Is OfflineAudioContext supported?

[JohnWeisz]

I've been reading up this project's description (as well as the code itself), and first I'd like to say I appreciate the effort behind it.

However, I saw that it uses dedicated workers for audio processing, and passes audio data back and forth. Which is async.

So my question is: how does this work with OfflineAudioContext, in which the onaudioprocess handler can be called faster than time progresses? Does it work at all?

[jariseon]

The current version does not support offline rendering, but it would be a cool feature, and actually quite straight forward to implement: render function request a new buffer from the worker, and the response appears in onRender (as this.outputBus[0][0][curbuf]). of course, render method needs to be promoted to public, and audioContext.currentTime needs to be replaced with a variable that is updated for each render call.

then offline rendering could be achieved with a main thread code like

function renderOffline(endtime, callback) {
   var curtime = 0;
   var buffers = [];
   // polyfill should invoke this from onRender
   node.onBufferReceived = (buf) => {
      buffers.push(buf.slice());   // maybe slice() is not required
      curtime += bufduration;
      if (curtime < endtime) {
         postMessagesToWorklet()   // MIDI, params, etc
         node.render(curtime);
      }
      else callback(buffers);
   }
   node.render(curtime);
}