ref: 89fd1e51ade2960fddfd27406353f80c4e519c3e
parent: d3b1eb196325b80ad269ca74456b8f08d1ea4f27
author: Paul Brossier <piem@piem.org>
date: Fri Jul 27 05:28:31 EDT 2012
demo_spectrogram.py: added simple spectrogram demo
--- /dev/null
+++ b/interfaces/python/demo_spectrogram.py
@@ -1,0 +1,41 @@
+#! /usr/bin/python
+
+import sys
+from aubio import pvoc, source
+from numpy import array, arange, zeros, shape, log10, vstack
+from pylab import imshow, show, gray, autumn, axis, ylabel, xlabel, xticks, yticks
+
+def get_spectrogram(filename):
+ win_s = 512 # fft size
+ hop_s = win_s / 2 # hop size
+ fft_s = win_s / 2 + 1 # number of spectrum bins
+ samplerate = 16000
+ specgram = zeros([0, fft_s], dtype='float32')
+ a = source(filename, samplerate, hop_s) # mono 8kHz only please
+ pv = pvoc(win_s, hop_s) # phase vocoder
+ while True:
+ samples, read = a() # read file
+ #specgram = vstack((specgram,1.-log10(1.+pv(samples).norm))) # store new norm vector
+ specgram = vstack((specgram,pv(samples).norm)) # store new norm vector
+ if read < a.hop_size: break
+
+ autumn()
+ from pylab import gray
+ gray()
+ imshow(specgram.T, origin = 'bottom', aspect = 'auto')
+ axis([0, len(specgram), 0, len(specgram[0])])
+ ylabel('Frequency (Hz)')+ xlabel('Time (s)')+ time_step = hop_s / float(samplerate)
+ total_time = len(specgram) * time_step
+ ticks = 10
+ xticks( arange(ticks) / float(ticks) * len(specgram),
+ [x * total_time / float(ticks) for x in range(ticks) ] )
+ yticks( arange(ticks) / float(ticks) * len(specgram[0]),
+ [x * samplerate / 2. / float(ticks) for x in range(ticks) ] )
+ show()
+
+if len(sys.argv) < 2:
+ print "Usage: %s <filename>" % sys.argv[0]
+else:
+ [get_spectrogram(soundfile) for soundfile in sys.argv[1:]]