Media Source Extension support with WebAudio AudioContext

Originator:andy
Number:rdar://37084774 Date Originated:2018-01-31
Status:Open Resolved:
Product:Safari Product Version:11.0.3
Classification: Reproducible:Yes
 
Summary:
Based on the Web Audio and Media Source Extension specifications, it should be possible to connect an AudioNode to a MediaStreamDestination and, in turn, specify the stream property of that destination as the srcObject for an Audio element. This process works successfully in Blink/Chrome.

Steps to Reproduce:
<html>
<audio id="a" controls>
<script type="module">
  const context = new webkitAudioContext();
  const destination = context.createMediaStreamDestination();

  const audioElement = document.getElementById('a');
  audioElement.srcObject = destination.stream;

  // trigger events on AudioNodes connected to destination
</script>

Expected Results:
Audio should play as if nodes were connected to the context destination, but controlled via the Audio element.

Actual Results:
Safari shows an audio playback state in the status bar, but no audio is ever heard. Auto play audio blocks are disabled.

Version/Build:
Safari 11.0.3 (12604.5.6.1.1)
Safari Technology Preview 11.2 Release 48 (12606.1.2.2)

Comments


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