Notify SourceBufferStream of each cluster's start time as it gets parsed

Passes cluster start time information from WebMStreamParser to ChunkDemuxer
to SourceBufferStream. SourceBufferStream can then use this information when
fulfilling seeks.

BUG=131438
TEST=media_unittests, go/vekbm

Review URL: https://chromiumcodereview.appspot.com/10540122

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@142221 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 36 insertions, 3 deletions

diff --git a/media/webm/webm_stream_parser.cc b/media/webm/webm_stream_parser.cc
index c8ca10e..b063a26 100644
--- a/media/webm/webm_stream_parser.cc
+++ b/media/webm/webm_stream_parser.cc
@@ -181,7 +181,8 @@ bool FFmpegConfigHelper::SetupStreamConfigs() {
 }
 
 WebMStreamParser::WebMStreamParser()
-    : state_(kWaitingForInit) {
+    : state_(kWaitingForInit),
+      waiting_for_buffers_(false) {
 }
 
 WebMStreamParser::~WebMStreamParser() {}
@@ -190,13 +191,15 @@ void WebMStreamParser::Init(const InitCB& init_cb,
                             const NewConfigCB& config_cb,
                             const NewBuffersCB& audio_cb,
                             const NewBuffersCB& video_cb,
-                            const KeyNeededCB& key_needed_cb) {
+                            const KeyNeededCB& key_needed_cb,
+                            const NewMediaSegmentCB& new_segment_cb) {
   DCHECK_EQ(state_, kWaitingForInit);
   DCHECK(init_cb_.is_null());
   DCHECK(!init_cb.is_null());
   DCHECK(!config_cb.is_null());
   DCHECK(!audio_cb.is_null() || !video_cb.is_null());
   DCHECK(!key_needed_cb.is_null());
+  DCHECK(!new_segment_cb.is_null());
 
   ChangeState(kParsingHeaders);
   init_cb_ = init_cb;
@@ -204,6 +207,7 @@ void WebMStreamParser::Init(const InitCB& init_cb,
   audio_cb_ = audio_cb;
   video_cb_ = video_cb;
   key_needed_cb_ = key_needed_cb;
+  new_segment_cb_ = new_segment_cb;
 }
 
 void WebMStreamParser::Flush() {
@@ -381,6 +385,9 @@ int WebMStreamParser::ParseCluster(const uint8* data, int size) {
   if (result <= 0)
     return result;
 
+  if (id == kWebMIdCluster)
+    waiting_for_buffers_ = true;
+
   if (id == kWebMIdCues) {
     if (size < (result + element_size)) {
       // We don't have the whole element yet. Signal we need more data.
@@ -403,6 +410,26 @@ int WebMStreamParser::ParseCluster(const uint8* data, int size) {
   const BufferQueue& audio_buffers = cluster_parser_->audio_buffers();
   const BufferQueue& video_buffers = cluster_parser_->video_buffers();
 
+  if (waiting_for_buffers_) {
+    base::TimeDelta audio_start_timestamp = kInfiniteDuration();
+    base::TimeDelta video_start_timestamp = kInfiniteDuration();
+
+    if (!audio_buffers.empty())
+      audio_start_timestamp = audio_buffers.front()->GetTimestamp();
+    if (!video_buffers.empty())
+      video_start_timestamp = video_buffers.front()->GetTimestamp();
+
+    base::TimeDelta cluster_start_timestamp =
+        std::min(audio_start_timestamp, video_start_timestamp);
+
+    // If we haven't gotten any buffers yet, return early.
+    if (cluster_start_timestamp == kInfiniteDuration())
+      return bytes_parsed;
+
+    new_segment_cb_.Run(cluster_start_timestamp);
+    waiting_for_buffers_ = false;
+  }
+
   if (!audio_buffers.empty() && !audio_cb_.Run(audio_buffers))
     return -1;
 
diff --git a/media/webm/webm_stream_parser.h b/media/webm/webm_stream_parser.h
index 0d37992..003171e 100644
--- a/media/webm/webm_stream_parser.h
+++ b/media/webm/webm_stream_parser.h
@@ -25,7 +25,8 @@ class WebMStreamParser : public StreamParser {
   virtual void Init(const InitCB& init_cb, const NewConfigCB& config_cb,
                     const NewBuffersCB& audio_cb,
                     const NewBuffersCB& video_cb,
-                    const KeyNeededCB& key_needed_cb) OVERRIDE;
+                    const KeyNeededCB& key_needed_cb,
+                    const NewMediaSegmentCB& new_segment_cb) OVERRIDE;
   virtual void Flush() OVERRIDE;
   virtual bool Parse(const uint8* buf, int size) OVERRIDE;
 
@@ -64,6 +65,11 @@ class WebMStreamParser : public StreamParser {
   NewBuffersCB audio_cb_;
   NewBuffersCB video_cb_;
   KeyNeededCB key_needed_cb_;
+  NewMediaSegmentCB new_segment_cb_;
+
+  // True if a new cluster id has been seen, but no audio or video buffers have
+  // been parsed yet.
+  bool waiting_for_buffers_;
 
   scoped_ptr<WebMClusterParser> cluster_parser_;
   ByteQueue byte_queue_;