C++ Constant-Q

h1. Synthetic test material

h2. Sinusoid at fs/4

In Yeti terms:

<pre>

testStream = manipulate.withDuration 64 (syn.sinusoid 8 2);

cq = cqt { maxFreq = testStream.sampleRate/2, minFreq = 1, binsPerOctave = 4 } testStream;

</pre>

Or to put it another way (in MATLAB this time):

<pre>

test = [0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1,0,1,0,-1 ];

out = cqt(test,1,4,4,8)

</pre>

That is, a 64-sample input of 8Hz sample rate containing a sinusoid at fs/4, transformed using CQ parameters fmin = 1, fmax = 4 (or fs/2), and bpo = 4.

h3. Data from MATLAB implementation

<pre>

actual fmin = 1.1892

octaves = 2

weight = 16.3452

drop = 3

kernel size = 32x20

output size = 8x59

</pre>