Render inband text tracks in the media pipeline

content/renderer/media/webmediaplayer_impl.cc

Index: content/renderer/media/webmediaplayer_impl.cc
diff --git a/content/renderer/media/webmediaplayer_impl.cc b/content/renderer/media/webmediaplayer_impl.cc
index 94bb678921c7ad5930f53d3aafaca2c370264f65..dfdf88700a7b86dd4ef54a78913cb62ed45ae942 100644
--- a/content/renderer/media/webmediaplayer_impl.cc
+++ b/content/renderer/media/webmediaplayer_impl.cc
@@ -37,6 +37,8 @@
 #include "media/base/media_log.h"
 #include "media/base/media_switches.h"
 #include "media/base/pipeline.h"
+#include "media/base/text_cue.h"

[acolwell GONE FROM CHROMIUM, 2013/10/08 15:45:24]

nit: no longer needed.

[Matthew Heaney (Chromium), 2013/10/13 05:30:17]

Done.

+#include "media/base/text_renderer.h"
 #include "media/base/video_frame.h"
 #include "media/filters/audio_renderer_impl.h"
 #include "media/filters/chunk_demuxer.h"
@@ -46,6 +48,7 @@
 #include "media/filters/gpu_video_accelerator_factories.h"
 #include "media/filters/gpu_video_decoder.h"
 #include "media/filters/opus_audio_decoder.h"
+#include "media/filters/text_decoder_impl.h"
 #include "media/filters/video_renderer_base.h"
 #include "media/filters/vpx_video_decoder.h"
 #include "third_party/WebKit/public/platform/WebMediaSource.h"
@@ -948,6 +951,8 @@ scoped_ptr<media::TextTrack>
 WebMediaPlayerImpl::OnTextTrack(media::TextKind kind,
                                 const std::string& label,
                                 const std::string& language) {
+  DCHECK(main_loop_->BelongsToCurrentThread());
+
   typedef WebInbandTextTrackImpl::Kind webkind_t;
   const webkind_t webkind = static_cast<webkind_t>(kind);
   const WebKit::WebString weblabel = WebKit::WebString::fromUTF8(label);
@@ -957,10 +962,22 @@ WebMediaPlayerImpl::OnTextTrack(media::TextKind kind,
     new WebInbandTextTrackImpl(webkind, weblabel, weblanguage,
                                text_track_index_++);
 
-  return scoped_ptr<media::TextTrack>(new TextTrackImpl(GetClient(),
+  return scoped_ptr<media::TextTrack>(new TextTrackImpl(main_loop_,
+                                                        GetClient(),
                                                         text_track));
 }
 
+void WebMediaPlayerImpl::OnAddTextStream(
+    media::DemuxerStream* text_stream,
+    media::TextKind kind,
+    const std::string& label,
+    const std::string& language,
+    const media::AddTextTrackDoneCB& done_cb) {
+  DCHECK(main_loop_->BelongsToCurrentThread());
+  scoped_ptr<media::TextTrack> text_track = OnTextTrack(kind, label, language);
+  done_cb.Run(text_stream, text_track.Pass());

[acolwell GONE FROM CHROMIUM, 2013/10/08 15:45:24]

WebMediaPlayerImpl should not need to know about DemuxerStream. If you need it
in lower layers, just use base::Bind to bind the value when creating done_cb.

[Matthew Heaney (Chromium), 2013/10/13 05:30:17]

Done.

+}
+
 void WebMediaPlayerImpl::OnKeyError(const std::string& session_id,
                                     media::MediaKeys::KeyError error_code,
                                     int system_code) {
@@ -1029,6 +1046,9 @@ void WebMediaPlayerImpl::StartPipeline() {
   UMA_HISTOGRAM_BOOLEAN("Media.MSE.Playback",
                         (load_type_ == LoadTypeMediaSource));
 
+  const bool enable_inband_text_tracks =
+      cmd_line->HasSwitch(switches::kEnableInbandTextTracks);
+
   // Figure out which demuxer to use.
   if (load_type_ != LoadTypeMediaSource) {
     DCHECK(!chunk_demuxer_);
@@ -1037,14 +1057,17 @@ void WebMediaPlayerImpl::StartPipeline() {
     demuxer_.reset(new media::FFmpegDemuxer(
         media_loop_, data_source_.get(),
         BIND_TO_RENDER_LOOP_1(&WebMediaPlayerImpl::OnNeedKey, ""),
+        enable_inband_text_tracks,
         media_log_));
   } else {
     DCHECK(!chunk_demuxer_);
     DCHECK(!data_source_);
 
+    // TODO(matthewjheaney): Once we have resolved the threading issues,
+    // change the chunk demuxer to user the same mechanism as for ffmpeg.

[acolwell GONE FROM CHROMIUM, 2013/10/08 15:45:24]

nit: s/user/use/.

[Matthew Heaney (Chromium), 2013/10/13 05:30:17]

Done.

     media::AddTextTrackCB add_text_track_cb;
 
-    if (cmd_line->HasSwitch(switches::kEnableInbandTextTracks)) {
+    if (enable_inband_text_tracks) {
       add_text_track_cb =
           base::Bind(&WebMediaPlayerImpl::OnTextTrack, base::Unretained(this));
     }
@@ -1122,6 +1145,22 @@ void WebMediaPlayerImpl::StartPipeline() {
           true));
   filter_collection->SetVideoRenderer(video_renderer.Pass());
 
+  if (load_type_ != LoadTypeMediaSource && enable_inband_text_tracks) {
+    scoped_ptr<media::TextDecoder> text_decoder(
+        new media::TextDecoderImpl(media_loop_));

[acolwell GONE FROM CHROMIUM, 2013/10/08 15:45:24]

Move this into the TextRenderer constructor since there is no need for this
class to be aware of its existence.

[Matthew Heaney (Chromium), 2013/10/13 05:30:17]

Done.

+
+    media::AddTextTrackCB2 add_text_track_cb =
+        BIND_TO_RENDER_LOOP(&WebMediaPlayerImpl::OnAddTextStream);
+
+    scoped_ptr<media::TextRenderer> text_renderer(
+        new media::TextRenderer(
+            media_loop_,
+            text_decoder.Pass(),
+            add_text_track_cb));
+
+    filter_collection->SetTextRenderer(text_renderer.Pass());
+  }
+
   // ... and we're ready to go!
   starting_ = true;
   pipeline_->Start(