diff --git a/dom/media/MediaDecoderStateMachine.cpp b/dom/media/MediaDecoderStateMachine.cpp
index 58fd9c89dfe1..f87c317662d5 100644
--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -142,36 +142,6 @@ static_assert(LOW_DATA_THRESHOLD_USECS > AMPLE_AUDIO_USECS,
 // Amount of excess usecs of data to add in to the "should we buffer" calculation.
 static const uint32_t EXHAUSTED_DATA_MARGIN_USECS = 100000;
 
-// If we enter buffering within QUICK_BUFFER_THRESHOLD_USECS seconds of starting
-// decoding, we'll enter "quick buffering" mode, which exits a lot sooner than
-// normal buffering mode. This exists so that if the decode-ahead exhausts the
-// downloaded data while decode/playback is just starting up (for example
-// after a seek while the media is still playing, or when playing a media
-// as soon as it's load started), we won't necessarily stop for 30s and wait
-// for buffering. We may actually be able to playback in this case, so exit
-// buffering early and try to play. If it turns out we can't play, we'll fall
-// back to buffering normally.
-static const uint32_t QUICK_BUFFER_THRESHOLD_USECS = 2000000;
-
-namespace detail {
-
-// If we're quick buffering, we'll remain in buffering mode while we have less than
-// QUICK_BUFFERING_LOW_DATA_USECS of decoded data available.
-static const uint32_t QUICK_BUFFERING_LOW_DATA_USECS = 1000000;
-
-// If QUICK_BUFFERING_LOW_DATA_USECS is > AMPLE_AUDIO_USECS, we won't exit
-// quick buffering in a timely fashion, as the decode pauses when it
-// reaches AMPLE_AUDIO_USECS decoded data, and thus we'll never reach
-// QUICK_BUFFERING_LOW_DATA_USECS.
-static_assert(QUICK_BUFFERING_LOW_DATA_USECS <= AMPLE_AUDIO_USECS,
-              "QUICK_BUFFERING_LOW_DATA_USECS is too large");
-
-} // namespace detail
-
-static TimeDuration UsecsToDuration(int64_t aUsecs) {
-  return TimeDuration::FromMicroseconds(aUsecs);
-}
-
 static int64_t DurationToUsecs(TimeDuration aDuration) {
   return static_cast<int64_t>(aDuration.ToSeconds() * USECS_PER_S);
 }
@@ -611,14 +581,12 @@ MediaDecoderStateMachine::MediaDecoderStateMachine(MediaDecoder* aDecoder,
   mPlaybackRate(1.0),
   mLowAudioThresholdUsecs(detail::LOW_AUDIO_USECS),
   mAmpleAudioThresholdUsecs(detail::AMPLE_AUDIO_USECS),
-  mQuickBufferingLowDataThresholdUsecs(detail::QUICK_BUFFERING_LOW_DATA_USECS),
   mIsAudioPrerolling(false),
   mIsVideoPrerolling(false),
   mAudioCaptured(false),
   INIT_WATCHABLE(mAudioCompleted, false),
   INIT_WATCHABLE(mVideoCompleted, false),
   mNotifyMetadataBeforeFirstFrame(false),
-  mQuickBuffering(false),
   mMinimizePreroll(false),
   mDecodeThreadWaiting(false),
   mSentLoadedMetadataEvent(false),
@@ -1386,7 +1354,7 @@ MediaDecoderStateMachine::MaybeStartBuffering()
   bool shouldBuffer;
   if (mReader->UseBufferingHeuristics()) {
     shouldBuffer = HasLowDecodedData(EXHAUSTED_DATA_MARGIN_USECS) &&
-                   (JustExitedQuickBuffering() || HasLowBufferedData());
+                   HasLowBufferedData();
   } else {
     MOZ_ASSERT(mReader->IsWaitForDataSupported());
     shouldBuffer = (OutOfDecodedAudio() && mReader->IsWaitingAudioData()) ||
@@ -2470,11 +2438,6 @@ MediaDecoderStateMachine::SeekCompleted()
   // Try to decode another frame to detect if we're at the end...
   DECODER_LOG("Seek completed, mCurrentPosition=%lld", mCurrentPosition.Ref());
 
-  // Reset quick buffering status. This ensures that if we began the
-  // seek while quick-buffering, we won't bypass quick buffering mode
-  // if we need to buffer after the seek.
-  mQuickBuffering = false;
-
   if (video) {
     mMediaSink->Redraw(mInfo.mVideo);
     mOnPlaybackEvent.Notify(MediaEventType::Invalidate);
@@ -2550,12 +2513,10 @@ MediaDecoderStateMachine::StepBuffering()
     bool isLiveStream = mResource->IsLiveStream();
     if ((isLiveStream || !CanPlayThrough()) &&
         elapsed < TimeDuration::FromSeconds(mBufferingWait * mPlaybackRate) &&
-        (mQuickBuffering ? HasLowDecodedData(mQuickBufferingLowDataThresholdUsecs)
-                         : HasLowBufferedData(mBufferingWait * USECS_PER_S)) &&
+        HasLowBufferedData(mBufferingWait * USECS_PER_S) &&
         mResource->IsExpectingMoreData()) {
-      DECODER_LOG("Buffering: wait %ds, timeout in %.3lfs %s",
-                  mBufferingWait, mBufferingWait - elapsed.ToSeconds(),
-                  (mQuickBuffering ? "(quick exit)" : ""));
+      DECODER_LOG("Buffering: wait %ds, timeout in %.3lfs",
+                  mBufferingWait, mBufferingWait - elapsed.ToSeconds());
       ScheduleStateMachineIn(USECS_PER_S);
       return;
     }
@@ -2755,14 +2716,6 @@ void MediaDecoderStateMachine::UpdateNextFrameStatus()
   mNextFrameStatus = status;
 }
 
-bool MediaDecoderStateMachine::JustExitedQuickBuffering()
-{
-  MOZ_ASSERT(OnTaskQueue());
-  return !mDecodeStartTime.IsNull() &&
-    mQuickBuffering &&
-    (TimeStamp::Now() - mDecodeStartTime) < TimeDuration::FromMicroseconds(QUICK_BUFFER_THRESHOLD_USECS);
-}
-
 bool
 MediaDecoderStateMachine::CanPlayThrough()
 {
@@ -2796,12 +2749,6 @@ MediaDecoderStateMachine::StartBuffering()
   }
 
   TimeDuration decodeDuration = TimeStamp::Now() - mDecodeStartTime;
-  // Go into quick buffering mode provided we've not just left buffering using
-  // a "quick exit". This stops us flip-flopping between playing and buffering
-  // when the download speed is similar to the decode speed.
-  mQuickBuffering =
-    !JustExitedQuickBuffering() &&
-    decodeDuration < UsecsToDuration(QUICK_BUFFER_THRESHOLD_USECS);
   mBufferingStart = TimeStamp::Now();
 
   DECODER_LOG("Changed state from DECODING to BUFFERING, decoded for %.3lfs",
diff --git a/dom/media/MediaDecoderStateMachine.h b/dom/media/MediaDecoderStateMachine.h
index 46fdcc06b8d9..c6165180db07 100644
--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -411,9 +411,6 @@ protected:
   // The decoder monitor must be held.
   bool HasFutureAudio();
 
-  // Returns true if we recently exited "quick buffering" mode.
-  bool JustExitedQuickBuffering();
-
   // Recomputes mNextFrameStatus, possibly dispatching notifications to interested
   // parties.
   void UpdateNextFrameStatus();
@@ -712,10 +709,6 @@ private:
   // we detect that the decode can't keep up with rendering.
   int64_t mAmpleAudioThresholdUsecs;
 
-  // If we're quick buffering, we'll remain in buffering mode while we have less than
-  // QUICK_BUFFERING_LOW_DATA_USECS of decoded data available.
-  int64_t mQuickBufferingLowDataThresholdUsecs;
-
   // At the start of decoding we want to "preroll" the decode until we've
   // got a few frames decoded before we consider whether decode is falling
   // behind. Otherwise our "we're falling behind" logic will trigger
@@ -818,13 +811,6 @@ private:
   // simplified.
   bool mNotifyMetadataBeforeFirstFrame;
 
-  // If this is true while we're in buffering mode, we can exit early,
-  // as it's likely we may be able to playback. This happens when we enter
-  // buffering mode soon after the decode starts, because the decode-ahead
-  // ran fast enough to exhaust all data while the download is starting up.
-  // Synchronised via decoder monitor.
-  bool mQuickBuffering;
-
   // True if we should not decode/preroll unnecessary samples, unless we're
   // played. "Prerolling" in this context refers to when we decode and
   // buffer decoded samples in advance of when they're needed for playback.