Additional info to synch

Author: pschatzmann

src/api/SnapOutput.h

@@ -187,9 +187,10 @@ class SnapOutput {
   /// ignored - update playback speed
   bool synchronizePlayback() {
     bool result = true;
+    SnapTimeSync& ts = *p_snap_time_sync;
 
+    // calculate how long we need to wait to playback the audio
     auto delay_ms = getDelayMs();
-    SnapTimeSync& ts = *p_snap_time_sync;
 
     if (!is_sync_started) {
 
@@ -198,6 +199,8 @@ class SnapOutput {
       // start audio when first package in the future becomes valid
       result = synchronizeOnStart(delay_ms);
     } else {
+      // provide the actual delay to the synch 
+      ts.updateActualDelay(delay_ms);
 
       if (ts.isSync()) {
         // update speed

src/api/SnapTimeSync.h

@@ -27,6 +27,9 @@ class SnapTimeSync {
   /// Records the actual server time in millisecondes
   virtual void updateServerTime(uint32_t serverMillis) = 0;
 
+  /// Records the actual playback delay (currently not used)
+  virtual void updateActualDelay(int delay) {}
+
   /// Calculate the resampling factor: with a positive delay we play too fast
   /// and need to slow down
   virtual float getFactor() = 0;