[Vorbis-dev] contstant bittrate mode - block size - packet size

xiphmont at xiph.org xiphmont at xiph.org
Wed May 2 02:19:06 PDT 2007


Argh, I should proof more to avoid small but numerous technical errors...

I'm using a slightly different definition of 'frame' and 'packet' than
the mp3 spec is, so to clarify:

A 'packet' is a group of bytes in the file.  A 'frame' is a
self-contained amount of decoded audio...  Most mp3 docs just use
'frame' for both and pretend they're the same thing.

On 5/2/07, xiphmont at xiph.org <xiphmont at xiph.org> wrote:

> (the frame size is kept the same but the amount of audio it holds

s/frame size/packet size/

> sloshes around using a 'bit reservoir').  I believe the rule of thumb
> in mp3 is that you need up to nine frames to make sure you're certain

s/nine frames/nine packets

> implementing a 'bit reservoir' like in mp3, but the reservoir is not
> hidden behind constant sized frames.  However, like mp3, the reservoir

constant sized 'packets'

> to do short/long block detection.  Unlike most mp3 decoders, it is not

mp3 *en*coders

Monty


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