audioeffects

audioeffects — 45 studio and guitar-pedal effects, in pure Python.

audioeffects Compressors, EQs, reverbs, delays, modulation, drive and amp simulation, pitch shifters and racks, pure Python on audiodsp's audio nodes, the same on MicroPython-compatible boards, CircuitPython-compatible boards and a desktop. Install omnipython-audioeffects from TestPyPI, or audioeffects from the MIP index.

GitHub Repo Docs Effects TestPyPI
Live Pure-Python Device

Install

TestPyPI for CPython, the MIP index for boards 
# CPython: audiodsp comes along from PyPI
pip install -i https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple/ omnipython-audioeffects
# MicroPython, on a firmware that has audiodsp in it
import mip
mip.install("audioeffects", index="https://PyDevices.github.io/mip")

Both are pure Python. On a board they need a firmware built with audiodsp, whose nodes they are made of.

Try this first

One click through a digital delay 
import array
import audiocore
import audioeffects

RATE = 48000
click = array.array("h", [20000] + [0] * (RATE - 1))  # one click, one second
source = audiocore.RawSample(click, sample_rate=RATE, channel_count=1)
echo = audioeffects.create("DigitalDelay", source, RATE,
                           time_ms=250, feedback=0.5, mix=0.5)
heard = array.array("h")
while len(heard) < RATE:
    _, block = audiocore.get_buffer(echo.output)
    heard.extend(array.array("h", bytes(block)))
for ms in range(0, 1000, 250):
    start = ms * RATE // 1000
    print(ms, "ms: loudest sample", max(abs(v) for v in heard[start:start + 12000]))

It prints the click, then echoes at 250, 500 and 750 ms, each half as loud as the last because feedback is 0.5. On a board, hand echo.output to audio_out.play() instead of pulling it yourself. To put something worth processing in front of it, add audioinstruments, and to use the effects in a DAW, install MPVST.

Read more

Depth lives in the repository

Docs

Install, first program, guides and the reference.

The effects

Every effect and rack, by name, with its controls.

Chain effects

Wire one effect into the next and keep the wire stable.

audiodsp

The CircuitPython-compatible audio nodes underneath.