synchronize timestamp offsets between h.264 and AAC streams

@@ -30,29 +30,25 @@ window.videojs.Hls.AacStream = function() {
 
   this.tags = [];
 
-  // (pts:uint, pes_size:int, dataAligned:Boolean):void
-  this.setNextTimeStamp = function(pts, pes_size, dataAligned) {
-
-    // on the first invocation, capture the starting PTS value
+  // (pts:uint):void
+  this.setTimeStampOffset = function(pts) {
     pts_offset = pts;
 
     // keep track of the last time a metadata tag was written out
     // set the initial value so metadata will be generated before any
     // payload data
     lastMetaPts = pts - 1000;
+  };
 
-    // on subsequent invocations, calculate the PTS based on the starting offset
-    this.setNextTimeStamp = function(pts, pes_size, dataAligned) {
-      next_pts = pts - pts_offset;
-      pes_length = pes_size;
-
-      // If data is aligned, flush all internal buffers
-      if (dataAligned) {
-        state = 0;
-      }
-    };
+  // (pts:uint, pes_size:int, dataAligned:Boolean):void
+  this.setNextTimeStamp = function(pts, pes_size, dataAligned) {
+    next_pts = pts - pts_offset;
+    pes_length = pes_size;
 
-    this.setNextTimeStamp(pts, pes_size, dataAligned);
+    // If data is aligned, flush all internal buffers
+    if (dataAligned) {
+      state = 0;
+    }
   };
 
   // (data:ByteArray, o:int = 0, l:int = 0):void

@@ -258,24 +258,21 @@
 
     this.tags = [];
 
-    //(pts:uint, dts:uint, dataAligned:Boolean):void
-    this.setNextTimeStamp = function(pts, dts, dataAligned) {
-      // on the first invocation, capture the starting PTS value
+    //(pts:uint):void
+    this.setTimeStampOffset = function(pts) {
       pts_offset = pts;
+    };
 
-      // on subsequent invocations, calculate the PTS based on the starting offset
-      this.setNextTimeStamp = function(pts, dts, dataAligned) {
-        // We could end up with a DTS less than 0 here. We need to deal with that!
-        next_pts = pts - pts_offset;
-        next_dts = dts - pts_offset;
-
-        // If data is aligned, flush all internal buffers
-        if (dataAligned) {
-          this.finishFrame();
-        }
-      };
+    //(pts:uint, dts:uint, dataAligned:Boolean):void
+    this.setNextTimeStamp = function(pts, dts, dataAligned) {
+      // We could end up with a DTS less than 0 here. We need to deal with that!
+      next_pts = pts - pts_offset;
+      next_dts = dts - pts_offset;
 
-      this.setNextTimeStamp(pts, dts, dataAligned);
+      // If data is aligned, flush all internal buffers
+      if (dataAligned) {
+        this.finishFrame();
+      }
     };
 
     this.finishFrame = function() {

@@ -19,7 +19,10 @@
       streamBuffer = new Uint8Array(MP2T_PACKET_LENGTH),
       streamBufferByteCount = 0,
       h264Stream = new H264Stream(),
-      aacStream = new AacStream();
+      aacStream = new AacStream(),
+      h264HasTimeStampOffset = false,
+      aacHasTimeStampOffset = false,
+      timeStampOffset;
 
     // expose the stream metadata
     self.stream = {
@@ -344,10 +347,24 @@
           }
 
           if (pid === self.stream.programMapTable[STREAM_TYPES.h264]) {
+            if (!h264HasTimeStampOffset) {
+              h264HasTimeStampOffset = true;
+              if (timeStampOffset === undefined) {
+                timeStampOffset = pts;
+              }
+              h264Stream.setTimeStampOffset(timeStampOffset);
+            }
             h264Stream.setNextTimeStamp(pts,
                                         dts,
                                         dataAlignmentIndicator);
           } else if (pid === self.stream.programMapTable[STREAM_TYPES.adts]) {
+            if (!aacHasTimeStampOffset) {
+              aacHasTimeStampOffset = true;
+              if (timeStampOffset === undefined) {
+                timeStampOffset = pts;
+              }
+              aacStream.setTimeStampOffset(timeStampOffset);
+            }
             aacStream.setNextTimeStamp(pts,
                                        pesPacketSize,
                                        dataAlignmentIndicator);

@@ -70,6 +70,7 @@ test('starting PTS values can be negative', function() {
       nalUnitTypes.access_unit_delimiter_rbsp
     ]);
 
+  h264Stream.setTimeStampOffset(-100);
   h264Stream.setNextTimeStamp(-100, -100, true);
   h264Stream.writeBytes(accessUnitDelimiter, 0, accessUnitDelimiter.byteLength);
   h264Stream.setNextTimeStamp(-99, -99, true);