Convolution2L : UGen : AbstractFunction : Object

Description

Strict convolution with fixed kernel which can be updated using a trigger signal. There is a linear crossfade between the buffers upon change.

See Steven W Smith, The Scientist and Engineer's Guide to Digital Signal Processing: chapter 18 - http://www.dspguide.com/ch18.htm

Class Methods

Convolution2L.ar(in, kernel, trigger: 0, framesize: 2048, crossfade: 1, mul: 1.0, add: 0.0)

Inherited class methods

Instance Methods

Inherited instance methods

Examples

( SynthDef(\conv_test, { |out, kernel, t_trig=0| var input = Impulse.ar(1); var framesize = 2048; // must have power of two var result = Convolution2L.ar(input, kernel, t_trig, framesize, 1, 0.5); Out.ar(out, result); }).add ) x = Synth(\conv_test, [\kernel, b]); // changing the buffer number: x.set(\kernel, c); x.set(\t_trig, 1); // after this trigger, the change will take effect. x.set(\kernel, d); x.set(\t_trig, 1); // after this trigger, the change will take effect. d.zero; 40.do { |it| d.set(20 * it + 10, 1) };// changing the buffers' contents x.set(\t_trig, 1); // after this trigger, the change will take effect. x.set(\kernel, b); x.set(\t_trig, 1); // after this trigger, the change will take effect. x.free; // longer crossfade ( SynthDef(\conv_test2, { |out, kernel, t_trig=0| var input = Impulse.ar(1); var framesize = 2048; // must have power of two var result = Convolution2L.ar(input, kernel, t_trig, 2048, 5, 0.5); Out.ar(out, result); }).add ) x = Synth(\conv_test2, [\kernel, b]); // changing the buffer number: x.set(\kernel, c); x.set(\t_trig, 1); // after this trigger, the change will take effect. x.set(\kernel, d); x.set(\t_trig, 1); // after this trigger, the change will take effect. d.zero; 40.do { |it| d.set(20 * it + 10, 1) };// changing the buffers' contents x.set(\t_trig, 1); // after this trigger, the change will take effect. x.set(\kernel, b); x.set(\t_trig, 1); // after this trigger, the change will take effect. x.free; // next example b = Buffer.read(s, Platform.resourceDir +/+ "sounds/a11wlk01.wav"); ( { var input = SoundIn.ar(0); var framesize = 2048; // must have power of two Convolution2L.ar(input, b, 0, 512, 1, 0.5); }.play ) // another example ( // must have power of two framesize- FFT size will be sorted by Convolution2 to be double this // maximum is currently a=8192 for FFT of size 16384 a = 2048; // kernel buffer g = Buffer.alloc(s, a, 1); ) ( g.set(0, 1.0); 100.do { |i| g.set(a.rand, (i + 1).reciprocal) }; ) ( // random impulse response { var input, inputAmp, threshhold, gate; input = SoundIn.ar(0); inputAmp = Amplitude.kr(input); threshhold = 0.02; // noise gating threshold gate = Lag.kr(inputAmp > threshhold, 0.01); Convolution2L.ar(input * gate, g, 0, a, 1, 0.5); }.play ) g.free; // one last example ( b = Buffer.alloc(s, 512, 1); b.sine1(1.0/[1, 2, 3, 4, 5, 6], true, true, true); ) ( { var input = SoundIn.ar(0); var framesize = 512; Convolution2L.ar(input, b, 0, framesize, 1, 0.5); }.play ) b.free;