Bug 1345599 - part 3: for recyclable decoder, don't drain/flush when stream ID/SPS change. r=jya

MozReview-Commit-ID: 4qtlbMWgfPo

--HG--
extra : rebase_source : f5b71b6803e2f725639e675081bc30cd0b1bde2a

dom/media/MediaFormatReader.cpp

@@ -1961,8 +1961,11 @@ MediaFormatReader::HandleDemuxedSamples(
     RefPtr<TrackInfoSharedPtr> info = sample->mTrackInfo;
 
     if (info && decoder.mLastStreamSourceID != info->GetID()) {
-      if (decoder.mNextStreamSourceID.isNothing()
-          || decoder.mNextStreamSourceID.ref() != info->GetID()) {
+      bool recyclable = MediaPrefs::MediaDecoderCheckRecycling()
+                        && decoder.mDecoder->SupportDecoderRecycling();
+      if (!recyclable
+          && (decoder.mNextStreamSourceID.isNothing()
+              || decoder.mNextStreamSourceID.ref() != info->GetID())) {
         LOG("%s stream id has changed from:%d to:%d, draining decoder.",
           TrackTypeToStr(aTrack), decoder.mLastStreamSourceID,
           info->GetID());
@@ -1978,8 +1981,7 @@ MediaFormatReader::HandleDemuxedSamples(
       decoder.mLastStreamSourceID = info->GetID();
       decoder.mNextStreamSourceID.reset();
 
-      if (!MediaPrefs::MediaDecoderCheckRecycling()
-          || !decoder.mDecoder->SupportDecoderRecycling()) {
+      if (!recyclable) {
         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.

dom/media/platforms/wrappers/H264Converter.cpp

@@ -332,32 +332,11 @@ H264Converter::CheckForSPSChange(MediaRawData* aSample)
   if (CanRecycleDecoder()) {
     // Do not recreate the decoder, reuse it.
     UpdateConfigFromExtraData(extra_data);
-    // Ideally we would want to drain the decoder instead of flushing it.
-    // However the draining operation requires calling Drain and looping several
-    // times which isn't possible from within the H264Converter. So instead we
-    // flush the decoder. In practice, this is a no-op as SPS change will only
-    // be used with MSE. And with MSE, the MediaFormatReader would have drained
-    // the decoder already.
-    RefPtr<H264Converter> self = this;
     if (!sample->mTrackInfo) {
       sample->mTrackInfo = new TrackInfoSharedPtr(mCurrentConfig, 0);
     }
-    mDecoder->Flush()
-      ->Then(AbstractThread::GetCurrent()->AsTaskQueue(),
-             __func__,
-             [self, sample, this]() {
-               mFlushRequest.Complete();
-               DecodeFirstSample(sample);
-             },
-             [self, this](const MediaResult& aError) {
-               mFlushRequest.Complete();
-               mDecodePromise.Reject(aError, __func__);
-             })
-      ->Track(mFlushRequest);
     mNeedKeyframe = true;
-    // This is not really initializing the decoder, but it will do as it
-    // indicates an operation is pending.
-    return NS_ERROR_DOM_MEDIA_INITIALIZING_DECODER;
+    return NS_OK;
   }
 
   // The SPS has changed, signal to flush the current decoder and create a