Bug 623637 - Initiate media buffering when decode hits end of downloaded data, rather than when they're close. r=roc a=roc

content/media/nsBuiltinDecoder.h

@@ -303,6 +303,8 @@ public:
   // with the decode monitor held. Called on the state machine thread and
   // the main thread.
   virtual void StartBuffering() = 0;
+
+  virtual void NotifyDataExhausted() = 0;
 };
 
 class nsBuiltinDecoder : public nsMediaDecoder
@@ -367,6 +369,10 @@ class nsBuiltinDecoder : public nsMediaDecoder
   // from the resource.
   void NotifyBytesConsumed(PRInt64 aBytes);
 
+  void NotifyDataExhausted() {
+    mDecoderStateMachine->NotifyDataExhausted();
+  }
+
   // Called when the video file has completed downloading.
   // Call on the main thread only.
   void ResourceLoaded();

content/media/nsBuiltinDecoderStateMachine.cpp

@@ -901,7 +901,23 @@ PRBool nsBuiltinDecoderStateMachine::IsDecodeCloseToDownload()
   double threshold = (bufferTarget > 0 && length != -1) ?
     (length / (bufferTarget)) : LIVE_BUFFER_MARGIN;
   return (downloadPos - decodePos) < threshold;
-}        
+}
+
+void nsBuiltinDecoderStateMachine::NotifyDataExhausted()
+{
+  MonitorAutoEnter mon(mDecoder->GetMonitor());
+  nsMediaStream* stream = mDecoder->GetCurrentStream();
+  NS_ASSERTION(!stream->IsDataCachedToEndOfStream(mDecoder->mDecoderPosition),
+               "We shouldn't be notified in this case!");
+  if (mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING &&
+      mState == DECODER_STATE_DECODING &&
+      !stream->IsSuspended())
+  {
+    // Our decode has caught up with the download. Let's buffer to make sure
+    // we can play a decent amount of video in the future.
+    StartBuffering();
+  }
+}
 
 nsresult nsBuiltinDecoderStateMachine::Run()
 {
@@ -991,17 +1007,6 @@ nsresult nsBuiltinDecoderStateMachine::Run()
 
         if (mState != DECODER_STATE_DECODING)
           continue;
-
-        if (IsDecodeCloseToDownload() &&
-            mDecoder->GetState() == nsBuiltinDecoder::PLAY_STATE_PLAYING &&
-            !stream->IsDataCachedToEndOfStream(mDecoder->mDecoderPosition) &&
-            !stream->IsSuspended())
-        {
-          // We're low on decoded data, and/or our decode has caught up with
-          // the download. Let's buffer to make sure we can play a decent
-          // amount of video in the future.
-          StartBuffering();
-        }
       }
       break;
 
@@ -1107,6 +1112,11 @@ nsresult nsBuiltinDecoderStateMachine::Run()
 
     case DECODER_STATE_BUFFERING:
       {
+        if (IsPlaying()) {
+          StopPlayback(AUDIO_PAUSE);
+          mDecoder->GetMonitor().NotifyAll();
+        }
+
         TimeStamp now = TimeStamp::Now();
         if (mBufferingEndOffset == -1) {
           // This is the first time we've entered the buffering state.
@@ -1479,10 +1489,6 @@ void nsBuiltinDecoderStateMachine::LoadMetadata()
 void nsBuiltinDecoderStateMachine::StartBuffering()
 {
   mDecoder->GetMonitor().AssertCurrentThreadIn();
-  if (IsPlaying()) {
-    StopPlayback(AUDIO_PAUSE);
-    mDecoder->GetMonitor().NotifyAll();
-  }
 
   // We need to tell the element that buffering has started.
   // We can't just directly send an asynchronous runnable that

content/media/nsBuiltinDecoderStateMachine.h

@@ -250,6 +250,8 @@ public:
     return mEndTime;
   }
 
+  void NotifyDataExhausted();
+
 protected:
 
   // Returns PR_TRUE if the decode is withing an estimated one tenth of a

content/media/nsMediaDecoder.h

@@ -286,6 +286,11 @@ public:
   // to buffer, given the current download and playback rates.
   PRBool CanPlayThrough();
 
+  // Called by the nsMediaStream when a read on the stream by the decoder
+  // is about to block due to insuffient data. Decoders may want to pause
+  // playback and go into buffering mode when this is called.
+  virtual void NotifyDataExhausted() = 0;
+
 protected:
 
   // Start timer to update download progress information.

content/media/nsMediaStream.cpp

@@ -571,6 +571,15 @@ nsresult nsMediaChannelStream::Read(char* aBuffer,
 {
   NS_ASSERTION(!NS_IsMainThread(), "Don't call on main thread");
 
+  PRInt64 pos = Tell();
+  PRInt64 endOfRead = pos + aCount;
+  if (endOfRead > mCacheStream.GetCachedDataEnd(pos) &&
+      !IsDataCachedToEndOfStream(pos)) {
+    // Our read will almost certainly block waiting for more data to download.
+    // Notify the decoder, so it can move to buffering state if need be.
+    mDecoder->NotifyDataExhausted();
+  }
+
   return mCacheStream.Read(aBuffer, aCount, aBytes);
 }
 

content/media/test/test_paused_after_ended.html

@@ -21,8 +21,8 @@ function ended(evt) {
 
 function startTest(test, token) {
   var v = document.createElement('video');
-  v.token = v;
-  manager.started(v);
+  v.token = token;
+  manager.started(v.token);
   v.src = test.name;
   v._name = test.name;
   v._finished = false;

content/media/wave/nsWaveDecoder.h

@@ -244,6 +244,7 @@ class nsWaveDecoder : public nsMediaDecoder
 
   virtual void NotifyDataArrived(const char* aBuffer, PRUint32 aLength, PRUint32 aOffset) {}
 
+  void NotifyDataExhausted() {}
 private:
   // Notifies the element that seeking has started.
   void SeekingStarted();