[CM] Fw: Re: Increasing frequency without shorten runtime

Bill Schottstaedt bil@ccrma.Stanford.EDU
Fri, 18 May 2007 07:47:26 -0700

> is it possible to increase  the frequency of this voice (makeing a Donal Duck 
> pitch from a bass...    without shorten the runtime / quicken the speaking ? 
> And how can I achieve such an effect?  Is it possible to "tune" the frequence over 
> the recording (variable freq by constant speed) ?

There are 3 or 4 ways to do this, each of which has problems.  I always
try the expsrc path first -- it's a combination of sampling rate conversion
and granular synthesis.  There's another version of this called ssb-am
(very cool -- "an Idea that is mine, My Idea!").  Then there are FFT tricks
that almost never work (the phase vocoder),  or take
the age of the universe to compute (dsp.scm has a few of these).
Then, there's rubber-sound, which really does never work.

I once had a donald duck transform (back in mus10 days), but I thought
it was a joke and forgot about it -- now I don't know what I did.