node-web-audio-api
v0.21.3
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Node.js bindings for web-audio-api-rs using napi-rs
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Node Web Audio API
Node.js bindings for the Rust implementation of the Web Audio API.
This library aims to provide an implementation that is both efficient and compliant with the specification.
- see
orottier/web-audio-api-rs
for the "real" audio guts - use
napi-rs
for the Node.js bindings
Install
npm install [--save] node-web-audio-api
Example Use
import { AudioContext, OscillatorNode, GainNode } from 'node-web-audio-api';
// or using old fashioned commonjs syntax:
// const { AudioContext, OscillatorNode, GainNode } = require('node-web-audio-api');
const audioContext = new AudioContext();
setInterval(() => {
const now = audioContext.currentTime;
const frequency = 200 + Math.random() * 2800;
const env = new GainNode(audioContext, { gain: 0 });
env.connect(audioContext.destination);
env.gain
.setValueAtTime(0, now)
.linearRampToValueAtTime(0.2, now + 0.02)
.exponentialRampToValueAtTime(0.0001, now + 1);
const osc = new OscillatorNode(audioContext, { frequency });
osc.connect(env);
osc.start(now);
osc.stop(now + 1);
}, 80);
Running the Examples
To run all examples locally on your machine you will need to:
- Install Rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
- Clone the repo and build the binary on your machine
git clone https://github.com/ircam-ismm/node-web-audio-api.git
cd node-web-audio-api
npm install
npm run build
- Run the examples from the project's root directory
node examples/granular-scrub.mjs
Caveats
Streams
: only a minimal audio input stream and theMediaStreamSourceNode
are provided. All otherMediaStream
features are left on the side for now as they principally concern a different API specification, which is not a trivial problem.
Supported Platforms
| | binaries | tested | | --------------------------- | ------ | ------ | | Windows x64 | ✓ | | | Windows arm64 | ✓ | | | macOS x64 | ✓ | ✓ | | macOS aarch64 | ✓ | ✓ | | Linux x64 gnu | ✓ | | | Linux arm gnueabihf (RPi) | ✓ | ✓ | | Linux arm64 gnu (RPi) | ✓ | ✓ |
Manual Build
If prebuilt binaries are not shippped for your platform, you will need to:
- Install the Rust toolchain
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
- Install and build from github
git clone https://github.com/ircam-ismm/node-web-audio-api.git node_modules/node-web-audio-api
cd node_modules/node-web-audio-api
npm install
npm run build
The package will be built on your machine, which might take some time.
Be aware that the package won't be listed on your package.json
file, and that it won't be re-installed if running npm install
again. A possible workaround would be to include the above in a postinstall script.
Notes for Linux users
Build
To build the library, you will need to manually install the libasound2-dev
package:
sudo apt install libasound2-dev
Optionally, if you use the Jack Audio Backend, the libjack-jackd2-dev
package:
sudo apt install libjack-jackd2-dev
In such case, you can use the npm run build:jack
script to enable the Jack feature.
Audio backend and latency
Using the library on Linux with the ALSA backend might lead to unexpected cranky sound with the default render size (i.e. 128 frames). In such cases, a simple workaround is to pass the playback
latency hint when creating the audio context, which will increase the render size to 1024 frames:
const audioContext = new AudioContext({ latencyHint: 'playback' });
For real-time and interactive applications where low latency is crucial, you should instead rely on the JACK backend provided by cpal
. By default the audio context will use that backend if a running JACK server is found.
If you don't have JACK installed, you can still pass the WEB_AUDIO_LATENCY=playback
environment variable to all examples to create the audio context with the playback latency hint, e.g.:
WEB_AUDIO_LATENCY=playback node examples/amplitude-modulation.mjs
Development notes
Synchronize versioning
The npm postversion
script rely on cargo-bump
to maintain versions synced between the package.json
and the Cargo.toml
files. Therefore, you will need to install cargo-bump
on your machine
cargo install cargo-bump
Running the web-platform-test suite
Follow the steps for 'Manual Build' first. Then checkout the web-platform-tests submodule with:
git submodule init
git submodule update
Then run:
npm run wpt # build in debug mode and run all wpt test
npm run wpt:only # run all wpt test without build
npm run wpt -- --list # list all wpt test files
npm run wpt -- --filter <string> # apply <string> filter on executed/listed wpt tests