Bug 1568058 - pt 1 - Add DecoderTraits::CreateDemuxer and use it in CreateReader. r=jya

CreateDemuxer will be used in MediaBufferDecoder as we remove MediaFormatReader.

Differential Revision: https://phabricator.services.mozilla.com/D45094

--HG--
extra : moz-landing-system : lando

dom/media/DecoderTraits.cpp

@@ -228,33 +228,50 @@ bool DecoderTraits::ShouldHandleMediaType(
 }
 
 /* static */
-MediaFormatReader* DecoderTraits::CreateReader(const MediaContainerType& aType,
-                                               MediaFormatReaderInit& aInit) {
+already_AddRefed<MediaDataDemuxer> DecoderTraits::CreateDemuxer(
+    const MediaContainerType& aType, MediaResource* aResource) {
   MOZ_ASSERT(NS_IsMainThread());
-  MediaFormatReader* decoderReader = nullptr;
-  MediaResource* resource = aInit.mResource;
+  RefPtr<MediaDataDemuxer> demuxer;
 
 #ifdef MOZ_FMP4
   if (MP4Decoder::IsSupportedType(aType,
                                   /* DecoderDoctorDiagnostics* */ nullptr)) {
-    decoderReader = new MediaFormatReader(aInit, new MP4Demuxer(resource));
+    demuxer = new MP4Demuxer(aResource);
   } else
 #endif
       if (MP3Decoder::IsSupportedType(aType)) {
-    decoderReader = new MediaFormatReader(aInit, new MP3Demuxer(resource));
+    demuxer = new MP3Demuxer(aResource);
   } else if (ADTSDecoder::IsSupportedType(aType)) {
-    decoderReader = new MediaFormatReader(aInit, new ADTSDemuxer(resource));
+    demuxer = new ADTSDemuxer(aResource);
   } else if (WaveDecoder::IsSupportedType(aType)) {
-    decoderReader = new MediaFormatReader(aInit, new WAVDemuxer(resource));
+    demuxer = new WAVDemuxer(aResource);
   } else if (FlacDecoder::IsSupportedType(aType)) {
-    decoderReader = new MediaFormatReader(aInit, new FlacDemuxer(resource));
+    demuxer = new FlacDemuxer(aResource);
   } else if (OggDecoder::IsSupportedType(aType)) {
-    RefPtr<OggDemuxer> demuxer = new OggDemuxer(resource);
-    decoderReader = new MediaFormatReader(aInit, demuxer);
-    demuxer->SetChainingEvents(&decoderReader->TimedMetadataProducer(),
-                               &decoderReader->MediaNotSeekableProducer());
+    demuxer = new OggDemuxer(aResource);
   } else if (WebMDecoder::IsSupportedType(aType)) {
-    decoderReader = new MediaFormatReader(aInit, new WebMDemuxer(resource));
+    demuxer = new WebMDemuxer(aResource);
+  }
+
+  return demuxer.forget();
+}
+
+/* static */
+MediaFormatReader* DecoderTraits::CreateReader(const MediaContainerType& aType,
+                                               MediaFormatReaderInit& aInit) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  RefPtr<MediaDataDemuxer> demuxer = CreateDemuxer(aType, aInit.mResource);
+  if (!demuxer) {
+    return nullptr;
+  }
+
+  MediaFormatReader* decoderReader = new MediaFormatReader(aInit, demuxer);
+
+  if (OggDecoder::IsSupportedType(aType)) {
+    static_cast<OggDemuxer*>(demuxer.get())
+        ->SetChainingEvents(&decoderReader->TimedMetadataProducer(),
+                            &decoderReader->MediaNotSeekableProducer());
   }
 
   return decoderReader;

dom/media/DecoderTraits.h

@@ -15,8 +15,10 @@ namespace mozilla {
 
 class DecoderDoctorDiagnostics;
 class MediaContainerType;
+class MediaDataDemuxer;
 struct MediaFormatReaderInit;
 class MediaFormatReader;
+class MediaResource;
 class TrackInfo;
 
 enum CanPlayStatus { CANPLAY_NO, CANPLAY_MAYBE, CANPLAY_YES };
@@ -35,6 +37,11 @@ class DecoderTraits {
   static bool ShouldHandleMediaType(const char* aMIMEType,
                                     DecoderDoctorDiagnostics* aDiagnostics);
 
+  // Create a demuxer for the given MIME type aType.  Returns null if we
+  // were unable to create the demuxer.
+  static already_AddRefed<MediaDataDemuxer> CreateDemuxer(
+      const MediaContainerType& aType, MediaResource* aResource);
+
   // Create a reader for thew given MIME type aType. Returns null
   // if we were unable to create the reader.
   static MediaFormatReader* CreateReader(const MediaContainerType& aType,