[vorbis] One important thing

[Monty]

> Anyway, the problem is that all audio encoders out there add a small amount
> of silence to the start/end of the encoded file. This is usually a small
> amount, around 0.03 seconds. Most of the time it goes unnoticed, BUT when
> you have tracks that flow into one another (live albums are the best
> example) you get a noticeable click. 

Vorbis adds no delay or padding to the beginning or end of a sample.  Actually,
libvorbis right now is missing a feature to make sure the end of a track is not
padded.  I just recently realized I'd missed that (it's an oversight in our
code, not in the format spec).

> I also wanted to ask how good Ogg Vorbis is in dealing with pre-echo since
> this troubles almost all encoders, except AAC (Liquid Audio) which does an
> excellent job in eliminating pre-echo. I know that it is early to ask this
> question, but a general answer would be appreciated.

Right now, we just use short blocks and can set the trigger threshhold
arbitrarily low.  This will be hybridized with a partial time-domain pre-coding
stage after Vorbis 1.0.  Vorbis currently has no real preecho problems (people 
have accidentally misidentified other bogs as 'preecho').

Monty

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