ref: 6639eb1c46a01cc3b58845cd8f951424b1e79ff3
parent: e4c2169d143635b6f8a3079a5333d9ba809d393b
author: Paul Brossier <[email protected]>
date: Fri Jul 27 08:08:48 EDT 2012
demo_onset_sinusoid.py: added some onset examples
--- /dev/null
+++ b/interfaces/python/demo_onset_sinusoid.py
@@ -1,0 +1,84 @@
+#! /usr/bin/python
+
+from numpy import random, sin, arange, ones, zeros
+from math import pi
+from aubio import fvec, onset
+
+def build_sinusoid(length, freqs, samplerate):
+ return sin( 2. * pi * arange(length) * freqs / samplerate)
+
+def run_onset(p, input_vec):
+ f = fvec (p.hop_size)
+ cands = []
+ count = 0
+ for vec_slice in input_vec.reshape((-1, p.hop_size)):
+ f[:] = vec_slice
+ cands.append(o(f))
+ return cands
+
+methods = ['default',
+ 'energy',
+ 'complex',
+ 'phase',
+ 'specdiff',
+ 'kl',
+ 'mkl',
+ 'specflux',
+ 'centroid',
+ 'spread',
+ 'skewness',
+ 'kurtosis',
+ 'slope',
+ 'decrease',
+ 'rolloff',
+ ]
+
+cands = {}+buf_size = 2048
+hop_size = 512
+samplerate = 44100
+sin_length = (samplerate * 10) % 512 * 512
+freqs = zeros(sin_length)
+
+partition = sin_length / 8
+pointer = 0
+
+pointer += partition
+freqs[pointer: pointer + partition] = 440
+
+pointer += partition
+pointer += partition
+freqs[ pointer : pointer + partition ] = 740
+
+pointer += partition
+freqs[ pointer : pointer + partition ] = 1480
+
+pointer += partition
+pointer += partition
+freqs[ pointer : pointer + partition ] = 400 + 5 * random.random(sin_length/8)
+
+a = build_sinusoid(sin_length, freqs, samplerate)
+
+for method in methods:
+ o = onset(method, buf_size, hop_size, samplerate)
+ cands[method] = run_onset(o, a)
+
+print "done computing"
+
+if 1:
+ from pylab import plot, show, xlabel, ylabel, legend, ylim, subplot
+ subplot (211)
+ legend(methods+['ground truth'], 'upper right')
+ xlabel('time (s)')+ ylabel('amplitude')+ ramp = arange(0, sin_length).astype('float') / samplerate+ plot(ramp, a, ':')
+ subplot (212)
+ ramp = arange(0, sin_length / hop_size).astype('float') * hop_size / samplerate+ for method in methods:
+ plot(ramp, cands[method],'.-')
+ legend(methods, 'upper right')
+ xlabel('time (s)')+ ylabel('spectral descriptor value')+ show()
+