xm.js

FastTracker 2 .XM player, written for fun.

Demo

There is an XM player and a visualizer which are separate components. The player API looks like this:

• XMPlayer.init -> starts up audio context; it's available as XMPlayer.audioctx
• XMPlayer.load(ArrayBuffer) -> returns true if loaded, otherwise barfs randomly
• XMPlayer.play() -> starts playing
• XMPlayer.pause() -> obvious
• XMPlayer.stop() -> obvious; call this before loading a new one

Loading trackview.js is optional; without it, the player won't do any visualizations. Or, you can override the following to get callbacks:

• XMView.pushEvent(e) -> push an audio event onto the queue. Called once per tick (about 50Hz, controlled by song). e contains fields:
  • t - audio timestamp
  • vu - Float32Array of RMS power (volume) for each channel
  • scopes - [Float32Array] of oscilloscope data, one array per channel; XMView.scope_width contains # of samples to produce here
  • songpos - position in the song (# patterns played)
  • pat - pattern number currently playing
  • row - row within pattern
• XMView.pause() - pause visualization
• XMView.stop() - stop/reset visualization

The code which defines what the buttons do and downloads songs and so forth is in shell.js.

The player is fairly feature-complete, but is missing a bunch of effects.

MIT license.