--- a/dom/media/MediaFormatReader.cpp
+++ b/dom/media/MediaFormatReader.cpp
@@ -2041,16 +2041,18 @@ 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.HasWaitingPromise()) {
+        decoder.Flush();
       }
 
       decoder.mInfo = info;
 
       if (sample->mKeyframe) {
         ScheduleUpdate(aTrack);
       } else {
         auto time = TimeInterval(sample->mTime, sample->GetEndTime());
@@ -3061,17 +3063,17 @@ MediaFormatReader::GetMozDebugReaderData
 
   result += nsPrintfCString("Audio Decoder: %s\n", audioName);
   result += nsPrintfCString("Audio Frames Decoded: %" PRIu64 "\n",
                             mAudio.mNumSamplesOutputTotal);
   if (HasAudio()) {
     result += nsPrintfCString(
       "Audio State: ni=%d no=%d wp=%d demuxr=%d demuxq=%u decoder=%d tt=%.1f "
       "tths=%d in=%" PRIu64 " out=%" PRIu64
-      " qs=%u pending=%u wfd=%d eos=%d ds=%d wfk=%d sid=%u\n",
+      " qs=%u pending=%u wfd=%d eos=%d ds=%d wfk=%d sid=%u nsid=%d\n",
       NeedInput(mAudio),
       mAudio.HasPromise(),
       !mAudio.mWaitingPromise.IsEmpty(),
       mAudio.mDemuxRequest.Exists(),
       uint32_t(mAudio.mQueuedSamples.Length()),
       mAudio.mDecodeRequest.Exists(),
       mAudio.mTimeThreshold ? mAudio.mTimeThreshold.ref().Time().ToSeconds()
                             : -1.0,
@@ -3079,31 +3081,33 @@ MediaFormatReader::GetMozDebugReaderData
       mAudio.mNumSamplesInput,
       mAudio.mNumSamplesOutput,
       unsigned(size_t(mAudio.mSizeOfQueue)),
       unsigned(mAudio.mOutput.Length()),
       mAudio.mWaitingForData,
       mAudio.mDemuxEOS,
       int32_t(mAudio.mDrainState),
       mAudio.mWaitingForKey,
-      mAudio.mLastStreamSourceID);
+      mAudio.mLastStreamSourceID,
+      int32_t(mAudio.mNextStreamSourceID.refOr(-1)));
   }
   result += nsPrintfCString("Video Decoder: %s\n", videoName);
   result +=
     nsPrintfCString("Hardware Video Decoding: %s\n",
                     VideoIsHardwareAccelerated() ? "enabled" : "disabled");
   result +=
     nsPrintfCString("Video Frames Decoded: %" PRIu64 " (skipped=%" PRIu64 ")\n",
                     mVideo.mNumSamplesOutputTotal,
                     mVideo.mNumSamplesSkippedTotal);
   if (HasVideo()) {
     result += nsPrintfCString(
       "Video State: ni=%d no=%d wp=%d demuxr=%d demuxq=%u decoder=%d tt=%.1f "
       "tths=%d in=%" PRIu64 " out=%" PRIu64
-      " qs=%u pending:%u wfd=%d eos=%d ds=%d wfk=%d sid=%u\n",
+      " qs=%u pending:%u wfd=%d eos=%d ds=%d wfk=%d sid=%u nsid=%d lts=%" PRId64
+      "pt=%" PRId64 "\n",
       NeedInput(mVideo),
       mVideo.HasPromise(),
       !mVideo.mWaitingPromise.IsEmpty(),
       mVideo.mDemuxRequest.Exists(),
       uint32_t(mVideo.mQueuedSamples.Length()),
       mVideo.mDecodeRequest.Exists(),
       mVideo.mTimeThreshold ? mVideo.mTimeThreshold.ref().Time().ToSeconds()
                             : -1.0,
@@ -3111,17 +3115,20 @@ MediaFormatReader::GetMozDebugReaderData
       mVideo.mNumSamplesInput,
       mVideo.mNumSamplesOutput,
       unsigned(size_t(mVideo.mSizeOfQueue)),
       unsigned(mVideo.mOutput.Length()),
       mVideo.mWaitingForData,
       mVideo.mDemuxEOS,
       int32_t(mVideo.mDrainState),
       mVideo.mWaitingForKey,
-      mVideo.mLastStreamSourceID);
+      mVideo.mLastStreamSourceID,
+      int32_t(mVideo.mNextStreamSourceID.refOr(-1)),
+      mVideo.mLastTimeThreshold.ToMicroseconds(),
+      mVideo.mOutput.Length() ? mVideo.mOutput[0]->mTime.ToMicroseconds() : -1);
   }
   aString += result;
 }
 
 void
 MediaFormatReader::SetVideoNullDecode(bool aIsNullDecode)
 {
   MOZ_ASSERT(OnTaskQueue());