Bug 895754 - Update VideoPlaybackQuality to current MSE spec (remove playbackJitter, add totalFrameDelay). r=doublec

content/html/content/src/HTMLVideoElement.cpp

@@ -264,7 +264,7 @@ HTMLVideoElement::GetVideoPlaybackQuality()
   uint64_t totalFrames = 0;
   uint64_t droppedFrames = 0;
   uint64_t corruptedFrames = 0;
-  double playbackJitter = 0.0;
+  double totalFrameDelay = 0.0;
 
   if (sVideoStatsEnabled) {
     nsPIDOMWindow* window = OwnerDoc()->GetInnerWindow();
@@ -280,13 +280,13 @@ HTMLVideoElement::GetVideoPlaybackQuality()
       totalFrames = stats.GetParsedFrames();
       droppedFrames = totalFrames - stats.GetPresentedFrames();
       corruptedFrames = totalFrames - stats.GetDecodedFrames();
-      playbackJitter = stats.GetPlaybackJitter();
+      totalFrameDelay = stats.GetTotalFrameDelay();
     }
   }
 
   nsRefPtr<VideoPlaybackQuality> playbackQuality =
     new VideoPlaybackQuality(this, creationTime, totalFrames, droppedFrames,
-                             corruptedFrames, playbackJitter);
+                             corruptedFrames, totalFrameDelay);
   return playbackQuality.forget();
 }
 

content/media/MediaDecoder.h

@@ -818,7 +818,7 @@ public:
 
     FrameStatistics() :
         mReentrantMonitor("MediaDecoder::FrameStats"),
-        mPlaybackJitter(0.0),
+        mTotalFrameDelay(0.0),
         mParsedFrames(0),
         mDecodedFrames(0),
         mPresentedFrames(0) {}
@@ -845,9 +845,9 @@ public:
       return mPresentedFrames;
     }
 
-    double GetPlaybackJitter() {
+    double GetTotalFrameDelay() {
       ReentrantMonitorAutoEnter mon(mReentrantMonitor);
-      return mPlaybackJitter;
+      return mTotalFrameDelay;
     }
 
     // Increments the parsed and decoded frame counters by the passed in counts.
@@ -867,11 +867,11 @@ public:
       ++mPresentedFrames;
     }
 
-    // Tracks the sum of display errors.
+    // Tracks the sum of display delay.
     // Can be called on any thread.
-    void NotifyPlaybackJitter(double aDisplayError) {
+    void NotifyFrameDelay(double aFrameDelay) {
       ReentrantMonitorAutoEnter mon(mReentrantMonitor);
-      mPlaybackJitter += aDisplayError;
+      mTotalFrameDelay += aFrameDelay;
     }
 
   private:
@@ -879,20 +879,20 @@ public:
     // ReentrantMonitor to protect access of playback statistics.
     ReentrantMonitor mReentrantMonitor;
 
-    // Sum of display duration error.
-    // Access protected by mStatsReentrantMonitor.
-    double mPlaybackJitter;
+    // Sum of displayed frame delays.
+    // Access protected by mReentrantMonitor.
+    double mTotalFrameDelay;
 
     // Number of frames parsed and demuxed from media.
-    // Access protected by mStatsReentrantMonitor.
+    // Access protected by mReentrantMonitor.
     uint32_t mParsedFrames;
 
     // Number of parsed frames which were actually decoded.
-    // Access protected by mStatsReentrantMonitor.
+    // Access protected by mReentrantMonitor.
     uint32_t mDecodedFrames;
 
     // Number of decoded frames which were actually sent down the rendering
-    // pipeline to be painted ("presented"). Access protected by mStatsReentrantMonitor.
+    // pipeline to be painted ("presented"). Access protected by mReentrantMonitor.
     uint32_t mPresentedFrames;
   };
 

content/media/MediaDecoderStateMachine.cpp

@@ -2540,10 +2540,10 @@ void MediaDecoderStateMachine::AdvanceFrame()
     }
     MediaDecoder::FrameStatistics& frameStats = mDecoder->GetFrameStatistics();
     frameStats.NotifyPresentedFrame();
+    double frameDelay = double(clock_time - currentFrame->mTime) / USECS_PER_S;
+    NS_ASSERTION(frameDelay >= 0.0, "Frame should never be displayed early.");
+    frameStats.NotifyFrameDelay(frameDelay);
     remainingTime = currentFrame->mEndTime - clock_time;
-    int64_t frameDuration = currentFrame->mEndTime - currentFrame->mTime;
-    double displayError = fabs(double(frameDuration - remainingTime) / USECS_PER_S);
-    frameStats.NotifyPlaybackJitter(displayError);
     currentFrame = nullptr;
   }
 

content/media/VideoPlaybackQuality.cpp

@@ -21,13 +21,13 @@ VideoPlaybackQuality::VideoPlaybackQuality(HTMLMediaElement* aElement,
                                            uint64_t aTotalFrames,
                                            uint64_t aDroppedFrames,
                                            uint64_t aCorruptedFrames,
-                                           double aPlaybackJitter)
+                                           double aTotalFrameDelay)
   : mElement(aElement)
   , mCreationTime(aCreationTime)
   , mTotalFrames(aTotalFrames)
   , mDroppedFrames(aDroppedFrames)
   , mCorruptedFrames(aCorruptedFrames)
-  , mPlaybackJitter(aPlaybackJitter)
+  , mTotalFrameDelay(aTotalFrameDelay)
 {
   SetIsDOMBinding();
 }

content/media/VideoPlaybackQuality.h

@@ -23,7 +23,7 @@ public:
 
   VideoPlaybackQuality(HTMLMediaElement* aElement, DOMHighResTimeStamp aCreationTime,
                        uint64_t aTotalFrames, uint64_t aDroppedFrames,
-                       uint64_t aCorruptedFrames, double aPlaybackJitter);
+                       uint64_t aCorruptedFrames, double aTotalFrameDelay);
 
   HTMLMediaElement* GetParentObject() const;
 
@@ -49,9 +49,9 @@ public:
     return mCorruptedFrames;
   }
 
-  double PlaybackJitter()
+  double TotalFrameDelay()
   {
-    return mPlaybackJitter;
+    return mTotalFrameDelay;
   }
 
 private:
@@ -60,7 +60,7 @@ private:
   uint64_t mTotalFrames;
   uint64_t mDroppedFrames;
   uint64_t mCorruptedFrames;
-  double mPlaybackJitter;
+  double mTotalFrameDelay;
 };
 
 } // namespace dom

content/media/test/test_VideoPlaybackQuality.html

@@ -21,7 +21,7 @@ function test() {
   is(vpq.totalVideoFrames, 0, "totalVideoFrames should be 0");
   is(vpq.droppedVideoFrames, 0, "droppedVideoFrames should be 0");
   is(vpq.corruptedVideoFrames, 0, "corruptedVideoFrames should be 0");
-  is(vpq.playbackJitter, 0, "playbackJitter should be 0");
+  is(vpq.totalFrameDelay, 0, "totalFrameDelay should be 0");
 
   var vpq2 = video.getVideoPlaybackQuality();
   ok(vpq !== vpq2, "getVideoPlaybackQuality should return a new object");
@@ -38,7 +38,7 @@ function test() {
     ok(vpq.totalVideoFrames > 0, "totalVideoFrames should be > 0");
     ok(vpq.droppedVideoFrames >= 0, "droppedVideoFrames should be >= 0");
     ok(vpq.corruptedVideoFrames >= 0, "corruptedVideoFrames should be >= 0");
-    ok(vpq.playbackJitter >= 0, "playbackJitter should be >= 0");
+    ok(vpq.totalFrameDelay >= 0, "totalFrameDelay should be >= 0");
 
     SpecialPowers.pushPrefEnv({"set": [["media.video_stats.enabled", false]]}, function () {
       vpq = video.getVideoPlaybackQuality();
@@ -46,7 +46,7 @@ function test() {
       is(vpq.totalVideoFrames, 0, "totalVideoFrames should be 0");
       is(vpq.droppedVideoFrames, 0, "droppedVideoFrames should be 0");
       is(vpq.corruptedVideoFrames, 0, "corruptedVideoFrames should be 0");
-      is(vpq.playbackJitter, 0, "playbackJitter should be 0");
+      is(vpq.totalFrameDelay, 0, "totalFrameDelay should be 0");
 
       SimpleTest.finish();
     });

dom/webidl/VideoPlaybackQuality.webidl

@@ -16,6 +16,6 @@ interface VideoPlaybackQuality {
   readonly attribute unsigned long totalVideoFrames;
   readonly attribute unsigned long droppedVideoFrames;
   readonly attribute unsigned long corruptedVideoFrames;
-  readonly attribute double playbackJitter;
+  readonly attribute double totalFrameDelay;
 };