[Vorbis-dev] How to specify sample sizes?

[Ralph Giles]

On Fri, May 20, 2005 at 08:22:10PM +0200, Nico Sabbi wrote:

> I want to explicitly specify the sample size, so, how can I do it?

These are generally referred to as "block sizes". They're in the vorbis 
info header if you're curious what your files are using.

They can't be easily changed; doing so involves developing new modes for 
the encoder.

> Can I set min_size == max_size?
> If so, is there any disadvantage? which ?

The idea is to use short blocks for impulsive sounds (percussion, 
instrument 'attack's and so on) and longer blocks for tonal sounds.
Longer blocks are more efficient, but cause artefacts with sharp sounds, 
so the best thing is to mix the two depending on the input audio. One 
can of course produce valid vorbis streams where both block sizes are 
the same, or where only one block size is actually used, but such 
streams will generally be lower quality per bitrate.

HTH,
 -r