Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1277 insertions, 0 deletions

diff --git a/dom/media/ExternalEngineStateMachine.cpp b/dom/media/ExternalEngineStateMachine.cpp
new file mode 100644
index 0000000000..68fb053b83
--- /dev/null
+++ b/dom/media/ExternalEngineStateMachine.cpp
@@ -0,0 +1,1277 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ExternalEngineStateMachine.h"
+
+#include "PerformanceRecorder.h"
+#ifdef MOZ_WMF_MEDIA_ENGINE
+#  include "MFMediaEngineDecoderModule.h"
+#  include "mozilla/MFMediaEngineChild.h"
+#  include "mozilla/StaticPrefs_media.h"
+#endif
+#include "mozilla/Atomics.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/glean/GleanMetrics.h"
+#include "nsThreadUtils.h"
+#include "VideoUtils.h"
+
+namespace mozilla {
+
+extern LazyLogModule gMediaDecoderLog;
+
+#define FMT(x, ...) \
+  "Decoder=%p, State=%s, " x, mDecoderID, GetStateStr(), ##__VA_ARGS__
+#define LOG(x, ...)                                                        \
+  DDMOZ_LOG(gMediaDecoderLog, LogLevel::Debug, "Decoder=%p, State=%s, " x, \
+            mDecoderID, GetStateStr(), ##__VA_ARGS__)
+#define LOGV(x, ...)                                                         \
+  DDMOZ_LOG(gMediaDecoderLog, LogLevel::Verbose, "Decoder=%p, State=%s, " x, \
+            mDecoderID, GetStateStr(), ##__VA_ARGS__)
+#define LOGW(x, ...) NS_WARNING(nsPrintfCString(FMT(x, ##__VA_ARGS__)).get())
+#define LOGE(x, ...)                                                   \
+  NS_DebugBreak(NS_DEBUG_WARNING,                                      \
+                nsPrintfCString(FMT(x, ##__VA_ARGS__)).get(), nullptr, \
+                __FILE__, __LINE__)
+
+const char* ExternalEngineEventToStr(ExternalEngineEvent aEvent) {
+#define EVENT_TO_STR(event)        \
+  case ExternalEngineEvent::event: \
+    return #event
+  switch (aEvent) {
+    EVENT_TO_STR(LoadedMetaData);
+    EVENT_TO_STR(LoadedFirstFrame);
+    EVENT_TO_STR(LoadedData);
+    EVENT_TO_STR(Waiting);
+    EVENT_TO_STR(Playing);
+    EVENT_TO_STR(Seeked);
+    EVENT_TO_STR(BufferingStarted);
+    EVENT_TO_STR(BufferingEnded);
+    EVENT_TO_STR(Timeupdate);
+    EVENT_TO_STR(Ended);
+    EVENT_TO_STR(RequestForAudio);
+    EVENT_TO_STR(RequestForVideo);
+    EVENT_TO_STR(AudioEnough);
+    EVENT_TO_STR(VideoEnough);
+    default:
+      MOZ_ASSERT_UNREACHABLE("Undefined event!");
+      return "Undefined";
+  }
+#undef EVENT_TO_STR
+}
+
+/**
+ * This class monitors the amount of crash happened for a remote engine
+ * process. It the amount of crash of the remote process exceeds the defined
+ * threshold, then `ShouldRecoverProcess()` will return false to indicate that
+ * we should not keep spawning that remote process because it's too easy to
+ * crash.
+ *
+ * In addition, we also have another mechanism in the media format reader
+ * (MFR) to detect crash amount of remote processes, but that would only
+ * happen during the decoding process. The main reason to choose using this
+ * simple monitor, instead of the mechanism in the MFR is because that
+ * mechanism can't detect every crash happening in the remote process, such as
+ * crash happening during initializing the remote engine, or setting the CDM
+ * pipepline, which can happen prior to decoding.
+ */
+class ProcessCrashMonitor final {
+ public:
+  static void NotifyCrash() {
+    StaticMutexAutoLock lock(sMutex);
+    auto* monitor = ProcessCrashMonitor::EnsureInstance();
+    if (!monitor) {
+      return;
+    }
+    monitor->mCrashNums++;
+  }
+  static bool ShouldRecoverProcess() {
+    StaticMutexAutoLock lock(sMutex);
+    auto* monitor = ProcessCrashMonitor::EnsureInstance();
+    if (!monitor) {
+      return false;
+    }
+    return monitor->mCrashNums <= monitor->mMaxCrashes;
+  }
+
+ private:
+  ProcessCrashMonitor() : mCrashNums(0) {
+#ifdef MOZ_WMF_MEDIA_ENGINE
+    mMaxCrashes = StaticPrefs::media_wmf_media_engine_max_crashes();
+#else
+    mMaxCrashes = 0;
+#endif
+  };
+  ProcessCrashMonitor(const ProcessCrashMonitor&) = delete;
+  ProcessCrashMonitor& operator=(const ProcessCrashMonitor&) = delete;
+
+  static ProcessCrashMonitor* EnsureInstance() {
+    if (sIsShutdown) {
+      return nullptr;
+    }
+    if (!sCrashMonitor) {
+      sCrashMonitor.reset(new ProcessCrashMonitor());
+      GetMainThreadSerialEventTarget()->Dispatch(
+          NS_NewRunnableFunction("ProcessCrashMonitor::EnsureInstance", [&] {
+            RunOnShutdown(
+                [&] {
+                  StaticMutexAutoLock lock(sMutex);
+                  sCrashMonitor.reset();
+                  sIsShutdown = true;
+                },
+                ShutdownPhase::XPCOMShutdown);
+          }));
+    }
+    return sCrashMonitor.get();
+  }
+
+  static inline StaticMutex sMutex;
+  static inline UniquePtr<ProcessCrashMonitor> sCrashMonitor;
+  static inline Atomic<bool> sIsShutdown{false};
+
+  uint32_t mCrashNums;
+  uint32_t mMaxCrashes;
+};
+
+/* static */
+const char* ExternalEngineStateMachine::StateToStr(State aNextState) {
+#define STATE_TO_STR(state) \
+  case State::state:        \
+    return #state
+  switch (aNextState) {
+    STATE_TO_STR(InitEngine);
+    STATE_TO_STR(ReadingMetadata);
+    STATE_TO_STR(RunningEngine);
+    STATE_TO_STR(SeekingData);
+    STATE_TO_STR(ShutdownEngine);
+    STATE_TO_STR(RecoverEngine);
+    default:
+      MOZ_ASSERT_UNREACHABLE("Undefined state!");
+      return "Undefined";
+  }
+#undef STATE_TO_STR
+}
+
+const char* ExternalEngineStateMachine::GetStateStr() const {
+  return StateToStr(mState.mName);
+}
+
+void ExternalEngineStateMachine::ChangeStateTo(State aNextState) {
+  LOG("Change state : '%s' -> '%s' (play-state=%d)", StateToStr(mState.mName),
+      StateToStr(aNextState), mPlayState.Ref());
+  // Assert the possible state transitions.
+  MOZ_ASSERT_IF(mState.IsInitEngine(), aNextState == State::ReadingMetadata ||
+                                           aNextState == State::ShutdownEngine);
+  MOZ_ASSERT_IF(mState.IsReadingMetadata(),
+                aNextState == State::RunningEngine ||
+                    aNextState == State::ShutdownEngine);
+  MOZ_ASSERT_IF(mState.IsRunningEngine(),
+                aNextState == State::SeekingData ||
+                    aNextState == State::ShutdownEngine ||
+                    aNextState == State::RecoverEngine);
+  MOZ_ASSERT_IF(mState.IsSeekingData(),
+                aNextState == State::RunningEngine ||
+                    aNextState == State::ShutdownEngine ||
+                    aNextState == State::RecoverEngine);
+  MOZ_ASSERT_IF(mState.IsShutdownEngine(), aNextState == State::ShutdownEngine);
+  MOZ_ASSERT_IF(
+      mState.IsRecoverEngine(),
+      aNextState == State::SeekingData || aNextState == State::ShutdownEngine);
+  if (aNextState == State::SeekingData) {
+    mState = StateObject({StateObject::SeekingData()});
+  } else if (aNextState == State::ReadingMetadata) {
+    mState = StateObject({StateObject::ReadingMetadata()});
+  } else if (aNextState == State::RunningEngine) {
+    mState = StateObject({StateObject::RunningEngine()});
+  } else if (aNextState == State::ShutdownEngine) {
+    mState = StateObject({StateObject::ShutdownEngine()});
+  } else if (aNextState == State::RecoverEngine) {
+    mState = StateObject({StateObject::RecoverEngine()});
+  } else {
+    MOZ_ASSERT_UNREACHABLE("Wrong state!");
+  }
+}
+
+ExternalEngineStateMachine::ExternalEngineStateMachine(
+    MediaDecoder* aDecoder, MediaFormatReader* aReader)
+    : MediaDecoderStateMachineBase(aDecoder, aReader) {
+  LOG("Created ExternalEngineStateMachine");
+  MOZ_ASSERT(mState.IsInitEngine());
+  InitEngine();
+}
+
+void ExternalEngineStateMachine::InitEngine() {
+  MOZ_ASSERT(mState.IsInitEngine() || mState.IsRecoverEngine());
+#ifdef MOZ_WMF_MEDIA_ENGINE
+  mEngine.reset(new MFMediaEngineWrapper(this, mFrameStats));
+#endif
+  if (mEngine) {
+    auto* state = mState.AsInitEngine();
+    state->mInitPromise = mEngine->Init(!mMinimizePreroll);
+    state->mInitPromise
+        ->Then(OwnerThread(), __func__, this,
+               &ExternalEngineStateMachine::OnEngineInitSuccess,
+               &ExternalEngineStateMachine::OnEngineInitFailure)
+        ->Track(state->mEngineInitRequest);
+  }
+}
+
+void ExternalEngineStateMachine::OnEngineInitSuccess() {
+  AssertOnTaskQueue();
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::OnEngineInitSuccess",
+                      MEDIA_PLAYBACK);
+  MOZ_ASSERT(mState.IsInitEngine() || mState.IsRecoverEngine());
+  LOG("Initialized the external playback engine %" PRIu64, mEngine->Id());
+  auto* state = mState.AsInitEngine();
+  state->mEngineInitRequest.Complete();
+  mReader->UpdateMediaEngineId(mEngine->Id());
+  state->mInitPromise = nullptr;
+  if (mState.IsInitEngine()) {
+    ChangeStateTo(State::ReadingMetadata);
+    ReadMetadata();
+    return;
+  }
+  // We just recovered from CDM process crash, so we need to update the media
+  // info to the new CDM process.
+  MOZ_ASSERT(mInfo);
+  mEngine->SetMediaInfo(*mInfo);
+  SeekTarget target(mCurrentPosition.Ref(), SeekTarget::Type::Accurate);
+  Seek(target);
+}
+
+void ExternalEngineStateMachine::OnEngineInitFailure() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsInitEngine() || mState.IsRecoverEngine());
+  LOGE("Failed to initialize the external playback engine");
+  auto* state = mState.AsInitEngine();
+  state->mEngineInitRequest.Complete();
+  state->mInitPromise = nullptr;
+  // TODO : Should fallback to the normal playback with media engine.
+  ReportTelemetry(NS_ERROR_DOM_MEDIA_FATAL_ERR);
+  DecodeError(MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR, __func__));
+}
+
+void ExternalEngineStateMachine::ReadMetadata() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsReadingMetadata());
+  mReader->ReadMetadata()
+      ->Then(OwnerThread(), __func__, this,
+             &ExternalEngineStateMachine::OnMetadataRead,
+             &ExternalEngineStateMachine::OnMetadataNotRead)
+      ->Track(mState.AsReadingMetadata()->mMetadataRequest);
+}
+
+void ExternalEngineStateMachine::OnMetadataRead(MetadataHolder&& aMetadata) {
+  AssertOnTaskQueue();
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::OnMetadataRead",
+                      MEDIA_PLAYBACK);
+  MOZ_ASSERT(mState.IsReadingMetadata());
+  LOG("OnMetadataRead");
+
+  mState.AsReadingMetadata()->mMetadataRequest.Complete();
+  mInfo.emplace(*aMetadata.mInfo);
+  mMediaSeekable = Info().mMediaSeekable;
+  mMediaSeekableOnlyInBufferedRanges =
+      Info().mMediaSeekableOnlyInBufferedRanges;
+
+  if (!IsFormatSupportedByExternalEngine(*mInfo)) {
+    // The external engine doesn't support the type, try to notify the decoder
+    // to use our own state machine again. Not a real "error", because it would
+    // fallback to another state machine.
+    DecodeError(
+        MediaResult(NS_ERROR_DOM_MEDIA_EXTERNAL_ENGINE_NOT_SUPPORTED_ERR));
+    return;
+  }
+
+#ifdef MOZ_WMF_MEDIA_ENGINE
+  // Only support encrypted playback. Not a real "error", because it would
+  // fallback to another state machine.
+  if (!mInfo->IsEncrypted() &&
+      StaticPrefs::media_wmf_media_engine_enabled() == 2) {
+    LOG("External engine only supports encrypted playback by the pref");
+    DecodeError(
+        MediaResult(NS_ERROR_DOM_MEDIA_EXTERNAL_ENGINE_NOT_SUPPORTED_ERR));
+    return;
+  }
+#endif
+
+  mEngine->SetMediaInfo(*mInfo);
+
+  if (Info().mMetadataDuration.isSome()) {
+    mDuration = Info().mMetadataDuration;
+  } else if (Info().mUnadjustedMetadataEndTime.isSome()) {
+    const media::TimeUnit unadjusted = Info().mUnadjustedMetadataEndTime.ref();
+    const media::TimeUnit adjustment = Info().mStartTime;
+    mInfo->mMetadataDuration.emplace(unadjusted - adjustment);
+    mDuration = Info().mMetadataDuration;
+  }
+
+  // If we don't know the duration by this point, we assume infinity, per spec.
+  if (mDuration.Ref().isNothing()) {
+    mDuration = Some(media::TimeUnit::FromInfinity());
+  }
+  MOZ_ASSERT(mDuration.Ref().isSome());
+
+  if (mInfo->HasVideo()) {
+    mVideoDisplay = mInfo->mVideo.mDisplay;
+  }
+
+  LOG("Metadata loaded : a=%s, v=%s, size=[%dx%d], duration=%s",
+      mInfo->HasAudio() ? mInfo->mAudio.mMimeType.get() : "none",
+      mInfo->HasVideo() ? mInfo->mVideo.mMimeType.get() : "none",
+      mVideoDisplay.width, mVideoDisplay.height,
+      mDuration.Ref()->ToString().get());
+
+  mMetadataLoadedEvent.Notify(std::move(aMetadata.mInfo),
+                              std::move(aMetadata.mTags),
+                              MediaDecoderEventVisibility::Observable);
+  StartRunningEngine();
+}
+
+void ExternalEngineStateMachine::OnMetadataNotRead(const MediaResult& aError) {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsReadingMetadata());
+  LOGE("Decode metadata failed, shutting down decoder");
+  mState.AsReadingMetadata()->mMetadataRequest.Complete();
+  ReportTelemetry(aError);
+  DecodeError(aError);
+}
+
+bool ExternalEngineStateMachine::IsFormatSupportedByExternalEngine(
+    const MediaInfo& aInfo) {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsReadingMetadata());
+#ifdef MOZ_WMF_MEDIA_ENGINE
+  const bool audioSupported =
+      !aInfo.HasAudio() ||
+      MFMediaEngineDecoderModule::SupportsConfig(aInfo.mAudio);
+  const bool videoSupported =
+      !aInfo.HasVideo() ||
+      MFMediaEngineDecoderModule::SupportsConfig(aInfo.mVideo);
+  LOG("audio=%s (supported=%d), video=%s(supported=%d)",
+      aInfo.HasAudio() ? aInfo.mAudio.mMimeType.get() : "none", audioSupported,
+      aInfo.HasVideo() ? aInfo.mVideo.mMimeType.get() : "none", videoSupported);
+  return audioSupported && videoSupported;
+#else
+  return false;
+#endif
+}
+
+RefPtr<MediaDecoder::SeekPromise> ExternalEngineStateMachine::Seek(
+    const SeekTarget& aTarget) {
+  AssertOnTaskQueue();
+  if (!mState.IsRunningEngine() && !mState.IsSeekingData() &&
+      !mState.IsRecoverEngine()) {
+    MOZ_ASSERT(false, "Can't seek due to unsupported state.");
+    return MediaDecoder::SeekPromise::CreateAndReject(true, __func__);
+  }
+  // We don't support these type of seek, because they're depending on the
+  // implementation of the external engine, which might not be supported.
+  if (aTarget.IsNextFrame() || aTarget.IsVideoOnly()) {
+    return MediaDecoder::SeekPromise::CreateAndReject(true, __func__);
+  }
+
+  LOG("Start seeking to %" PRId64, aTarget.GetTime().ToMicroseconds());
+  auto* state = mState.AsSeekingData();
+  if (!state) {
+    // We're in other states, so change the state to seeking.
+    ChangeStateTo(State::SeekingData);
+    state = mState.AsSeekingData();
+  }
+  state->SetTarget(aTarget);
+
+  // Update related status.
+  mSentPlaybackEndedEvent = false;
+  mOnPlaybackEvent.Notify(MediaPlaybackEvent::SeekStarted);
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE_SEEKING);
+
+  // Notify the external playback engine about seeking. After the engine changes
+  // its current time, it would send `seeked` event.
+  mEngine->Seek(aTarget.GetTime());
+  state->mWaitingEngineSeeked = true;
+  SeekReader();
+  return state->mSeekJob.mPromise.Ensure(__func__);
+}
+
+void ExternalEngineStateMachine::SeekReader() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsSeekingData());
+  auto* state = mState.AsSeekingData();
+
+  // Reset the reader first and ask it to perform a demuxer seek.
+  ResetDecode();
+  state->mWaitingReaderSeeked = true;
+  LOG("Seek reader to %" PRId64, state->GetTargetTime().ToMicroseconds());
+  mReader->Seek(state->mSeekJob.mTarget.ref())
+      ->Then(OwnerThread(), __func__, this,
+             &ExternalEngineStateMachine::OnSeekResolved,
+             &ExternalEngineStateMachine::OnSeekRejected)
+      ->Track(state->mSeekRequest);
+}
+
+void ExternalEngineStateMachine::OnSeekResolved(const media::TimeUnit& aUnit) {
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::OnSeekResolved",
+                      MEDIA_PLAYBACK);
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsSeekingData());
+  auto* state = mState.AsSeekingData();
+
+  LOG("OnReaderSeekResolved");
+  state->mSeekRequest.Complete();
+  state->mWaitingReaderSeeked = false;
+
+  // Start sending new data to the external playback engine.
+  if (HasAudio()) {
+    mHasEnoughAudio = false;
+    OnRequestAudio();
+  }
+  if (HasVideo()) {
+    mHasEnoughVideo = false;
+    OnRequestVideo();
+  }
+  CheckIfSeekCompleted();
+}
+
+void ExternalEngineStateMachine::OnSeekRejected(
+    const SeekRejectValue& aReject) {
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::OnSeekRejected",
+                      MEDIA_PLAYBACK);
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsSeekingData());
+  auto* state = mState.AsSeekingData();
+
+  LOG("OnReaderSeekRejected");
+  state->mSeekRequest.Complete();
+  if (aReject.mError == NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA) {
+    LOG("OnSeekRejected reason=WAITING_FOR_DATA type=%s",
+        MediaData::TypeToStr(aReject.mType));
+    MOZ_ASSERT_IF(aReject.mType == MediaData::Type::AUDIO_DATA,
+                  !IsRequestingAudioData());
+    MOZ_ASSERT_IF(aReject.mType == MediaData::Type::VIDEO_DATA,
+                  !IsRequestingVideoData());
+    MOZ_ASSERT_IF(aReject.mType == MediaData::Type::AUDIO_DATA,
+                  !IsWaitingAudioData());
+    MOZ_ASSERT_IF(aReject.mType == MediaData::Type::VIDEO_DATA,
+                  !IsWaitingVideoData());
+
+    // Fire 'waiting' to notify the player that we are waiting for data.
+    mOnNextFrameStatus.Notify(
+        MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE_SEEKING);
+    WaitForData(aReject.mType);
+    return;
+  }
+
+  if (aReject.mError == NS_ERROR_DOM_MEDIA_END_OF_STREAM) {
+    EndOfStream(aReject.mType);
+    return;
+  }
+
+  MOZ_ASSERT(NS_FAILED(aReject.mError),
+             "Cancels should also disconnect mSeekRequest");
+  state->RejectIfExists(__func__);
+  ReportTelemetry(aReject.mError);
+  DecodeError(aReject.mError);
+}
+
+bool ExternalEngineStateMachine::IsSeeking() {
+  AssertOnTaskQueue();
+  const auto* state = mState.AsSeekingData();
+  return state && state->IsSeeking();
+}
+
+void ExternalEngineStateMachine::CheckIfSeekCompleted() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsSeekingData());
+  auto* state = mState.AsSeekingData();
+  if (state->mWaitingEngineSeeked || state->mWaitingReaderSeeked) {
+    LOG("Seek hasn't been completed yet, waitEngineSeeked=%d, "
+        "waitReaderSeeked=%d",
+        state->mWaitingEngineSeeked, state->mWaitingReaderSeeked);
+    return;
+  }
+
+  // As seeking should be accurate and we can't control the exact timing inside
+  // the external media engine. We always set the newCurrentTime = seekTime
+  // so that the updated HTMLMediaElement.currentTime will always be the seek
+  // target.
+  if (state->GetTargetTime() != mCurrentPosition) {
+    LOG("Force adjusting current time (%" PRId64
+        ") to match to target (%" PRId64 ")",
+        mCurrentPosition.Ref().ToMicroseconds(),
+        state->GetTargetTime().ToMicroseconds());
+    mCurrentPosition = state->GetTargetTime();
+  }
+
+  LOG("Seek completed");
+  state->Resolve(__func__);
+  mOnPlaybackEvent.Notify(MediaPlaybackEvent::Invalidate);
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_AVAILABLE);
+  StartRunningEngine();
+}
+
+void ExternalEngineStateMachine::ResetDecode() {
+  AssertOnTaskQueue();
+  if (!mInfo) {
+    return;
+  }
+
+  LOG("ResetDecode");
+  MediaFormatReader::TrackSet tracks;
+  if (HasVideo()) {
+    mVideoDataRequest.DisconnectIfExists();
+    mVideoWaitRequest.DisconnectIfExists();
+    tracks += TrackInfo::kVideoTrack;
+  }
+  if (HasAudio()) {
+    mAudioDataRequest.DisconnectIfExists();
+    mAudioWaitRequest.DisconnectIfExists();
+    tracks += TrackInfo::kAudioTrack;
+  }
+  mReader->ResetDecode(tracks);
+}
+
+RefPtr<GenericPromise> ExternalEngineStateMachine::InvokeSetSink(
+    const RefPtr<AudioDeviceInfo>& aSink) {
+  MOZ_ASSERT(NS_IsMainThread());
+  // TODO : can media engine support this?
+  return GenericPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
+}
+
+RefPtr<ShutdownPromise> ExternalEngineStateMachine::Shutdown() {
+  AssertOnTaskQueue();
+  if (mState.IsShutdownEngine()) {
+    LOG("Already shutdown");
+    return mState.AsShutdownEngine()->mShutdown;
+  }
+
+  LOG("Shutdown");
+  ChangeStateTo(State::ShutdownEngine);
+  ResetDecode();
+
+  mAudioDataRequest.DisconnectIfExists();
+  mVideoDataRequest.DisconnectIfExists();
+  mAudioWaitRequest.DisconnectIfExists();
+  mVideoWaitRequest.DisconnectIfExists();
+
+  mDuration.DisconnectAll();
+  mCurrentPosition.DisconnectAll();
+  // TODO : implement audible check
+  mIsAudioDataAudible.DisconnectAll();
+
+  mMetadataManager.Disconnect();
+
+  mSetCDMProxyPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_ABORT_ERR, __func__);
+  mSetCDMProxyRequest.DisconnectIfExists();
+
+  mEngine->Shutdown();
+
+  auto* state = mState.AsShutdownEngine();
+  state->mShutdown = mReader->Shutdown()->Then(
+      OwnerThread(), __func__, [self = RefPtr{this}, this]() {
+        LOG("Shutting down state machine task queue");
+        return OwnerThread()->BeginShutdown();
+      });
+  return state->mShutdown;
+}
+
+void ExternalEngineStateMachine::BufferedRangeUpdated() {
+  AssertOnTaskQueue();
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::BufferedRangeUpdated",
+                      MEDIA_PLAYBACK);
+
+  // While playing an unseekable stream of unknown duration, mDuration
+  // is updated as we play. But if data is being downloaded
+  // faster than played, mDuration won't reflect the end of playable data
+  // since we haven't played the frame at the end of buffered data. So update
+  // mDuration here as new data is downloaded to prevent such a lag.
+  if (mBuffered.Ref().IsInvalid()) {
+    return;
+  }
+
+  bool exists;
+  media::TimeUnit end{mBuffered.Ref().GetEnd(&exists)};
+  if (!exists) {
+    return;
+  }
+
+  // Use estimated duration from buffer ranges when mDuration is unknown or
+  // the estimated duration is larger.
+  if (mDuration.Ref().isNothing() || mDuration.Ref()->IsInfinite() ||
+      end > mDuration.Ref().ref()) {
+    mDuration = Some(end);
+    DDLOG(DDLogCategory::Property, "duration_us",
+          mDuration.Ref()->ToMicroseconds());
+  }
+}
+
+// Note: the variadic only supports passing member variables.
+#define PERFORM_WHEN_ALLOW(Func, ...)                                         \
+  do {                                                                        \
+    /* Initialzation is not done yet, postpone the operation */               \
+    if ((mState.IsInitEngine() || mState.IsRecoverEngine()) &&                \
+        mState.AsInitEngine()->mInitPromise) {                                \
+      LOG("%s is called before init", __func__);                              \
+      mState.AsInitEngine()->mInitPromise->Then(                              \
+          OwnerThread(), __func__,                                            \
+          [self = RefPtr{this}, this](                                        \
+              const GenericNonExclusivePromise::ResolveOrRejectValue& aVal) { \
+            if (aVal.IsResolve()) {                                           \
+              Func(__VA_ARGS__);                                              \
+            }                                                                 \
+          });                                                                 \
+      return;                                                                 \
+    } else if (mState.IsShutdownEngine()) {                                   \
+      return;                                                                 \
+    }                                                                         \
+  } while (false)
+
+void ExternalEngineStateMachine::SetPlaybackRate(double aPlaybackRate) {
+  AssertOnTaskQueue();
+  mPlaybackRate = aPlaybackRate;
+  PERFORM_WHEN_ALLOW(SetPlaybackRate, mPlaybackRate);
+  mEngine->SetPlaybackRate(aPlaybackRate);
+}
+
+void ExternalEngineStateMachine::VolumeChanged() {
+  AssertOnTaskQueue();
+  PERFORM_WHEN_ALLOW(VolumeChanged);
+  mEngine->SetVolume(mVolume);
+}
+
+void ExternalEngineStateMachine::PreservesPitchChanged() {
+  AssertOnTaskQueue();
+  PERFORM_WHEN_ALLOW(PreservesPitchChanged);
+  mEngine->SetPreservesPitch(mPreservesPitch);
+}
+
+void ExternalEngineStateMachine::PlayStateChanged() {
+  AssertOnTaskQueue();
+  PERFORM_WHEN_ALLOW(PlayStateChanged);
+  if (mPlayState == MediaDecoder::PLAY_STATE_PLAYING) {
+    mEngine->Play();
+  } else if (mPlayState == MediaDecoder::PLAY_STATE_PAUSED) {
+    mEngine->Pause();
+  }
+}
+
+void ExternalEngineStateMachine::LoopingChanged() {
+  AssertOnTaskQueue();
+  PERFORM_WHEN_ALLOW(LoopingChanged);
+  mEngine->SetLooping(mLooping);
+}
+
+#undef PERFORM_WHEN_ALLOW
+
+void ExternalEngineStateMachine::EndOfStream(MediaData::Type aType) {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+  static auto DataTypeToTrackType = [](const MediaData::Type& aType) {
+    if (aType == MediaData::Type::VIDEO_DATA) {
+      return TrackInfo::TrackType::kVideoTrack;
+    }
+    if (aType == MediaData::Type::AUDIO_DATA) {
+      return TrackInfo::TrackType::kAudioTrack;
+    }
+    return TrackInfo::TrackType::kUndefinedTrack;
+  };
+  mEngine->NotifyEndOfStream(DataTypeToTrackType(aType));
+}
+
+void ExternalEngineStateMachine::WaitForData(MediaData::Type aType) {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::WaitForData",
+                      MEDIA_PLAYBACK);
+  MOZ_ASSERT(aType == MediaData::Type::AUDIO_DATA ||
+             aType == MediaData::Type::VIDEO_DATA);
+
+  LOG("WaitForData");
+  RefPtr<ExternalEngineStateMachine> self = this;
+  if (aType == MediaData::Type::AUDIO_DATA) {
+    MOZ_ASSERT(HasAudio());
+    mReader->WaitForData(MediaData::Type::AUDIO_DATA)
+        ->Then(
+            OwnerThread(), __func__,
+            [self, this](MediaData::Type aType) {
+              AUTO_PROFILER_LABEL(
+                  "ExternalEngineStateMachine::WaitForData:AudioResolved",
+                  MEDIA_PLAYBACK);
+              MOZ_ASSERT(aType == MediaData::Type::AUDIO_DATA);
+              LOG("Done waiting for audio data");
+              mAudioWaitRequest.Complete();
+              MaybeFinishWaitForData();
+            },
+            [self, this](const WaitForDataRejectValue& aRejection) {
+              AUTO_PROFILER_LABEL(
+                  "ExternalEngineStateMachine::WaitForData:AudioRejected",
+                  MEDIA_PLAYBACK);
+              mAudioWaitRequest.Complete();
+              DecodeError(NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA);
+            })
+        ->Track(mAudioWaitRequest);
+  } else {
+    MOZ_ASSERT(HasVideo());
+    mReader->WaitForData(MediaData::Type::VIDEO_DATA)
+        ->Then(
+            OwnerThread(), __func__,
+            [self, this](MediaData::Type aType) {
+              AUTO_PROFILER_LABEL(
+                  "ExternalEngineStateMachine::WaitForData:VideoResolved",
+                  MEDIA_PLAYBACK);
+              MOZ_ASSERT(aType == MediaData::Type::VIDEO_DATA);
+              LOG("Done waiting for video data");
+              mVideoWaitRequest.Complete();
+              MaybeFinishWaitForData();
+            },
+            [self, this](const WaitForDataRejectValue& aRejection) {
+              AUTO_PROFILER_LABEL(
+                  "ExternalEngineStateMachine::WaitForData:VideoRejected",
+                  MEDIA_PLAYBACK);
+              mVideoWaitRequest.Complete();
+              DecodeError(NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA);
+            })
+        ->Track(mVideoWaitRequest);
+  }
+}
+
+void ExternalEngineStateMachine::MaybeFinishWaitForData() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+
+  bool isWaitingForAudio = HasAudio() && mAudioWaitRequest.Exists();
+  bool isWaitingForVideo = HasVideo() && mVideoWaitRequest.Exists();
+  if (isWaitingForAudio || isWaitingForVideo) {
+    LOG("Still waiting for data (waitAudio=%d, waitVideo=%d)",
+        isWaitingForAudio, isWaitingForVideo);
+    return;
+  }
+
+  LOG("Finished waiting for data");
+  if (mState.IsSeekingData()) {
+    SeekReader();
+    return;
+  }
+  if (HasAudio()) {
+    RunningEngineUpdate(MediaData::Type::AUDIO_DATA);
+  }
+  if (HasVideo()) {
+    RunningEngineUpdate(MediaData::Type::VIDEO_DATA);
+  }
+}
+
+void ExternalEngineStateMachine::StartRunningEngine() {
+  ChangeStateTo(State::RunningEngine);
+  // Manually check the play state because the engine might be recovered from
+  // crash or just get recreated, so PlayStateChanged() won't be triggered.
+  if (mPlayState == MediaDecoder::PLAY_STATE_PLAYING) {
+    mEngine->Play();
+  }
+  if (HasAudio()) {
+    RunningEngineUpdate(MediaData::Type::AUDIO_DATA);
+  }
+  if (HasVideo()) {
+    RunningEngineUpdate(MediaData::Type::VIDEO_DATA);
+  }
+}
+
+void ExternalEngineStateMachine::RunningEngineUpdate(MediaData::Type aType) {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+  if (aType == MediaData::Type::AUDIO_DATA && !mHasEnoughAudio) {
+    OnRequestAudio();
+  }
+  if (aType == MediaData::Type::VIDEO_DATA && !mHasEnoughVideo) {
+    OnRequestVideo();
+  }
+}
+
+void ExternalEngineStateMachine::OnRequestAudio() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+  LOGV("OnRequestAudio");
+
+  if (!HasAudio()) {
+    return;
+  }
+
+  if (IsRequestingAudioData() || mAudioWaitRequest.Exists() || IsSeeking()) {
+    LOGV(
+        "No need to request audio, isRequesting=%d, waitingAudio=%d, "
+        "isSeeking=%d",
+        IsRequestingAudioData(), mAudioWaitRequest.Exists(), IsSeeking());
+    return;
+  }
+
+  LOGV("Start requesting audio");
+  PerformanceRecorder<PlaybackStage> perfRecorder(MediaStage::RequestData);
+  RefPtr<ExternalEngineStateMachine> self = this;
+  mReader->RequestAudioData()
+      ->Then(
+          OwnerThread(), __func__,
+          [this, self, perfRecorder(std::move(perfRecorder))](
+              const RefPtr<AudioData>& aAudio) mutable {
+            perfRecorder.Record();
+            mAudioDataRequest.Complete();
+            LOGV("Completed requesting audio");
+            AUTO_PROFILER_LABEL(
+                "ExternalEngineStateMachine::OnRequestAudio:Resolved",
+                MEDIA_PLAYBACK);
+            MOZ_ASSERT(aAudio);
+            RunningEngineUpdate(MediaData::Type::AUDIO_DATA);
+          },
+          [this, self](const MediaResult& aError) {
+            mAudioDataRequest.Complete();
+            AUTO_PROFILER_LABEL(
+                "ExternalEngineStateMachine::OnRequestAudio:Rejected",
+                MEDIA_PLAYBACK);
+            LOG("OnRequestAudio ErrorName=%s Message=%s",
+                aError.ErrorName().get(), aError.Message().get());
+            switch (aError.Code()) {
+              case NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA:
+                WaitForData(MediaData::Type::AUDIO_DATA);
+                break;
+              case NS_ERROR_DOM_MEDIA_CANCELED:
+                OnRequestAudio();
+                break;
+              case NS_ERROR_DOM_MEDIA_END_OF_STREAM:
+                LOG("Reach to the end, no more audio data");
+                EndOfStream(MediaData::Type::AUDIO_DATA);
+                break;
+              case NS_ERROR_DOM_MEDIA_REMOTE_DECODER_CRASHED_MF_CDM_ERR:
+                // We will handle the process crash in `NotifyErrorInternal()`
+                // so here just silently ignore this.
+                break;
+              default:
+                ReportTelemetry(aError);
+                DecodeError(aError);
+            }
+          })
+      ->Track(mAudioDataRequest);
+}
+
+void ExternalEngineStateMachine::OnRequestVideo() {
+  AssertOnTaskQueue();
+  MOZ_ASSERT(mState.IsRunningEngine() || mState.IsSeekingData());
+  LOGV("OnRequestVideo");
+
+  if (!HasVideo()) {
+    return;
+  }
+
+  if (IsRequestingVideoData() || mVideoWaitRequest.Exists() || IsSeeking()) {
+    LOGV(
+        "No need to request video, isRequesting=%d, waitingVideo=%d, "
+        "isSeeking=%d",
+        IsRequestingVideoData(), mVideoWaitRequest.Exists(), IsSeeking());
+    return;
+  }
+
+  LOGV("Start requesting video");
+  PerformanceRecorder<PlaybackStage> perfRecorder(MediaStage::RequestData,
+                                                  Info().mVideo.mImage.height);
+  RefPtr<ExternalEngineStateMachine> self = this;
+  mReader->RequestVideoData(GetVideoThreshold(), false)
+      ->Then(
+          OwnerThread(), __func__,
+          [this, self, perfRecorder(std::move(perfRecorder))](
+              const RefPtr<VideoData>& aVideo) mutable {
+            perfRecorder.Record();
+            mVideoDataRequest.Complete();
+            LOGV("Completed requesting video");
+            AUTO_PROFILER_LABEL(
+                "ExternalEngineStateMachine::OnRequestVideo:Resolved",
+                MEDIA_PLAYBACK);
+            MOZ_ASSERT(aVideo);
+            if (!mHasReceivedFirstDecodedVideoFrame) {
+              mHasReceivedFirstDecodedVideoFrame = true;
+              OnLoadedFirstFrame();
+            }
+            RunningEngineUpdate(MediaData::Type::VIDEO_DATA);
+            // Send image to PIP window.
+            if (mSecondaryVideoContainer.Ref()) {
+              mSecondaryVideoContainer.Ref()->SetCurrentFrame(
+                  mVideoDisplay, aVideo->mImage, TimeStamp::Now());
+            } else {
+              mVideoFrameContainer->SetCurrentFrame(
+                  mVideoDisplay, aVideo->mImage, TimeStamp::Now());
+            }
+          },
+          [this, self](const MediaResult& aError) {
+            mVideoDataRequest.Complete();
+            AUTO_PROFILER_LABEL(
+                "ExternalEngineStateMachine::OnRequestVideo:Rejected",
+                MEDIA_PLAYBACK);
+            LOG("OnRequestVideo ErrorName=%s Message=%s",
+                aError.ErrorName().get(), aError.Message().get());
+            switch (aError.Code()) {
+              case NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA:
+                WaitForData(MediaData::Type::VIDEO_DATA);
+                break;
+              case NS_ERROR_DOM_MEDIA_CANCELED:
+                OnRequestVideo();
+                break;
+              case NS_ERROR_DOM_MEDIA_END_OF_STREAM:
+                LOG("Reach to the end, no more video data");
+                EndOfStream(MediaData::Type::VIDEO_DATA);
+                break;
+              case NS_ERROR_DOM_MEDIA_REMOTE_DECODER_CRASHED_MF_CDM_ERR:
+                // We will handle the process crash in `NotifyErrorInternal()`
+                // so here just silently ignore this.
+                break;
+              default:
+                ReportTelemetry(aError);
+                DecodeError(aError);
+            }
+          })
+      ->Track(mVideoDataRequest);
+}
+
+void ExternalEngineStateMachine::OnLoadedFirstFrame() {
+  AssertOnTaskQueue();
+  // We will wait until receive the first video frame.
+  if (mInfo->HasVideo() && !mHasReceivedFirstDecodedVideoFrame) {
+    LOGV("Hasn't received first decoded video frame");
+    return;
+  }
+  LOGV("OnLoadedFirstFrame");
+  MediaDecoderEventVisibility visibility =
+      mSentFirstFrameLoadedEvent ? MediaDecoderEventVisibility::Suppressed
+                                 : MediaDecoderEventVisibility::Observable;
+  mSentFirstFrameLoadedEvent = true;
+  mFirstFrameLoadedEvent.Notify(UniquePtr<MediaInfo>(new MediaInfo(Info())),
+                                visibility);
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_AVAILABLE);
+}
+
+void ExternalEngineStateMachine::OnLoadedData() {
+  AssertOnTaskQueue();
+  // In case the external engine doesn't send the first frame loaded event
+  // correctly.
+  if (!mSentFirstFrameLoadedEvent) {
+    OnLoadedFirstFrame();
+  }
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_AVAILABLE);
+}
+
+void ExternalEngineStateMachine::OnWaiting() {
+  AssertOnTaskQueue();
+  mOnNextFrameStatus.Notify(
+      MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE_BUFFERING);
+}
+
+void ExternalEngineStateMachine::OnPlaying() {
+  AssertOnTaskQueue();
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_AVAILABLE);
+}
+
+void ExternalEngineStateMachine::OnSeeked() {
+  AssertOnTaskQueue();
+  if (!mState.IsSeekingData()) {
+    LOG("Engine Seeking has been completed, ignore the event");
+    return;
+  }
+  MOZ_ASSERT(mState.IsSeekingData());
+
+  const auto currentTime = mEngine->GetCurrentPosition();
+  auto* state = mState.AsSeekingData();
+  LOG("OnEngineSeeked, target=%" PRId64 ", currentTime=%" PRId64,
+      state->GetTargetTime().ToMicroseconds(), currentTime.ToMicroseconds());
+  // It's possible to receive multiple seeked event if we seek the engine
+  // before the previous seeking finishes, so we would wait until the last
+  // seeking is finished.
+  if (currentTime >= state->GetTargetTime()) {
+    state->mWaitingEngineSeeked = false;
+    CheckIfSeekCompleted();
+  }
+}
+
+void ExternalEngineStateMachine::OnBufferingStarted() {
+  AssertOnTaskQueue();
+  mOnNextFrameStatus.Notify(
+      MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE_BUFFERING);
+  if (HasAudio()) {
+    WaitForData(MediaData::Type::AUDIO_DATA);
+  }
+  if (HasVideo()) {
+    WaitForData(MediaData::Type::VIDEO_DATA);
+  }
+}
+
+void ExternalEngineStateMachine::OnBufferingEnded() {
+  AssertOnTaskQueue();
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_AVAILABLE);
+}
+
+void ExternalEngineStateMachine::OnEnded() {
+  AssertOnTaskQueue();
+  if (mSentPlaybackEndedEvent) {
+    return;
+  }
+  LOG("Playback is ended");
+  mOnNextFrameStatus.Notify(MediaDecoderOwner::NEXT_FRAME_UNAVAILABLE);
+  mOnPlaybackEvent.Notify(MediaPlaybackEvent::PlaybackEnded);
+  mSentPlaybackEndedEvent = true;
+}
+
+void ExternalEngineStateMachine::OnTimeupdate() {
+  AssertOnTaskQueue();
+  if (IsSeeking()) {
+    return;
+  }
+  mCurrentPosition = mEngine->GetCurrentPosition();
+  if (mDuration.Ref().ref() < mCurrentPosition.Ref()) {
+    mDuration = Some(mCurrentPosition.Ref());
+  }
+}
+
+void ExternalEngineStateMachine::NotifyEventInternal(
+    ExternalEngineEvent aEvent) {
+  AssertOnTaskQueue();
+  AUTO_PROFILER_LABEL("ExternalEngineStateMachine::NotifyEventInternal",
+                      MEDIA_PLAYBACK);
+  LOG("Receive event %s", ExternalEngineEventToStr(aEvent));
+  if (mState.IsShutdownEngine()) {
+    return;
+  }
+  switch (aEvent) {
+    case ExternalEngineEvent::LoadedMetaData:
+      // We read metadata by ourselves, ignore this if there is any.
+      MOZ_ASSERT(mInfo);
+      break;
+    case ExternalEngineEvent::LoadedFirstFrame:
+      OnLoadedFirstFrame();
+      break;
+    case ExternalEngineEvent::LoadedData:
+      OnLoadedData();
+      break;
+    case ExternalEngineEvent::Waiting:
+      OnWaiting();
+      break;
+    case ExternalEngineEvent::Playing:
+      OnPlaying();
+      break;
+    case ExternalEngineEvent::Seeked:
+      OnSeeked();
+      break;
+    case ExternalEngineEvent::BufferingStarted:
+      OnBufferingStarted();
+      break;
+    case ExternalEngineEvent::BufferingEnded:
+      OnBufferingEnded();
+      break;
+    case ExternalEngineEvent::Timeupdate:
+      OnTimeupdate();
+      break;
+    case ExternalEngineEvent::Ended:
+      OnEnded();
+      break;
+    case ExternalEngineEvent::RequestForAudio:
+      mHasEnoughAudio = false;
+      if (ShouldRunEngineUpdateForRequest()) {
+        RunningEngineUpdate(MediaData::Type::AUDIO_DATA);
+      }
+      break;
+    case ExternalEngineEvent::RequestForVideo:
+      mHasEnoughVideo = false;
+      if (ShouldRunEngineUpdateForRequest()) {
+        RunningEngineUpdate(MediaData::Type::VIDEO_DATA);
+      }
+      break;
+    case ExternalEngineEvent::AudioEnough:
+      mHasEnoughAudio = true;
+      break;
+    case ExternalEngineEvent::VideoEnough:
+      mHasEnoughVideo = true;
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Undefined event!");
+      break;
+  }
+}
+
+bool ExternalEngineStateMachine::ShouldRunEngineUpdateForRequest() {
+  // Running engine update will request new data, which could be run on
+  // `RunningEngine` or `SeekingData` state. However, in `SeekingData` we should
+  // only request new data after finishing reader seek, otherwise the reader
+  // would start requesting data from a wrong position.
+  return mState.IsRunningEngine() ||
+         (mState.AsSeekingData() &&
+          !mState.AsSeekingData()->mWaitingReaderSeeked);
+}
+
+void ExternalEngineStateMachine::NotifyErrorInternal(
+    const MediaResult& aError) {
+  AssertOnTaskQueue();
+  LOG("Engine error: %s", aError.Description().get());
+  if (aError == NS_ERROR_DOM_MEDIA_NOT_SUPPORTED_ERR) {
+    // The external engine doesn't support the type, try to notify the decoder
+    // to use our own state machine again.
+    ReportTelemetry(NS_ERROR_DOM_MEDIA_EXTERNAL_ENGINE_NOT_SUPPORTED_ERR);
+    DecodeError(
+        MediaResult(NS_ERROR_DOM_MEDIA_EXTERNAL_ENGINE_NOT_SUPPORTED_ERR));
+  } else if (aError == NS_ERROR_DOM_MEDIA_REMOTE_DECODER_CRASHED_MF_CDM_ERR) {
+    ReportTelemetry(NS_ERROR_DOM_MEDIA_REMOTE_DECODER_CRASHED_MF_CDM_ERR);
+    RecoverFromCDMProcessCrashIfNeeded();
+  } else {
+    ReportTelemetry(aError);
+    DecodeError(aError);
+  }
+}
+
+void ExternalEngineStateMachine::NotifyResizingInternal(uint32_t aWidth,
+                                                        uint32_t aHeight) {
+  LOG("video resize from [%d,%d] to [%d,%d]", mVideoDisplay.width,
+      mVideoDisplay.height, aWidth, aHeight);
+  mVideoDisplay = gfx::IntSize{aWidth, aHeight};
+}
+
+void ExternalEngineStateMachine::RecoverFromCDMProcessCrashIfNeeded() {
+  AssertOnTaskQueue();
+  if (mState.IsRecoverEngine()) {
+    return;
+  }
+  ProcessCrashMonitor::NotifyCrash();
+  if (!ProcessCrashMonitor::ShouldRecoverProcess()) {
+    LOG("CDM process has crashed too many times, abort recovery");
+    DecodeError(
+        MediaResult(NS_ERROR_DOM_MEDIA_EXTERNAL_ENGINE_NOT_SUPPORTED_ERR));
+    return;
+  }
+
+  LOG("CDM process crashed, recover the engine again (last time=%" PRId64 ")",
+      mCurrentPosition.Ref().ToMicroseconds());
+  ChangeStateTo(State::RecoverEngine);
+  if (HasVideo()) {
+    mVideoDataRequest.DisconnectIfExists();
+    mVideoWaitRequest.DisconnectIfExists();
+  }
+  if (HasAudio()) {
+    mAudioDataRequest.DisconnectIfExists();
+    mAudioWaitRequest.DisconnectIfExists();
+  }
+  // Ask the reader to shutdown current decoders which are no longer available
+  // due to the remote process crash.
+  mReader->ReleaseResources();
+  InitEngine();
+}
+
+media::TimeUnit ExternalEngineStateMachine::GetVideoThreshold() {
+  AssertOnTaskQueue();
+  if (auto* state = mState.AsSeekingData()) {
+    return state->GetTargetTime();
+  }
+  return mCurrentPosition.Ref();
+}
+
+void ExternalEngineStateMachine::UpdateSecondaryVideoContainer() {
+  AssertOnTaskQueue();
+  LOG("UpdateSecondaryVideoContainer=%p", mSecondaryVideoContainer.Ref().get());
+  mOnSecondaryVideoContainerInstalled.Notify(mSecondaryVideoContainer.Ref());
+}
+
+RefPtr<SetCDMPromise> ExternalEngineStateMachine::SetCDMProxy(
+    CDMProxy* aProxy) {
+  if (mState.IsShutdownEngine()) {
+    return SetCDMPromise::CreateAndReject(NS_ERROR_FAILURE, __func__);
+  }
+
+  if (mState.IsInitEngine() && mState.AsInitEngine()->mInitPromise) {
+    LOG("SetCDMProxy is called before init");
+    mState.AsInitEngine()->mInitPromise->Then(
+        OwnerThread(), __func__,
+        [self = RefPtr{this}, proxy = RefPtr{aProxy},
+         this](const GenericNonExclusivePromise::ResolveOrRejectValue& aVal) {
+          SetCDMProxy(proxy)
+              ->Then(OwnerThread(), __func__,
+                     [self = RefPtr{this},
+                      this](const SetCDMPromise::ResolveOrRejectValue& aVal) {
+                       mSetCDMProxyRequest.Complete();
+                       if (aVal.IsResolve()) {
+                         mSetCDMProxyPromise.Resolve(true, __func__);
+                       } else {
+                         mSetCDMProxyPromise.Reject(NS_ERROR_DOM_MEDIA_CDM_ERR,
+                                                    __func__);
+                       }
+                     })
+              ->Track(mSetCDMProxyRequest);
+        });
+    return mSetCDMProxyPromise.Ensure(__func__);
+  }
+
+  // TODO : set CDM proxy again if we recreate the media engine after crash.
+  mKeySystem = NS_ConvertUTF16toUTF8(aProxy->KeySystem());
+  LOG("SetCDMProxy=%p (key-system=%s)", aProxy, mKeySystem.get());
+  MOZ_DIAGNOSTIC_ASSERT(mEngine);
+  if (!mEngine->SetCDMProxy(aProxy)) {
+    LOG("Failed to set CDM proxy on the engine");
+    return SetCDMPromise::CreateAndReject(NS_ERROR_DOM_MEDIA_CDM_ERR, __func__);
+  }
+  return MediaDecoderStateMachineBase::SetCDMProxy(aProxy);
+}
+
+bool ExternalEngineStateMachine::IsCDMProxySupported(CDMProxy* aProxy) {
+#ifdef MOZ_WMF_CDM
+  MOZ_ASSERT(aProxy);
+  // 1=enabled encrypted and clear, 2=enabled encrytped
+  if (StaticPrefs::media_wmf_media_engine_enabled() != 1 &&
+      StaticPrefs::media_wmf_media_engine_enabled() != 2) {
+    return false;
+  }
+
+  // The CDM needs to be hosted in the same process of the external engine, and
+  // only WMFCDM meets this requirement.
+  return aProxy->AsWMFCDMProxy();
+#else
+  return false;
+#endif
+}
+
+void ExternalEngineStateMachine::ReportTelemetry(const MediaResult& aError) {
+  glean::mfcdm::ErrorExtra extraData;
+  extraData.errorName = Some(aError.ErrorName());
+  nsAutoCString resolution;
+  if (mInfo) {
+    if (mInfo->HasAudio()) {
+      extraData.audioCodec = Some(mInfo->mAudio.mMimeType);
+    }
+    if (mInfo->HasVideo()) {
+      extraData.videoCodec = Some(mInfo->mVideo.mMimeType);
+      DetermineResolutionForTelemetry(*mInfo, resolution);
+      extraData.resolution = Some(resolution);
+    }
+  }
+  if (!mKeySystem.IsEmpty()) {
+    extraData.keySystem = Some(mKeySystem);
+  }
+  glean::mfcdm::error.Record(Some(extraData));
+  if (MOZ_LOG_TEST(gMediaDecoderLog, LogLevel::Debug)) {
+    nsPrintfCString logMessage{"MFCDM Error event, error=%s",
+                               aError.ErrorName().get()};
+    if (mInfo) {
+      if (mInfo->HasAudio()) {
+        logMessage.Append(
+            nsPrintfCString{", audio=%s", mInfo->mAudio.mMimeType.get()});
+      }
+      if (mInfo->HasVideo()) {
+        logMessage.Append(nsPrintfCString{", video=%s, resolution=%s",
+                                          mInfo->mVideo.mMimeType.get(),
+                                          resolution.get()});
+      }
+    }
+    if (!mKeySystem.IsEmpty()) {
+      logMessage.Append(nsPrintfCString{", keySystem=%s", mKeySystem.get()});
+    }
+    LOG("%s", logMessage.get());
+  }
+}
+
+#undef FMT
+#undef LOG
+#undef LOGV
+#undef LOGW
+#undef LOGE
+
+}  // namespace mozilla