Is OfflineAudioContext supported? about audioworklet-polyfill HOT 1 OPEN

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);
}

from audioworklet-polyfill.