title: Control volume gain for Video/Audio stream in Firefox
body: <p>I'm trying to record Video/Audio files using MediaRecorder API for Firefox.</p>
  
  <p>When I'm using web Audio API for creating the nodes (source -> Gain -> Destination) </p>
  
  <p>The output of the recorded file is only Audio as the return stream from the destination node is Audio stream only referring to this documentation 
  <a href="https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamAudioDestinationNode" rel="nofollow">https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamAudioDestinationNode</a></p>
  
  <p>Any suggestion for getting Audio/video stream in the destination output to record audio/video not audio only.</p>
  
  <blockquote>
  <pre><code>    var mediastream;
  
      var ctx = new AudioContext();
  
      var mediaStreamSource = ctx.createMediaStreamSource(mediaStream); 
  
      var destination = ctx.createMediaStreamDestination();
  
      ObjectStore.VolumeGainNode = ctx.createGain();
      ObjectStore.VolumeGainNode.gain.value = 0.5;
  
      mediaStreamSource.connect(ObjectStore.VolumeGainNode);
  
      ObjectStore.VolumeGainNode.connect(destination);
  
      mediaStream = destination.stream;
  </code></pre>
  </blockquote>