Bug 571822 - Fire timeupdate event less frequently than once per frame - r=kinetik a=blocking2.0

content/media/nsBuiltinDecoder.cpp

@@ -145,6 +145,8 @@ void nsBuiltinDecoder::Shutdown()
 
   mShuttingDown = PR_TRUE;
 
+  StopTimeUpdate();
+
   // This changes the decoder state to SHUTDOWN and does other things
   // necessary to unblock the state machine thread if it's blocked, so
   // the asynchronous shutdown in nsDestroyStateMachine won't deadlock.
@@ -387,6 +389,8 @@ void nsBuiltinDecoder::MetadataLoaded(PRUint32 aChannels,
   if (resourceIsLoaded) {
     ResourceLoaded();
   }
+
+  StartTimeUpdate();
 }
 
 void nsBuiltinDecoder::ResourceLoaded()
@@ -773,7 +777,7 @@ void nsBuiltinDecoder::PlaybackPositionChanged()
   Invalidate();
 
   if (mElement && lastTime != mCurrentTime) {
-    mElement->DispatchEvent(NS_LITERAL_STRING("timeupdate"));
+    FireTimeUpdate();
   }
 }
 

content/media/nsMediaDecoder.cpp

@@ -68,12 +68,14 @@
 // Number of milliseconds of no data before a stall event is fired as defined by spec
 #define STALL_MS 3000
 
+// Number of milliseconds between timeupdate events as defined by spec
+#define TIMEUPDATE_MS 250
+
 nsMediaDecoder::nsMediaDecoder() :
   mElement(0),
   mRGBWidth(-1),
   mRGBHeight(-1),
-  mProgressTime(),
-  mDataTime(),
+  mLastCurrentTime(0.0),
   mVideoUpdateLock(nsnull),
   mPixelAspectRatio(1.0),
   mFrameBufferLength(0),
@@ -235,6 +237,54 @@ nsresult nsMediaDecoder::StopProgress()
   return rv;
 }
 
+static void TimeUpdateCallback(nsITimer* aTimer, void* aClosure)
+{
+  nsMediaDecoder* decoder = static_cast<nsMediaDecoder*>(aClosure);
+  decoder->FireTimeUpdate();
+}
+
+void nsMediaDecoder::FireTimeUpdate()
+{
+  if (!mElement)
+    return;
+
+  TimeStamp now = TimeStamp::Now();
+  float time = GetCurrentTime();
+
+  // If TIMEUPDATE_MS has passed since the last timeupdate event fired and the time
+  // has changed, fire a timeupdate event.
+  if ((mTimeUpdateTime.IsNull() ||
+       now - mTimeUpdateTime >= TimeDuration::FromMilliseconds(TIMEUPDATE_MS)) &&
+       mLastCurrentTime != time) {
+    mElement->DispatchEvent(NS_LITERAL_STRING("timeupdate"));
+    mTimeUpdateTime = now;
+    mLastCurrentTime = time;
+  }
+}
+
+nsresult nsMediaDecoder::StartTimeUpdate()
+{
+  if (mTimeUpdateTimer)
+    return NS_OK;
+
+  mTimeUpdateTimer = do_CreateInstance("@mozilla.org/timer;1");
+  return mTimeUpdateTimer->InitWithFuncCallback(TimeUpdateCallback,
+                                                this,
+                                                TIMEUPDATE_MS,
+                                                nsITimer::TYPE_REPEATING_SLACK);
+}
+
+nsresult nsMediaDecoder::StopTimeUpdate()
+{
+  if (!mTimeUpdateTimer)
+    return NS_OK;
+
+  nsresult rv = mTimeUpdateTimer->Cancel();
+  mTimeUpdateTimer = nsnull;
+
+  return rv;
+}
+
 void nsMediaDecoder::SetVideoData(const gfxIntSize& aSize,
                                   float aPixelAspectRatio,
                                   Image* aImage)

content/media/nsMediaDecoder.h

@@ -205,6 +205,10 @@ public:
   // than the result of downloaded data.
   virtual void Progress(PRBool aTimer);
 
+  // Fire timeupdate events if needed according to the time constraints
+  // outlined in the specification.
+  virtual void FireTimeUpdate();
+
   // Called by nsMediaStream when the "cache suspended" status changes.
   // If nsMediaStream::IsSuspendedByCache returns true, then the decoder
   // should stop buffering or otherwise waiting for download progress and
@@ -285,6 +289,12 @@ protected:
   // Stop progress information timer.
   nsresult StopProgress();
 
+  // Start timer to send timeupdate event
+  nsresult StartTimeUpdate();
+
+  // Stop timeupdate timer
+  nsresult StopTimeUpdate();
+
   // Ensures our media stream has been pinned.
   void PinForSeek();
 
@@ -295,6 +305,9 @@ protected:
   // Timer used for updating progress events
   nsCOMPtr<nsITimer> mProgressTimer;
 
+  // Timer used for updating timeupdate events
+  nsCOMPtr<nsITimer> mTimeUpdateTimer;
+
   // This should only ever be accessed from the main thread.
   // It is set in Init and cleared in Shutdown when the element goes away.
   // The decoder does not add a reference the element.
@@ -309,6 +322,10 @@ protected:
   // main thread only.
   TimeStamp mProgressTime;
 
+  // Time that the last timeupdate event was fired. Read/Write from the
+  // main thread only.
+  TimeStamp mTimeUpdateTime;
+
   // Time that data was last read from the media resource. Used for
   // computing if the download has stalled and to rate limit progress events
   // when data is arriving slower than PROGRESS_MS. A value of null indicates
@@ -316,6 +333,10 @@ protected:
   // more data is received. Read/Write from the main thread only.
   TimeStamp mDataTime;
 
+  // Media 'currentTime' value when the last timeupdate event occurred.
+  // Read/Write from the main thread only.
+  float mLastCurrentTime;
+
   // Lock around the video RGB, width and size data. This
   // is used in the decoder backend threads and the main thread
   // to ensure that repainting the video does not use these

content/media/wave/nsWaveDecoder.cpp

@@ -1433,6 +1433,7 @@ nsWaveDecoder::MetadataLoaded()
   } else {
     StartProgress();
   }
+  StartTimeUpdate();
 }
 
 void
@@ -1552,6 +1553,7 @@ nsWaveDecoder::Shutdown()
     return;
 
   mShuttingDown = PR_TRUE;
+  StopTimeUpdate();
 
   nsMediaDecoder::Shutdown();
 
@@ -1678,7 +1680,7 @@ nsWaveDecoder::PlaybackPositionChanged()
 
   if (mElement && lastTime != mCurrentTime) {
     UpdateReadyStateForData();
-    mElement->DispatchEvent(NS_LITERAL_STRING("timeupdate"));
+    FireTimeUpdate();
   }
 }