Media Source dispatches inband text tracks

webkit/media/webmediaplayer_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "webkit/media/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <string>
 #include <vector>
@@ skipping 28 matching lines @@
 #include "third_party/WebKit/Source/Platform/chromium/public/WebSize.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebString.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebURL.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebMediaSource.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebRuntimeFeatures.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebView.h"
 #include "v8/include/v8.h"
 #include "webkit/compositor_bindings/web_layer_impl.h"
 #include "webkit/media/buffered_data_source.h"
 #include "webkit/media/webaudiosourceprovider_impl.h"
+#include "webkit/media/webinbandtexttrack_impl.h"
 #include "webkit/media/webmediaplayer_delegate.h"
 #include "webkit/media/webmediaplayer_params.h"
 #include "webkit/media/webmediaplayer_util.h"
 #include "webkit/media/webmediasourceclient_impl.h"
+#include "webkit/media/webtexttrack_impl.h"
 #include "webkit/plugins/ppapi/ppapi_webplugin_impl.h"
 
 using WebKit::WebCanvas;
 using WebKit::WebMediaPlayer;
 using WebKit::WebRect;
 using WebKit::WebSize;
 using WebKit::WebString;
 using media::PipelineStatus;
 
 namespace {
@@ skipping 76 matching lines @@
       media_log_(params.media_log()),
       accelerated_compositing_reported_(false),
       incremented_externally_allocated_memory_(false),
       gpu_factories_(params.gpu_factories()),
       is_local_source_(false),
       supports_save_(true),
       starting_(false),
       chunk_demuxer_(NULL),
       pending_repaint_(false),
       pending_size_change_(false),
-      video_frame_provider_client_(NULL) {
+      video_frame_provider_client_(NULL),
+      text_track_index_(0) {
   media_log_->AddEvent(
       media_log_->CreateEvent(media::MediaLogEvent::WEBMEDIAPLAYER_CREATED));
 
   CHECK(media_thread_.Start());
   pipeline_.reset(new media::Pipeline(
       media_thread_.message_loop_proxy(), media_log_));
 
   // Let V8 know we started new thread if we did not do it yet.
   // Made separate task to avoid deletion of player currently being created.
   // Also, delaying GC until after player starts gets rid of starting lag --
@@ skipping 820 matching lines @@
   DCHECK(init_data_type_.empty() || type.empty() || type == init_data_type_);
   if (init_data_type_.empty())
     init_data_type_ = type;
 
   GetClient()->keyNeeded(WebString::fromUTF8(key_system),
                          WebString::fromUTF8(session_id),
                          init_data.get(),
                          init_data_size);
 }
 
+media::TextTrack*
+WebMediaPlayerImpl::OnTextTrack(media::TextKind kind,
+                                const std::string& label,
+                                const std::string& language) {
+  typedef WebInbandTextTrackImpl::Kind webkind_t;
+  const webkind_t webkind = static_cast<webkind_t>(kind);
+  const WebKit::WebString weblabel = WebKit::WebString::fromUTF8(label);
+  const WebKit::WebString weblanguage = WebKit::WebString::fromUTF8(language);
+
+  // TODO(matthewjheaney): resolve lifetime issues for text_track_.
+  // Note that the text track object is adopted by its client, and so
+  // it does get destroyed during teardown of the tracks, and
+  // therefore there's no memory leak. However, there is the issue of
+  // lifetime, since we share a pointer to this text track object with
+  // its (owning) client.
+
+  WebInbandTextTrackImpl* const text_track =
+    new WebInbandTextTrackImpl(webkind, weblabel, weblanguage,
+                               text_track_index_++);
+  GetClient()->addTextTrack(text_track);
+
+  // TODO(matthewjheaney): better name for WebTextTrackImpl?
+  WebTextTrackImpl* const text_cb = new WebTextTrackImpl(text_track->client());

[acolwell GONE FROM CHROMIUM, 2013/05/10 02:22:08]

I think you need to be careful about ownership here. Does addTextTrack()
transfers ownership of text_track to Blink? If so then you need to be careful
about situations where Blink blows away text_track, but text_cb is still alive.

If ownership is not transfered, then text_cb should probably own text_track so
that when the TextTrack is destroyed text_track is also destroyed.

[Matthew Heaney (Chromium), 2013/05/10 05:21:08]

OK, that makes sense.  I'll make the necessary changes to webkit and create a
separate CL for that.

+
+  // TODO(matthewjheaney): need to keep record of created text tracks?
+  //text_tracks_.insert(text_cb);
+
+  // TODO(matthewjheaney): for now, rely on caller to destroy text_cb.
+  return text_cb;
+}
+
 #define COMPILE_ASSERT_MATCHING_ENUM(name) \
   COMPILE_ASSERT(static_cast<int>(WebKit::WebMediaPlayerClient::name) == \
                  static_cast<int>(media::Decryptor::k ## name), \
                  mismatching_enums)
 COMPILE_ASSERT_MATCHING_ENUM(UnknownError);
 COMPILE_ASSERT_MATCHING_ENUM(ClientError);
 COMPILE_ASSERT_MATCHING_ENUM(ServiceError);
 COMPILE_ASSERT_MATCHING_ENUM(OutputError);
 COMPILE_ASSERT_MATCHING_ENUM(HardwareChangeError);
 COMPILE_ASSERT_MATCHING_ENUM(DomainError);
@@ skipping 75 matching lines @@
         BIND_TO_RENDER_LOOP_2(&WebMediaPlayerImpl::OnNeedKey, "", "")));
   } else {
     DCHECK(!chunk_demuxer_);
     DCHECK(!data_source_);
 
     scoped_ptr<WebKit::WebMediaSource> ms(media_source);
     chunk_demuxer_ = new media::ChunkDemuxer(
         BIND_TO_RENDER_LOOP_1(&WebMediaPlayerImpl::OnDemuxerOpened,
                               base::Passed(&ms)),
         BIND_TO_RENDER_LOOP_2(&WebMediaPlayerImpl::OnNeedKey, "", ""),
+        // TODO(matthewjheaney): need confirmation that Unretained is OK here
+        base::Bind(&WebMediaPlayerImpl::OnTextTrack, base::Unretained(this)),

[acolwell GONE FROM CHROMIUM, 2013/05/10 02:22:08]

Yes. this is fine.

[Matthew Heaney (Chromium), 2013/05/10 05:21:08]

Done.

         base::Bind(&LogMediaSourceError, media_log_));
     demuxer_.reset(chunk_demuxer_);
 
     // Disable GpuVideoDecoder creation until it supports codec config changes.
     // TODO(acolwell): Remove this once http://crbug.com/151045 is fixed.
     gpu_factories_ = NULL;
   }
 
   scoped_ptr<media::FilterCollection> filter_collection(
       new media::FilterCollection());
@@ skipping 171 matching lines @@
 
   if (pending_repaint_)
     return;
 
   pending_repaint_ = true;
   main_loop_->PostTask(FROM_HERE, base::Bind(
       &WebMediaPlayerImpl::Repaint, AsWeakPtr()));
 }
 
 }  // namespace webkit_media