oh, and the thing about the FFTease object is that it always fits the partials into a fixed scale. I mean the frequencies are always the same, and the scale isn't transposed according to a continuous fundamental. Maybe it's because it's using and dealing with the fixed bins in the FFT... not sure. Now I'm trying to do that according to the fundamental in a more loose and free way.
2013/11/26 Alexandre Torres Porres <por...@gmail.com> > well, let me tell you how I did it, I can send some of my last work, but, > as usual, needs some cleaning up and documenting. > > But basically I'm using [sigmund~], then getting "tracks" output to use > all the partial information to feed an oscillator bank for resynthesis. > This is pretty much what you can call a phase vocoder, hence you can tweak > with it and mess around with partials. > > I also have a patch where you can control the partials individually and > very arbitrarily. > > So, for spectral mapping, what I do is I try to map all the harmonic > relationship from partials and "detune" them according to a different > "harmonic series". > > It's a lot of work getting all of the data mapped and in order, then apply > the math and stuff. It's also tricky because you need the right tuning of > [sigmund~] to get better results according to the kind of musical audio > signal that is coming through... > > Anyway, anyone got a better idea than that? > > I think that if you use FFT you will go crazy trying yo get this right, > and I assume that [sigmund~] does work in the best way for this and it is > based on FFT anywy (Am I right?). > > Cheers > > > 2013/11/26 peiman khosravi <peimankhosr...@gmail.com> > >> Hello, >> >> Yes, your description of warp is correct. >> >> Partial detection is more tricky because often the energy in 4 or more >> FFT bins amounts to one partial. So firstly, you need to derive the >> partials from the FFT data, then you need to quantise the partials' >> frequencies. >> >> One possible cheat would be to trace the loudest FFT-bins and then >> transfer their energy to the bins whose frequencies are nearest to the >> harmonics of a given fundamental. >> >> If I'm not mistaken, at a sampling rate of 44100 and an FFT size of 4096, >> the frequency of bin 10 would be calculated as (44100/4096)*10=107.66. Just >> note that only FFT-size/2+1 bins are usable. That's the Nyquist frequency >> (half of the sampling frequency). If you take 107.66 as your fundamental >> (and zero all the bins below that) then you can do the following: >> >> For each analysis window... >> 1- Detect the next FFT bin whose magnitude is above a certain threshold >> 2- Transfer the frequency and amplitude content of this bin to the >> nearest harmonic of the fundamental. So for input bin 15 (and a fundamental >> frequency of 107.66) this would be bin 20. The bin number to frequency >> mapping is linear so it's easy to calculate. >> >> Even, using fiddle~, you can get the fundamental frequency from the input >> and have it change dynamically from window to window. >> >> You're likely to get some bubbly artefacts thought, but once you have a >> basic working patch you should be able to fine tune it. So you may want to >> group the bins so that you transfer not just the energy in one bin but also >> the bins around it. You might also want to do some averaging of the >> amplitude of 6 windows or so to avoid rapidly changing values, before you >> pass the signal into a threshold detector. I can do this in Csound but I'm >> not that familiar with how FFT works in PD and I don't have a patch that >> does this. If I get the time I might make one next weekend though and post >> it here. >> >> P >> >> >> >> >> *www.peimankhosravi.co.uk <http://www.peimankhosravi.co.uk> || RSS Feed >> <http://peimankhosravi.co.uk/miscposts.rss> || Concert News >> <http://spectralkimia.wordpress.com/>* >> >> >> On 26 November 2013 11:48, Eran Sachs <eransa...@hotmail.com> wrote: >> >>> Peiman, >>> It works great! I've been messing various sounds all day now, plus >>> there's a thing in my computer with Barry Vercoe's name on it which I find >>> oddly elevating. >>> However, if I understand the wrap function correctly, it substitutes bin >>> values for values of other bins through whatever function you apply. But >>> the bins are still all derived from the FFT procedure. Or am I missing >>> something there? >>> >>> What I would like to do is to move from bins to partials, so that they >>> are essentially mapped to harmonic overtones of a given fundamental >>> according to nearest match. Like a clever phase-vocoder Autotune of some >>> kind. >>> >>> Is there a way to do that, to the best of anyone's knowledge? >>> >>> Much obliged, >>> E. >>> ------------------------------ >>> Date: Mon, 25 Nov 2013 15:12:50 +0000 >>> >>> Subject: Re: [PD] spectral mapping, anyone? >>> From: peimankhosr...@gmail.com >>> To: eransa...@hotmail.com >>> CC: por...@gmail.com; jaime.oliv...@gmail.com; pd-list@iem.at >>> >>> yes csound6 should work on windows too as far as I know. >>> >>> >>> >>> >>> *www.peimankhosravi.co.uk <http://www.peimankhosravi.co.uk> || RSS Feed >>> <http://peimankhosravi.co.uk/miscposts.rss> || Concert News >>> <http://spectralkimia.wordpress.com/>* >>> >>> >>> On 24 November 2013 22:06, Eran Sachs <eransa...@hotmail.com> wrote: >>> >>> Thanks Peiman. >>> Alas, I'm living the life of a PC/Windows user. AFAICT, no csound6? >>> Z >>> >>> ------------------------------ >>> Date: Sun, 24 Nov 2013 20:27:39 +0000 >>> >>> Subject: Re: [PD] spectral mapping, anyone? >>> From: peimankhosr...@gmail.com >>> To: eransa...@hotmail.com >>> CC: por...@gmail.com; jaime.oliv...@gmail.com; pd-list@iem.at >>> >>> >>> With spectral warping you can do any frequency-based manipulation, >>> depending on the transfer function. I have one for pd but it requires >>> Csound to be installed and a couple of other externals. See attached. On an >>> intel mac and with pd vanilla 4.5.3/4 this should just work out of the box >>> as long as you have csound 6 installed. >>> >>> P >>> >>> >>> >>> >>> >>> >>> *www.peimankhosravi.co.uk <http://www.peimankhosravi.co.uk> || RSS Feed >>> <http://peimankhosravi.co.uk/miscposts.rss> || Concert News >>> <http://spectralkimia.wordpress.com/>* >>> >>> >>> On 24 November 2013 20:12, Eran Sachs <eransa...@hotmail.com> wrote: >>> >>> oops, I messed up the names. sorry. Once more, with feeling: >>> >>> Josep, >>> Making harmonic sounds sound inharmonic can be down with spectral >>> shifting. Try looking at Hilbert~ or at spec2_shift~ on extended. >>> >>> But Alexandre, I'd also would be interested in stuff that can manipulate >>> the spectrum. >>> I also made a little graphic control to all the cross-synthesis objects >>> in FFTease. if anyone is interested I can post. >>> >>> A few years ago I tried to replicate the technique that Trevor Wishart >>> refers to as "Spectral Focusing", namely - one that moves the other way - >>> from inharmonic to harmonic sonds, by moving from bins to partials (a >>> little like FFTease's pvtune~, but moving bins to nearest matching >>> partial). >>> >>> I'm still looking for such an object. Does anyone have any suggestions? >>> >>> Zax. >>> >>> ------------------------------ >>> From: eransa...@hotmail.com >>> To: por...@gmail.com; jaime.oliv...@gmail.com >>> Date: Sun, 24 Nov 2013 21:58:50 +0200 >>> >>> CC: pd-list@iem.at >>> Subject: Re: [PD] spectral mapping, anyone? >>> >>> Alexandre, >>> Making harmonic sounds sound inharmonic can be down with spectral >>> shifting. Try looking at Hilbert~ or at spec2_shift~ on extended. >>> >>> But Jaime, I'd also would be interested in that. >>> A few years ago I tried to replicate the technique that Trevor Wishart >>> refers to as "Spectral Focusing", namely - one that moves the other way - >>> from inharmonic to harmonic sonds, by moving from bins to partials (a >>> little like FFTease's pvtune~, but moving bins to nearest matching >>> partial). >>> >>> I'm still looking for such an object. Does anyone have any suggestions? >>> >>> Zax. >>> >>> >>> ------------------------------ >>> Date: Sun, 24 Nov 2013 01:05:29 -0200 >>> From: por...@gmail.com >>> To: jaime.oliv...@gmail.com >>> CC: pd-list@iem.at >>> Subject: Re: [PD] spectral mapping, anyone? >>> >>> Hi, I'm Alexandre, I can send you stuff >>> >>> cheers >>> >>> >>> 2013/11/11 Jaime E Oliver <jaime.oliv...@gmail.com> >>> >>> These are older, but I understand E. Lyon might re-release them? >>> >>> http://www.somasa.qub.ac.uk/~elyon/LyonSoftware/MaxMSP/FFTease/ >>> >>> J >>> >>> >>> >>> On Nov 11, 2013, at 7:23 AM, Jeppi Jeppi <jepp...@hotmail.com> wrote: >>> >>> Hi, >>> just looking for some ready to be used spectral mapping effects >>> implemented in pd, anything available? >>> Specifically, just a way to slightly remap harmonics to make pitched >>> sounds inharmonic. >>> There is a paper by Alexandre >>> http://www.uni-weimar.de/medien/wiki/images/Dissonance_Model_Toolbox_in_Pure_Data.pdf >>> but >>> I couldn't find the link to the sources. >>> >>> >>> Many thanks in advance! >>> Josep m >>> >>> _______________________________________________ >>> Pd-list@iem.at mailing list >>> UNSUBSCRIBE and account-management -> >>> http://lists.puredata.info/listinfo/pd-list >>> >>> >>> >>> _______________________________________________ >>> Pd-list@iem.at mailing list >>> UNSUBSCRIBE and account-management -> >>> http://lists.puredata.info/listinfo/pd-list >>> >>> >>> >>> _______________________________________________ Pd-list@iem.at mailing >>> list UNSUBSCRIBE and account-management -> >>> http://lists.puredata.info/listinfo/pd-list >>> >>> _______________________________________________ Pd-list@iem.at mailing >>> list UNSUBSCRIBE and account-management -> >>> http://lists.puredata.info/listinfo/pd-list >>> >>> _______________________________________________ >>> Pd-list@iem.at mailing list >>> UNSUBSCRIBE and account-management -> >>> http://lists.puredata.info/listinfo/pd-list >>> >>> >>> >>> >> >
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