[vorbis] Amplify Ogg files without decode/encode

[Mike Coleman]

Michael Smith <msmith at labyrinth.net.au> writes:
> I think it should be possible (though maybe difficult) to adjust volume
> without a full reencode. Not sure of details, though. Would need to read
> some source again.

It seems like it should be possible.  I was hoping, though, that there was
a constant stored in each frame that could be easily updated; it doesn't look
like it's that easy.

Probably you could do something like extract the floor and residue, scale them
both, and reencode, but that's so much work it's probably simpler to just
decode/reencode.

> As for your other suggestion of allowing one to ignore n samples at the 
> start/end of the stream, this exists already (and has for a long time).
> vcut is a tool which adjusts these for specific purposes - libvorbis uses
> them when decoding, of course.

I skimmed it and it looks like it only allows you to cut on (Vorbis) packet
boundaries.  I was thinking of something that would let you say "ignore the
first 53 samples in this packet" without having to reencode anything.


-- 
Mike Coleman, mkc at mathdogs.com
  http://www.mathdogs.com -- problem solving, expert software development

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