[vorbis-dev] -b flag at low sample rates?

[Geoff Shang]

On Thu, 10 Jan 2002, Mike Shapiro wrote:

> As the subject implies, my question is: is it possible to use the -b (or
> -M) flag at non-44K sample rates?

No.  As Stan said, this will be available in RC4.

> I'm working with an application that is trying to optimize for very small
> audio filesize.  I found that downsampling to 11K and then using q0 gives
> high compression, but won't seem to drop below 64kbps or so.

You sure you're down-sampling properly?  I tested -q0 on the same song for
both mono and stereo for 11.025khz, 16khz, 22.05khz, 32khz and 44.1khz.  I
can produce my results if people are interested.  For 11.025khz mono I got
18.4kbps and for stereo I got 35.5kbps.  Interestingly, these figures are
higher than for RC2 (using -b1), particularly for 11.025khz stereo which is
about 8kbps higher.

For down-sampling I used

ox private-universe.wav -r 11025 [-c 1] -t wav - resample |oggenc -q 0 -o
output.ogg -

Geoff.

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