreeing on certain wav files being capable of producing
> meaningful analysis of the quality of the encoded sound.
>
> Monty wrote:
> >
> > > What's the delay?
> >
> > I'm a perfectionist :-) I'm after one last bug (tuning issue; the
> > problem is well understood, I just have to decide how to fix the
> > bugger).  This is the bug causing noise in velvet.wav even at
> > high bitrates.
> >
> > Monty
>
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