PV_ConformalMap complex plane attack 


PV_ConformalMap(buffer, real, imag)


Applies the conformal mapping z -> (z-a)/(1-za*) to the phase vocoder bins z with a given by the real and imag inputs to the UGen.


ie, makes a transformation of the complex plane so the output is full of phase vocoder artifacts but may be musically fun. Usually keep |a|<1 but you can of course try bigger values to make it really noisy. a=0 should give back the input mostly unperturbed.


See http://mathworld.wolfram.com/ConformalMapping.html


buffer - buffer number of buffer to act on, passed in through a chain (see examples below).

real - real part of a. 

imag - imaginary part of a.


See also FFT Overview.


//explore the effect

(

SynthDef("conformer1", {

var in, chain;

in = AudioIn.ar(1,0.5);

chain = FFT(0, in);

chain=PV_ConformalMap(chain, MouseX.kr(-1.0,1.0), MouseY.kr(-1.0,1.0));

Out.ar(0, Pan2.ar(IFFT(chain),0));

}).load(s);

)


s.sendMsg("/b_alloc", 0, 1024, 1);

s.sendMsg("/s_new", "conformer1", 2002, 1, 0);

s.sendMsg("/n_free", 2002);




(

SynthDef("conformer2", {

var in, chain, out;

in = Mix(LFSaw.ar(SinOsc.kr(Array.rand(3,0.1,0.5),0,10,[1,1.1,1.5,1.78,2.45,6.7]*220),0,0.3));

chain = FFT(0, in);

chain=PV_ConformalMap(chain, MouseX.kr(0.01,2.0, 'exponential'), MouseY.kr(0.01,10.0, 'exponential'));

out=IFFT(chain);

Out.ar(0, Pan2.ar(CombN.ar(out,0.1,0.1,10,0.5,out),0));

}).load(s);

)



s.sendMsg("/b_alloc", 0, 2048, 1);

s.sendMsg("/s_new", "conformer2", 2002, 1, 0);

s.sendMsg("/n_free", 2002);

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