[vorbis] just an idea about quality evaluation

[Tony Rielly]

See 

http://www.hydrogenaudio.org/index.php?act=ST&f=1&t=3314&hl=invert,and,q
uality&s=419608f687d5452e48fe4c330432c565

for why this is a terrible idea.

<p><p>-----Original Message-----
From: owner-vorbis at xiph.org [mailto:owner-vorbis at xiph.org] On Behalf Of
Stoffke
Sent: 24 January 2003 16:16
To: vorbis at xiph.org
Subject: [vorbis] just an idea about quality evaluation

<p>Hello 

I had an idea about judging the quality of ogg vorbis 
(or any other lossy codec)

I took a wave-file and encoded it to ogg.
Then decoded ogg to wav and inverted it's phase. When mixing the
original
wav with the phase-inverted decoded ogg-file, any identic parts of
compressed and uncompressed audio should be eliminated. 
Of course there's always a "rest" of sound because the encoder is not
lossless.
Could this "rest" be an indicator for the quality of the encoder ?

I know that evaluating the quality of a perceptual encoder with any
technical equipment is nearly impossible and it would be better to let
the  ear do this.
But I'd like to know what you think about this idea .

Greetings
Stoffke

<p>--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.

<p>--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.