Added support to control Opus DTX.

static/js/mediastream/utils.js

@@ -81,6 +81,14 @@ define([], function() {
       sdp = removeCodecParam(sdp, 'opus/48000', 'useinbandfec');
     }
 
+    // Set Opus DTX, if opusdtx is true, unset it, if opusdtx is false, and
+    // do nothing if otherwise.
+    if (params.opusDtx === 'true') {
+      sdp = setCodecParam(sdp, 'opus/48000', 'usedtx', '1');
+    } else if (params.opusDtx === 'false') {
+      sdp = removeCodecParam(sdp, 'opus/48000', 'usedtx');
+    }
+
     // Set Opus maxplaybackrate, if requested.
     if (params.opusMaxPbr) {
       sdp = setCodecParam(