6 files changed, 1536 insertions, 0 deletions
diff --git a/dom/media/platforms/wrappers/AudioTrimmer.cpp b/dom/media/platforms/wrappers/AudioTrimmer.cpp
new file mode 100644
index 0000000000..fa37132314
--- /dev/null
+++ b/dom/media/platforms/wrappers/AudioTrimmer.cpp
@@ -0,0 +1,214 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "AudioTrimmer.h"
+
+#define LOG(arg, ...)                                                  \
+  DDMOZ_LOG(sPDMLog, mozilla::LogLevel::Debug, "::%s: " arg, __func__, \
+            ##__VA_ARGS__)
+
+#define LOGV(arg, ...)                                                   \
+  DDMOZ_LOG(sPDMLog, mozilla::LogLevel::Verbose, "::%s: " arg, __func__, \
+            ##__VA_ARGS__)
+
+namespace mozilla {
+
+using media::TimeInterval;
+using media::TimeUnit;
+
+RefPtr<MediaDataDecoder::InitPromise> AudioTrimmer::Init() {
+  mThread = GetCurrentSerialEventTarget();
+  return mDecoder->Init();
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> AudioTrimmer::Decode(
+    MediaRawData* aSample) {
+  MOZ_ASSERT(mThread->IsOnCurrentThread(),
+             "We're not on the thread we were first initialized on");
+  RefPtr<MediaRawData> sample = aSample;
+  PrepareTrimmers(sample);
+  RefPtr<AudioTrimmer> self = this;
+  RefPtr<DecodePromise> p = mDecoder->Decode(sample)->Then(
+      GetCurrentSerialEventTarget(), __func__,
+      [self, sample](DecodePromise::ResolveOrRejectValue&& aValue) {
+        return self->HandleDecodedResult(std::move(aValue), sample);
+      });
+  return p;
+}
+
+RefPtr<MediaDataDecoder::FlushPromise> AudioTrimmer::Flush() {
+  MOZ_ASSERT(mThread->IsOnCurrentThread(),
+             "We're not on the thread we were first initialized on");
+  RefPtr<FlushPromise> p = mDecoder->Flush();
+  mTrimmers.Clear();
+  return p;
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> AudioTrimmer::Drain() {
+  MOZ_ASSERT(mThread->IsOnCurrentThread(),
+             "We're not on the thread we were first initialized on");
+  LOG("Draining");
+  RefPtr<DecodePromise> p = mDecoder->Drain()->Then(
+      GetCurrentSerialEventTarget(), __func__,
+      [self = RefPtr{this}](DecodePromise::ResolveOrRejectValue&& aValue) {
+        return self->HandleDecodedResult(std::move(aValue), nullptr);
+      });
+  return p;
+}
+
+RefPtr<ShutdownPromise> AudioTrimmer::Shutdown() {
+  // mThread may not be set if Init hasn't been called first.
+  MOZ_ASSERT(!mThread || mThread->IsOnCurrentThread());
+  return mDecoder->Shutdown();
+}
+
+nsCString AudioTrimmer::GetDescriptionName() const {
+  return mDecoder->GetDescriptionName();
+}
+
+bool AudioTrimmer::IsHardwareAccelerated(nsACString& aFailureReason) const {
+  return mDecoder->IsHardwareAccelerated(aFailureReason);
+}
+
+void AudioTrimmer::SetSeekThreshold(const media::TimeUnit& aTime) {
+  mDecoder->SetSeekThreshold(aTime);
+}
+
+bool AudioTrimmer::SupportDecoderRecycling() const {
+  return mDecoder->SupportDecoderRecycling();
+}
+
+MediaDataDecoder::ConversionRequired AudioTrimmer::NeedsConversion() const {
+  return mDecoder->NeedsConversion();
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> AudioTrimmer::HandleDecodedResult(
+    DecodePromise::ResolveOrRejectValue&& aValue, MediaRawData* aRaw) {
+  MOZ_ASSERT(mThread->IsOnCurrentThread(),
+             "We're not on the thread we were first initialized on");
+  if (aValue.IsReject()) {
+    return DecodePromise::CreateAndReject(std::move(aValue.RejectValue()),
+                                          __func__);
+  }
+  int64_t rawStart = aRaw ? aRaw->mTime.ToMicroseconds() : 0;
+  int64_t rawEnd = aRaw ? aRaw->GetEndTime().ToMicroseconds() : 0;
+  MediaDataDecoder::DecodedData results = std::move(aValue.ResolveValue());
+  if (results.IsEmpty()) {
+    // No samples returned, we assume this is due to the latency of the
+    // decoder and that the related decoded sample will be returned during
+    // the next call to Decode().
+    LOG("No sample returned for sample[%" PRId64 ",%" PRId64 "]", rawStart,
+        rawEnd);
+  }
+  for (uint32_t i = 0; i < results.Length();) {
+    const RefPtr<MediaData>& data = results[i];
+    MOZ_ASSERT(data->mType == MediaData::Type::AUDIO_DATA);
+    TimeInterval sampleInterval(data->mTime, data->GetEndTime());
+    if (mTrimmers.IsEmpty()) {
+      // mTrimmers being empty can only occurs if the decoder returned more
+      // frames than we pushed in. We can't handle this case, abort trimming.
+      LOG("sample[%" PRId64 ",%" PRId64 "] (decoded[%" PRId64 ",%" PRId64
+          "] no trimming information",
+          rawStart, rawEnd, sampleInterval.mStart.ToMicroseconds(),
+          sampleInterval.mEnd.ToMicroseconds());
+      i++;
+      continue;
+    }
+
+    Maybe<TimeInterval> trimmer = mTrimmers[0];
+    mTrimmers.RemoveElementAt(0);
+    if (!trimmer) {
+      // Those frames didn't need trimming.
+      LOGV("sample[%" PRId64 ",%" PRId64 "] (decoded[%" PRId64 ",%" PRId64
+           "] no trimming needed",
+           rawStart, rawEnd, sampleInterval.mStart.ToMicroseconds(),
+           sampleInterval.mEnd.ToMicroseconds());
+      i++;
+      continue;
+    }
+    if (!trimmer->Intersects(sampleInterval)) {
+      LOG("sample[%" PRId64 ",%" PRId64 "] (decoded[%" PRId64 ",%" PRId64
+          "] would be empty after trimming, dropping it",
+          rawStart, rawEnd, sampleInterval.mStart.ToMicroseconds(),
+          sampleInterval.mEnd.ToMicroseconds());
+      results.RemoveElementAt(i);
+      continue;
+    }
+    LOG("Trimming sample[%" PRId64 ",%" PRId64 "] to [%" PRId64 ",%" PRId64
+        "] (raw "
+        "was:[%" PRId64 ",%" PRId64 "])",
+        sampleInterval.mStart.ToMicroseconds(),
+        sampleInterval.mEnd.ToMicroseconds(), trimmer->mStart.ToMicroseconds(),
+        trimmer->mEnd.ToMicroseconds(), rawStart, rawEnd);
+
+    TimeInterval trim({std::max(trimmer->mStart, sampleInterval.mStart),
+                       std::min(trimmer->mEnd, sampleInterval.mEnd)});
+    AudioData* sample = static_cast<AudioData*>(data.get());
+    bool ok = sample->SetTrimWindow(trim);
+    NS_ASSERTION(ok, "Trimming of audio sample failed");
+    Unused << ok;
+    if (sample->Frames() == 0) {
+      LOG("sample[%" PRId64 ",%" PRId64
+          "] is empty after trimming, dropping it",
+          rawStart, rawEnd);
+      results.RemoveElementAt(i);
+      continue;
+    }
+    i++;
+  }
+  return DecodePromise::CreateAndResolve(std::move(results), __func__);
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> AudioTrimmer::DecodeBatch(
+    nsTArray<RefPtr<MediaRawData>>&& aSamples) {
+  MOZ_ASSERT(mThread->IsOnCurrentThread(),
+             "We're not on the thread we were first initialized on");
+  LOG("DecodeBatch");
+
+  for (auto&& sample : aSamples) {
+    PrepareTrimmers(sample);
+  }
+  RefPtr<DecodePromise> p =
+      mDecoder->DecodeBatch(std::move(aSamples))
+          ->Then(GetCurrentSerialEventTarget(), __func__,
+                 [self = RefPtr{this}](
+                     DecodePromise::ResolveOrRejectValue&& aValue) {
+                   // If the decoder returned less samples than what we fed it.
+                   // We can assume that this is due to the decoder encoding
+                   // delay and that all decoded frames have been shifted by n =
+                   // compressedSamples.Length() - decodedSamples.Length() and
+                   // that the first n compressed samples returned nothing.
+                   return self->HandleDecodedResult(std::move(aValue), nullptr);
+                 });
+  return p;
+}
+
+void AudioTrimmer::PrepareTrimmers(MediaRawData* aRaw) {
+  // A compress sample indicates that it needs to be trimmed after decoding by
+  // having its mOriginalPresentationWindow member set; in which case
+  // mOriginalPresentationWindow contains the original time and duration of
+  // the frame set by the demuxer and mTime and mDuration set to what it
+  // should be after trimming.
+  if (aRaw->mOriginalPresentationWindow) {
+    LOG("sample[%" PRId64 ",%" PRId64 "] has trimming info ([%" PRId64
+        ",%" PRId64 "]",
+        aRaw->mOriginalPresentationWindow->mStart.ToMicroseconds(),
+        aRaw->mOriginalPresentationWindow->mEnd.ToMicroseconds(),
+        aRaw->mTime.ToMicroseconds(), aRaw->GetEndTime().ToMicroseconds());
+    mTrimmers.AppendElement(
+        Some(TimeInterval(aRaw->mTime, aRaw->GetEndTime())));
+    aRaw->mTime = aRaw->mOriginalPresentationWindow->mStart;
+    aRaw->mDuration = aRaw->mOriginalPresentationWindow->Length();
+  } else {
+    LOGV("sample[%" PRId64 ",%" PRId64 "] no trimming information",
+         aRaw->mTime.ToMicroseconds(), aRaw->GetEndTime().ToMicroseconds());
+    mTrimmers.AppendElement(Nothing());
+  }
+}
+
+}  // namespace mozilla
+
+#undef LOG
diff --git a/dom/media/platforms/wrappers/AudioTrimmer.h b/dom/media/platforms/wrappers/AudioTrimmer.h
new file mode 100644
index 0000000000..dd7ac1a57b
--- /dev/null
+++ b/dom/media/platforms/wrappers/AudioTrimmer.h
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#if !defined(AudioTrimmer_h_)
+#  define AudioTrimmer_h_
+
+#  include "PlatformDecoderModule.h"
+#  include "mozilla/Mutex.h"
+
+namespace mozilla {
+
+DDLoggedTypeDeclNameAndBase(AudioTrimmer, MediaDataDecoder);
+
+class AudioTrimmer : public MediaDataDecoder {
+ public:
+  AudioTrimmer(already_AddRefed<MediaDataDecoder> aDecoder,
+               const CreateDecoderParams& aParams)
+      : mDecoder(aDecoder) {}
+
+  RefPtr<InitPromise> Init() override;
+  RefPtr<DecodePromise> Decode(MediaRawData* aSample) override;
+  bool CanDecodeBatch() const override { return mDecoder->CanDecodeBatch(); }
+  RefPtr<DecodePromise> DecodeBatch(
+      nsTArray<RefPtr<MediaRawData>>&& aSamples) override;
+  RefPtr<DecodePromise> Drain() override;
+  RefPtr<FlushPromise> Flush() override;
+  RefPtr<ShutdownPromise> Shutdown() override;
+  nsCString GetDescriptionName() const override;
+  bool IsHardwareAccelerated(nsACString& aFailureReason) const override;
+  void SetSeekThreshold(const media::TimeUnit& aTime) override;
+  bool SupportDecoderRecycling() const override;
+  ConversionRequired NeedsConversion() const override;
+
+ private:
+  // Apply trimming information on decoded data. aRaw can be null as it's only
+  // used for logging purposes.
+  RefPtr<DecodePromise> HandleDecodedResult(
+      DecodePromise::ResolveOrRejectValue&& aValue, MediaRawData* aRaw);
+  void PrepareTrimmers(MediaRawData* aRaw);
+  const RefPtr<MediaDataDecoder> mDecoder;
+  nsCOMPtr<nsISerialEventTarget> mThread;
+  AutoTArray<Maybe<media::TimeInterval>, 2> mTrimmers;
+};
+
+}  // namespace mozilla
+
+#endif  // AudioTrimmer_h_
diff --git a/dom/media/platforms/wrappers/MediaChangeMonitor.cpp b/dom/media/platforms/wrappers/MediaChangeMonitor.cpp
new file mode 100644
index 0000000000..17387204ed
--- /dev/null
+++ b/dom/media/platforms/wrappers/MediaChangeMonitor.cpp
@@ -0,0 +1,951 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "MediaChangeMonitor.h"
+
+#include "AnnexB.h"
+#include "H264.h"
+#include "GeckoProfiler.h"
+#include "ImageContainer.h"
+#include "MP4Decoder.h"
+#include "MediaInfo.h"
+#include "PDMFactory.h"
+#include "VPXDecoder.h"
+#ifdef MOZ_AV1
+#  include "AOMDecoder.h"
+#endif
+#include "gfxUtils.h"
+#include "mozilla/ProfilerMarkers.h"
+#include "mozilla/StaticPrefs_media.h"
+#include "mozilla/TaskQueue.h"
+
+namespace mozilla {
+
+extern LazyLogModule gMediaDecoderLog;
+
+#define LOG(x, ...) \
+  MOZ_LOG(gMediaDecoderLog, LogLevel::Debug, (x, ##__VA_ARGS__))
+
+// H264ChangeMonitor is used to ensure that only AVCC or AnnexB is fed to the
+// underlying MediaDataDecoder. The H264ChangeMonitor allows playback of content
+// where the SPS NAL may not be provided in the init segment (e.g. AVC3 or Annex
+// B) H264ChangeMonitor will monitor the input data, and will delay creation of
+// the MediaDataDecoder until a SPS and PPS NALs have been extracted.
+
+class H264ChangeMonitor : public MediaChangeMonitor::CodecChangeMonitor {
+ public:
+  explicit H264ChangeMonitor(const VideoInfo& aInfo, bool aFullParsing)
+      : mCurrentConfig(aInfo), mFullParsing(aFullParsing) {
+    if (CanBeInstantiated()) {
+      UpdateConfigFromExtraData(aInfo.mExtraData);
+    }
+  }
+
+  bool CanBeInstantiated() const override {
+    return H264::HasSPS(mCurrentConfig.mExtraData);
+  }
+
+  MediaResult CheckForChange(MediaRawData* aSample) override {
+    // To be usable we need to convert the sample to 4 bytes NAL size AVCC.
+    if (!AnnexB::ConvertSampleToAVCC(aSample)) {
+      // We need AVCC content to be able to later parse the SPS.
+      // This is a no-op if the data is already AVCC.
+      return MediaResult(NS_ERROR_OUT_OF_MEMORY,
+                         RESULT_DETAIL("ConvertSampleToAVCC"));
+    }
+
+    if (!AnnexB::IsAVCC(aSample)) {
+      return MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                         RESULT_DETAIL("Invalid H264 content"));
+    }
+
+    RefPtr<MediaByteBuffer> extra_data =
+        aSample->mKeyframe || !mGotSPS || mFullParsing
+            ? H264::ExtractExtraData(aSample)
+            : nullptr;
+
+    if (!H264::HasSPS(extra_data) && !H264::HasSPS(mCurrentConfig.mExtraData)) {
+      // We don't have inband data and the original config didn't contain a SPS.
+      // We can't decode this content.
+      return NS_ERROR_NOT_INITIALIZED;
+    }
+
+    mGotSPS = true;
+
+    if (!H264::HasSPS(extra_data)) {
+      // This sample doesn't contain inband SPS/PPS
+      // We now check if the out of band one has changed.
+      // This scenario can currently only occur on Android with devices that can
+      // recycle a decoder.
+      bool hasOutOfBandExtraData = H264::HasSPS(aSample->mExtraData);
+      if (!hasOutOfBandExtraData || !mPreviousExtraData ||
+          H264::CompareExtraData(aSample->mExtraData, mPreviousExtraData)) {
+        if (hasOutOfBandExtraData && !mPreviousExtraData) {
+          // We are decoding the first sample, store the out of band sample's
+          // extradata so that we can check for future change.
+          mPreviousExtraData = aSample->mExtraData;
+        }
+        return NS_OK;
+      }
+      extra_data = aSample->mExtraData;
+    } else if (H264::CompareExtraData(extra_data, mCurrentConfig.mExtraData)) {
+      return NS_OK;
+    }
+
+    // Store the sample's extradata so we don't trigger a false positive
+    // with the out of band test on the next sample.
+    mPreviousExtraData = aSample->mExtraData;
+    UpdateConfigFromExtraData(extra_data);
+
+    PROFILER_MARKER_TEXT("H264 Stream Change", MEDIA_PLAYBACK, {},
+                         "H264ChangeMonitor::CheckForChange has detected a "
+                         "change in the stream and will request a new decoder");
+    return NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER;
+  }
+
+  const TrackInfo& Config() const override { return mCurrentConfig; }
+
+  MediaResult PrepareSample(MediaDataDecoder::ConversionRequired aConversion,
+                            MediaRawData* aSample,
+                            bool aNeedKeyFrame) override {
+    MOZ_DIAGNOSTIC_ASSERT(
+        aConversion == MediaDataDecoder::ConversionRequired::kNeedAnnexB ||
+            aConversion == MediaDataDecoder::ConversionRequired::kNeedAVCC,
+        "Conversion must be either AVCC or AnnexB");
+
+    aSample->mExtraData = mCurrentConfig.mExtraData;
+    aSample->mTrackInfo = mTrackInfo;
+
+    if (aConversion == MediaDataDecoder::ConversionRequired::kNeedAnnexB) {
+      auto res = AnnexB::ConvertSampleToAnnexB(aSample, aNeedKeyFrame);
+      if (res.isErr()) {
+        return MediaResult(res.unwrapErr(),
+                           RESULT_DETAIL("ConvertSampleToAnnexB"));
+      }
+    }
+
+    return NS_OK;
+  }
+
+ private:
+  void UpdateConfigFromExtraData(MediaByteBuffer* aExtraData) {
+    SPSData spsdata;
+    if (H264::DecodeSPSFromExtraData(aExtraData, spsdata) &&
+        spsdata.pic_width > 0 && spsdata.pic_height > 0) {
+      H264::EnsureSPSIsSane(spsdata);
+      mCurrentConfig.mImage.width = spsdata.pic_width;
+      mCurrentConfig.mImage.height = spsdata.pic_height;
+      mCurrentConfig.mDisplay.width = spsdata.display_width;
+      mCurrentConfig.mDisplay.height = spsdata.display_height;
+      mCurrentConfig.mColorDepth = spsdata.ColorDepth();
+      mCurrentConfig.mColorSpace = Some(spsdata.ColorSpace());
+      // spsdata.colour_primaries has the same values as
+      // gfx::CICP::ColourPrimaries.
+      mCurrentConfig.mColorPrimaries = gfxUtils::CicpToColorPrimaries(
+          static_cast<gfx::CICP::ColourPrimaries>(spsdata.colour_primaries),
+          gMediaDecoderLog);
+      // spsdata.transfer_characteristics has the same values as
+      // gfx::CICP::TransferCharacteristics.
+      mCurrentConfig.mTransferFunction = gfxUtils::CicpToTransferFunction(
+          static_cast<gfx::CICP::TransferCharacteristics>(
+              spsdata.transfer_characteristics));
+      mCurrentConfig.mColorRange = spsdata.video_full_range_flag
+                                       ? gfx::ColorRange::FULL
+                                       : gfx::ColorRange::LIMITED;
+    }
+    mCurrentConfig.mExtraData = aExtraData;
+    mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, mStreamID++);
+  }
+
+  VideoInfo mCurrentConfig;
+  uint32_t mStreamID = 0;
+  const bool mFullParsing;
+  bool mGotSPS = false;
+  RefPtr<TrackInfoSharedPtr> mTrackInfo;
+  RefPtr<MediaByteBuffer> mPreviousExtraData;
+};
+
+// Gets the pixel aspect ratio from the decoded video size and the rendered
+// size.
+inline double GetPixelAspectRatio(const gfx::IntSize& aImage,
+                                  const gfx::IntSize& aDisplay) {
+  return (static_cast<double>(aDisplay.Width()) / aImage.Width()) /
+         (static_cast<double>(aDisplay.Height()) / aImage.Height());
+}
+
+// Returns the render size based on the PAR and the new image size.
+inline gfx::IntSize ApplyPixelAspectRatio(double aPixelAspectRatio,
+                                          const gfx::IntSize& aImage) {
+  return gfx::IntSize(static_cast<int32_t>(aImage.Width() * aPixelAspectRatio),
+                      aImage.Height());
+}
+
+class VPXChangeMonitor : public MediaChangeMonitor::CodecChangeMonitor {
+ public:
+  explicit VPXChangeMonitor(const VideoInfo& aInfo)
+      : mCurrentConfig(aInfo),
+        mCodec(VPXDecoder::IsVP8(aInfo.mMimeType) ? VPXDecoder::Codec::VP8
+                                                  : VPXDecoder::Codec::VP9),
+        mPixelAspectRatio(GetPixelAspectRatio(aInfo.mImage, aInfo.mDisplay)) {
+    mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, mStreamID++);
+
+    if (mCurrentConfig.mExtraData && !mCurrentConfig.mExtraData->IsEmpty()) {
+      // If we're passed VP codec configuration, store it so that we can
+      // instantiate the decoder on init.
+      VPXDecoder::VPXStreamInfo vpxInfo;
+      vpxInfo.mImage = mCurrentConfig.mImage;
+      vpxInfo.mDisplay = mCurrentConfig.mDisplay;
+      VPXDecoder::ReadVPCCBox(vpxInfo, mCurrentConfig.mExtraData);
+      mInfo = Some(vpxInfo);
+    }
+  }
+
+  bool CanBeInstantiated() const override {
+    // We want to see at least one sample before we create a decoder so that we
+    // can create the vpcC content on mCurrentConfig.mExtraData.
+    return mCodec == VPXDecoder::Codec::VP8 || mInfo ||
+           mCurrentConfig.mCrypto.IsEncrypted();
+  }
+
+  MediaResult CheckForChange(MediaRawData* aSample) override {
+    // Don't look at encrypted content.
+    if (aSample->mCrypto.IsEncrypted()) {
+      return NS_OK;
+    }
+    auto dataSpan = Span<const uint8_t>(aSample->Data(), aSample->Size());
+
+    // We don't trust the keyframe flag as set on the MediaRawData.
+    VPXDecoder::VPXStreamInfo info;
+    if (!VPXDecoder::GetStreamInfo(dataSpan, info, mCodec)) {
+      return NS_ERROR_DOM_MEDIA_DECODE_ERR;
+    }
+    // For both VP8 and VP9, we only look for resolution changes
+    // on keyframes. Other resolution changes are invalid.
+    if (!info.mKeyFrame) {
+      return NS_OK;
+    }
+
+    nsresult rv = NS_OK;
+    if (mInfo) {
+      if (mInfo.ref().IsCompatible(info)) {
+        return rv;
+      }
+      // We can't properly determine the image rect once we've had a resolution
+      // change.
+      mCurrentConfig.ResetImageRect();
+      PROFILER_MARKER_TEXT(
+          "VPX Stream Change", MEDIA_PLAYBACK, {},
+          "VPXChangeMonitor::CheckForChange has detected a change in the "
+          "stream and will request a new decoder");
+      rv = NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER;
+    } else if (mCurrentConfig.mImage != info.mImage ||
+               mCurrentConfig.mDisplay != info.mDisplay) {
+      // We can't properly determine the image rect if we're changing
+      // resolution based on sample information.
+      mCurrentConfig.ResetImageRect();
+      PROFILER_MARKER_TEXT("VPX Stream Init Discrepancy", MEDIA_PLAYBACK, {},
+                           "VPXChangeMonitor::CheckForChange has detected a "
+                           "discrepancy between initialization data and stream "
+                           "content and will request a new decoder");
+      rv = NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER;
+    }
+
+    LOG("Detect inband %s resolution changes, image (%" PRId32 ",%" PRId32
+        ")->(%" PRId32 ",%" PRId32 "), display (%" PRId32 ",%" PRId32
+        ")->(%" PRId32 ",%" PRId32 " %s)",
+        mCodec == VPXDecoder::Codec::VP9 ? "VP9" : "VP8",
+        mCurrentConfig.mImage.Width(), mCurrentConfig.mImage.Height(),
+        info.mImage.Width(), info.mImage.Height(),
+        mCurrentConfig.mDisplay.Width(), mCurrentConfig.mDisplay.Height(),
+        info.mDisplay.Width(), info.mDisplay.Height(),
+        info.mDisplayAndImageDifferent ? "specified" : "unspecified");
+
+    mInfo = Some(info);
+    mCurrentConfig.mImage = info.mImage;
+    if (info.mDisplayAndImageDifferent) {
+      // If the flag to change the display size is set in the sequence, we
+      // set our original values to begin rescaling according to the new values.
+      mCurrentConfig.mDisplay = info.mDisplay;
+      mPixelAspectRatio = GetPixelAspectRatio(info.mImage, info.mDisplay);
+    } else {
+      mCurrentConfig.mDisplay =
+          ApplyPixelAspectRatio(mPixelAspectRatio, info.mImage);
+    }
+
+    mCurrentConfig.mColorDepth = gfx::ColorDepthForBitDepth(info.mBitDepth);
+    mCurrentConfig.mColorSpace = Some(info.ColorSpace());
+    // VPX bitstream doesn't specify color primaries.
+
+    // We don't update the transfer function here, because VPX bitstream
+    // doesn't specify the transfer function. Instead, we keep the transfer
+    // function (if any) that was set in mCurrentConfig when we were created.
+    // If a video changes colorspaces away from BT2020, we won't clear
+    // mTransferFunction, in case the video changes back to BT2020 and we
+    // need the value again.
+
+    mCurrentConfig.mColorRange = info.ColorRange();
+    if (mCodec == VPXDecoder::Codec::VP9) {
+      mCurrentConfig.mExtraData->ClearAndRetainStorage();
+      VPXDecoder::GetVPCCBox(mCurrentConfig.mExtraData, info);
+    }
+    mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, mStreamID++);
+
+    return rv;
+  }
+
+  const TrackInfo& Config() const override { return mCurrentConfig; }
+
+  MediaResult PrepareSample(MediaDataDecoder::ConversionRequired aConversion,
+                            MediaRawData* aSample,
+                            bool aNeedKeyFrame) override {
+    aSample->mTrackInfo = mTrackInfo;
+
+    return NS_OK;
+  }
+
+ private:
+  VideoInfo mCurrentConfig;
+  const VPXDecoder::Codec mCodec;
+  Maybe<VPXDecoder::VPXStreamInfo> mInfo;
+  uint32_t mStreamID = 0;
+  RefPtr<TrackInfoSharedPtr> mTrackInfo;
+  double mPixelAspectRatio;
+};
+
+#ifdef MOZ_AV1
+class AV1ChangeMonitor : public MediaChangeMonitor::CodecChangeMonitor {
+ public:
+  explicit AV1ChangeMonitor(const VideoInfo& aInfo)
+      : mCurrentConfig(aInfo),
+        mPixelAspectRatio(GetPixelAspectRatio(aInfo.mImage, aInfo.mDisplay)) {
+    mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, mStreamID++);
+
+    if (mCurrentConfig.mExtraData && !mCurrentConfig.mExtraData->IsEmpty()) {
+      // If we're passed AV1 codec configuration, store it so that we can
+      // instantiate a decoder in MediaChangeMonitor::Create.
+      AOMDecoder::AV1SequenceInfo seqInfo;
+      MediaResult seqHdrResult;
+      AOMDecoder::TryReadAV1CBox(mCurrentConfig.mExtraData, seqInfo,
+                                 seqHdrResult);
+      // If the av1C box doesn't include a sequence header specifying image
+      // size, keep the one provided by VideoInfo.
+      if (seqHdrResult.Code() != NS_OK) {
+        seqInfo.mImage = mCurrentConfig.mImage;
+      }
+
+      UpdateConfig(seqInfo);
+    }
+  }
+
+  bool CanBeInstantiated() const override {
+    // We want to have enough codec configuration to determine whether hardware
+    // decoding can be used before creating a decoder. The av1C box or a
+    // sequence header from a sample will contain this information.
+    return mInfo || mCurrentConfig.mCrypto.IsEncrypted();
+  }
+
+  void UpdateConfig(const AOMDecoder::AV1SequenceInfo& aInfo) {
+    mInfo = Some(aInfo);
+    mCurrentConfig.mColorDepth = gfx::ColorDepthForBitDepth(aInfo.mBitDepth);
+    mCurrentConfig.mColorSpace = gfxUtils::CicpToColorSpace(
+        aInfo.mColorSpace.mMatrix, aInfo.mColorSpace.mPrimaries,
+        gMediaDecoderLog);
+    mCurrentConfig.mColorPrimaries = gfxUtils::CicpToColorPrimaries(
+        aInfo.mColorSpace.mPrimaries, gMediaDecoderLog);
+    mCurrentConfig.mTransferFunction =
+        gfxUtils::CicpToTransferFunction(aInfo.mColorSpace.mTransfer);
+    mCurrentConfig.mColorRange = aInfo.mColorSpace.mRange;
+
+    if (mCurrentConfig.mImage != mInfo->mImage) {
+      gfx::IntSize newDisplay =
+          ApplyPixelAspectRatio(mPixelAspectRatio, aInfo.mImage);
+      LOG("AV1ChangeMonitor detected a resolution change in-band, image "
+          "(%" PRIu32 ",%" PRIu32 ")->(%" PRIu32 ",%" PRIu32
+          "), display (%" PRIu32 ",%" PRIu32 ")->(%" PRIu32 ",%" PRIu32
+          " from PAR)",
+          mCurrentConfig.mImage.Width(), mCurrentConfig.mImage.Height(),
+          aInfo.mImage.Width(), aInfo.mImage.Height(),
+          mCurrentConfig.mDisplay.Width(), mCurrentConfig.mDisplay.Height(),
+          newDisplay.Width(), newDisplay.Height());
+      mCurrentConfig.mImage = aInfo.mImage;
+      mCurrentConfig.mDisplay = newDisplay;
+      mCurrentConfig.ResetImageRect();
+    }
+
+    bool wroteSequenceHeader = false;
+    // Our headers should all be around the same size.
+    mCurrentConfig.mExtraData->ClearAndRetainStorage();
+    AOMDecoder::WriteAV1CBox(aInfo, mCurrentConfig.mExtraData.get(),
+                             wroteSequenceHeader);
+    // Header should always be written ReadSequenceHeaderInfo succeeds.
+    MOZ_ASSERT(wroteSequenceHeader);
+  }
+
+  MediaResult CheckForChange(MediaRawData* aSample) override {
+    // Don't look at encrypted content.
+    if (aSample->mCrypto.IsEncrypted()) {
+      return NS_OK;
+    }
+    auto dataSpan = Span<const uint8_t>(aSample->Data(), aSample->Size());
+
+    // We don't trust the keyframe flag as set on the MediaRawData.
+    AOMDecoder::AV1SequenceInfo info;
+    MediaResult seqHdrResult =
+        AOMDecoder::ReadSequenceHeaderInfo(dataSpan, info);
+    nsresult seqHdrCode = seqHdrResult.Code();
+    if (seqHdrCode == NS_ERROR_DOM_MEDIA_WAITING_FOR_DATA) {
+      return NS_OK;
+    }
+    if (seqHdrCode != NS_OK) {
+      LOG("AV1ChangeMonitor::CheckForChange read a corrupted sample: %s",
+          seqHdrResult.Description().get());
+      return seqHdrResult;
+    }
+
+    nsresult rv = NS_OK;
+    if (mInfo.isSome() &&
+        (mInfo->mProfile != info.mProfile ||
+         mInfo->ColorDepth() != info.ColorDepth() ||
+         mInfo->mMonochrome != info.mMonochrome ||
+         mInfo->mSubsamplingX != info.mSubsamplingX ||
+         mInfo->mSubsamplingY != info.mSubsamplingY ||
+         mInfo->mChromaSamplePosition != info.mChromaSamplePosition ||
+         mInfo->mImage != info.mImage)) {
+      PROFILER_MARKER_TEXT(
+          "AV1 Stream Change", MEDIA_PLAYBACK, {},
+          "AV1ChangeMonitor::CheckForChange has detected a change in a "
+          "stream and will request a new decoder");
+      LOG("AV1ChangeMonitor detected a change and requests a new decoder");
+      rv = NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER;
+    }
+
+    UpdateConfig(info);
+
+    if (rv == NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER) {
+      mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, mStreamID++);
+    }
+    return rv;
+  }
+
+  const TrackInfo& Config() const override { return mCurrentConfig; }
+
+  MediaResult PrepareSample(MediaDataDecoder::ConversionRequired aConversion,
+                            MediaRawData* aSample,
+                            bool aNeedKeyFrame) override {
+    aSample->mTrackInfo = mTrackInfo;
+    return NS_OK;
+  }
+
+ private:
+  VideoInfo mCurrentConfig;
+  Maybe<AOMDecoder::AV1SequenceInfo> mInfo;
+  uint32_t mStreamID = 0;
+  RefPtr<TrackInfoSharedPtr> mTrackInfo;
+  double mPixelAspectRatio;
+};
+#endif
+
+MediaChangeMonitor::MediaChangeMonitor(
+    PDMFactory* aPDMFactory,
+    UniquePtr<CodecChangeMonitor>&& aCodecChangeMonitor,
+    MediaDataDecoder* aDecoder, const CreateDecoderParams& aParams)
+    : mChangeMonitor(std::move(aCodecChangeMonitor)),
+      mPDMFactory(aPDMFactory),
+      mCurrentConfig(aParams.VideoConfig()),
+      mDecoder(aDecoder),
+      mParams(aParams) {}
+
+/* static */
+RefPtr<PlatformDecoderModule::CreateDecoderPromise> MediaChangeMonitor::Create(
+    PDMFactory* aPDMFactory, const CreateDecoderParams& aParams) {
+  UniquePtr<CodecChangeMonitor> changeMonitor;
+  const VideoInfo& currentConfig = aParams.VideoConfig();
+  if (VPXDecoder::IsVPX(currentConfig.mMimeType)) {
+    changeMonitor = MakeUnique<VPXChangeMonitor>(currentConfig);
+#ifdef MOZ_AV1
+  } else if (AOMDecoder::IsAV1(currentConfig.mMimeType)) {
+    changeMonitor = MakeUnique<AV1ChangeMonitor>(currentConfig);
+#endif
+  } else {
+    MOZ_ASSERT(MP4Decoder::IsH264(currentConfig.mMimeType));
+    changeMonitor = MakeUnique<H264ChangeMonitor>(
+        currentConfig, aParams.mOptions.contains(
+                           CreateDecoderParams::Option::FullH264Parsing));
+  }
+
+  // The change monitor may have an updated track config. E.g. the h264 monitor
+  // may update the config after parsing extra data in the VideoInfo. Create a
+  // new set of params with the updated track info from our monitor and the
+  // other params for aParams and use that going forward.
+  const CreateDecoderParams updatedParams{changeMonitor->Config(), aParams};
+
+  RefPtr<MediaChangeMonitor> instance = new MediaChangeMonitor(
+      aPDMFactory, std::move(changeMonitor), nullptr, updatedParams);
+
+  if (instance->mChangeMonitor->CanBeInstantiated()) {
+    RefPtr<PlatformDecoderModule::CreateDecoderPromise> p =
+        instance->CreateDecoder()->Then(
+            GetCurrentSerialEventTarget(), __func__,
+            [instance = RefPtr{instance}] {
+              return PlatformDecoderModule::CreateDecoderPromise::
+                  CreateAndResolve(instance, __func__);
+            },
+            [](const MediaResult& aError) {
+              return PlatformDecoderModule::CreateDecoderPromise::
+                  CreateAndReject(aError, __func__);
+            });
+    return p;
+  }
+
+  return PlatformDecoderModule::CreateDecoderPromise::CreateAndResolve(
+      instance, __func__);
+}
+
+MediaChangeMonitor::~MediaChangeMonitor() = default;
+
+RefPtr<MediaDataDecoder::InitPromise> MediaChangeMonitor::Init() {
+  mThread = GetCurrentSerialEventTarget();
+  if (mDecoder) {
+    RefPtr<InitPromise> p = mInitPromise.Ensure(__func__);
+    RefPtr<MediaChangeMonitor> self = this;
+    mDecoder->Init()
+        ->Then(GetCurrentSerialEventTarget(), __func__,
+               [self, this](InitPromise::ResolveOrRejectValue&& aValue) {
+                 mInitPromiseRequest.Complete();
+                 if (aValue.IsResolve()) {
+                   mDecoderInitialized = true;
+                   mConversionRequired = Some(mDecoder->NeedsConversion());
+                   mCanRecycleDecoder = Some(CanRecycleDecoder());
+                 }
+                 return mInitPromise.ResolveOrRejectIfExists(std::move(aValue),
+                                                             __func__);
+               })
+        ->Track(mInitPromiseRequest);
+    return p;
+  }
+
+  // We haven't been able to initialize a decoder due to missing
+  // extradata.
+  return MediaDataDecoder::InitPromise::CreateAndResolve(TrackType::kVideoTrack,
+                                                         __func__);
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> MediaChangeMonitor::Decode(
+    MediaRawData* aSample) {
+  AssertOnThread();
+  MOZ_RELEASE_ASSERT(mFlushPromise.IsEmpty(),
+                     "Flush operation didn't complete");
+
+  MOZ_RELEASE_ASSERT(
+      !mDecodePromiseRequest.Exists() && !mInitPromiseRequest.Exists(),
+      "Can't request a new decode until previous one completed");
+
+  MediaResult rv = CheckForChange(aSample);
+
+  if (rv == NS_ERROR_NOT_INITIALIZED) {
+    // We are missing the required init data to create the decoder.
+    if (mParams.mOptions.contains(
+            CreateDecoderParams::Option::ErrorIfNoInitializationData)) {
+      // This frame can't be decoded and should be treated as an error.
+      return DecodePromise::CreateAndReject(rv, __func__);
+    }
+    // Swallow the frame, and await delivery of init data.
+    return DecodePromise::CreateAndResolve(DecodedData(), __func__);
+  }
+  if (rv == NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER) {
+    // The decoder is pending initialization.
+    RefPtr<DecodePromise> p = mDecodePromise.Ensure(__func__);
+    return p;
+  }
+
+  if (NS_FAILED(rv)) {
+    return DecodePromise::CreateAndReject(rv, __func__);
+  }
+
+  if (mNeedKeyframe && !aSample->mKeyframe) {
+    return DecodePromise::CreateAndResolve(DecodedData(), __func__);
+  }
+
+  rv = mChangeMonitor->PrepareSample(*mConversionRequired, aSample,
+                                     mNeedKeyframe);
+  if (NS_FAILED(rv)) {
+    return DecodePromise::CreateAndReject(rv, __func__);
+  }
+
+  mNeedKeyframe = false;
+
+  return mDecoder->Decode(aSample);
+}
+
+RefPtr<MediaDataDecoder::FlushPromise> MediaChangeMonitor::Flush() {
+  AssertOnThread();
+  mDecodePromiseRequest.DisconnectIfExists();
+  mDecodePromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+  mNeedKeyframe = true;
+  mPendingFrames.Clear();
+
+  MOZ_RELEASE_ASSERT(mFlushPromise.IsEmpty(), "Previous flush didn't complete");
+
+  /*
+    When we detect a change of content in the byte stream, we first drain the
+    current decoder (1), flush (2), shut it down (3) create a new decoder (4)
+    and initialize it (5). It is possible for MediaChangeMonitor::Flush to be
+    called during any of those times. If during (1):
+      - mDrainRequest will not be empty.
+      - The old decoder can still be used, with the current extradata as
+    stored in mCurrentConfig.mExtraData.
+
+    If during (2):
+      - mFlushRequest will not be empty.
+      - The old decoder can still be used, with the current extradata as
+    stored in mCurrentConfig.mExtraData.
+
+    If during (3):
+      - mShutdownRequest won't be empty.
+      - mDecoder is empty.
+      - The old decoder is no longer referenced by the MediaChangeMonitor.
+
+    If during (4):
+      - mDecoderRequest won't be empty.
+      - mDecoder is not set. Steps will continue to (5) to set and initialize it
+
+    If during (5):
+      - mInitPromiseRequest won't be empty.
+      - mDecoder is set but not usable yet.
+  */
+
+  if (mDrainRequest.Exists() || mFlushRequest.Exists() ||
+      mShutdownRequest.Exists() || mDecoderRequest.Exists() ||
+      mInitPromiseRequest.Exists()) {
+    // We let the current decoder complete and will resume after.
+    RefPtr<FlushPromise> p = mFlushPromise.Ensure(__func__);
+    return p;
+  }
+  if (mDecoder && mDecoderInitialized) {
+    return mDecoder->Flush();
+  }
+  return FlushPromise::CreateAndResolve(true, __func__);
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> MediaChangeMonitor::Drain() {
+  AssertOnThread();
+  MOZ_RELEASE_ASSERT(!mDrainRequest.Exists());
+  mNeedKeyframe = true;
+  if (mDecoder) {
+    return mDecoder->Drain();
+  }
+  return DecodePromise::CreateAndResolve(DecodedData(), __func__);
+}
+
+RefPtr<ShutdownPromise> MediaChangeMonitor::Shutdown() {
+  AssertOnThread();
+  mInitPromiseRequest.DisconnectIfExists();
+  mInitPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+  mDecodePromiseRequest.DisconnectIfExists();
+  mDecodePromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+  mDrainRequest.DisconnectIfExists();
+  mFlushRequest.DisconnectIfExists();
+  mFlushPromise.RejectIfExists(NS_ERROR_DOM_MEDIA_CANCELED, __func__);
+  mShutdownRequest.DisconnectIfExists();
+
+  if (mShutdownPromise) {
+    // We have a shutdown in progress, return that promise instead as we can't
+    // shutdown a decoder twice.
+    RefPtr<ShutdownPromise> p = std::move(mShutdownPromise);
+    return p;
+  }
+  return ShutdownDecoder();
+}
+
+RefPtr<ShutdownPromise> MediaChangeMonitor::ShutdownDecoder() {
+  AssertOnThread();
+  mConversionRequired.reset();
+  if (mDecoder) {
+    RefPtr<MediaDataDecoder> decoder = std::move(mDecoder);
+    return decoder->Shutdown();
+  }
+  return ShutdownPromise::CreateAndResolve(true, __func__);
+}
+
+bool MediaChangeMonitor::IsHardwareAccelerated(
+    nsACString& aFailureReason) const {
+  if (mDecoder) {
+    return mDecoder->IsHardwareAccelerated(aFailureReason);
+  }
+#ifdef MOZ_APPLEMEDIA
+  // On mac, we can assume H264 is hardware accelerated for now.
+  // This allows MediaCapabilities to report that playback will be smooth.
+  // Which will always be.
+  return true;
+#else
+  return MediaDataDecoder::IsHardwareAccelerated(aFailureReason);
+#endif
+}
+
+void MediaChangeMonitor::SetSeekThreshold(const media::TimeUnit& aTime) {
+  if (mDecoder) {
+    mDecoder->SetSeekThreshold(aTime);
+  } else {
+    MediaDataDecoder::SetSeekThreshold(aTime);
+  }
+}
+
+RefPtr<MediaChangeMonitor::CreateDecoderPromise>
+MediaChangeMonitor::CreateDecoder() {
+  mCurrentConfig = *mChangeMonitor->Config().GetAsVideoInfo();
+  RefPtr<CreateDecoderPromise> p =
+      mPDMFactory
+          ->CreateDecoder(
+              {mCurrentConfig, mParams, CreateDecoderParams::NoWrapper(true)})
+          ->Then(
+              GetCurrentSerialEventTarget(), __func__,
+              [self = RefPtr{this}, this](RefPtr<MediaDataDecoder>&& aDecoder) {
+                mDecoder = std::move(aDecoder);
+                DDLINKCHILD("decoder", mDecoder.get());
+                return CreateDecoderPromise::CreateAndResolve(true, __func__);
+              },
+              [self = RefPtr{this}](const MediaResult& aError) {
+                return CreateDecoderPromise::CreateAndReject(aError, __func__);
+              });
+
+  mDecoderInitialized = false;
+  mNeedKeyframe = true;
+
+  return p;
+}
+
+MediaResult MediaChangeMonitor::CreateDecoderAndInit(MediaRawData* aSample) {
+  MOZ_ASSERT(mThread && mThread->IsOnCurrentThread());
+
+  MediaResult rv = mChangeMonitor->CheckForChange(aSample);
+  if (!NS_SUCCEEDED(rv) && rv != NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER) {
+    return rv;
+  }
+
+  if (!mChangeMonitor->CanBeInstantiated()) {
+    // Nothing found yet, will try again later.
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  CreateDecoder()
+      ->Then(
+          GetCurrentSerialEventTarget(), __func__,
+          [self = RefPtr{this}, this, sample = RefPtr{aSample}] {
+            mDecoderRequest.Complete();
+            mDecoder->Init()
+                ->Then(
+                    GetCurrentSerialEventTarget(), __func__,
+                    [self, sample, this](const TrackType aTrackType) {
+                      mInitPromiseRequest.Complete();
+                      mDecoderInitialized = true;
+                      mConversionRequired = Some(mDecoder->NeedsConversion());
+                      mCanRecycleDecoder = Some(CanRecycleDecoder());
+
+                      if (!mFlushPromise.IsEmpty()) {
+                        // A Flush is pending, abort the current operation.
+                        mFlushPromise.Resolve(true, __func__);
+                        return;
+                      }
+
+                      DecodeFirstSample(sample);
+                    },
+                    [self, this](const MediaResult& aError) {
+                      mInitPromiseRequest.Complete();
+
+                      if (!mFlushPromise.IsEmpty()) {
+                        // A Flush is pending, abort the current operation.
+                        mFlushPromise.Reject(aError, __func__);
+                        return;
+                      }
+
+                      mDecodePromise.Reject(
+                          MediaResult(
+                              aError.Code(),
+                              RESULT_DETAIL("Unable to initialize decoder")),
+                          __func__);
+                    })
+                ->Track(mInitPromiseRequest);
+          },
+          [self = RefPtr{this}, this](const MediaResult& aError) {
+            mDecoderRequest.Complete();
+            if (!mFlushPromise.IsEmpty()) {
+              // A Flush is pending, abort the current operation.
+              mFlushPromise.Reject(aError, __func__);
+              return;
+            }
+            mDecodePromise.Reject(
+                MediaResult(NS_ERROR_DOM_MEDIA_FATAL_ERR,
+                            RESULT_DETAIL("Unable to create decoder")),
+                __func__);
+          })
+      ->Track(mDecoderRequest);
+  return NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER;
+}
+
+bool MediaChangeMonitor::CanRecycleDecoder() const {
+  MOZ_ASSERT(mDecoder);
+  return StaticPrefs::media_decoder_recycle_enabled() &&
+         mDecoder->SupportDecoderRecycling();
+}
+
+void MediaChangeMonitor::DecodeFirstSample(MediaRawData* aSample) {
+  // We feed all the data to AnnexB decoder as a non-keyframe could contain
+  // the SPS/PPS when used with WebRTC and this data is needed by the decoder.
+  if (mNeedKeyframe && !aSample->mKeyframe &&
+      *mConversionRequired != ConversionRequired::kNeedAnnexB) {
+    mDecodePromise.Resolve(std::move(mPendingFrames), __func__);
+    mPendingFrames = DecodedData();
+    return;
+  }
+
+  MediaResult rv = mChangeMonitor->PrepareSample(*mConversionRequired, aSample,
+                                                 mNeedKeyframe);
+
+  if (NS_FAILED(rv)) {
+    mDecodePromise.Reject(rv, __func__);
+    return;
+  }
+
+  if (aSample->mKeyframe) {
+    mNeedKeyframe = false;
+  }
+
+  RefPtr<MediaChangeMonitor> self = this;
+  mDecoder->Decode(aSample)
+      ->Then(
+          GetCurrentSerialEventTarget(), __func__,
+          [self, this](MediaDataDecoder::DecodedData&& aResults) {
+            mDecodePromiseRequest.Complete();
+            mPendingFrames.AppendElements(std::move(aResults));
+            mDecodePromise.Resolve(std::move(mPendingFrames), __func__);
+            mPendingFrames = DecodedData();
+          },
+          [self, this](const MediaResult& aError) {
+            mDecodePromiseRequest.Complete();
+            mDecodePromise.Reject(aError, __func__);
+          })
+      ->Track(mDecodePromiseRequest);
+}
+
+MediaResult MediaChangeMonitor::CheckForChange(MediaRawData* aSample) {
+  if (!mDecoder) {
+    return CreateDecoderAndInit(aSample);
+  }
+
+  MediaResult rv = mChangeMonitor->CheckForChange(aSample);
+
+  if (NS_SUCCEEDED(rv) || rv != NS_ERROR_DOM_MEDIA_NEED_NEW_DECODER) {
+    return rv;
+  }
+
+  if (*mCanRecycleDecoder) {
+    // Do not recreate the decoder, reuse it.
+    mNeedKeyframe = true;
+    return NS_OK;
+  }
+
+  // The content has changed, signal to drain the current decoder and once done
+  // create a new one.
+  DrainThenFlushDecoder(aSample);
+  return NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER;
+}
+
+void MediaChangeMonitor::DrainThenFlushDecoder(MediaRawData* aPendingSample) {
+  AssertOnThread();
+  MOZ_ASSERT(mDecoderInitialized);
+  RefPtr<MediaRawData> sample = aPendingSample;
+  RefPtr<MediaChangeMonitor> self = this;
+  mDecoder->Drain()
+      ->Then(
+          GetCurrentSerialEventTarget(), __func__,
+          [self, sample, this](MediaDataDecoder::DecodedData&& aResults) {
+            mDrainRequest.Complete();
+            if (!mFlushPromise.IsEmpty()) {
+              // A Flush is pending, abort the current operation.
+              mFlushPromise.Resolve(true, __func__);
+              return;
+            }
+            if (aResults.Length() > 0) {
+              mPendingFrames.AppendElements(std::move(aResults));
+              DrainThenFlushDecoder(sample);
+              return;
+            }
+            // We've completed the draining operation, we can now flush the
+            // decoder.
+            FlushThenShutdownDecoder(sample);
+          },
+          [self, this](const MediaResult& aError) {
+            mDrainRequest.Complete();
+            if (!mFlushPromise.IsEmpty()) {
+              // A Flush is pending, abort the current operation.
+              mFlushPromise.Reject(aError, __func__);
+              return;
+            }
+            mDecodePromise.Reject(aError, __func__);
+          })
+      ->Track(mDrainRequest);
+}
+
+void MediaChangeMonitor::FlushThenShutdownDecoder(
+    MediaRawData* aPendingSample) {
+  AssertOnThread();
+  MOZ_ASSERT(mDecoderInitialized);
+  RefPtr<MediaRawData> sample = aPendingSample;
+  RefPtr<MediaChangeMonitor> self = this;
+  mDecoder->Flush()
+      ->Then(
+          GetCurrentSerialEventTarget(), __func__,
+          [self, sample, this]() {
+            mFlushRequest.Complete();
+
+            if (!mFlushPromise.IsEmpty()) {
+              // A Flush is pending, abort the current operation.
+              mFlushPromise.Resolve(true, __func__);
+              return;
+            }
+
+            mShutdownPromise = ShutdownDecoder();
+            mShutdownPromise
+                ->Then(
+                    GetCurrentSerialEventTarget(), __func__,
+                    [self, sample, this]() {
+                      mShutdownRequest.Complete();
+                      mShutdownPromise = nullptr;
+
+                      if (!mFlushPromise.IsEmpty()) {
+                        // A Flush is pending, abort the current
+                        // operation.
+                        mFlushPromise.Resolve(true, __func__);
+                        return;
+                      }
+
+                      MediaResult rv = CreateDecoderAndInit(sample);
+                      if (rv == NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER) {
+                        // All good so far, will continue later.
+                        return;
+                      }
+                      MOZ_ASSERT(NS_FAILED(rv));
+                      mDecodePromise.Reject(rv, __func__);
+                      return;
+                    },
+                    [] { MOZ_CRASH("Can't reach here'"); })
+                ->Track(mShutdownRequest);
+          },
+          [self, this](const MediaResult& aError) {
+            mFlushRequest.Complete();
+            if (!mFlushPromise.IsEmpty()) {
+              // A Flush is pending, abort the current operation.
+              mFlushPromise.Reject(aError, __func__);
+              return;
+            }
+            mDecodePromise.Reject(aError, __func__);
+          })
+      ->Track(mFlushRequest);
+}
+
+#undef LOG
+
+}  // namespace mozilla
diff --git a/dom/media/platforms/wrappers/MediaChangeMonitor.h b/dom/media/platforms/wrappers/MediaChangeMonitor.h
new file mode 100644
index 0000000000..d77b1ca7eb
--- /dev/null
+++ b/dom/media/platforms/wrappers/MediaChangeMonitor.h
@@ -0,0 +1,127 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#ifndef mozilla_H264Converter_h
+#define mozilla_H264Converter_h
+
+#include "PDMFactory.h"
+#include "PlatformDecoderModule.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+
+DDLoggedTypeDeclNameAndBase(MediaChangeMonitor, MediaDataDecoder);
+
+// MediaChangeMonitor is a MediaDataDecoder wrapper used to ensure that
+// only one type of content is fed to the underlying MediaDataDecoder.
+// The MediaChangeMonitor allows playback of content where some out of band
+// extra data (such as SPS NAL for H264 content) may not be provided in the
+// init segment (e.g. AVC3 or Annex B) MediaChangeMonitor will monitor the
+// input data, and will delay creation of the MediaDataDecoder until such out
+// of band have been extracted should the underlying decoder required it.
+
+class MediaChangeMonitor : public MediaDataDecoder,
+                           public DecoderDoctorLifeLogger<MediaChangeMonitor> {
+ public:
+  static RefPtr<PlatformDecoderModule::CreateDecoderPromise> Create(
+      PDMFactory* aPDMFactory, const CreateDecoderParams& aParams);
+
+  RefPtr<InitPromise> Init() override;
+  RefPtr<DecodePromise> Decode(MediaRawData* aSample) override;
+  RefPtr<DecodePromise> Drain() override;
+  RefPtr<FlushPromise> Flush() override;
+  RefPtr<ShutdownPromise> Shutdown() override;
+  bool IsHardwareAccelerated(nsACString& aFailureReason) const override;
+  nsCString GetDescriptionName() const override {
+    if (mDecoder) {
+      return mDecoder->GetDescriptionName();
+    }
+    return "MediaChangeMonitor decoder (pending)"_ns;
+  }
+  void SetSeekThreshold(const media::TimeUnit& aTime) override;
+  bool SupportDecoderRecycling() const override {
+    if (mDecoder) {
+      return mDecoder->SupportDecoderRecycling();
+    }
+    return false;
+  }
+
+  ConversionRequired NeedsConversion() const override {
+    if (mDecoder) {
+      return mDecoder->NeedsConversion();
+    }
+    // Default so no conversion is performed.
+    return ConversionRequired::kNeedNone;
+  }
+
+  class CodecChangeMonitor {
+   public:
+    virtual bool CanBeInstantiated() const = 0;
+    virtual MediaResult CheckForChange(MediaRawData* aSample) = 0;
+    virtual const TrackInfo& Config() const = 0;
+    virtual MediaResult PrepareSample(
+        MediaDataDecoder::ConversionRequired aConversion, MediaRawData* aSample,
+        bool aNeedKeyFrame) = 0;
+    virtual ~CodecChangeMonitor() = default;
+  };
+
+ private:
+  MediaChangeMonitor(PDMFactory* aPDMFactory,
+                     UniquePtr<CodecChangeMonitor>&& aCodecChangeMonitor,
+                     MediaDataDecoder* aDecoder,
+                     const CreateDecoderParams& aParams);
+  virtual ~MediaChangeMonitor();
+
+  void AssertOnThread() const {
+    // mThread may not be set if Init hasn't been called first.
+    MOZ_ASSERT(!mThread || mThread->IsOnCurrentThread());
+  }
+
+  bool CanRecycleDecoder() const;
+
+  typedef MozPromise<bool, MediaResult, true /* exclusive */>
+      CreateDecoderPromise;
+  // Will create the required MediaDataDecoder if need AVCC and we have a SPS
+  // NAL. Returns NS_ERROR_FAILURE if error is permanent and can't be recovered
+  // and will set mError accordingly.
+  RefPtr<CreateDecoderPromise> CreateDecoder();
+  MediaResult CreateDecoderAndInit(MediaRawData* aSample);
+  MediaResult CheckForChange(MediaRawData* aSample);
+
+  void DecodeFirstSample(MediaRawData* aSample);
+  void DrainThenFlushDecoder(MediaRawData* aPendingSample);
+  void FlushThenShutdownDecoder(MediaRawData* aPendingSample);
+  RefPtr<ShutdownPromise> ShutdownDecoder();
+
+  UniquePtr<CodecChangeMonitor> mChangeMonitor;
+  RefPtr<PDMFactory> mPDMFactory;
+  VideoInfo mCurrentConfig;
+  nsCOMPtr<nsISerialEventTarget> mThread;
+  RefPtr<MediaDataDecoder> mDecoder;
+  MozPromiseRequestHolder<CreateDecoderPromise> mDecoderRequest;
+  MozPromiseRequestHolder<InitPromise> mInitPromiseRequest;
+  MozPromiseHolder<InitPromise> mInitPromise;
+  MozPromiseRequestHolder<DecodePromise> mDecodePromiseRequest;
+  MozPromiseHolder<DecodePromise> mDecodePromise;
+  MozPromiseRequestHolder<FlushPromise> mFlushRequest;
+  MediaDataDecoder::DecodedData mPendingFrames;
+  MozPromiseRequestHolder<DecodePromise> mDrainRequest;
+  MozPromiseRequestHolder<ShutdownPromise> mShutdownRequest;
+  RefPtr<ShutdownPromise> mShutdownPromise;
+  MozPromiseHolder<FlushPromise> mFlushPromise;
+
+  bool mNeedKeyframe = true;
+  Maybe<bool> mCanRecycleDecoder;
+  Maybe<MediaDataDecoder::ConversionRequired> mConversionRequired;
+  bool mDecoderInitialized = false;
+  const CreateDecoderParamsForAsync mParams;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_H264Converter_h
diff --git a/dom/media/platforms/wrappers/MediaDataDecoderProxy.cpp b/dom/media/platforms/wrappers/MediaDataDecoderProxy.cpp
new file mode 100644
index 0000000000..6bddb97e65
--- /dev/null
+++ b/dom/media/platforms/wrappers/MediaDataDecoderProxy.cpp
@@ -0,0 +1,137 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "MediaDataDecoderProxy.h"
+
+namespace mozilla {
+
+RefPtr<MediaDataDecoder::InitPromise> MediaDataDecoderProxy::Init() {
+  MOZ_ASSERT(!mIsShutdown);
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->Init();
+  }
+  return InvokeAsync(mProxyThread, __func__, [self = RefPtr{this}] {
+    return self->mProxyDecoder->Init();
+  });
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> MediaDataDecoderProxy::Decode(
+    MediaRawData* aSample) {
+  MOZ_ASSERT(!mIsShutdown);
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->Decode(aSample);
+  }
+  RefPtr<MediaRawData> sample = aSample;
+  return InvokeAsync(mProxyThread, __func__, [self = RefPtr{this}, sample] {
+    return self->mProxyDecoder->Decode(sample);
+  });
+}
+
+bool MediaDataDecoderProxy::CanDecodeBatch() const {
+  return mProxyDecoder->CanDecodeBatch();
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> MediaDataDecoderProxy::DecodeBatch(
+    nsTArray<RefPtr<MediaRawData>>&& aSamples) {
+  MOZ_ASSERT(!mIsShutdown);
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->DecodeBatch(std::move(aSamples));
+  }
+  return InvokeAsync(
+      mProxyThread, __func__,
+      [self = RefPtr{this}, samples = std::move(aSamples)]() mutable {
+        return self->mProxyDecoder->DecodeBatch(std::move(samples));
+      });
+}
+
+RefPtr<MediaDataDecoder::FlushPromise> MediaDataDecoderProxy::Flush() {
+  MOZ_ASSERT(!mIsShutdown);
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->Flush();
+  }
+  return InvokeAsync(mProxyThread, __func__, [self = RefPtr{this}] {
+    return self->mProxyDecoder->Flush();
+  });
+}
+
+RefPtr<MediaDataDecoder::DecodePromise> MediaDataDecoderProxy::Drain() {
+  MOZ_ASSERT(!mIsShutdown);
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->Drain();
+  }
+  return InvokeAsync(mProxyThread, __func__, [self = RefPtr{this}] {
+    return self->mProxyDecoder->Drain();
+  });
+}
+
+RefPtr<ShutdownPromise> MediaDataDecoderProxy::Shutdown() {
+  MOZ_ASSERT(!mIsShutdown);
+
+#if defined(DEBUG)
+  mIsShutdown = true;
+#endif
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    return mProxyDecoder->Shutdown();
+  }
+  // We chain another promise to ensure that the proxied decoder gets destructed
+  // on the proxy thread.
+  return InvokeAsync(mProxyThread, __func__, [self = RefPtr{this}] {
+    RefPtr<ShutdownPromise> p = self->mProxyDecoder->Shutdown()->Then(
+        self->mProxyThread, __func__,
+        [self](const ShutdownPromise::ResolveOrRejectValue& aResult) {
+          self->mProxyDecoder = nullptr;
+          return ShutdownPromise::CreateAndResolveOrReject(aResult, __func__);
+        });
+    return p;
+  });
+}
+
+nsCString MediaDataDecoderProxy::GetDescriptionName() const {
+  MOZ_ASSERT(!mIsShutdown);
+
+  return mProxyDecoder->GetDescriptionName();
+}
+
+bool MediaDataDecoderProxy::IsHardwareAccelerated(
+    nsACString& aFailureReason) const {
+  MOZ_ASSERT(!mIsShutdown);
+
+  return mProxyDecoder->IsHardwareAccelerated(aFailureReason);
+}
+
+void MediaDataDecoderProxy::SetSeekThreshold(const media::TimeUnit& aTime) {
+  MOZ_ASSERT(!mIsShutdown);
+
+  if (!mProxyThread || mProxyThread->IsOnCurrentThread()) {
+    mProxyDecoder->SetSeekThreshold(aTime);
+    return;
+  }
+  media::TimeUnit time = aTime;
+  mProxyThread->Dispatch(NS_NewRunnableFunction(
+      "MediaDataDecoderProxy::SetSeekThreshold", [self = RefPtr{this}, time] {
+        self->mProxyDecoder->SetSeekThreshold(time);
+      }));
+}
+
+bool MediaDataDecoderProxy::SupportDecoderRecycling() const {
+  MOZ_ASSERT(!mIsShutdown);
+
+  return mProxyDecoder->SupportDecoderRecycling();
+}
+
+MediaDataDecoder::ConversionRequired MediaDataDecoderProxy::NeedsConversion()
+    const {
+  MOZ_ASSERT(!mIsShutdown);
+
+  return mProxyDecoder->NeedsConversion();
+}
+
+}  // namespace mozilla
diff --git a/dom/media/platforms/wrappers/MediaDataDecoderProxy.h b/dom/media/platforms/wrappers/MediaDataDecoderProxy.h
new file mode 100644
index 0000000000..f69cb810b8
--- /dev/null
+++ b/dom/media/platforms/wrappers/MediaDataDecoderProxy.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+#if !defined(MediaDataDecoderProxy_h_)
+#  define MediaDataDecoderProxy_h_
+
+#  include "PlatformDecoderModule.h"
+#  include "mozilla/Atomics.h"
+#  include "mozilla/RefPtr.h"
+#  include "nsThreadUtils.h"
+#  include "nscore.h"
+
+namespace mozilla {
+
+DDLoggedTypeDeclNameAndBase(MediaDataDecoderProxy, MediaDataDecoder);
+
+class MediaDataDecoderProxy
+    : public MediaDataDecoder,
+      public DecoderDoctorLifeLogger<MediaDataDecoderProxy> {
+ public:
+  explicit MediaDataDecoderProxy(
+      already_AddRefed<MediaDataDecoder> aProxyDecoder,
+      already_AddRefed<nsISerialEventTarget> aProxyThread = nullptr)
+      : mProxyDecoder(aProxyDecoder), mProxyThread(aProxyThread) {
+    DDLINKCHILD("proxy decoder", mProxyDecoder.get());
+  }
+
+  RefPtr<InitPromise> Init() override;
+  RefPtr<DecodePromise> Decode(MediaRawData* aSample) override;
+  bool CanDecodeBatch() const override;
+  RefPtr<DecodePromise> DecodeBatch(
+      nsTArray<RefPtr<MediaRawData>>&& aSamples) override;
+  RefPtr<DecodePromise> Drain() override;
+  RefPtr<FlushPromise> Flush() override;
+  RefPtr<ShutdownPromise> Shutdown() override;
+  bool IsHardwareAccelerated(nsACString& aFailureReason) const override;
+  nsCString GetDescriptionName() const override;
+  void SetSeekThreshold(const media::TimeUnit& aTime) override;
+  bool SupportDecoderRecycling() const override;
+  ConversionRequired NeedsConversion() const override;
+
+ private:
+  // Set on construction and clear on the proxy thread if set.
+  RefPtr<MediaDataDecoder> mProxyDecoder;
+  const nsCOMPtr<nsISerialEventTarget> mProxyThread;
+
+#  if defined(DEBUG)
+  Atomic<bool> mIsShutdown = Atomic<bool>(false);
+#  endif
+};
+
+}  // namespace mozilla
+
+#endif  // MediaDataDecoderProxy_h_