Animated Gif comes out black w/ Web Workers about jsgif HOT 6 CLOSED

toggleSnapshotRecord() {
  this.isRecording = !this.isRecording;
  $(document.body).toggleClass("is-recording");

  let interval = (this.captureSecondsDelay - 1) * 1000;
  let snapCount = 0;

  if (this.isRecording) {
    this.snapshotInterval = setInterval(() => {
      let messageData = {
        size: [this.outputWidth, this.outputHeight],
        frame: this.canvasContext.getImageData(0, 0, this.outputWidth, this.outputHeight)
      };

      if (snapCount === 0)
        messageData["start"] = true;

      if (snapCount === this.captureFramesNumber - 1)
        messageData["finish"] = true;

      this.gifWorker.postMessage(messageData);

      snapCount = snapCount + 1;
      if (snapCount === this.captureFramesNumber)
        return this.toggleSnapshotRecord();
    }, interval);
  } else {
    clearInterval(this.snapshotInterval);

    this.gifWorker.onmessage = function(event) {
      console.log(event.data);
    };
  };
};

var encoder = new GIFEncoder();
    encoder.setRepeat(0);
    encoder.setDelay(300);

self.addEventListener("message", function(event) {
  var data = event.data;

  if (data.start) {
    encoder.start();
  } else {
    encoder.setProperties(true, true);
  }

  encoder.setSize(data.size[0], data.size[1]);
  encoder.addFrame(data.frame, true);

  if (data.finish) {
    encoder.finish();
    self.postMessage("data:image/gif;base64," + encode64(encoder.stream().getData()));
  }
}, false);