--- a/dom/media/MediaDecoderStateMachine.cpp
+++ b/dom/media/MediaDecoderStateMachine.cpp
@@ -1806,16 +1806,52 @@ public:
     }
   }
 
 private:
   bool mSentPlaybackEndedEvent = false;
 };
 
 /**
+ * Purpose: we enter this state when unrecoverable errors are encountered.
+ *          Decoders will be released and all playback requests (e.g. seek
+ *          or play/pause) will rejected in this state.
+ *
+ * Transition to:
+ *   SHUTDOWN if BeginShutdown() is called on MDSM.
+ */
+class MediaDecoderStateMachine::ErrorState
+  : public MediaDecoderStateMachine::StateObject
+{
+public:
+  explicit ErrorState(Master* aPtr) : StateObject(aPtr) {}
+
+  void Enter()
+  {
+    mMaster->StopPlayback();
+    mMaster->ResetDecode();
+    mMaster->StopMediaSink();
+    Reader()->ReleaseResources();
+  }
+
+  State GetState() const override
+  {
+    return DECODER_STATE_ERROR;
+  }
+
+  RefPtr<MediaDecoder::SeekPromise> HandleSeek(SeekTarget aTarget) override
+  {
+    return MediaDecoder::SeekPromise::CreateAndReject(true, __func__);
+  }
+
+  void HandleVideoSuspendTimeout() override {}
+  void HandleResumeVideoDecoding() override {}
+};
+
+/**
  * Purpose: release all resources allocated by MDSM.
  *
  * Transition to:
  *   None since this is the final state.
  *
  * Transition from:
  *   Any states other than SHUTDOWN.
  */
@@ -2818,16 +2854,17 @@ MediaDecoderStateMachine::ToStateStr(Sta
     case DECODER_STATE_DECODING_METADATA:   return "DECODING_METADATA";
     case DECODER_STATE_WAIT_FOR_CDM:        return "WAIT_FOR_CDM";
     case DECODER_STATE_DORMANT:             return "DORMANT";
     case DECODER_STATE_DECODING_FIRSTFRAME: return "DECODING_FIRSTFRAME";
     case DECODER_STATE_DECODING:            return "DECODING";
     case DECODER_STATE_SEEKING:             return "SEEKING";
     case DECODER_STATE_BUFFERING:           return "BUFFERING";
     case DECODER_STATE_COMPLETED:           return "COMPLETED";
+    case DECODER_STATE_ERROR:               return "ERROR";
     case DECODER_STATE_SHUTDOWN:            return "SHUTDOWN";
     default: MOZ_ASSERT_UNREACHABLE("Invalid state.");
   }
   return "UNKNOWN";
 }
 
 const char*
 MediaDecoderStateMachine::ToStateStr()

--- a/dom/media/MediaDecoderStateMachine.h
+++ b/dom/media/MediaDecoderStateMachine.h
@@ -153,16 +153,17 @@ public:
     DECODER_STATE_DECODING_METADATA,
     DECODER_STATE_WAIT_FOR_CDM,
     DECODER_STATE_DORMANT,
     DECODER_STATE_DECODING_FIRSTFRAME,
     DECODER_STATE_DECODING,
     DECODER_STATE_SEEKING,
     DECODER_STATE_BUFFERING,
     DECODER_STATE_COMPLETED,
+    DECODER_STATE_ERROR,
     DECODER_STATE_SHUTDOWN
   };
 
   void DumpDebugInfo();
 
   void AddOutputStream(ProcessedMediaStream* aStream, bool aFinishWhenEnded);
   // Remove an output stream added with AddOutputStream.
   void RemoveOutputStream(MediaStream* aStream);
@@ -228,16 +229,17 @@ private:
   class DormantState;
   class DecodingFirstFrameState;
   class DecodingState;
   class SeekingState;
   class AccurateSeekingState;
   class NextFrameSeekingState;
   class BufferingState;
   class CompletedState;
+  class ErrorState;
   class ShutdownState;
 
   static const char* ToStateStr(State aState);
   static const char* ToStr(NextFrameStatus aStatus);
   const char* ToStateStr();
 
   // Functions used by assertions to ensure we're calling things
   // on the appropriate threads.