Add many small performance optimizations

Over a dozen small performance optimizations 
* Memoization for linspace generation
* Removed unnecessary copies
* Limited the rate at which information is printed. Excessive `print()` output was causing issues for some SSH users
This commit is contained in:
Scott Lawson 2017-01-30 07:17:59 -08:00 committed by GitHub
parent d6bf763c67
commit 35c26ca7bb
1 changed files with 55 additions and 43 deletions

View File

@ -11,7 +11,7 @@ import led
_time_prev = time.time() * 1000.0
"""The previous time that the frames_per_second() function was called"""
_fps = dsp.ExpFilter(val=config.FPS, alpha_decay=0.002, alpha_rise=0.002)
_fps = dsp.ExpFilter(val=config.FPS, alpha_decay=0.2, alpha_rise=0.2)
"""The low-pass filter used to estimate frames-per-second"""
@ -41,6 +41,27 @@ def frames_per_second():
return _fps.update(1000.0 / dt)
def memoize(function):
"""Provides a decorator for memoizing functions"""
from functools import wraps
memo = {}
@wraps(function)
def wrapper(*args):
if args in memo:
return memo[args]
else:
rv = function(*args)
memo[args] = rv
return rv
return wrapper
@memoize
def _normalized_linspace(size):
return np.linspace(0, 1, size)
def interpolate(y, new_length):
"""Intelligently resizes the array by linearly interpolating the values
@ -60,8 +81,8 @@ def interpolate(y, new_length):
"""
if len(y) == new_length:
return y
x_old = np.linspace(0, 1, len(y))
x_new = np.linspace(0, 1, new_length)
x_old = _normalized_linspace(len(y))
x_new = _normalized_linspace(new_length)
z = np.interp(x_new, x_old, y)
return z
@ -84,15 +105,15 @@ gain = dsp.ExpFilter(np.tile(0.01, config.N_FFT_BINS),
def visualize_scroll(y):
"""Effect that originates in the center and scrolls outwards"""
global p
y = np.copy(y)**2.0
y = y**2.0
gain.update(y)
y /= gain.value
y *= 255.0
r = int(max(y[:len(y) // 3]))
g = int(max(y[len(y) // 3: 2 * len(y) // 3]))
b = int(max(y[2 * len(y) // 3:]))
r = int(np.max(y[:len(y) // 3]))
g = int(np.max(y[len(y) // 3: 2 * len(y) // 3]))
b = int(np.max(y[2 * len(y) // 3:]))
# Scrolling effect window
p = np.roll(p, 1, axis=1)
p[:, 1:] = p[:, :-1]
p *= 0.98
p = gaussian_filter1d(p, sigma=0.2)
# Create new color originating at the center
@ -140,22 +161,18 @@ def visualize_spectrum(y):
"""Effect that maps the Mel filterbank frequencies onto the LED strip"""
global _prev_spectrum
y = np.copy(interpolate(y, config.N_PIXELS // 2))
common_mode.update(gaussian_filter1d(y, sigma=2.0))
common_mode.update(y)
diff = y - _prev_spectrum
_prev_spectrum = np.copy(y)
r = gaussian_filter1d(y, sigma=0.5) - common_mode.value
# g = gaussian_filter1d(y, sigma=0.5) - common_mode.value
b = gaussian_filter1d(y, sigma=0.0) - common_mode.value
# Update temporal filters
r = r_filt.update(r)
# g = g_filt.update(g)
# Color channel mappings
r = r_filt.update(y - common_mode.value)
g = np.abs(diff)
b = b_filt.update(b)
b = b_filt.update(np.copy(y))
# Mirror the color channels for symmetric output
pixel_r = np.concatenate((r[::-1], r))
pixel_g = np.concatenate((g[::-1], g))
pixel_b = np.concatenate((b[::-1], b))
output = np.array([pixel_r, pixel_g, pixel_b]) * 255.0
r = np.concatenate((r[::-1], r))
g = np.concatenate((g[::-1], g))
b = np.concatenate((b[::-1], b))
output = np.array([r, g,b]) * 255
return output
@ -168,31 +185,21 @@ mel_smoothing = dsp.ExpFilter(np.tile(1e-1, config.N_FFT_BINS),
volume = dsp.ExpFilter(config.MIN_VOLUME_THRESHOLD,
alpha_decay=0.02, alpha_rise=0.02)
fft_window = np.hamming(int(config.MIC_RATE / config.FPS) * config.N_ROLLING_HISTORY)
# Keeps track of the number of buffer overflows
# Lots of buffer overflows could mean that FPS is set too high
buffer_overflows = 1
prev_fps_update = time.time()
def microphone_update(stream):
global y_roll, prev_rms, prev_exp
# Retrieve and normalize the new audio samples
try:
y = np.fromstring(stream.read(samples_per_frame), dtype=np.int16)
except IOError:
y = y_roll[config.N_ROLLING_HISTORY - 1, :]
global buffer_overflows
print('Buffer overflows: {0}'.format(buffer_overflows))
buffer_overflows += 1
def microphone_update(audio_samples):
global y_roll, prev_rms, prev_exp, prev_fps_update
# Normalize samples between 0 and 1
y = y / 2.0**15
y = audio_samples / 2.0**15
# Construct a rolling window of audio samples
y_roll[:-1] = y_roll[1:]
y_roll[-1, :] = np.copy(y)
y_data = np.concatenate(y_roll, axis=0)
volume.update(np.nanmean(y_data ** 2))
if volume.value < config.MIN_VOLUME_THRESHOLD:
print('No audio input. Volume below threshold. Volume:', volume.value)
y_data = np.concatenate(y_roll, axis=0).astype(np.float32)
vol = np.max(np.abs(y_data))
if vol < config.MIN_VOLUME_THRESHOLD:
print('No audio input. Volume below threshold. Volume:', vol)
led.pixels = np.tile(0, (3, config.N_PIXELS))
led.update()
else:
@ -204,13 +211,14 @@ def microphone_update(stream):
y_padded = np.pad(y_data, (0, N_zeros), mode='constant')
YS = np.abs(np.fft.rfft(y_padded)[:N // 2])
# Construct a Mel filterbank from the FFT data
mel = np.atleast_2d(np.abs(YS)).T * dsp.mel_y.T
mel = np.atleast_2d(YS).T * dsp.mel_y.T
# Scale data to values more suitable for visualization
mel = np.mean(mel, axis=0)
# mel = np.sum(mel, axis=0)
mel = np.sum(mel, axis=0)
mel = mel**2.0
# Gain normalization
mel_gain.update(np.max(gaussian_filter1d(mel, sigma=1.0)))
mel = mel / mel_gain.value
mel /= mel_gain.value
mel = mel_smoothing.update(mel)
# Map filterbank output onto LED strip
output = visualization_effect(mel)
@ -226,8 +234,12 @@ def microphone_update(stream):
b_curve.setData(y=led.pixels[2])
if config.USE_GUI:
app.processEvents()
if config.DISPLAY_FPS:
print('FPS {:.0f} / {:.0f}'.format(frames_per_second(), config.FPS))
fps = frames_per_second()
if time.time() - 0.5 > prev_fps_update:
prev_fps_update = time.time()
print('FPS {:.0f} / {:.0f}'.format(fps, config.FPS))
# Number of audio samples to read every time frame