title: WebRTC mix local and remote audio steams and record
body: <p>So far i've found a way only to record either local or remote using <code>MediaRecorder</code> API but is it possible to mix and record both steams and get a blob?</p>
  
  <p>Please note its audio steam only and i don't want to mix/record in server side.</p>
  
  <p>I've a <code>RTCPeerConnection</code> as <code>pc</code>. </p>
  
  <pre><code>var local_stream = pc.getLocalStreams()[0];
  var remote_stream = pc.getRemoteStreams()[0];
  var audioChunks = [];
  var rec = new MediaRecorder(local_stream);
  rec.ondataavailable = e =&gt; {
      audioChunks.push(e.data);
      if (rec.state == "inactive") 
          // Play audio using new blob
  }
  rec.start();
  </code></pre>
  
  <p>Even i tried adding multiple tracks in <code>MediaStream</code> API but it still gives only first track audio. Any help or insight 'd be appreciated!</p>