Alex Robinson <alex_python_...@tranzoa.com> added the comment:
Oh golly. I was confused. For some reason I was thinking
"writesamples()" when using "writeframes()".
So the current code reads ok. Which makes this "bug" a request for
writesamples() and readsamples() to be added to wave.py. They would
shield sleep deprived saps from the .wav file data frame format. :)
Here are python2.4-ish versions written for outside wave.py. Combos of 8
and 16 bit samples, mone and stereo, are tested. I did not test the
32-bit sample logic.
Sample values are expected to be +-32767 or +-128 ints (or +-2.x gig if
32-bit).
def readsamples(wf, nframes) :
""" Read an array of number-of-channels normalized int sample
arrays. """
wav = wf.readframes(nframes)
if wf.getsampwidth() == 4 :
wav = struct.unpack("<%ul" % (len(wav) / 4), wav)
elif wf.getsampwidth() == 2 :
wav = struct.unpack("<%uh" % (len(wav) / 2), wav)
else :
wav = struct.unpack("%uB" % len(wav), wav)
wav = [ s - 128 for s in wav ]
nc = wf.getnchannels()
if nc > 1 :
wavs = []
for i in xrange(nc) :
wavs.append([ wav[si] for si in xrange(0, len(wav), nc) ])
pass
else :
wavs = [ wav ]
return(wavs)
def writesamples(wf, wavs) :
"""
Write samples to the wave file.
'wavs' looks like this:
[ left_channel_samples, right_channel_samples ]
or [ left_channel_samples ]
or mono_samples
This routine calls setnchannels() from information about 'wavs'
length.
"""
if wavs :
if len(wavs) not in [ 1, 2, 4 ] :
wavs = [ wavs, wv ]
wf.setnchannels(len(wavs))
if len(wavs) > 1 :
wav = []
for w in zip(*wavs):
wav += w
pass
else :
wav = wavs[0]
if wf.getsampwidth() == 4 :
ws = array.array('l', [ s for s in wav ])
elif wf.getsampwidth() == 2 :
ws = array.array('h', [ s for s in wav ])
else :
ws = array.array('B', [ s + 128 for s in wav ])
ws = ws.tostring()
wf.writeframes(ws)
pass
# end of code to edit and insert in wave.py
----------
type: behavior -> feature request
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Python tracker <rep...@bugs.python.org>
<http://bugs.python.org/issue4913>
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