[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.