def octave_filters(Nbands, BandsPerOctave): # Bandpass Filter Generation pbrip = .5 # Pass band ripple sbrip = 50 # Stop band rejection #Filter order order = 2 fi, f_low, f_high = octave_frequencies(Nbands, BandsPerOctave) fs = 44100 # sampling rate wi = fi/(fs/2.) # normalized frequencies w_low = f_low/(fs/2.) w_high = f_high/(fs/2.) B = [] A = [] # For each band for w, wl, wh in zip(wi, w_low, w_high): # normalized frequency vector freq = [wl, wh] # could be another IIR filter [b, a] = ellip(order, pbrip, sbrip, freq, btype='bandpass') B += [b] A += [a] return [B, A, fi, f_low, f_high]
def octave_filters(Nbands, BandsPerOctave):
# Bandpass Filter Generation
pbrip = .5 # Pass band ripple
sbrip = 50 # Stop band rejection
#Filter order
order = 2
fi, f_low, f_high = octave_frequencies(Nbands, BandsPerOctave)
fs = 44100 # sampling rate
wi = fi / (fs / 2.) # normalized frequencies
w_low = f_low / (fs / 2.)
w_high = f_high / (fs / 2.)
B = []
A = []
# For each band
for w, wl, wh in zip(wi, w_low, w_high):
# normalized frequency vector
freq = [wl, wh]
# could be another IIR filter
[b, a] = ellip(order, pbrip, sbrip, freq, btype='bandpass')
B += [b]
A += [a]
return [B, A, fi, f_low, f_high]
def octave_filters_oneoctave(Nbands, BandsPerOctave):
# Bandpass Filter Generation
pbrip = .5 # Pass band ripple
sbrip = 50 # Stop band rejection
#Filter order
order = 2
fi, f_low, f_high = octave_frequencies(Nbands, BandsPerOctave)
fi = fi[-BandsPerOctave:]
f_low = f_low[-BandsPerOctave:]
f_high = f_high[-BandsPerOctave:]
fs = 44100 # sampling rate
wi = fi / (fs / 2.) # normalized frequencies
w_low = f_low / (fs / 2.)
w_high = f_high / (fs / 2.)
B = []
A = []
# For each band
for w, wl, wh, f, fl, fh in zip(wi, w_low, w_high, fi, f_low, f_high):
# normalized frequency vector
freq = [wl, wh]
# could be another IIR filter
#[b, a] = ellip(order, pbrip, sbrip, freq, btype='bandpass')
a = (fh - fl) / f * 0.3
bands = [
0., fl / fs * (1 - a), fl / fs * (1 + a), fh / fs * (1 - a),
fh / fs * (1 + a), 0.5
]
b = remez(numtaps=BandsPerOctave / 24. * 1000,
bands=bands,
desired=[0., 1., 0.])
a = [1.]
B += [b]
A += [a]
return [B, A, fi, f_low, f_high]
def octave_filters_oneoctave(Nbands, BandsPerOctave): # Bandpass Filter Generation pbrip = .5 # Pass band ripple sbrip = 50 # Stop band rejection #Filter order order = 2 fi, f_low, f_high = octave_frequencies(Nbands, BandsPerOctave) fi = fi[-BandsPerOctave:] f_low = f_low[-BandsPerOctave:] f_high = f_high[-BandsPerOctave:] fs = 44100 # sampling rate wi = fi/(fs/2.) # normalized frequencies w_low = f_low/(fs/2.) w_high = f_high/(fs/2.) B = [] A = [] # For each band for w, wl, wh, f, fl, fh in zip(wi, w_low, w_high, fi, f_low, f_high): # normalized frequency vector freq = [wl, wh] # could be another IIR filter #[b, a] = ellip(order, pbrip, sbrip, freq, btype='bandpass') a = (fh - fl)/f*0.3 bands = [0.,fl/fs*(1-a),fl/fs*(1+a),fh/fs*(1-a),fh/fs*(1+a),0.5] b = remez(numtaps=BandsPerOctave/24.*1000, bands=bands, desired=[0.,1.,0.]); a = [1.] B += [b] A += [a] return [B, A, fi, f_low, f_high]