Complete reference for the decibri-web browser API. For installation and basic usage, see Getting Started.
+ +new Decibri(options?)Creates a new capture instance. Does not start capture. Call start() to begin.
import { Decibri } from 'decibri-web';
+const mic = new Decibri(options?);| Option | +Type | +Default | +Description | +
|---|---|---|---|
sampleRate |
+ number |
+ 16000 |
+ Target sample rate in Hz (1,000 to 384,000) | +
channels |
+ number |
+ 1 |
+ Number of channels (browsers reliably support 1) | +
framesPerBuffer |
+ number |
+ 1600 |
+ Frames per chunk. 1,600 at 16 kHz = 100 ms chunks (64 to 65,536) | +
device |
+ string |
+ system default | +deviceId string from Decibri.devices() |
+
format |
+ 'int16' | 'float32' |
+ 'int16' |
+ Sample encoding format | +
vad |
+ boolean |
+ false |
+ Enable voice activity detection | +
vadThreshold |
+ number |
+ 0.01 |
+ RMS energy threshold for speech detection (0 to 1) | +
vadHoldoff |
+ number |
+ 300 |
+ Milliseconds of sub-threshold audio before 'silence' is emitted |
+
echoCancellation |
+ boolean |
+ true |
+ Browser echo cancellation. Set false for music/tuner apps |
+
noiseSuppression |
+ boolean |
+ true |
+ Browser noise suppression. Set false for raw signal |
+
workletUrl |
+ string |
+ (inline Blob URL) | +URL for AudioWorklet processor file. Override if CSP blocks blob: URLs |
+
mic.start()Returns Promise<void>. Requests microphone permission and begins capture. Must be called from a user gesture in Safari. No-op if already started. Rejects with a clear error on permission denial.
mic.stop()Stops capture and releases all resources (tracks, context, nodes). Safe to call anytime, including before start() or multiple times. Emits 'end' then 'close'.
mic.isOpenboolean (read-only). Returns true while actively capturing audio.
Decibri.devices()Returns Promise<DeviceInfo[]>. Lists available audio input devices. Labels may be empty before microphone permission is granted.
const devices = await Decibri.devices();
+console.log(devices);
+// [
+// { deviceId: 'abc123', label: 'Built-in Microphone', groupId: 'g1' },
+// ...
+// ]Decibri.version()Returns version information for decibri-web.
+Decibri.version();
+// { decibriWeb: '0.1.0' }| Event | +Payload | +Description | +
|---|---|---|
'data' |
+ Int16Array or Float32Array |
+ Audio chunk. Format depends on format option. Emitted ~10 times/sec at default settings. |
+
'error' |
+ Error |
+ Permission denied, worklet load failure, AudioContext creation failure. | +
'end' |
+ (none) | +Emitted after stop(). |
+
'close' |
+ (none) | +Emitted after stop(), after 'end'. |
+
'speech' |
+ (none) | +VAD: RMS energy crossed threshold. Requires vad: true. |
+
'silence' |
+ (none) | +VAD: sub-threshold audio for vadHoldoff ms. Requires vad: true. |
+
// DeviceInfo
+{
+ deviceId: string,
+ label: string,
+ groupId: string,
+}
+
+// VersionInfo
+{
+ decibriWeb: string,
+}| Feature | +Node.js decibri |
+ decibri-web |
+ Notes | +
|---|---|---|---|
| Class name | +Decibri |
+ Decibri |
+ Identical | +
| Constructor | +Sync, capture starts on read | +Sync, requires await start() |
+ Browser needs async permission | +
'data' payload |
+ Buffer |
+ Int16Array / Float32Array |
+ Different types, same PCM data | +
devices() |
+ Sync | +Async (returns Promise) | +Browser API is async | +
device option |
+ Number index or name substring | +String deviceId only |
+ Browser uses opaque device IDs | +
version() |
+ { decibri, portaudio } |
+ { decibriWeb } |
+ Different runtime info | +
echoCancellation |
+ N/A | +boolean (default true) |
+ Browser-only option | +
noiseSuppression |
+ N/A | +boolean (default true) |
+ Browser-only option | +
'backpressure' event |
+ Available | +Not available | +No browser equivalent | +
pipe() / streams |
+ Full Readable stream | +Not available | +Browser has no Node streams | +
sampleRate |
+ Any (PortAudio resamples) | +Any (AudioWorklet resamples) | +Same behavior | +
format |
+ 'int16' or 'float32' |
+ 'int16' or 'float32' |
+ Identical | +
VAD (speech/silence) |
+ RMS-based | +RMS-based (same algorithm) | +Identical | +
decibri-web is a browser-based microphone capture library. It uses the Web Audio API and AudioWorklet to capture raw PCM audio chunks in real-time. Same API as decibri for Node.js, different runtime. Zero dependencies, 6.4KB ESM bundle.
+ +| Package | +Environment | +Backend | +
|---|---|---|
| decibri | +Node.js | +Native C++ (PortAudio) | +
| decibri-web | +Browser | +Web Audio API | +
Or via CDN:
+<script src="https://unpkg.com/decibri-web/dist/index.global.js"></script>Capture microphone audio and log the chunk size:
+import { Decibri } from 'decibri-web';
+
+const mic = new Decibri({ sampleRate: 16000 });
+
+mic.on('data', (chunk) => {
+ console.log(`Received ${chunk.length} samples`);
+});
+
+await mic.start();start() must be called from a user gesture (click/tap) in Safari. Each chunk contains 100 ms of audio by default (1,600 frames at 16 kHz).
Microphone access requires HTTPS (or localhost). The browser will show a permission prompt when start() is called.
start() rejects with Error('Microphone permission denied')'error' event also fires with the same errorDecibri.devices() may be empty before permission is grantedmic.stop();stop() releases all resources: MediaStream tracks are stopped, AudioContext is closed, all nodes are disconnected, references are nulled. Safe for React/Vue component unmount cycles. Safe to call multiple times or before start().
To restart after stopping:
+await mic.start(); // creates a fresh audio pipeline// Start first to trigger permission, then enumerate with labels
+await mic.start();
+const devices = await Decibri.devices();
+console.log(devices);
+// [{ deviceId: 'abc123', label: 'Built-in Microphone', groupId: 'g1' }, ...]
+
+// Use a specific device
+const usbMic = new Decibri({ device: devices[1].deviceId });
+await usbMic.start();// Int16 PCM (default) - ready for most STT engines
+const mic = new Decibri({ format: 'int16' });
+mic.on('data', (chunk) => {
+ // chunk is an Int16Array
+});
+
+// Float32 - native browser format, no conversion
+const mic2 = new Decibri({ format: 'float32' });
+mic2.on('data', (chunk) => {
+ // chunk is a Float32Array
+});Enable the built-in VAD to receive 'speech' and 'silence' events based on RMS energy thresholding:
const mic = new Decibri({
+ sampleRate: 16000,
+ vad: true,
+ vadThreshold: 0.01,
+ vadHoldoff: 300,
+});
+
+mic.on('speech', () => console.log('Speaking...'));
+mic.on('silence', () => console.log('Silence'));
+
+await mic.start();const ws = new WebSocket('wss://your-server.com/audio');
+const mic = new Decibri({ sampleRate: 16000, format: 'int16' });
+
+mic.on('data', (chunk) => {
+ if (ws.readyState === WebSocket.OPEN) {
+ ws.send(chunk.buffer);
+ }
+});
+
+document.getElementById('start').onclick = () => mic.start();
+document.getElementById('stop').onclick = () => mic.stop();Requires HTTPS (or localhost) for microphone access.
+| Browser | +Minimum Version | +
|---|---|
| Chrome | +66+ | +
| Firefox | +76+ | +
| Safari | +14.1+ (requires user gesture) | +
| Edge | +79+ | +
| iOS Safari | +14.5+ | +
| Android Chrome | +66+ | +
By default, decibri-web loads its AudioWorklet processor via an inline Blob URL. If your Content Security Policy blocks blob: URLs:
const mic = new Decibri({
+ workletUrl: '/static/decibri-worklet.js',
+});Copy node_modules/decibri-web/dist/worklet.js to your static assets directory and pass the URL.
This documentation is here to help you get up and running with decibri and integrate it into your voice and audio applications. decibri is a cross-platform Node.js package for real-time microphone audio capture, built on PortAudio with pre-built native binaries. No ffmpeg, no SoX, and no build tools required.
+This documentation is here to help you get up and running with decibri and integrate it into your voice and audio applications. decibri is a cross-platform audio capture library for JavaScript. The Node.js package uses a native PortAudio addon with pre-built binaries. The browser package uses the Web Audio API with zero dependencies. Same API, different runtimes.
Install, capture audio in the browser, and stream to your backend
+ + +Constructor options, methods, events, and browser compatibility
+ +Step-by-step guides for using decibri with speech and audio processing tools.
diff --git a/docs/docs/nav.js b/docs/docs/nav.js index 6cfaeaf..3b2c11e 100644 --- a/docs/docs/nav.js +++ b/docs/docs/nav.js @@ -87,6 +87,11 @@ + '' + '' + '' + + '' + '' + '