--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -560,20 +560,16 @@ public:
   void SetSeekThreshold(const media::TimeUnit& aTime) override
   {
     mDecoder->SetSeekThreshold(aTime);
   }
   bool SupportDecoderRecycling() const override
   {
     return mDecoder->SupportDecoderRecycling();
   }
-  void ConfigurationChanged(const TrackInfo& aConfig) override
-  {
-    mDecoder->ConfigurationChanged(aConfig);
-  }
   RefPtr<ShutdownPromise> Shutdown() override
   {
     RefPtr<MediaDataDecoder> decoder = mDecoder.forget();
     RefPtr<Token> token = mToken.forget();
     return decoder->Shutdown()->Then(
       AbstractThread::GetCurrent(), __func__,
       [token]() {},
       [token]() { MOZ_RELEASE_ASSERT(false, "Can't reach here"); });
@@ -1986,19 +1982,16 @@ MediaFormatReader::HandleDemuxedSamples(
         LOG("Decoder does not support recycling, recreate decoder.");
         // If flushing is required, it will clear our array of queued samples.
         // So make a copy now.
         nsTArray<RefPtr<MediaRawData>> samples{ Move(decoder.mQueuedSamples) };
         ShutdownDecoder(aTrack);
         if (sample->mKeyframe) {
           decoder.mQueuedSamples.AppendElements(Move(samples));
         }
-      } else if (decoder.mInfo && *decoder.mInfo != *info) {
-        const TrackInfo* trackInfo = *info;
-        decoder.mDecoder->ConfigurationChanged(*trackInfo);
       }
 
       decoder.mInfo = info;
 
       if (sample->mKeyframe) {
         ScheduleUpdate(aTrack);
       } else {
         TimeInterval time =

--- a/dom/media/platforms/PlatformDecoderModule.h
+++ b/dom/media/platforms/PlatformDecoderModule.h
@@ -292,30 +292,16 @@ public:
   virtual void SetSeekThreshold(const media::TimeUnit& aTime) { }
 
   // When playing adaptive playback, recreating an Android video decoder will
   // cause the transition not smooth during resolution change.
   // Reuse the decoder if the decoder support recycling.
   // Currently, only Android video decoder will return true.
   virtual bool SupportDecoderRecycling() const { return false; }
 
-  // ConfigurationChanged will be called to inform the video or audio decoder
-  // that the format of the next input sample is about to change.
-  // If video decoder, aConfig will be a VideoInfo object.
-  // If audio decoder, aConfig will be a AudioInfo object.
-  // It is not safe to store a reference to this object and the decoder must
-  // make a copy.
-  // Care should be taken as ConfigurationChanged is called on the reader's
-  // taskqueue.
-  virtual void ConfigurationChanged(const TrackInfo& aConfig)
-  {
-    MOZ_ASSERT(SupportDecoderRecycling(),
-               "Can only work with a decoder supporting recycling.");
-  }
-
   enum class ConversionRequired
   {
     kNeedNone = 0,
     kNeedAVCC = 1,
     kNeedAnnexB = 2,
   };
 
   // Indicates that the decoder requires a specific format.

--- a/dom/media/platforms/wrappers/H264Converter.cpp
+++ b/dom/media/platforms/wrappers/H264Converter.cpp
@@ -14,17 +14,16 @@
 #include "mp4_demuxer/H264.h"
 
 namespace mozilla
 {
 
 H264Converter::H264Converter(PlatformDecoderModule* aPDM,
                              const CreateDecoderParams& aParams)
   : mPDM(aPDM)
-  , mOriginalConfig(aParams.VideoConfig())
   , mCurrentConfig(aParams.VideoConfig())
   , mKnowsCompositor(aParams.mKnowsCompositor)
   , mImageContainer(aParams.mImageContainer)
   , mTaskQueue(aParams.mTaskQueue)
   , mDecoder(nullptr)
   , mGMPCrashHelper(aParams.mCrashHelper)
   , mLastError(NS_OK)
   , mType(aParams.mType)
@@ -199,33 +198,32 @@ H264Converter::CreateDecoder(DecoderDoct
     }
   } else {
     // SPS was invalid.
     mLastError = NS_ERROR_FAILURE;
     return NS_ERROR_FAILURE;
   }
 
   mDecoder = mPDM->CreateVideoDecoder({
-    mUseOriginalConfig ? mOriginalConfig : mCurrentConfig,
+    mCurrentConfig,
     mTaskQueue,
     aDiagnostics,
     mImageContainer,
     mKnowsCompositor,
     mGMPCrashHelper,
     mType,
     mOnWaitingForKeyEvent,
     mDecoderOptions
   });
 
   if (!mDecoder) {
     mLastError = NS_ERROR_FAILURE;
     return NS_ERROR_FAILURE;
   }
 
-  mUseOriginalConfig = false;
   mNeedKeyframe = true;
 
   return NS_OK;
 }
 
 nsresult
 H264Converter::CreateDecoderAndInit(MediaRawData* aSample)
 {
@@ -285,19 +283,17 @@ H264Converter::DecodeFirstSample(MediaRa
   if (!*mNeedAVCC
       && !mp4_demuxer::AnnexB::ConvertSampleToAnnexB(aSample, mNeedKeyframe)) {
     mDecodePromise.Reject(
       MediaResult(NS_ERROR_OUT_OF_MEMORY,
                   RESULT_DETAIL("ConvertSampleToAnnexB")),
       __func__);
     return;
   }
-  if (CanRecycleDecoder()) {
-    mDecoder->ConfigurationChanged(mCurrentConfig);
-  }
+
   RefPtr<H264Converter> self = this;
   mDecoder->Decode(aSample)
     ->Then(AbstractThread::GetCurrent()->AsTaskQueue(), __func__,
            [self, this](const MediaDataDecoder::DecodedData& aResults) {
              mDecodePromiseRequest.Complete();
              mDecodePromise.Resolve(aResults, __func__);
            },
            [self, this](const MediaResult& aError) {

--- a/dom/media/platforms/wrappers/H264Converter.h
+++ b/dom/media/platforms/wrappers/H264Converter.h
@@ -43,22 +43,17 @@ public:
   void SetSeekThreshold(const media::TimeUnit& aTime) override;
   bool SupportDecoderRecycling() const override
   {
     if (mDecoder) {
       return mDecoder->SupportDecoderRecycling();
     }
     return false;
   }
-  void ConfigurationChanged(const TrackInfo& aConfig) override
-  {
-    if (mDecoder && mDecoder->SupportDecoderRecycling()) {
-      mDecoder->ConfigurationChanged(aConfig);
-    }
-  }
+
   ConversionRequired NeedsConversion() const override
   {
     if (mDecoder) {
       return mDecoder->NeedsConversion();
     }
     // Default so no conversion is performed.
     return ConversionRequired::kNeedAVCC;
   }
@@ -81,17 +76,16 @@ private:
     MOZ_ASSERT(mDecoder);
     return MediaPrefs::MediaDecoderCheckRecycling()
            && mDecoder->SupportDecoderRecycling();
   }
 
   void DecodeFirstSample(MediaRawData* aSample);
 
   RefPtr<PlatformDecoderModule> mPDM;
-  const VideoInfo mOriginalConfig;
   VideoInfo mCurrentConfig;
   RefPtr<layers::KnowsCompositor> mKnowsCompositor;
   RefPtr<layers::ImageContainer> mImageContainer;
   const RefPtr<TaskQueue> mTaskQueue;
   RefPtr<MediaRawData> mPendingSample;
   RefPtr<MediaDataDecoder> mDecoder;
   MozPromiseRequestHolder<InitPromise> mInitPromiseRequest;
   MozPromiseRequestHolder<DecodePromise> mDecodePromiseRequest;
@@ -99,18 +93,16 @@ private:
   MozPromiseRequestHolder<FlushPromise> mFlushRequest;
   MozPromiseRequestHolder<ShutdownPromise> mShutdownRequest;
   RefPtr<ShutdownPromise> mShutdownPromise;
 
   RefPtr<GMPCrashHelper> mGMPCrashHelper;
   Maybe<bool> mNeedAVCC;
   nsresult mLastError;
   bool mNeedKeyframe = true;
-  // Set to true once a decoder has been created.
-  bool mUseOriginalConfig = true;
   const TrackInfo::TrackType mType;
   MediaEventProducer<TrackInfo::TrackType>* const mOnWaitingForKeyEvent;
   const CreateDecoderParams::OptionSet mDecoderOptions;
 };
 
 } // namespace mozilla
 
 #endif // mozilla_H264Converter_h

--- a/dom/media/platforms/wrappers/MediaDataDecoderProxy.cpp
+++ b/dom/media/platforms/wrappers/MediaDataDecoderProxy.cpp
@@ -113,33 +113,16 @@ MediaDataDecoderProxy::SetSeekThreshold(
 bool
 MediaDataDecoderProxy::SupportDecoderRecycling() const
 {
   MOZ_ASSERT(!mIsShutdown);
 
   return mProxyDecoder->SupportDecoderRecycling();
 }
 
-void
-MediaDataDecoderProxy::ConfigurationChanged(const TrackInfo& aConfig)
-{
-  MOZ_ASSERT(!mIsShutdown);
-
-  if (!mProxyThread) {
-    mProxyDecoder->ConfigurationChanged(aConfig);
-    return;
-  }
-  RefPtr<MediaDataDecoderProxy> self = this;
-  RefPtr<TrackInfoSharedPtr> config = new TrackInfoSharedPtr(aConfig, 0);
-  mProxyThread->Dispatch(NS_NewRunnableFunction([self, config] {
-    const TrackInfo* trackInfo = *config;
-    self->mProxyDecoder->ConfigurationChanged(*trackInfo);
-  }));
-}
-
 MediaDataDecoder::ConversionRequired
 MediaDataDecoderProxy::NeedsConversion() const
 {
   MOZ_ASSERT(!mIsShutdown);
 
   return mProxyDecoder->NeedsConversion();
 }
 

--- a/dom/media/platforms/wrappers/MediaDataDecoderProxy.h
+++ b/dom/media/platforms/wrappers/MediaDataDecoderProxy.h
@@ -45,17 +45,16 @@ public:
   RefPtr<DecodePromise> Decode(MediaRawData* aSample) override;
   RefPtr<DecodePromise> Drain() override;
   RefPtr<FlushPromise> Flush() override;
   RefPtr<ShutdownPromise> Shutdown() override;
   const char* GetDescriptionName() const override;
   bool IsHardwareAccelerated(nsACString& aFailureReason) const override;
   void SetSeekThreshold(const media::TimeUnit& aTime) override;
   bool SupportDecoderRecycling() const override;
-  void ConfigurationChanged(const TrackInfo& aConfig) override;
   ConversionRequired NeedsConversion() const override;
 
 private:
   RefPtr<MediaDataDecoder> mProxyDecoder;
   RefPtr<AbstractThread> mProxyThread;
 
 #if defined(DEBUG)
   Atomic<bool> mIsShutdown;