audiospeed – Audio processing tools

class audiospeed.SpeedChanger(source: circuitpython_typing.AudioSample, rate: float = 1.0)

Wraps an audio sample to play it back at a different speed.

Uses nearest-neighbor resampling with a fixed-point phase accumulator for CPU-efficient variable-speed playback.

Create a SpeedChanger that wraps source.

Parameters:

  • source (audiosample) – The audio source to resample.

  • rate (float) – Playback speed multiplier. 1.0 = normal, 2.0 = double speed, 0.5 = half speed. Must be positive.

Playing a wave file at 1.5x speed:

import board
import audiocore
import audiospeed
import audioio

wav = audiocore.WaveFile("drum.wav")
fast = audiospeed.SpeedChanger(wav, rate=1.5)
audio = audioio.AudioOut(board.A0)
audio.play(fast)

# Change speed during playback:
fast.rate = 2.0   # double speed
fast.rate = 0.5   # half speed
deinit() → None

Deinitialises the SpeedChanger and releases all memory resources for reuse.

rate: float

Playback speed multiplier. Can be changed during playback.