title: NotReadableError: Failed to allocate audiosource in Firefox for getUserMedia
body: <p>Running the below snippet in my Firefox console returns the following error [FF/56.0.2 (64-bit) on Mac OS 10.13.1]:</p>
  
  <blockquote>
    <p>MediaStreamError { name: "NotReadableError", message: "Failed to
    allocate audiosource", constraint: "", stack: "" }  (unknown)</p>
  </blockquote>
  
  <pre><code>// Sippet
  navigator.mediaDevices
        .getUserMedia({
    audio: true,
    video: true
  })
        .then(stream=&gt;{
  console.log(stream.getAudioTracks())
  document.getElementById('storybook-preview-iframe').contentWindow.document.getElementById('video-camera').srcObject = stream
  mr = new window.MediaRecorder(stream,  {
        mimeType: 'video/webm'
      })
  mr.ondataavailable = console.log
  })
        .catch(console.log)
  </code></pre>
  
  <p>What is most troubling is it worked at one point, and then it stopped. As if something is permanently locked up... I have no way (as far as I can tell) to see what is wrong with the audio source.</p>
  
  <p>I ran these insanity checks to no avail:</p>
  
  <ul>
  <li>No other browsers or app were open and/or using camera</li>
  <li>Restarted browser, and eventually restarted computer</li>
  <li>I'm on a mac, and heard this would help <code>#&gt; sudo killall AppleCameraAssistant;sudo killall VDCAssistant</code>. It did not.</li>
  <li>Ran a separate script (<a href="https://jsfiddle.net/App7P/348/" rel="nofollow noreferrer">https://jsfiddle.net/App7P/348/</a>) but when I turned the <code>audio</code> to true (<a href="https://jsfiddle.net/3k89sy27/2/" rel="nofollow noreferrer">https://jsfiddle.net/3k89sy27/2/</a>), I got the same error as above.</li>
  <li>This example/demo page on getusermedia also garnered the same error: <a href="https://webrtc.github.io/samples/src/content/getusermedia/record/" rel="nofollow noreferrer">https://webrtc.github.io/samples/src/content/getusermedia/record/</a></li>
  </ul>
  
  <p><strong>Update</strong>: I've simplified the failure code even more.</p>
  
  <pre><code>navigator.mediaDevices.getUserMedia({
      audio: true
  }).then(function (stream) {
      console.log(stream)
  }).catch(console.log)
  </code></pre>
  
  <p>Audio does not want to register.....</p>
  
  <p>Even tried FF's own Test Pilot and that failed too <a href="https://testpilot.firefox.com/experiments/voice-fill/" rel="nofollow noreferrer">https://testpilot.firefox.com/experiments/voice-fill/</a></p>