Add SourceBuffer implementations of Audio/VideoTracks

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 487011521a9927f26b3a9bbc7281173505267668..bac2a2fb8aa81f437a7cbb7c675dd7876e48ba39 100644
--- a/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
+++ b/third_party/WebKit/Source/modules/mediasource/SourceBuffer.cpp
@@ -48,7 +48,9 @@
 #include "core/html/track/VideoTrack.h"
 #include "core/html/track/VideoTrackList.h"
 #include "core/streams/Stream.h"
+#include "modules/mediasource/AudioTrackSourceBuffer.h"
 #include "modules/mediasource/MediaSource.h"
+#include "modules/mediasource/VideoTrackSourceBuffer.h"
 #include "platform/Logging.h"
 #include "platform/TraceEvent.h"
 #include "public/platform/WebSourceBuffer.h"
@@ -232,6 +234,18 @@ 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;
@@ -506,11 +520,18 @@ void SourceBuffer::initializationSegmentReceived(const WebVector<WebMediaPlayer:
         return;
     }
 
+    if (!m_audioTracks)
+        m_audioTracks = AudioTrackList::create(*m_source->mediaElement());
+    if (!m_videoTracks)
+        m_videoTracks = VideoTrackList::create(*m_source->mediaElement());
+
     for (const auto& trackId : m_audioTrackIds) {
         m_source->mediaElement()->audioTracks().remove(trackId);
+        audioTracks().remove(trackId);

[philipj_slow, 2016/03/10 13:12:17]

This makes it clear that the order in which the track is removed from both track
lists will affect the order of the ends. This doesn't seem to be spelled out by
https://w3c.github.io/media-source/#audio-track-extensions but I could be
looking in the wrong place. This would also need tests.

[servolk, 2016/03/11 02:00:58]

see below

     }
     for (const auto& trackId : m_videoTrackIds) {
         m_source->mediaElement()->videoTracks().remove(trackId);
+        videoTracks().remove(trackId);
     }
     m_audioTrackIds.clear();
     m_videoTrackIds.clear();
@@ -521,11 +542,13 @@ void SourceBuffer::initializationSegmentReceived(const WebVector<WebMediaPlayer:
                 if (track->type() == WebMediaPlayer::AudioTrack) {
                     AudioTrack* audioTrack = static_cast<AudioTrack*>(track.get());
                     WTF_LOG(Media, "Tracks (sb=%p): adding audioTrack %p trackId=%d id=%s label=%s lang=%s", this, audioTrack, audioTrack->trackId(), audioTrack->id().utf8().data(), audioTrack->label().utf8().data(), audioTrack->language().utf8().data());
+                    audioTracks().add(audioTrack);

[philipj_slow, 2016/03/10 13:12:17]

Order tests needed for adding tracks too.

[servolk, 2016/03/11 02:00:58]

I think we are better off postponing these tests until a separate CL that will
implement a fully spec-compliant MSE init segment received algorithm. The
current code removes all the old tracks, but the spec compliant algorithm will
need to check the new track ids and match them with existing tracks, verify that
track properties haven't changed and leave those track in the lists. The MSE
spec does specify the order here, the track must be added to the SB track list
first and then to the HTMLMediaElement (see for example for audio tracks items
5.2.8.8 and 5.2.8.10 at
https://w3c.github.io/media-source/#sourcebuffer-init-segment-received).

                     m_source->mediaElement()->audioTracks().add(audioTrack);
                     m_audioTrackIds.append(trackId);
                 } else if (track->type() == WebMediaPlayer::VideoTrack) {
                     VideoTrack* videoTrack = static_cast<VideoTrack*>(track.get());
                     WTF_LOG(Media, "Tracks (sb=%p): adding videoTrack %p trackId=%d id=%s label=%s lang=%s", this, videoTrack, videoTrack->trackId(), videoTrack->id().utf8().data(), videoTrack->label().utf8().data(), videoTrack->language().utf8().data());
+                    videoTracks().add(videoTrack);
                     m_source->mediaElement()->videoTracks().add(videoTrack);
                     m_videoTrackIds.append(trackId);
                 }
@@ -541,14 +564,28 @@ WebMediaPlayer::TrackId SourceBuffer::createMediaTrack(WebMediaPlayer::TrackType
     TrackBase* result = nullptr;
     switch (type) {
     case WebMediaPlayer::AudioTrack:
-        result = AudioTrack::create(id, kind, label, language, false);
-        break;
+        {
+            AudioTrack* audioTrack = AudioTrack::create(id, kind, label, language, false);
+            if (audioTrack) {

[philipj_slow, 2016/03/10 13:12:17]

It can't be null, can it? On OOM we should have crashed already?

[servolk, 2016/03/11 02:00:58]

Done.

+                new AudioTrackSourceBuffer(*audioTrack, this);
+                result = audioTrack;
+            }
+            WTF_LOG(Media, "SourceBuffer(%p)::createMediaTrack: audioTrack %p trackId=%d id=%s label=%s lang=%s", this, audioTrack, audioTrack->trackId(), audioTrack->id().utf8().data(), audioTrack->label().utf8().data(), audioTrack->language().utf8().data());
+            break;
+        }
     case WebMediaPlayer::TextTrack:
         result = TextTrack::create(kind, label, language);
         break;
     case WebMediaPlayer::VideoTrack:
-        result = VideoTrack::create(id, kind, label, language, false);
-        break;
+        {
+            VideoTrack* videoTrack = VideoTrack::create(id, kind, label, language, false);
+            if (videoTrack) {
+                new VideoTrackSourceBuffer(*videoTrack, this);
+                result = videoTrack;
+            }
+            WTF_LOG(Media, "SourceBuffer(%p)::createMediaTrack: videoTrack %p trackId=%d id=%s label=%s lang=%s", this, videoTrack, videoTrack->trackId(), videoTrack->id().utf8().data(), videoTrack->label().utf8().data(), videoTrack->language().utf8().data());
+            break;
+        }
     }
 
     ASSERT(result);
@@ -937,6 +974,8 @@ DEFINE_TRACE(SourceBuffer)
     visitor->trace(m_pendingTracks);
     visitor->trace(m_audioTrackIds);
     visitor->trace(m_videoTrackIds);
+    visitor->trace(m_audioTracks);
+    visitor->trace(m_videoTracks);
     RefCountedGarbageCollectedEventTargetWithInlineData<SourceBuffer>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }