Pass MSE media track info from ChunkDemuxer to blink::SourceBuffer

third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp

Index: third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
diff --git a/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp b/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
index d8b8e8a59271ae800fca7006260dc6a950d2dfc7..7f11656eb32160c68b85310ad8767ec0b3b95548 100644
--- a/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
+++ b/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
@@ -42,6 +42,10 @@
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/MediaError.h"
 #include "core/html/TimeRanges.h"
+#include "core/html/track/AudioTrack.h"
+#include "core/html/track/AudioTrackList.h"
+#include "core/html/track/VideoTrack.h"
+#include "core/html/track/VideoTrackList.h"
 #include "core/streams/Stream.h"
 #include "modules/mediasource/MediaSource.h"
 #include "platform/Logging.h"
@@ -122,6 +126,9 @@ SourceBuffer::SourceBuffer(PassOwnPtr<WebSourceBuffer> webSourceBuffer, MediaSou
 {
     ASSERT(m_webSourceBuffer);
     ASSERT(m_source);
+    ASSERT(m_source->mediaElement());
+    m_audioTracks = AudioTrackList::create(*m_source->mediaElement());
+    m_videoTracks = VideoTrackList::create(*m_source->mediaElement());
     m_webSourceBuffer->setClient(this);
 }
 
@@ -131,6 +138,8 @@ SourceBuffer::~SourceBuffer()
     // explicitly removed first, hence the asserts below will not
     // hold.
 #if !ENABLE(OILPAN)
+    m_audioTracks->shutdown();
+    m_videoTracks->shutdown();
     ASSERT(isRemoved());
     ASSERT(!m_loader);
     ASSERT(!m_stream);
@@ -228,6 +237,18 @@ void SourceBuffer::setTimestampOffset(double offset, ExceptionState& exceptionSt
     m_timestampOffset = offset;
 }
 
+AudioTrackList& SourceBuffer::audioTracks()
+{
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+    return *m_audioTracks;
+}
+
+VideoTrackList& SourceBuffer::videoTracks()
+{
+    ASSERT(RuntimeEnabledFeatures::audioVideoTracksEnabled());
+    return *m_videoTracks;
+}
+
 double SourceBuffer::appendWindowStart() const
 {
     return m_appendWindowStart;
@@ -471,17 +492,76 @@ void SourceBuffer::removedFromMediaSource()
     m_asyncEventQueue = nullptr;
 }
 
-void SourceBuffer::initializationSegmentReceived()
+template<class T>
+T* findExistingTrackById(const TrackListBase<T>& trackList, const String& id)
+{
+    // According to MSE specification (https://w3c.github.io/media-source/#sourcebuffer-init-segment-received) step 3.1:
+    // > If more than one track for a single type are present (ie 2 audio tracks), then the Track IDs match the ones in the first initialization segment.
+    // I.e. we only need to search by TrackID if there is more than one track, otherwise we can assume that the only
+    // track of the given type is the same one that we had in previous init segments.
+    if (trackList.length() == 1)
+        return trackList.anonymousIndexedGetter(0);
+    return trackList.getTrackById(id);
+}
+
+std::vector<WebMediaPlayer::TrackId> SourceBuffer::initializationSegmentReceived(const std::vector<MediaTrackInfo>& newTracks)
 {
-    WTF_LOG(Media, "SourceBuffer::initializationSegmentReceived %p", this);
+    WTF_LOG(Media, "SourceBuffer::initializationSegmentReceived %p tracks=%zu", this, newTracks.size());
     ASSERT(m_source);
+    ASSERT(m_source->mediaElement());
     ASSERT(m_updating);
 
-    // https://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html#sourcebuffer-init-segment-received
-    // FIXME: Make steps 1-7 synchronous with this call.
-    // FIXME: Augment the interface to this method to implement compliant steps 4-7 here.
-    // Step 3 (if the first initialization segment received flag is true) is
-    // implemented by caller.
+    // TODO(servolk): Implement proper 'initialization segment received' algorithm according to MSE spec:
+    // https://w3c.github.io/media-source/#sourcebuffer-init-segment-received
+    std::vector<WebMediaPlayer::TrackId> result;
+    for (const auto& trackInfo : newTracks) {
+        const auto& trackType = std::get<0>(trackInfo);
+        const auto& id = std::get<1>(trackInfo);
+        const auto& kind = std::get<2>(trackInfo);
+        const auto& label = std::get<3>(trackInfo);
+        const auto& language = std::get<4>(trackInfo);
+
+        if (!RuntimeEnabledFeatures::audioVideoTracksEnabled()) {
+            static WebMediaPlayer::TrackId nextTrackId = 0;
+            result.push_back(++nextTrackId);
+            continue;
+        }
+
+        const TrackBase* trackBase = nullptr;
+        if (trackType == WebMediaPlayer::AudioTrack) {
+            AudioTrack* audioTrack = nullptr;
+            if (!m_firstInitializationSegmentReceived) {
+                audioTrack = AudioTrack::create(id, kind, label, language, false);
+                audioTracks().add(audioTrack);
+                m_source->mediaElement()->audioTracks().add(audioTrack);
+            } else {
+                audioTrack = findExistingTrackById(audioTracks(), id);
+                ASSERT(audioTrack);
+            }
+            trackBase = audioTrack;
+            result.push_back(audioTrack->trackId());
+        } else if (trackType == WebMediaPlayer::VideoTrack) {
+            VideoTrack* videoTrack = nullptr;
+            if (!m_firstInitializationSegmentReceived) {
+                videoTrack = VideoTrack::create(id, kind, label, language, false);
+                videoTracks().add(videoTrack);
+                m_source->mediaElement()->videoTracks().add(videoTrack);
+            } else {
+                videoTrack = findExistingTrackById(videoTracks(), id);
+                ASSERT(videoTrack);
+            }
+            trackBase = videoTrack;
+            result.push_back(videoTrack->trackId());
+        } else {
+            NOTREACHED();
+        }
+        (void)trackBase;
+#if !LOG_DISABLED
+        const char* logActionStr = m_firstInitializationSegmentReceived ? "using existing" : "added";
+        const char* logTrackTypeStr = (trackType == WebMediaPlayer::AudioTrack) ? "audio" : "video";
+        WTF_LOG(Media, "Tracks (sb=%p): %s %sTrack %p trackId=%d id=%s label=%s lang=%s", this, logActionStr, logTrackTypeStr, trackBase, trackBase->trackId(), trackBase->id().utf8().data(), trackBase->label().utf8().data(), trackBase->language().utf8().data());
+#endif
+    }
 
     if (!m_firstInitializationSegmentReceived) {
         // 5. If active track flag equals true, then run the following steps:
@@ -493,6 +573,8 @@ void SourceBuffer::initializationSegmentReceived()
         // 6. Set first initialization segment received flag to true.
         m_firstInitializationSegmentReceived = true;
     }
+
+    return result;
 }
 
 bool SourceBuffer::hasPendingActivity() const
@@ -873,6 +955,8 @@ DEFINE_TRACE(SourceBuffer)
     visitor->trace(m_removeAsyncPartRunner);
     visitor->trace(m_appendStreamAsyncPartRunner);
     visitor->trace(m_stream);
+    visitor->trace(m_audioTracks);
+    visitor->trace(m_videoTracks);
     RefCountedGarbageCollectedEventTargetWithInlineData<SourceBuffer>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }