ledcat-nyancat/nyan/pcm.py

36 lines
1.5 KiB
Python

#!/usr/bin/env python3
from nyancat import Nyancat
INTERVAL = 1 / 20
WAVE_FACTOR = 3
class NyancatSignal(Nyancat):
def __init__(self, w, h, signal):
super().__init__(w, h)
self.signal = signal
self.samples_history = [[0] * int(INTERVAL * signal.sample_rate * WAVE_FACTOR)] * 6
def plot_tail(self, width):
# Calculate the wave
samples = self.signal.get_signal(INTERVAL)
samples_offset = 0
smallest_diff = float('inf')
# Find a part in the new sample window that resembles the previous one.
for i in range(min(len(samples), len(self.samples_history[-1])) - width * WAVE_FACTOR):
z = zip(self.samples_history[-1][0:width], samples[i:i + width * WAVE_FACTOR])
diff = sum(map(lambda t: (t[0] - t[1]) ** 2, z))
if diff < smallest_diff:
samples_offset = i
smallest_diff = diff
assert samples_offset + width * WAVE_FACTOR < len(samples), 'w=%d < len=%d' % (samples_offset + width * WAVE_FACTOR, len(samples))
self.samples_history.append(samples[samples_offset:samples_offset + width * WAVE_FACTOR])
self.samples_history.pop(0)
# Render the tail
for x in range(width):
amplitude = sum(map(lambda hist: hist[x * WAVE_FACTOR], self.samples_history)) / len(self.samples_history) * 3
yield int((amplitude * .5 - .5) * self.height) + self.height
def sleep(self):
pass # Handled by a blocking read from the audio source