ref: bef979aa867d5d6189ba72f864d534db45fcc2ad
dir: /python/demos/demo_pitch_sinusoid.py/
#! /usr/bin/env python
from numpy import random, sin, arange, ones, zeros
from math import pi
from aubio import fvec, pitch
def build_sinusoid(length, freqs, samplerate):
return sin( 2. * pi * arange(length) * freqs / samplerate)
def run_pitch(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(p(f))
return cands
methods = ['default', 'schmitt', 'fcomb', 'mcomb', 'yin', 'yinfft']
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:
p = pitch(method, buf_size, hop_size, samplerate)
cands[method] = run_pitch(p, a)
print "done computing"
if 1:
from pylab import plot, show, xlabel, ylabel, legend, ylim
ramp = arange(0, sin_length / hop_size).astype('float') * hop_size / samplerate
for method in methods:
plot(ramp, cands[method],'.-')
# plot ground truth
ramp = arange(0, sin_length).astype('float') / samplerate
plot(ramp, freqs, ':')
legend(methods+['ground truth'], 'upper right')
xlabel('time (s)')
ylabel('frequency (Hz)')
ylim([0,2000])
show()