def echocancel(outputdata, inputdata):
pos = audioop.findmax(outputdata, 800) # one tenth second
out_test = outputdata[pos * 2:]
in_test = inputdata[pos * 2:]
ipos, factor = audioop.findfit(in_test, out_test)
prefill = '\0' * (pos + ipos) * 2
postfill = '\0' * (len(inputdata) - len(prefill) - len(outputdata))
outputdata = prefill + audioop.mul(outputdata, 2 - factor) + postfill
return audioop.add(inputdata, outputdata, 2)
def echocancel(outputdata, inputdata):
pos = audioop.findmax(outputdata, 800) # one tenth second
out_test = outputdata[pos*2:]
in_test = inputdata[pos*2:]
ipos, factor = audioop.findfit(in_test,out_test)
prefill = '\0'*(pos+ipos)*2
postfill = '\0'*(len(inputdata)-len(prefill)-len(outputdata))
outputdata = prefill + audioop.mul(outputdata,2-factor) + postfill
return audioop.add(inputdata, outputdata,2)
def echocancel(outputdata, inputdata):
"""Try to identify an echo and remove it.
Should contain 2-byte samples"""
pos = audioop.findmax(outputdata, 800)
out_test = outputdata[pos*2:]
in_test = inputdata[pos*2:]
ipos, factor = audioop.findfit(in_test, out_test)
factor = audioop.findfactor(in_test[ipos*2:ipos*2+len(out_test)], out_test)
prefill = '\0'*(pos+ipos)*2
postfill = '\0'*(len(inputdata) - len(prefill) - len(outputdata))
outputdata = prefill + audioop.mul(outputdata, 2, -factor) + postfill
return audioop.add(inputdata, outputdata, 2)
def findfit(scratch_frag, final_frag, sound_file):
'''Calculates the offset (in seconds) between scratch_frag & final_frag.
Both fragments are assumed to contain the same, loud "clapper" event.
The SoundFile object is used for common stream parameters.'''
import audioop
nchannels = sound_file.stream.getnchannels()
framerate = sound_file.stream.getframerate()
width = sound_file.stream.getsampwidth()
assert(width==2)
# Simplify the sound streams to make it quicker to find a match.
# Left channel only.
if nchannels > 1:
scratch_frag_ = audioop.tomono(scratch_frag, width, 1, 0)
final_frag_ = audioop.tomono(final_frag, width, 1, 0)
else:
scratch_frag_ = scratch_frag
final_frag_ = final_frag
nchannels_ = 1
# Downsample to 8000/sec
framerate_ = 8000
scratch_frag_,state =\
audioop.ratecv(scratch_frag_, width, nchannels_, framerate, framerate_, None)
final_frag_,state =\
audioop.ratecv(final_frag_, width, nchannels_, framerate, framerate_, None)
bytes_per_second_ = nchannels_ * framerate_ * width
# Find the clapper in final
length_samples = int(0.001 * framerate * nchannels_) # 0.1 sec
final_off_samples = audioop.findmax(final_frag_, length_samples)
# Search for a 2 second 'needle' centred on where we found the 'clapper'
needle_bytes = 2 * bytes_per_second_
b0 = max(0, final_off_samples * width - int(needle_bytes/2))
print '"clapper" at final:', 1.0*b0/bytes_per_second_, 'sec'
b1 = b0 + needle_bytes
final_clapper_frag = final_frag_[b0:b1]
scratch_off_samples,factor = audioop.findfit(scratch_frag_, final_clapper_frag)
scratch_off_bytes = scratch_off_samples * width
print 'match at scratch:', 1.0*scratch_off_bytes/bytes_per_second_, 'sec', " factor =",factor
# Calculate the offset (shift) between the two fragments.
shift_sec = (scratch_off_bytes - b0) * 1.0 / bytes_per_second_
print 'shift =', shift_sec, 'seconds'
return shift_sec
def _find_maxes(data, duration, start, stop, num):
global COUNT
return_list = []
if stop - start < duration:
return return_list
try:
m = audioop.findmax(data[start:stop], duration)
except audioop.error:
print('got an error with data: {} {}'.format(start, stop))
return return_list
COUNT += 1
return_list.append(m)
if COUNT < num:
return_list.extend(_find_maxes(data, duration, start, m * 2, num))
return_list.extend(
_find_maxes(data, duration, (m + duration) * 2, stop, num))
return return_list
def test_findmax(self):
self.assertEqual(audioop.findmax(datas[2], 1), 5)
self.assertEqual(audioop.findmax(bytearray(datas[2]), 1), 5)
self.assertEqual(audioop.findmax(memoryview(datas[2]), 1), 5)
def test_findmax(self):
self.assertEqual(audioop.findmax(data[1], 1), 2)
def test_findmax(self):
self.assertEqual(audioop.findmax(data[1], 1), 2)
def testfindmax(data): if audioop.findmax(data[1], 1) <> 2: return 0 return 1
def testfindmax(data):
if verbose:
print 'findmax'
if audioop.findmax(data[1], 1) <> 2:
return 0
return 1
def testfindmax(data):
if verbose:
print 'findmax'
if audioop.findmax(data[1], 1) != 2:
return 0
return 1
def test_findmax(self):
self.assertEqual(audioop.findmax(datas[2], 1), 5)
self.assertEqual(audioop.findmax(bytearray(datas[2]), 1), 5)
self.assertEqual(audioop.findmax(memoryview(datas[2]), 1), 5)
