[Vorbis] What the difference between oggenc &

[Andrew Snare]

On Fri, Nov 17, 2006 at 09:24:43AM -0600, Chris Harrington (Personal) wrote:
> Considering that it they are considering merging the aoTuV tunings into 
> the main encoder, I'd wager that the default encoder is somehow inferior 
> to the aoTuV tuned encoder. Also, considering how out of date GT3 is, 
> I'd wager it is inferior to both.
> 
> I use aoTuV at q6 for virtually all of my "mid-fi" music, and aoTuV q0 
> for all of my "portable-fi" music.

Traditionally with ogg, and contrary to many other compression
schemes with a 'numbered' compression level[1], the -q flags are
intended to specify the level of quality you expect at playback.

Now although I'm not aware of clear benchmarks in this area to
ensure consistency, wouldn't this mean that the 'tunings' to the
ogg encoders should not significantly affect the quality of playback,
but rather result in higher data compression for the same perceptual
quality?

This leads me to wonder:
a) Is the reference encoder maintaining the -qX 'playback quality' across
releases?
b) Do the various 'tuned' releases try to honour that scale?

The reason I wonder this is because I can understand (and laud) the
choices of -q6 for 'mid-fi' and -q0 for 'portable-fi', but wonder
if it matters whether the reference or aoTuV encoder is used from
a quality perspective. I understand the aoTuV-encoded versions may
be smaller and/or quicker to encode, but that's not what was implied
by the original post.

Cheers,

 - Andrew
[1] I'm thinking: compress, gzip, zip, bzip2, flac, for example.