react-native-soundfont

Getting started

$ npm install react-native-soundfont react-native-sound --save

Usage

Example

import SoundFont from 'react-native-soundfont';

...
SoundFont.instrument('violin', {
  notes: ['C4', 'A3'] // only load 'C4' and 'A3' for speed
  gain: 1,
  release: 0.5 // release after half second
}).then(violin => {
  violin.play('C4', {gain: 0.5}); // Play 'C4' immediately at half gain
  violen.start('A3', 1000); // Start 'A3' after a second
  violin.stop('A3', 2000); // Stop after a second
  violin.destroy(); // release the Sound resources used (should be called, eventually)
});
...

Functions

The main API can be imported directly like import { instrument } from 'react-native-soundfont':

| Function | Arguments | Returns | Description | |----------|-----------------|---------|-----------------------------| | instrument | name, options | Promise<Player> | Initializes player for specific instrument |

Options:

{
  notes: ['A3','B3'], // list of all valid notes (there is a matching sound file). Defaults to all notes (A0->G8)
  path: Sound.MAIN_BUNDLE, // path to sound files. defaults to res/raw (assumes imported react-native-sound as Sound)
  ext: 'mp3', // sound file extension

  // Global Player options (applies to all start, stop functions unless overridden)
  gain: 1, // (volume)
  clip: 0, // second into sound to seek to before playing
  duration: undefined, // length to play before stopping (or undefined for full length)
  loop: false, // loop sound while key is pressed
  pan: 0.5, // left (0) to right (1)
  speed: 1 // speed of playback
  release: undefined, // time taken for the level to decay to zero after key is released (or undefined to play rest of sound)
}

Player

The following can be invoked on the Player object that is returned by instrument()

| Function | Arguments | Returns | Description | |----------|-----------------|---------|-----------------------------| | start | note, when, options | Player | Starts note playback in when milliseconds | | play | note, options | Player | Starts note now | | stop | note, when, options | Player | Stops note playback in when milliseconds | | destroy | | | Releases sound files for player |

Options:

{
  gain: 1, // (volume)
  clip: 0, // second into sound to seek to before playing
  duration: undefined, // length to play before stopping (or undefined for full length)
  loop: false, // loop sound while key is pressed
  pan: 0.5, // left (0) to right (1)
  speed: 1 // speed of playback
  release: undefined, // time taken for the level to decay to zero after key is released (or undefined to play rest of sound)
}

Adding sounds

By default, MP3 sounds will be loaded from android/app/src/main/res/raw. You may specify a different directory using the path option for intrument():

ex: Load from the "Document" directory (using react-native-sound path macros for convenience)

import Sound from 'react-native-sound';
...
Soundfont.instrument('acoustic_piano` { path: Sound.DOCUMENT });

MP3 filenames must be in the following format for the player to recognize them:

<instrument>_<note>.mp3

For example: violin_C4.mp3

Some prepacked libraries can be found here.

To Do

• iOS support
• Implement an artifical sound envelope?
• ~~Custom sound fonts (mp3 libs, sfz or midi.js?)~~