Bug 855130 - Implement HTMLVideoElement's VideoPlaybackQuality (from Media Source Extensions spec). r=roc

content/html/content/public/HTMLMediaElement.h

@@ -25,6 +25,7 @@
 #include "nsIDOMWakeLock.h"
 #include "AudioChannelCommon.h"
 #include "DecoderTraits.h"
+#include "MediaDecoder.h"
 #include "MediaMetadataManager.h"
 #include "AudioChannelAgent.h"
 #include "mozilla/Attributes.h"
@@ -522,6 +523,12 @@ public:
     mTextTracks->AddTextTrack(aTextTrack);
   }
 
+  MediaDecoder::FrameStatistics& GetFrameStatistics()
+  {
+    MediaDecoder::FrameStatistics empty;
+    return mDecoder ? mDecoder->GetFrameStatistics() : empty;
+  }
+
 protected:
   class MediaLoadListener;
   class StreamListener;

content/html/content/public/HTMLVideoElement.h

@@ -10,6 +10,8 @@
 #include "mozilla/Attributes.h"
 #include "nsIDOMHTMLVideoElement.h"
 #include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/VideoPlaybackQuality.h"
+#include "nsPerformance.h"
 
 namespace mozilla {
 namespace dom {
@@ -114,6 +116,8 @@ public:
 
   void NotifyOwnerDocumentActivityChanged() MOZ_OVERRIDE;
 
+  already_AddRefed<dom::VideoPlaybackQuality> VideoPlaybackQuality();
+
 protected:
   virtual JSObject* WrapNode(JSContext* aCx,
                              JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;

content/html/content/src/HTMLVideoElement.cpp

@@ -258,6 +258,33 @@ HTMLVideoElement::NotifyOwnerDocumentActivityChanged()
   WakeLockUpdate();
 }
 
+already_AddRefed<dom::VideoPlaybackQuality>
+HTMLVideoElement::VideoPlaybackQuality()
+{
+  nsPIDOMWindow* window = OwnerDoc()->GetInnerWindow();
+  NS_ENSURE_TRUE(window, nullptr);
+  nsPerformance* perf = window->GetPerformance();
+  NS_ENSURE_TRUE(perf, nullptr);
+  DOMHighResTimeStamp creationTime = perf->GetDOMTiming()->TimeStampToDOMHighRes(TimeStamp::Now());
+
+  uint64_t totalFrames = 0;
+  uint64_t droppedFrames = 0;
+  uint64_t corruptedFrames = 0;
+  double playbackJitter = 0.0;
+  if (mDecoder && sVideoStatsEnabled) {
+    MediaDecoder::FrameStatistics& stats = mDecoder->GetFrameStatistics();
+    totalFrames = stats.GetParsedFrames();
+    droppedFrames = totalFrames - stats.GetPresentedFrames();
+    corruptedFrames = totalFrames - stats.GetDecodedFrames();
+    playbackJitter = stats.GetPlaybackJitter();
+  }
+
+  nsRefPtr<dom::VideoPlaybackQuality> playbackQuality =
+    new dom::VideoPlaybackQuality(this, creationTime, totalFrames, droppedFrames,
+                                  corruptedFrames, playbackJitter);
+  return playbackQuality.forget();
+}
+
 void
 HTMLVideoElement::WakeLockCreate()
 {

content/media/MediaDecoder.h

@@ -818,6 +818,7 @@ public:
 
     FrameStatistics() :
         mReentrantMonitor("MediaDecoder::FrameStats"),
+        mPlaybackJitter(0.0),
         mParsedFrames(0),
         mDecodedFrames(0),
         mPresentedFrames(0) {}
@@ -844,6 +845,11 @@ public:
       return mPresentedFrames;
     }
 
+    double GetPlaybackJitter() {
+      ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+      return mPlaybackJitter;
+    }
+
     // Increments the parsed and decoded frame counters by the passed in counts.
     // Can be called on any thread.
     void NotifyDecodedFrames(uint32_t aParsed, uint32_t aDecoded) {
@@ -861,11 +867,22 @@ public:
       ++mPresentedFrames;
     }
 
+    // Tracks the sum of display errors.
+    // Can be called on any thread.
+    void NotifyPlaybackJitter(double aDisplayError) {
+      ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+      mPlaybackJitter += aDisplayError;
+    }
+
   private:
 
     // ReentrantMonitor to protect access of playback statistics.
     ReentrantMonitor mReentrantMonitor;
 
+    // Sum of display duration error.
+    // Access protected by mStatsReentrantMonitor.
+    double mPlaybackJitter;
+
     // Number of frames parsed and demuxed from media.
     // Access protected by mStatsReentrantMonitor.
     uint32_t mParsedFrames;

content/media/MediaDecoderStateMachine.cpp

@@ -2533,8 +2533,12 @@ void MediaDecoderStateMachine::AdvanceFrame()
       ScheduleStateMachine();
       return;
     }
-    mDecoder->GetFrameStatistics().NotifyPresentedFrame();
+    MediaDecoder::FrameStatistics& frameStats = mDecoder->GetFrameStatistics();
+    frameStats.NotifyPresentedFrame();
     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

@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "VideoPlaybackQuality.h"
+
+#include "mozilla/dom/HTMLMediaElement.h"
+#include "mozilla/dom/VideoPlaybackQualityBinding.h"
+#include "nsContentUtils.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsWrapperCache.h"
+#include "MediaDecoder.h"
+
+namespace mozilla {
+namespace dom {
+
+VideoPlaybackQuality::VideoPlaybackQuality(HTMLMediaElement* aElement,
+                                           DOMHighResTimeStamp aCreationTime,
+                                           uint64_t aTotalFrames,
+                                           uint64_t aDroppedFrames,
+                                           uint64_t aCorruptedFrames,
+                                           double aPlaybackJitter)
+  : mElement(aElement)
+  , mCreationTime(aCreationTime)
+  , mTotalFrames(aTotalFrames)
+  , mDroppedFrames(aDroppedFrames)
+  , mCorruptedFrames(aCorruptedFrames)
+  , mPlaybackJitter(aPlaybackJitter)
+{
+  SetIsDOMBinding();
+}
+
+HTMLMediaElement*
+VideoPlaybackQuality::GetParentObject() const
+{
+  return mElement;
+}
+
+JSObject*
+VideoPlaybackQuality::WrapObject(JSContext *aCx, JS::Handle<JSObject*> aScope)
+{
+  return VideoPlaybackQualityBinding::Wrap(aCx, aScope, this);
+}
+
+NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(VideoPlaybackQuality, AddRef)
+NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(VideoPlaybackQuality, Release)
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_1(VideoPlaybackQuality, mElement)
+
+} // namespace dom
+} // namespace mozilla

content/media/VideoPlaybackQuality.h

@@ -0,0 +1,68 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_VideoPlaybackQuality_h_
+#define mozilla_dom_VideoPlaybackQuality_h_
+
+#include "mozilla/dom/HTMLMediaElement.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsDOMNavigationTiming.h"
+#include "nsWrapperCache.h"
+
+namespace mozilla {
+namespace dom {
+
+class VideoPlaybackQuality MOZ_FINAL : public nsWrapperCache
+{
+public:
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(VideoPlaybackQuality)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(VideoPlaybackQuality)
+
+  VideoPlaybackQuality(HTMLMediaElement* aElement, DOMHighResTimeStamp aCreationTime,
+                       uint64_t aTotalFrames, uint64_t aDroppedFrames,
+                       uint64_t aCorruptedFrames, double aPlaybackJitter);
+
+  HTMLMediaElement* GetParentObject() const;
+
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aScope) MOZ_OVERRIDE;
+
+  DOMHighResTimeStamp CreationTime() const
+  {
+    return mCreationTime;
+  }
+
+  uint64_t TotalVideoFrames()
+  {
+    return mTotalFrames;
+  }
+
+  uint64_t DroppedVideoFrames()
+  {
+    return mDroppedFrames;
+  }
+
+  uint64_t CorruptedVideoFrames()
+  {
+    return mCorruptedFrames;
+  }
+
+  double PlaybackJitter()
+  {
+    return mPlaybackJitter;
+  }
+
+private:
+  nsRefPtr<HTMLMediaElement> mElement;
+  DOMHighResTimeStamp mCreationTime;
+  uint64_t mTotalFrames;
+  uint64_t mDroppedFrames;
+  uint64_t mCorruptedFrames;
+  double mPlaybackJitter;
+};
+
+} // namespace dom
+} // namespace mozilla
+#endif /* mozilla_dom_VideoPlaybackQuality_h_ */

content/media/moz.build

@@ -85,6 +85,7 @@ EXPORTS.mozilla.dom += [
     'TextTrackCue.h',
     'TextTrackCueList.h',
     'TextTrackList.h',
+    'VideoPlaybackQuality.h',
     'VideoStreamTrack.h',
 ]
 
@@ -112,6 +113,7 @@ CPP_SOURCES += [
     'TextTrackCueList.cpp',
     'TextTrackList.cpp',
     'VideoFrameContainer.cpp',
+    'VideoPlaybackQuality.cpp',
     'VideoSegment.cpp',
     'VideoStreamTrack.cpp',
     'VideoUtils.cpp',

dom/base/moz.build

@@ -28,6 +28,7 @@ EXPORTS += [
     'nsDOMClassInfoClasses.h',
     'nsDOMClassInfoID.h',
     'nsDOMJSUtils.h',
+    'nsDOMNavigationTiming.h',
     'nsDOMString.h',
     'nsFocusManager.h',
     'nsIDOMClassInfo.h',
@@ -47,6 +48,7 @@ EXPORTS += [
     'nsJSUtils.h',
     'nsPIDOMWindow.h',
     'nsPIWindowRoot.h',
+    'nsPerformance.h',
     'nsStructuredCloneContainer.h',
     'nsWindowMemoryReporter.h',
     'nsWrapperCache.h',

dom/bindings/Bindings.conf

@@ -1122,6 +1122,10 @@ DOMInterfaces = {
     'workers': True,
 }],
 
+'VideoPlaybackQuality': {
+   'nativeOwnership': 'refcounted',
+},
+
 'VideoStreamTrack': {
 },
 

dom/webidl/HTMLVideoElement.webidl

@@ -45,3 +45,9 @@ partial interface HTMLVideoElement {
   // True if the video has an audio track available.
   readonly attribute boolean mozHasAudio;
 };
+
+// https://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html#idl-def-HTMLVideoElement
+partial interface HTMLVideoElement {
+  [Pref="media.mediasource.enabled", Creator]
+  readonly attribute VideoPlaybackQuality videoPlaybackQuality;
+};

dom/webidl/VideoPlaybackQuality.webidl

@@ -0,0 +1,20 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * http://dvcs.w3.org/hg/html-media/raw-file/default/media-source/media-source.html
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+[Pref="media.mediasource.enabled"]
+interface VideoPlaybackQuality {
+  readonly attribute unsigned long totalVideoFrames;
+  readonly attribute unsigned long droppedVideoFrames;
+  readonly attribute unsigned long corruptedVideoFrames;
+  readonly attribute double playbackJitter;
+};
+

dom/webidl/WebIDL.mk

@@ -345,6 +345,7 @@ webidl_files = \
   WheelEvent.webidl \
   UndoManager.webidl \
   URLUtils.webidl \
+  VideoPlaybackQuality.webidl \
   VideoStreamTrack.webidl \
   WaveShaperNode.webidl \
   Window.webidl \