You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
554 lines
13 KiB
554 lines
13 KiB
try:
|
|
from __builtin__ import max as builtin_max
|
|
from __builtin__ import min as builtin_min
|
|
except ImportError:
|
|
from builtins import max as builtin_max
|
|
from builtins import min as builtin_min
|
|
import math
|
|
import struct
|
|
try:
|
|
from fractions import gcd
|
|
except ImportError: # Python 3.9+
|
|
from math import gcd
|
|
from ctypes import create_string_buffer
|
|
|
|
|
|
class error(Exception):
|
|
pass
|
|
|
|
|
|
def _check_size(size):
|
|
if size != 1 and size != 2 and size != 4:
|
|
raise error("Size should be 1, 2 or 4")
|
|
|
|
|
|
def _check_params(length, size):
|
|
_check_size(size)
|
|
if length % size != 0:
|
|
raise error("not a whole number of frames")
|
|
|
|
|
|
def _sample_count(cp, size):
|
|
return len(cp) / size
|
|
|
|
|
|
def _get_samples(cp, size, signed=True):
|
|
for i in range(_sample_count(cp, size)):
|
|
yield _get_sample(cp, size, i, signed)
|
|
|
|
|
|
def _struct_format(size, signed):
|
|
if size == 1:
|
|
return "b" if signed else "B"
|
|
elif size == 2:
|
|
return "h" if signed else "H"
|
|
elif size == 4:
|
|
return "i" if signed else "I"
|
|
|
|
|
|
def _get_sample(cp, size, i, signed=True):
|
|
fmt = _struct_format(size, signed)
|
|
start = i * size
|
|
end = start + size
|
|
return struct.unpack_from(fmt, buffer(cp)[start:end])[0]
|
|
|
|
|
|
def _put_sample(cp, size, i, val, signed=True):
|
|
fmt = _struct_format(size, signed)
|
|
struct.pack_into(fmt, cp, i * size, val)
|
|
|
|
|
|
def _get_maxval(size, signed=True):
|
|
if signed and size == 1:
|
|
return 0x7f
|
|
elif size == 1:
|
|
return 0xff
|
|
elif signed and size == 2:
|
|
return 0x7fff
|
|
elif size == 2:
|
|
return 0xffff
|
|
elif signed and size == 4:
|
|
return 0x7fffffff
|
|
elif size == 4:
|
|
return 0xffffffff
|
|
|
|
|
|
def _get_minval(size, signed=True):
|
|
if not signed:
|
|
return 0
|
|
elif size == 1:
|
|
return -0x80
|
|
elif size == 2:
|
|
return -0x8000
|
|
elif size == 4:
|
|
return -0x80000000
|
|
|
|
|
|
def _get_clipfn(size, signed=True):
|
|
maxval = _get_maxval(size, signed)
|
|
minval = _get_minval(size, signed)
|
|
return lambda val: builtin_max(min(val, maxval), minval)
|
|
|
|
|
|
def _overflow(val, size, signed=True):
|
|
minval = _get_minval(size, signed)
|
|
maxval = _get_maxval(size, signed)
|
|
if minval <= val <= maxval:
|
|
return val
|
|
|
|
bits = size * 8
|
|
if signed:
|
|
offset = 2**(bits-1)
|
|
return ((val + offset) % (2**bits)) - offset
|
|
else:
|
|
return val % (2**bits)
|
|
|
|
|
|
def getsample(cp, size, i):
|
|
_check_params(len(cp), size)
|
|
if not (0 <= i < len(cp) / size):
|
|
raise error("Index out of range")
|
|
return _get_sample(cp, size, i)
|
|
|
|
|
|
def max(cp, size):
|
|
_check_params(len(cp), size)
|
|
|
|
if len(cp) == 0:
|
|
return 0
|
|
|
|
return builtin_max(abs(sample) for sample in _get_samples(cp, size))
|
|
|
|
|
|
def minmax(cp, size):
|
|
_check_params(len(cp), size)
|
|
|
|
max_sample, min_sample = 0, 0
|
|
for sample in _get_samples(cp, size):
|
|
max_sample = builtin_max(sample, max_sample)
|
|
min_sample = builtin_min(sample, min_sample)
|
|
|
|
return min_sample, max_sample
|
|
|
|
|
|
def avg(cp, size):
|
|
_check_params(len(cp), size)
|
|
sample_count = _sample_count(cp, size)
|
|
if sample_count == 0:
|
|
return 0
|
|
return sum(_get_samples(cp, size)) / sample_count
|
|
|
|
|
|
def rms(cp, size):
|
|
_check_params(len(cp), size)
|
|
|
|
sample_count = _sample_count(cp, size)
|
|
if sample_count == 0:
|
|
return 0
|
|
|
|
sum_squares = sum(sample**2 for sample in _get_samples(cp, size))
|
|
return int(math.sqrt(sum_squares / sample_count))
|
|
|
|
|
|
def _sum2(cp1, cp2, length):
|
|
size = 2
|
|
total = 0
|
|
for i in range(length):
|
|
total += getsample(cp1, size, i) * getsample(cp2, size, i)
|
|
return total
|
|
|
|
|
|
def findfit(cp1, cp2):
|
|
size = 2
|
|
|
|
if len(cp1) % 2 != 0 or len(cp2) % 2 != 0:
|
|
raise error("Strings should be even-sized")
|
|
|
|
if len(cp1) < len(cp2):
|
|
raise error("First sample should be longer")
|
|
|
|
len1 = _sample_count(cp1, size)
|
|
len2 = _sample_count(cp2, size)
|
|
|
|
sum_ri_2 = _sum2(cp2, cp2, len2)
|
|
sum_aij_2 = _sum2(cp1, cp1, len2)
|
|
sum_aij_ri = _sum2(cp1, cp2, len2)
|
|
|
|
result = (sum_ri_2 * sum_aij_2 - sum_aij_ri * sum_aij_ri) / sum_aij_2
|
|
|
|
best_result = result
|
|
best_i = 0
|
|
|
|
for i in range(1, len1 - len2 + 1):
|
|
aj_m1 = _get_sample(cp1, size, i - 1)
|
|
aj_lm1 = _get_sample(cp1, size, i + len2 - 1)
|
|
|
|
sum_aij_2 += aj_lm1**2 - aj_m1**2
|
|
sum_aij_ri = _sum2(buffer(cp1)[i*size:], cp2, len2)
|
|
|
|
result = (sum_ri_2 * sum_aij_2 - sum_aij_ri * sum_aij_ri) / sum_aij_2
|
|
|
|
if result < best_result:
|
|
best_result = result
|
|
best_i = i
|
|
|
|
factor = _sum2(buffer(cp1)[best_i*size:], cp2, len2) / sum_ri_2
|
|
|
|
return best_i, factor
|
|
|
|
|
|
def findfactor(cp1, cp2):
|
|
size = 2
|
|
|
|
if len(cp1) % 2 != 0:
|
|
raise error("Strings should be even-sized")
|
|
|
|
if len(cp1) != len(cp2):
|
|
raise error("Samples should be same size")
|
|
|
|
sample_count = _sample_count(cp1, size)
|
|
|
|
sum_ri_2 = _sum2(cp2, cp2, sample_count)
|
|
sum_aij_ri = _sum2(cp1, cp2, sample_count)
|
|
|
|
return sum_aij_ri / sum_ri_2
|
|
|
|
|
|
def findmax(cp, len2):
|
|
size = 2
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
if len(cp) % 2 != 0:
|
|
raise error("Strings should be even-sized")
|
|
|
|
if len2 < 0 or sample_count < len2:
|
|
raise error("Input sample should be longer")
|
|
|
|
if sample_count == 0:
|
|
return 0
|
|
|
|
result = _sum2(cp, cp, len2)
|
|
best_result = result
|
|
best_i = 0
|
|
|
|
for i in range(1, sample_count - len2 + 1):
|
|
sample_leaving_window = getsample(cp, size, i - 1)
|
|
sample_entering_window = getsample(cp, size, i + len2 - 1)
|
|
|
|
result -= sample_leaving_window**2
|
|
result += sample_entering_window**2
|
|
|
|
if result > best_result:
|
|
best_result = result
|
|
best_i = i
|
|
|
|
return best_i
|
|
|
|
|
|
def avgpp(cp, size):
|
|
_check_params(len(cp), size)
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
prevextremevalid = False
|
|
prevextreme = None
|
|
avg = 0
|
|
nextreme = 0
|
|
|
|
prevval = getsample(cp, size, 0)
|
|
val = getsample(cp, size, 1)
|
|
|
|
prevdiff = val - prevval
|
|
|
|
for i in range(1, sample_count):
|
|
val = getsample(cp, size, i)
|
|
diff = val - prevval
|
|
|
|
if diff * prevdiff < 0:
|
|
if prevextremevalid:
|
|
avg += abs(prevval - prevextreme)
|
|
nextreme += 1
|
|
|
|
prevextremevalid = True
|
|
prevextreme = prevval
|
|
|
|
prevval = val
|
|
if diff != 0:
|
|
prevdiff = diff
|
|
|
|
if nextreme == 0:
|
|
return 0
|
|
|
|
return avg / nextreme
|
|
|
|
|
|
def maxpp(cp, size):
|
|
_check_params(len(cp), size)
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
prevextremevalid = False
|
|
prevextreme = None
|
|
max = 0
|
|
|
|
prevval = getsample(cp, size, 0)
|
|
val = getsample(cp, size, 1)
|
|
|
|
prevdiff = val - prevval
|
|
|
|
for i in range(1, sample_count):
|
|
val = getsample(cp, size, i)
|
|
diff = val - prevval
|
|
|
|
if diff * prevdiff < 0:
|
|
if prevextremevalid:
|
|
extremediff = abs(prevval - prevextreme)
|
|
if extremediff > max:
|
|
max = extremediff
|
|
prevextremevalid = True
|
|
prevextreme = prevval
|
|
|
|
prevval = val
|
|
if diff != 0:
|
|
prevdiff = diff
|
|
|
|
return max
|
|
|
|
|
|
def cross(cp, size):
|
|
_check_params(len(cp), size)
|
|
|
|
crossings = 0
|
|
last_sample = 0
|
|
for sample in _get_samples(cp, size):
|
|
if sample <= 0 < last_sample or sample >= 0 > last_sample:
|
|
crossings += 1
|
|
last_sample = sample
|
|
|
|
return crossings
|
|
|
|
|
|
def mul(cp, size, factor):
|
|
_check_params(len(cp), size)
|
|
clip = _get_clipfn(size)
|
|
|
|
result = create_string_buffer(len(cp))
|
|
|
|
for i, sample in enumerate(_get_samples(cp, size)):
|
|
sample = clip(int(sample * factor))
|
|
_put_sample(result, size, i, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def tomono(cp, size, fac1, fac2):
|
|
_check_params(len(cp), size)
|
|
clip = _get_clipfn(size)
|
|
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
result = create_string_buffer(len(cp) / 2)
|
|
|
|
for i in range(0, sample_count, 2):
|
|
l_sample = getsample(cp, size, i)
|
|
r_sample = getsample(cp, size, i + 1)
|
|
|
|
sample = (l_sample * fac1) + (r_sample * fac2)
|
|
sample = clip(sample)
|
|
|
|
_put_sample(result, size, i / 2, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def tostereo(cp, size, fac1, fac2):
|
|
_check_params(len(cp), size)
|
|
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
result = create_string_buffer(len(cp) * 2)
|
|
clip = _get_clipfn(size)
|
|
|
|
for i in range(sample_count):
|
|
sample = _get_sample(cp, size, i)
|
|
|
|
l_sample = clip(sample * fac1)
|
|
r_sample = clip(sample * fac2)
|
|
|
|
_put_sample(result, size, i * 2, l_sample)
|
|
_put_sample(result, size, i * 2 + 1, r_sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def add(cp1, cp2, size):
|
|
_check_params(len(cp1), size)
|
|
|
|
if len(cp1) != len(cp2):
|
|
raise error("Lengths should be the same")
|
|
|
|
clip = _get_clipfn(size)
|
|
sample_count = _sample_count(cp1, size)
|
|
result = create_string_buffer(len(cp1))
|
|
|
|
for i in range(sample_count):
|
|
sample1 = getsample(cp1, size, i)
|
|
sample2 = getsample(cp2, size, i)
|
|
|
|
sample = clip(sample1 + sample2)
|
|
|
|
_put_sample(result, size, i, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def bias(cp, size, bias):
|
|
_check_params(len(cp), size)
|
|
|
|
result = create_string_buffer(len(cp))
|
|
|
|
for i, sample in enumerate(_get_samples(cp, size)):
|
|
sample = _overflow(sample + bias, size)
|
|
_put_sample(result, size, i, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def reverse(cp, size):
|
|
_check_params(len(cp), size)
|
|
sample_count = _sample_count(cp, size)
|
|
|
|
result = create_string_buffer(len(cp))
|
|
for i, sample in enumerate(_get_samples(cp, size)):
|
|
_put_sample(result, size, sample_count - i - 1, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def lin2lin(cp, size, size2):
|
|
_check_params(len(cp), size)
|
|
_check_size(size2)
|
|
|
|
if size == size2:
|
|
return cp
|
|
|
|
new_len = (len(cp) / size) * size2
|
|
|
|
result = create_string_buffer(new_len)
|
|
|
|
for i in range(_sample_count(cp, size)):
|
|
sample = _get_sample(cp, size, i)
|
|
if size < size2:
|
|
sample = sample << (4 * size2 / size)
|
|
elif size > size2:
|
|
sample = sample >> (4 * size / size2)
|
|
|
|
sample = _overflow(sample, size2)
|
|
|
|
_put_sample(result, size2, i, sample)
|
|
|
|
return result.raw
|
|
|
|
|
|
def ratecv(cp, size, nchannels, inrate, outrate, state, weightA=1, weightB=0):
|
|
_check_params(len(cp), size)
|
|
if nchannels < 1:
|
|
raise error("# of channels should be >= 1")
|
|
|
|
bytes_per_frame = size * nchannels
|
|
frame_count = len(cp) / bytes_per_frame
|
|
|
|
if bytes_per_frame / nchannels != size:
|
|
raise OverflowError("width * nchannels too big for a C int")
|
|
|
|
if weightA < 1 or weightB < 0:
|
|
raise error("weightA should be >= 1, weightB should be >= 0")
|
|
|
|
if len(cp) % bytes_per_frame != 0:
|
|
raise error("not a whole number of frames")
|
|
|
|
if inrate <= 0 or outrate <= 0:
|
|
raise error("sampling rate not > 0")
|
|
|
|
d = gcd(inrate, outrate)
|
|
inrate /= d
|
|
outrate /= d
|
|
|
|
prev_i = [0] * nchannels
|
|
cur_i = [0] * nchannels
|
|
|
|
if state is None:
|
|
d = -outrate
|
|
else:
|
|
d, samps = state
|
|
|
|
if len(samps) != nchannels:
|
|
raise error("illegal state argument")
|
|
|
|
prev_i, cur_i = zip(*samps)
|
|
prev_i, cur_i = list(prev_i), list(cur_i)
|
|
|
|
q = frame_count / inrate
|
|
ceiling = (q + 1) * outrate
|
|
nbytes = ceiling * bytes_per_frame
|
|
|
|
result = create_string_buffer(nbytes)
|
|
|
|
samples = _get_samples(cp, size)
|
|
out_i = 0
|
|
while True:
|
|
while d < 0:
|
|
if frame_count == 0:
|
|
samps = zip(prev_i, cur_i)
|
|
retval = result.raw
|
|
|
|
# slice off extra bytes
|
|
trim_index = (out_i * bytes_per_frame) - len(retval)
|
|
retval = buffer(retval)[:trim_index]
|
|
|
|
return (retval, (d, tuple(samps)))
|
|
|
|
for chan in range(nchannels):
|
|
prev_i[chan] = cur_i[chan]
|
|
cur_i[chan] = samples.next()
|
|
|
|
cur_i[chan] = (
|
|
(weightA * cur_i[chan] + weightB * prev_i[chan])
|
|
/ (weightA + weightB)
|
|
)
|
|
|
|
frame_count -= 1
|
|
d += outrate
|
|
|
|
while d >= 0:
|
|
for chan in range(nchannels):
|
|
cur_o = (
|
|
(prev_i[chan] * d + cur_i[chan] * (outrate - d))
|
|
/ outrate
|
|
)
|
|
_put_sample(result, size, out_i, _overflow(cur_o, size))
|
|
out_i += 1
|
|
d -= inrate
|
|
|
|
|
|
def lin2ulaw(cp, size):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def ulaw2lin(cp, size):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def lin2alaw(cp, size):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def alaw2lin(cp, size):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def lin2adpcm(cp, size, state):
|
|
raise NotImplementedError()
|
|
|
|
|
|
def adpcm2lin(cp, size, state):
|
|
raise NotImplementedError()
|