diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 2c7e8fcd65f..2e83da16211 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -2658,28 +2658,41 @@ nsresult MediaDecoderStateMachine::RunStateMachine()
       TimeStamp now = TimeStamp::Now();
       NS_ASSERTION(!mBufferingStart.IsNull(), "Must know buffering start time.");
 
-      // We will remain in the buffering state if we've not decoded enough
-      // data to begin playback, or if we've not downloaded a reasonable
-      // amount of data inside our buffering time.
-      TimeDuration elapsed = now - mBufferingStart;
-      bool isLiveStream = resource->GetLength() == -1;
-      if ((isLiveStream || !mDecoder->CanPlayThrough()) &&
-            elapsed < TimeDuration::FromSeconds(mBufferingWait * mPlaybackRate) &&
-            (mQuickBuffering ? HasLowDecodedData(QUICK_BUFFERING_LOW_DATA_USECS)
-                             : HasLowUndecodedData(mBufferingWait * USECS_PER_S)) &&
-            mDecoder->IsExpectingMoreData())
-      {
-        DECODER_LOG("Buffering: wait %ds, timeout in %.3lfs %s",
-                    mBufferingWait, mBufferingWait - elapsed.ToSeconds(),
-                    (mQuickBuffering ? "(quick exit)" : ""));
+      // When we enter buffering mode from playback, we push our most recent
+      // video frame back into the queue. So depending on how we started
+      // buffering, we may have one dummy frame in the queue. :-(
+      bool outOfAudio = IsAudioDecoding() && !AudioQueue().IsFinished() && AudioQueue().GetSize() == 0;
+      bool outOfVideo = IsVideoDecoding() && !VideoQueue().IsFinished() && VideoQueue().GetSize() <= 1;
+
+      // With buffering heuristics we will remain in the buffering state if
+      // we've not decoded enough data to begin playback, or if we've not
+      // downloaded a reasonable amount of data inside our buffering time.
+      if (mReader->UseBufferingHeuristics()) {
+        TimeDuration elapsed = now - mBufferingStart;
+        bool isLiveStream = resource->GetLength() == -1;
+        if ((isLiveStream || !mDecoder->CanPlayThrough()) &&
+              elapsed < TimeDuration::FromSeconds(mBufferingWait * mPlaybackRate) &&
+              (mQuickBuffering ? HasLowDecodedData(QUICK_BUFFERING_LOW_DATA_USECS)
+                               : HasLowUndecodedData(mBufferingWait * USECS_PER_S)) &&
+              mDecoder->IsExpectingMoreData())
+        {
+          DECODER_LOG("Buffering: wait %ds, timeout in %.3lfs %s",
+                      mBufferingWait, mBufferingWait - elapsed.ToSeconds(),
+                      (mQuickBuffering ? "(quick exit)" : ""));
+          ScheduleStateMachine(USECS_PER_S);
+          return NS_OK;
+        }
+      } else if (outOfAudio || outOfVideo) {
+        DECODER_LOG("Out of decoded data - polling for 1s");
+        DispatchDecodeTasksIfNeeded();
         ScheduleStateMachine(USECS_PER_S);
         return NS_OK;
-      } else {
-        DECODER_LOG("Changed state from BUFFERING to DECODING");
-        DECODER_LOG("Buffered for %.3lfs", (now - mBufferingStart).ToSeconds());
-        StartDecoding();
       }
 
+      DECODER_LOG("Changed state from BUFFERING to DECODING");
+      DECODER_LOG("Buffered for %.3lfs", (now - mBufferingStart).ToSeconds());
+      StartDecoding();
+
       // Notify to allow blocked decoder thread to continue
       mDecoder->GetReentrantMonitor().NotifyAll();
       UpdateReadyState();
@@ -2938,7 +2951,7 @@ void MediaDecoderStateMachine::AdvanceFrame()
       mDecoder->GetState() == MediaDecoder::PLAY_STATE_PLAYING &&
       HasLowDecodedData(remainingTime + EXHAUSTED_DATA_MARGIN_USECS) &&
       mDecoder->IsExpectingMoreData()) {
-    if (JustExitedQuickBuffering() || HasLowUndecodedData()) {
+    if (!mReader->UseBufferingHeuristics() || JustExitedQuickBuffering() || HasLowUndecodedData()) {
       if (currentFrame) {
         VideoQueue().PushFront(currentFrame);
       }