# wavtools

wavtools is a library for both recording and streaming Waveform Audio (.wav) data
in the browser. It is intended for managing PCM16 audio streams directly.

This is a fork of open source, MIT licensed tooling initially
developed at OpenAI as part of the [OpenAI Realtime Console](https://github.com/openai/openai-realtime-console), developed by [Keith Horwood](https://x.com/keithwhor).

The two most important classes are the `WavRecorder` used for capturing audio
in the browser, and `WavStreamPlayer` for queueing and streaming audio chunks to the user.

## Installation and usage

To install wavtools in a Webpack project;

```shell
npm i wavtools --save
```

```javascript
import { WavRecorder, WavStreamPlayer } from "wavtools"

const wavRecorder = new WavRecorder({ sampleRate: 24000 })
wavRecorder.getStatus() // "ended"
```

To use as a standalone script, download the [script/wavtools.js](/script/wavtools.js) or
[script/wavtools.min.js](/script/wavtools.js) files and import them;

```html
<script src="/script/wavtools.js"></script>
<script>
  // works as part of `window` object
  const wavRecorder = new WavRecorder({ sampleRate: 24000 })
  wavRecorder.getStatus() // "ended"
</script>
```

## WavRecorder Quickstart

```javascript
import { WavRecorder } from "wavtools"

const wavRecorder = new WavRecorder({ sampleRate: 24000 })
wavRecorder.getStatus() // "ended"

// request permissions, connect microphone
await wavRecorder.begin()
wavRecorder.getStatus() // "paused"

// Start recording
// This callback will be triggered in chunks of 8192 samples by default
// { mono, raw } are Int16Array (PCM16) mono & full channel data
await wavRecorder.record((data) => {
  const { mono, raw } = data
})
wavRecorder.getStatus() // "recording"

// Stop recording
await wavRecorder.pause()
wavRecorder.getStatus() // "paused"

// outputs "audio/wav" audio file
const audio = await wavRecorder.save()

// clears current audio buffer and starts recording
await wavRecorder.clear()
await wavRecorder.record()

// get data for visualization
const frequencyData = wavRecorder.getFrequencies()

// Stop recording, disconnects microphone, output file
await wavRecorder.pause()
const finalAudio = await wavRecorder.end()

// Listen for device change; e.g. if somebody disconnects a microphone
// deviceList is array of MediaDeviceInfo[] + `default` property
wavRecorder.listenForDeviceChange((deviceList) => {})
```

## WavStreamPlayer Quickstart

```javascript
import { WavStreamPlayer } from "/src/lib/wavtools/index.js"

const wavStreamPlayer = new WavStreamPlayer({ sampleRate: 24000 })

// Connect to audio output
await wavStreamPlayer.connect()

// Create 1s of empty PCM16 audio
const audio = new Int16Array(24000)
// Queue 3s of audio, will start playing immediately
wavStreamPlayer.add16BitPCM(audio, "my-track")
wavStreamPlayer.add16BitPCM(audio, "my-track")
wavStreamPlayer.add16BitPCM(audio, "my-track")

// get data for visualization
const frequencyData = wavStreamPlayer.getFrequencies()

// Interrupt the audio (halt playback) at any time
// To restart, need to call .add16BitPCM() again
const trackOffset = await wavStreamPlayer.interrupt()
trackOffset.trackId // "my-track"
trackOffset.offset // sample number
trackOffset.currentTime // time in track
```

## AudioFilePlayer Quickstart

```javascript
import { AudioFilePlayer } from "wavtools"

const player = new AudioFilePlayer({ sampleRate: 44100 })

// Connect to audio output
await player.connect()

// Load an audio file (supports URL string, ArrayBuffer, or Blob)
await player.loadFile("path/to/audio.mp3")

// Play the loaded audio
player.play()

// Pause playback
player.pause()

// Stop playback and reset position
player.stop()

// Get frequency data for visualization
// Supports 'frequency', 'music', or 'voice' analysis types
const frequencyData = player.getFrequencies("frequency", -100, -30)
```

# Compilation

When modifying the repository, to create appropriate TypeScript types and
JavaScript bundles, use `npm run compile`.

# Acknowledgements and contact

Thanks to the OpenAI Realtime team! Without their awesome work this library would not
be needed.

- OpenAI Developers / [@OpenAIDevs](https://x.com/OpenAIDevs)
- Jordan Sitkin / API / [@dustmason](https://x.com/dustmason)
- Mark Hudnall / API / [@landakram](https://x.com/landakram)
- Peter Bakkum / API / [@pbbakkum](https://x.com/pbbakkum)
- Atty Eleti / API / [@athyuttamre](https://x.com/athyuttamre)
- Jason Clark / API / [@onebitToo](https://x.com/onebitToo)
- Karolis Kosas / Design / [@karoliskosas](https://x.com/karoliskosas)
- Romain Huet / DX / [@romainhuet](https://x.com/romainhuet)
- Katia Gil Guzman / DX / [@kagigz](https://x.com/kagigz)
- Ilan Bigio / DX / [@ilanbigio](https://x.com/ilanbigio)
- Kevin Whinnery / DX / [@kevinwhinnery](https://x.com/kevinwhinnery)

You can reach me directly at;

- Keith Horwood / [@keithwhor](https://x.com/keithwhor)