diff --git a/README.md b/README.md
index c54a0f2..c9067f7 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,27 @@ var pc = new RTCPeerConnection(yourConfiguration, {
 })
 ```
 
+The new peerConnection object offers additional functions and callbacks:
+```javascript
+/**
+ * This is the rtcstatistic id ("PC_0", "PC_1", ...) assigned while constructing the peerConnection object
+ */
+var assignedID = pc.getRtcStatsId();
+
+/**
+ * This is an optional callback that will be called after statistics have been fetched from the peerConnection
+ * It can be used to
+ * * modify or filter data from the statistics 
+ * * add own data to the statistics you need to have in the results 
+ *   (reflect status changes on the signalling layer you want to see in association with the statistics)
+ *   (e.g. switching from simulcast layers)
+ */
+ pc.statsCallback = function(rawData: RTCStatsReport) => RTCStatsReport
+
+
+```
+
+
 If that integration is not possible there is a fallback integration which allows
 sending per-client information about the user id and conference id. This
 can be used by calling
diff --git a/rtcstats.d.ts b/rtcstats.d.ts
index 647e8b6..64c9629 100644
--- a/rtcstats.d.ts
+++ b/rtcstats.d.ts
@@ -8,6 +8,34 @@ export type RTCStatsDataType = RTCConfiguration | RTCIceCandidate | RTCSignaling
                 RTCPeerConnectionState | undefined | ondatachannelArgs | string | RTCOfferOptions | undefined | createOfferArgs |
                 createAnswerArgs | RTCSessionDescriptionInit | addIceCandidateArgs | object;
 
+/**
+ * Type definition for an indexed object provided and returned in the statsCallback
+ */
+export interface RTCStatsData {
+    [index: string]: any
+}
+/**
+ * The extended functions of the peerConnection are exposed with this interface.
+ * Simply cast the peerConnection to this type to make use of em.
+ * const pc = new RTCPeerConnection(arg) as RTCStatsPeerConnection;
+ */
+export interface RTCStatsPeerConnection extends RTCPeerConnection
+{
+	/**
+	 * This is the rtcstatistic id ("PC_0", "PC_1", ...) assigned while constructing the peerConnection object
+	 */
+    public getRtcStatsId(): string;
+    /**
+     * This is an optional callback that will be called after statistics have been fetched from the peerConnection
+     * It can be used to
+     * * modify or filter data from the statistics 
+     * * add own data to the statistics you need to have in the results 
+     *   (reflect status changes on the signalling layer you want to see in association with the statistics)
+     *   (e.g. switching from simulcast layers)
+     */
+    public statsCallback?: (rawData: RTCStatsData) => RTCStatsData;
+}
+            
 declare module "rtcstats" {
     /**
      * Initializes the logging and statistics callback into the trace method for all noted methods
diff --git a/rtcstats.js b/rtcstats.js
index 8278fee..3f57c91 100644
--- a/rtcstats.js
+++ b/rtcstats.js
@@ -52,23 +52,6 @@ function deltaCompression(oldStats, newStats) {
   return newStats;
 }
 
-function mangleChromeStats(pc, response) {
-  var standardReport = {};
-  var reports = response.result();
-  reports.forEach(function(report) {
-    var standardStats = {
-      id: report.id,
-      timestamp: report.timestamp.getTime(),
-      type: report.type,
-    };
-    report.names().forEach(function(name) {
-      standardStats[name] = report.stat(name);
-    });
-    standardReport[standardStats.id] = standardStats;
-  });
-  return standardReport;
-}
-
 function dumpStream(stream) {
   return {
     id: stream.id,
@@ -124,10 +107,30 @@ module.exports = function(trace, getStatsInterval, prefixesToWrap) {
     }
     var origPeerConnection = window[prefix + 'RTCPeerConnection'];
     var peerconnection = function(config, constraints) {
-      var pc = new origPeerConnection(config, constraints);
+
+      // Chrome does not accept if the constraints contain something it is not aware of
+      // So we make a real copy and remove stuff we use internally
+      var constraintsCopy = JSON.parse(JSON.stringify(constraints));
+      if(constraintsCopy.rtcStatsClientId)
+        delete constraintsCopy.rtcStatsClientId;
+      if(constraintsCopy.rtcStatsPeerId)
+        delete constraintsCopy.rtcStatsPeerId;
+      if(constraintsCopy.rtcStatsConferenceId)
+        delete constraintsCopy.rtcStatsConferenceId;
+
+      var pc = new origPeerConnection(config, constraintsCopy);
       var id = 'PC_' + peerconnectioncounter++;
       pc.__rtcStatsId = id;
 
+      // The optional callback that is invoked after having received the statistics via getStats()
+      var callback = undefined;
+      pc.statsCallback = callback;
+
+      // Retrieve the rtcstats id used from outside
+      pc.getRtcStatsId = function() {
+        return pc.__rtcStatsId;
+      };
+
       if (!config) {
         config = { nullConfig: true };
       }
@@ -186,21 +189,16 @@ module.exports = function(trace, getStatsInterval, prefixesToWrap) {
 
       var prev = {};
       var getStats = function() {
-        if (isFirefox || isSafari) {
-          pc.getStats(null).then(function(res) {
-            var now = map2obj(res);
-            var base = JSON.parse(JSON.stringify(now)); // our new prev
-            trace('getstats', id, deltaCompression(prev, now));
-            prev = base;
-          });
-        } else {
-          pc.getStats(function(res) {
-            var now = mangleChromeStats(pc, res);
-            var base = JSON.parse(JSON.stringify(now)); // our new prev
-            trace('getstats', id, deltaCompression(prev, now));
-            prev = base;
-          });
-        }
+        pc.getStats(null).then(function(res) {
+          // If the callback has been set we call it now to let the implementation modify the statics
+          // e.g. add own properties from the signalling layer
+          var now = map2obj(res);
+          if(pc.statsCallback)
+            now = pc.statsCallback(now);
+          var base = JSON.parse(JSON.stringify(now)); // our new prev
+          trace('getstats', id, deltaCompression(prev, now));
+          prev = base;
+        });
       };
       // TODO: do we want one big interval and all peerconnections
       //    queried in that or one setInterval per PC?