node-sdl-speaker

Output PCM stream data to speaker with SDL2. Especially for realtime audio stream.

Installing / Getting started

You need SDL2 in your system.

• Mac: brew install sdl2.
• Windows: Download SDL2 from www.libsdl.org.

$ npm install sdl-speaker

Example

const Speaker = require('sdl-speaker');
const defaultFormat = {
  channels: 1,
  sampleRate: 16000,
  samplesPerFrame: 320,
};

// Init SDL Speaker.
Speaker.init(defaultFormat);

// Register a channel for write buf.
let test = Speaker.register('test');

// write some buffer;
test.write(buf);

// When you are ready..
// Start play audio
Speaker.start();

Api Reference

Speaker.init([ option ])

Init SDL. option is optional.

• channels: Channel count. default: 1.
• samplesRate: Sample rate for every channel. default: 16000.
• samplesPerFrame: Samples per frame. default: 320.

Speaker.start()

Start play audio. Read audio data from a ring buffer. If data in ring buffer less than samplesPerFrame, fill 0.

Speaker.stop()

Close and Destroy SDL player.

Speaker.pause()

Pause SDL player.

Speaker.resume()

Resume SDL player.

Speaker.detach(name)

Detach audio source from SDL.

Speaker.cleanAll()

Clean all audio sources's buffer.

Speaker.register(name) -> audioSource

Register a audio source for write buffer. The name must unique.

audioSource.write(buffer)

Write audio buffer to ring buffer. You can write before speaker start.

audioSource.clean()

Clean this audio source's buffer.

TODO

• [ ] More Test.
• [ ] Fix Travis-CI build failed.
• [ ] Pipe stream to audioSource.
• [ ] Customise rbuf capability.
• [x] Self contained SDL2.