--- a/dom/media/platforms/wrappers/H264Converter.cpp
+++ b/dom/media/platforms/wrappers/H264Converter.cpp
@@ -74,16 +74,25 @@ H264Converter::Decode(MediaRawData* aSam
     // contain a SPS.
     rv = CreateDecoderAndInit(aSample);
     if (rv == NS_ERROR_NOT_INITIALIZED) {
       // We are missing the required SPS to create the decoder.
       // Ignore for the time being, the MediaRawData will be dropped.
       return DecodePromise::CreateAndResolve(DecodedData(), __func__);
     }
   } else {
+    // Initialize the members that we couldn't if the extradata was given during
+    // H264Converter's construction.
+    if (!mNeedAVCC) {
+      mNeedAVCC =
+        Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
+    }
+    if (!mCanRecycleDecoder) {
+      mCanRecycleDecoder = Some(CanRecycleDecoder());
+    }
     rv = CheckForSPSChange(aSample);
   }
 
   if (rv == NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER) {
     // The decoder is pending initialization.
     RefPtr<DecodePromise> p = mDecodePromise.Ensure(__func__);
     return p;
   }
@@ -94,21 +103,16 @@ H264Converter::Decode(MediaRawData* aSam
                   RESULT_DETAIL("Unable to create H264 decoder")),
       __func__);
   }
 
   if (mNeedKeyframe && !aSample->mKeyframe) {
     return DecodePromise::CreateAndResolve(DecodedData(), __func__);
   }
 
-  if (!mNeedAVCC) {
-    mNeedAVCC =
-      Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
-  }
-
   if (!*mNeedAVCC
       && !mp4_demuxer::AnnexB::ConvertSampleToAnnexB(aSample, mNeedKeyframe)) {
     return DecodePromise::CreateAndReject(
       MediaResult(NS_ERROR_OUT_OF_MEMORY,
                   RESULT_DETAIL("ConvertSampleToAnnexB")),
       __func__);
   }
 
@@ -255,16 +259,21 @@ H264Converter::CreateDecoderAndInit(Medi
   return rv;
 }
 
 void
 H264Converter::OnDecoderInitDone(const TrackType aTrackType)
 {
   mInitPromiseRequest.Complete();
   RefPtr<MediaRawData> sample = mPendingSample.forget();
+
+  mNeedAVCC =
+    Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
+  mCanRecycleDecoder = Some(CanRecycleDecoder());
+
   DecodeFirstSample(sample);
 }
 
 void
 H264Converter::OnDecoderInitFailed(const MediaResult& aError)
 {
   mInitPromiseRequest.Complete();
   mDecodePromise.Reject(
@@ -284,19 +293,16 @@ H264Converter::CanRecycleDecoder() const
 void
 H264Converter::DecodeFirstSample(MediaRawData* aSample)
 {
   if (mNeedKeyframe && !aSample->mKeyframe) {
     mDecodePromise.Resolve(DecodedData(), __func__);
     return;
   }
 
-  mNeedAVCC =
-    Some(mDecoder->NeedsConversion() == ConversionRequired::kNeedAVCC);
-
   if (!*mNeedAVCC
       && !mp4_demuxer::AnnexB::ConvertSampleToAnnexB(aSample, mNeedKeyframe)) {
     mDecodePromise.Reject(
       MediaResult(NS_ERROR_OUT_OF_MEMORY,
                   RESULT_DETAIL("ConvertSampleToAnnexB")),
       __func__);
     return;
   }
@@ -324,18 +330,18 @@ H264Converter::CheckForSPSChange(MediaRa
     mp4_demuxer::AnnexB::ExtractExtraData(aSample);
   if (!mp4_demuxer::AnnexB::HasSPS(extra_data)
       || mp4_demuxer::AnnexB::CompareExtraData(extra_data,
                                                mCurrentConfig.mExtraData)) {
     return NS_OK;
   }
 
   RefPtr<MediaRawData> sample = aSample;
-
-  if (CanRecycleDecoder()) {
+  MOZ_ASSERT(mCanRecycleDecoder.isSome());
+  if (*mCanRecycleDecoder) {
     // Do not recreate the decoder, reuse it.
     UpdateConfigFromExtraData(extra_data);
     if (!sample->mTrackInfo) {
       sample->mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, 0);
     }
     mNeedKeyframe = true;
     return NS_OK;
   }

--- a/dom/media/platforms/wrappers/H264Converter.h
+++ b/dom/media/platforms/wrappers/H264Converter.h
@@ -95,13 +95,14 @@ private:
 
   RefPtr<GMPCrashHelper> mGMPCrashHelper;
   Maybe<bool> mNeedAVCC;
   nsresult mLastError;
   bool mNeedKeyframe = true;
   const TrackInfo::TrackType mType;
   MediaEventProducer<TrackInfo::TrackType>* const mOnWaitingForKeyEvent;
   const CreateDecoderParams::OptionSet mDecoderOptions;
+  Maybe<bool> mCanRecycleDecoder;
 };
 
 } // namespace mozilla
 
 #endif // mozilla_H264Converter_h