Bug 462957 - Pin media stream while seeking. r=roc a=blocking2.0

content/media/nsBuiltinDecoder.cpp

@@ -178,6 +178,7 @@ void nsBuiltinDecoder::Shutdown()
 nsBuiltinDecoder::~nsBuiltinDecoder()
 {
   NS_ASSERTION(NS_IsMainThread(), "Should be on main thread.");
+  UnpinForSeek();
   MOZ_COUNT_DTOR(nsBuiltinDecoder);
 }
 
@@ -262,6 +263,7 @@ nsresult nsBuiltinDecoder::Seek(float aTime)
     else {
       mNextState = mPlayState;
     }
+    PinForSeek();
     ChangeState(PLAY_STATE_SEEKING);
   }
 
@@ -608,10 +610,12 @@ void nsBuiltinDecoder::SeekingStopped()
 
     // An additional seek was requested while the current seek was
     // in operation.
-    if (mRequestedSeekTime >= 0.0)
+    if (mRequestedSeekTime >= 0.0) {
       ChangeState(PLAY_STATE_SEEKING);
-    else
+    } else {
+      UnpinForSeek();
       ChangeState(mNextState);
+    }
   }
 
   if (mElement) {
@@ -637,8 +641,8 @@ void nsBuiltinDecoder::SeekingStoppedAtEnd()
     // in operation.
     if (mRequestedSeekTime >= 0.0) {
       ChangeState(PLAY_STATE_SEEKING);
-    }
-    else {
+    } else {
+      UnpinForSeek();
       fireEnded = mNextState != PLAY_STATE_PLAYING;
       ChangeState(fireEnded ? PLAY_STATE_ENDED : mNextState);
     }

content/media/nsMediaDecoder.cpp

@@ -37,6 +37,7 @@
  * ***** END LICENSE BLOCK ***** */
 
 #include "nsMediaDecoder.h"
+#include "nsMediaStream.h"
 
 #include "prlog.h"
 #include "prmem.h"
@@ -72,6 +73,7 @@ nsMediaDecoder::nsMediaDecoder() :
   mDataTime(),
   mVideoUpdateLock(nsnull),
   mPixelAspectRatio(1.0),
+  mPinnedForSeek(PR_FALSE),
   mSizeChanged(PR_FALSE),
   mShuttingDown(PR_FALSE)
 {
@@ -232,6 +234,26 @@ void nsMediaDecoder::SetVideoData(const gfxIntSize& aSize,
   }
 }
 
+void nsMediaDecoder::PinForSeek()
+{
+  nsMediaStream* stream = GetCurrentStream();
+  if (!stream || mPinnedForSeek) {
+    return;
+  }
+  mPinnedForSeek = PR_TRUE;
+  stream->Pin();
+}
+
+void nsMediaDecoder::UnpinForSeek()
+{
+  nsMediaStream* stream = GetCurrentStream();
+  if (!stream || !mPinnedForSeek) {
+    return;
+  }
+  mPinnedForSeek = PR_FALSE;
+  stream->Unpin();
+}
+
 // Number of bytes to add to the download size when we're computing
 // when the download will finish --- a safety margin in case bandwidth
 // or other conditions are worse than expected

content/media/nsMediaDecoder.h

@@ -253,6 +253,12 @@ protected:
   // Stop progress information timer.
   nsresult StopProgress();
 
+  // Ensures our media stream has been pinned.
+  void PinForSeek();
+
+  // Ensures our media stream has been unpinned.
+  void UnpinForSeek();
+
 protected:
   // Timer used for updating progress events
   nsCOMPtr<nsITimer> mProgressTimer;
@@ -292,6 +298,10 @@ protected:
   // Pixel aspect ratio (ratio of the pixel width to pixel height)
   float mPixelAspectRatio;
 
+  // PR_TRUE when our media stream has been pinned. We pin the stream
+  // while seeking.
+  PRPackedBool mPinnedForSeek;
+
   // Has our size changed since the last repaint?
   PRPackedBool mSizeChanged;
 

content/media/wave/nsWaveDecoder.cpp

@@ -1218,6 +1218,7 @@ nsWaveDecoder::nsWaveDecoder()
 nsWaveDecoder::~nsWaveDecoder()
 {
   MOZ_COUNT_DTOR(nsWaveDecoder);
+  UnpinForSeek();
 }
 
 PRBool
@@ -1260,6 +1261,7 @@ nsresult
 nsWaveDecoder::Seek(float aTime)
 {
   if (mPlaybackStateMachine) {
+    PinForSeek();
     mPlaybackStateMachine->Seek(aTime);
     return NS_OK;
   }
@@ -1587,6 +1589,7 @@ nsWaveDecoder::SeekingStarted()
 void
 nsWaveDecoder::SeekingStopped()
 {
+  UnpinForSeek();
   if (mShuttingDown) {
     return;
   }