def read_spectrogram (exponent = 10, wavname = 'test.wav'):
"""
read a sound file, say a wav file;
compute a spectrogram or reassigned spectrogram;
write image to png file
"""
width = 1 << exponent
height = width
size = height * width
print "reading sound file"
sound = formats.read_wav(wavname, size, width)
image = K.Reals(height, width/2)
print "transforming data"
s = K.Spectrogram(exponent)
for i in range(height):
s.transform_fwd(sound[i,:],image[i,:])
print "saving image"
image = formats.energy_to_loudness(image)
formats.write_image(image, 'test.png')
def record_spectrogram(exponent=10):
width = 1 << exponent
height = width
size = height * width
sound = K.Complexes(width)
image = K.Reals(height, width / 2)
s = K.Spectrogram(exponent)
a = K.Audio(width)
time = size * a.rate / 60.0
print "recording & transforming sound for %g seconds..." % time
a.start()
for i in range(height):
a.read(sound)
s.transform_fwd(sound, image[i, :])
a.write(sound) # HACK
a.stop()
print "saving image"
image = formats.energy_to_loudness(image)
formats.write_image(image, "test.png")
