highpass.py

from __future__ import division, print_function

import struct, math

data = ""
for i in range(1, 2):
    text = open("output1", "r")
    data += text.read()
    text.close()

cutoff = 2
Q = 1

w0 = 2*math.pi * cutoff/128
cos_w0 = math.cos(w0)
sin_w0 = math.sin(w0)
alpha = sin_w0/(2*Q)

# Highpass
a0 =   1 + alpha
a1 =  -2*cos_w0
a2 =   1 - alpha
b0 =  (1 + cos_w0)/2
b1 = -(1 + cos_w0)
b2 =  (1 + cos_w0)/2

x = [0, 0]
y = [0, 0]
while len(data) > 0:
    x.append(struct.unpack_from("<f", data)[0])
    data = data[struct.calcsize("<f"):]
    y.append(max(-1, min(1, (b0/a0)*x[-1] + (b1/a0)*x[-2] + (b2/a0)*x[-3] - (a1/a0)*y[-1] - (a2/a0)*y[-2])))

data = ""
for num in y:
    data += struct.pack("<f", num)

text = open("output3", "w")
text.write(data)
text.close()

lowpass.py

from __future__ import division, print_function

import struct, math

data = ""
for i in range(1, 2):
    text = open("output1", "r")
    data += text.read()
    text.close()

cutoff = 2
Q = 1

w0 = 2*math.pi * cutoff/128
cos_w0 = math.cos(w0)
sin_w0 = math.sin(w0)
alpha = sin_w0/(2*Q)

# Lowpass
a0 =   1 + alpha
a1 =  -2*cos_w0
a2 =   1 - alpha
b0 =  (1 - cos_w0)/2
b1 =   1 - cos_w0
b2 =  (1 - cos_w0)/2

x = [0, 0]
y = [0, 0]
while len(data) > 0:
    x.append(struct.unpack_from("<f", data)[0])
    data = data[struct.calcsize("<f"):]
    y.append((b0/a0)*x[-1] + (b1/a0)*x[-2] + (b2/a0)*x[-3] - (a1/a0)*y[-1] - (a2/a0)*y[-2])

data = ""
for num in y:
    data += struct.pack("<f", num)

text = open("output2", "w")
text.write(data)
text.close()