[MPlayer-users] RFC: docs update for "how to create a high quality DVD rip"

[Jason Tackaberry]

On Wed, 2004-06-09 at 10:21 -0500, Wayde Milas wrote:
> Look. You cant compare codec a to codec b correctly (in an absolute
> sense) unless you do it by representing both signals the best way
> possible. This needs to be done with high end gear, in a sound dampened
> neutral room (studio).

Testing two codecs under studio conditions will tell you which codec is
better under studio conditions.  This, by itself, isn't especially
meaningful.

Now, if it's the case that with audio gear that if you can't hear
defects in expensive equipment then you won't hear it with cheap
equipment, then the results gotten from testing under studio conditions
can be applied to Joe Blow at home.  Otherwise, truthfully, who cares.
I have pretty good gear at home, but it's crap compared to what you'll
find in a studio.

Let's suppose we're testing composite versus S-video.  We take our
composite video cable and plug it into a $5k Sony Wega XBR and note the
results.  Then we plug S-video in and note the results.  We see that the
composite video and S-video looks roughly the same.  We conclude that
S-video does not offer significant advantages over composite video.

But this conclusion is wrong, because when we repeat this test on a $2k
RCA 52" rear projection, we see appreciable improvement in the S-video
input.  The test was fundamentally broken, because the $5k Sony has a
vastly superior comb filter to the RCA.  And we're not comparing the XBR
against a cheap 20" Walmart special either.  The quality of the
equipment makes every difference, but the conclusions drawn from the
high quality equipment will not necessary be the same (or even more
supportable) by low quality equipment.  In fact they may be opposite.

So, whichever codec wins out in the studio setting testing doesn't
necessarily mean that's the one that will win on a pair of tin cans, or
even a $500 or $2000 system.  You have to test in all sorts of
environments to get anything meaningful.  If codec A beats out codec B
in every tested environment, well that's a lot more convincing to me
than testing in a $100k studio room.

Cheers,
Jason.