Gurkengewuerz/audio-reactive-led-strip
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dsp module now creates a mel filterbank

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Mel filterbank generated based on settings in config.py. Other small
pep8 formatting changes. Renamed ExponentialFilter to ExpFilter.
This commit is contained in:
Scott Lawson 2016-11-07 17:41:26 -08:00
parent 696d684c79
commit 65d35c2724
1 changed files with 14 additions and 5 deletions
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19
python/dsp.py
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@ -2,9 +2,10 @@ from __future__ import print_function
import numpy as np
from scipy.interpolate import interp1d
import config
import melbank
class ExponentialFilter:
class ExpFilter:
"""Simple exponential smoothing filter"""
def __init__(self, val=0.0, alpha_decay=0.5, alpha_rise=0.5):
"""Small rise / decay factors = more smoothing"""
@ -141,23 +142,23 @@ def onset(yt):
SF = np.nan_to_num(SF)
NWPD = np.nan_to_num(NWPD)
RCD = np.nan_to_num(RCD)
# Convert onset detection to logarithmically spaced bins
_, SF = log_partition(xs, SF, subbands=config.N_SUBBANDS)
_, NWPD = log_partition(xs, NWPD, subbands=config.N_SUBBANDS)
_, RCD = log_partition(xs, RCD, subbands=config.N_SUBBANDS)
return SF, NWPD, RCD
def rfft(data, window=None):
window = 1.0 if window is None else window(len(data))
ys = np.abs(np.fft.rfft(data*window))
ys = np.abs(np.fft.rfft(data * window))
xs = np.fft.rfftfreq(len(data), 1.0 / config.MIC_RATE)
return xs, ys
def fft(data, window=None):
window = 1.0 if window is None else window(len(data))
ys = np.fft.fft(data*window)
ys = np.fft.fft(data * window)
xs = np.fft.fftfreq(len(data), 1.0 / config.MIC_RATE)
return xs, ys
@ -172,4 +173,12 @@ def log_partition(xs, ys, subbands):
for i in range(0, subbands * 24, 24):
X.append(np.mean(xs_log[i:i + 24]))
Y.append(np.mean(ys_log[i:i + 24]))
return np.array(X), np.array(Y)
return np.array(X), np.array(Y)
samples = int(round(config.MIC_RATE * config.N_ROLLING_HISTORY / (2.0 * config.FPS)))
mel_y, (_, mel_x) = melbank.compute_melmat(num_mel_bands=config.N_SUBBANDS,
freq_min=config.MIN_FREQUENCY,
freq_max=config.MAX_FREQUENCY,
num_fft_bands=samples,
sample_rate=config.MIC_RATE)