Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!uunet!mcsun!sunic!draken!d88-jwa From: d88-jwa@nada.kth.se (Jon W{tte) Newsgroups: comp.dsp,alt.conspiracy Subject: Re: My pitch shifter for 56000 Message-ID: <1786@draken.nada.kth.se> Date: 26 Sep 89 21:07:06 GMT References: <5334@merlin.usc.edu> <1989Sep25.172140.27543@sun.soe.clarkson.edu> Reply-To: d88-jwa@nada.kth.se (Jon W{tte) Organization: Royal Institute of Technology, Stockholm, Sweden Lines: 30 In article <1989Sep25.172140.27543@sun.soe.clarkson.edu> dean@image.soe.clarkson.edu (Dean Swan) writes: > Assume that your input is of the form: > Y=Sin( F*A ) > Then F = ArcSin(Y)/A > Next do F=F+pitch shift amount ^^^ That should be a * ! a * ! a * ! > and reconstruct with Y=Sin(F*A). How many times will I have to read this ? Pitch shift isn't about "adding 100 Hz", it's about scaling a spectra. Are you people conspiring against me just to drive me mad ? (note the crosspost) The problem is; input is sum i from 1 to n sin ( Fi * t + Pi ) for some unknown (often large) n, unknown F and unknown P... You could not possibly solve that equation fast enough. Someone mentioned a 1024-point FFT with a sliding window. That just might be the solution ? But the 5600{0,1} does a 1024-point FFT in 3.3 ms which is 100 times too slow for any kind of HiFi quality. (ONE channel only !) h+@nada.kth.se -- Another good night not to sleep in a eucalyptus tree.