[Vorbis] Bitrate Peeling (no. really)

[Geoff Shang]

Monty wrote:

> There is more than one way to appraoch the problem.
>
> One approach seeks to implement a peeler that will work on any stream.
> I think this approach is perfectly possible.  However...
>
> Approach B relies on the encoder pre-structuring a stream to be easy
> to peel.  I think this approach is simpler/faster to implement in the
> decoder/splitter, and will result in higher final quality.  It will
> require a more complex encoder.

Ok, so we've got higher quality that only works with new streams on one 
side, and lower quality that works on existing streams on the other. 
Ideally of course, we'd have both, so that people wanting to peel legacy 
streams could do so whilst those with newer streams could benefit from the 
increased quality.

Personally, I'm leaning towards option B.   I know it will probably take 
longer, needing encoder changes, but it'll be higher quality and I'm 
inclined to think that if you're going to do a job, you may as well do it 
properly.  but I don't have a big collection of Vorbis files and I don't 
yet have a portable capable of playing them, so I guess I'm biased.

Since this is mentioned in the bounty, let me ask this then.  If we were to 
go with strategy B above, would it be possible in theory to be able to 
convert existing files to the new format without having to reencode, or 
would it be so radically different as to make this impossible/impractical? 
I think that if a transcode were possible, option B would look a lot more 
appealing to those with existing collections.

Geoff.