Convolution real-time convolver

Convolution.ar(in, kernel, framesize, mul, add)

Strict convolution of two continuously changing inputs. Also see [Convolution2] for a cheaper CPU cost alternative for the case of a fixed kernel which can be changed with a trigger message. 

//see ch18 http://www.dspguide.com/ch18.htm Steven W Smith

in - processing target

kernel - processing kernel. 

framesize- size of FFT frame, must be a power of two

(

{ var input, kernel;

input=AudioIn.ar(1);

kernel= Mix.ar(LFSaw.ar([300,500,800,1000]*MouseX.kr(1.0,2.0),0,1.0));

//must have power of two framesize

Out.ar(0,Convolution.ar(input,kernel, 1024, 0.5));

}.play;

)

(

//must have power of two framesize- FFT size will be sorted by Convolution to be double this

//maximum is currently a=8192 for FFT of size 16384

a=2048;

s = Server.local; 

//kernel buffer

g = Buffer.alloc(s,a,1);

)

(

//random impulse response

g.set(0,1.0);

100.do({arg i; g.set(a.rand, 1.0.rand)});

{ var input, kernel;

input=AudioIn.ar(1);

kernel= PlayBuf.ar(1,g.bufnum,BufRateScale.kr(g.bufnum),1,0,1);

Out.ar(0,Convolution.ar(input,kernel, 2*a, 0.5));

}.play;

)