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  • License MIT

Opus codec ported with emscripten, supports PCM in 32-bits Float format. Useful for Web Audio AudioWorkletProcessor

Package Exports

  • @vocaltale/opus.js

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@vocaltale/opus.js) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

opus.js

Inspired by OpusScript and opus-recorder,a JavaScript library compiled from libopus using Emscripten.

Usage

Here is an example using Node.js to encode PCM in 32-bits floating point to opus and write it to a file using Ogg container format.

const fs = require('fs')
const {
  Encoder,
  Ogg,
} = require('@vocaltale/opus.js')

const encoder = new Encoder(48000, 1, { maxFrameSize: 960 })
// const decoder = new Decoder(48000, 1, { maxFrameSize: 960 })

const raw = new Float32Array(960)
let encoded = null
const ogg = new Ogg(48000, 1, 960, 16)
const stream = fs.createWriteStream('test.opus')

stream.write(ogg.generateIdPage())
stream.write(ogg.generateCommentPage())

raw.fill(0.1)
encoded = encoder.encodeFloat(raw)

// console.log(encoded.length)
const packet = ogg.segmentPacket(encoded)
const all = ogg.finalize()
stream.write(all)
stream.end()

encoder.delete()

Enhancements

  1. Webpack 5 Lazy-loading support (using await import() syntax) (only available for esModule, @vocaltale/opus.js/esm)
  2. Automatically fallback to opus.asm.js if WASM is not supported
  3. Support 32-bits Float formatted PCM data
  4. Lower memory usage by limiting the stack size and the heap size further
  5. Separated encoder and decoder. (original codec is also there)