Chrome-side implementation of media source timestamp offset

media/webm/webm_stream_parser.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 "media/webm/webm_stream_parser.h"
 
 #include "base/callback.h"
 #include "base/logging.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 #include "media/filters/ffmpeg_glue.h"
@@ skipping 246 matching lines @@
 
     cur += result;
     cur_size -= result;
     bytes_parsed += result;
   } while (result > 0 && cur_size > 0);
 
   byte_queue_.Pop(bytes_parsed);
   return true;
 }
 
+void WebMStreamParser::SetTimestampOffset(base::TimeDelta offset) {
+  timestamp_offset_ = offset;
+}
+
+void WebMStreamParser::ClearTimestampOffset() {
+  SetTimestampOffset(base::TimeDelta());
+}
+
 void WebMStreamParser::ChangeState(State new_state) {
   DVLOG(1) << "ChangeState() : " << state_ << " -> " << new_state;
   state_ = new_state;
 }
 
 int WebMStreamParser::ParseInfoAndTracks(const uint8* data, int size) {
   DCHECK(data);
   DCHECK_GT(size, 0);
 
   const uint8* cur = data;
@@ skipping 101 matching lines @@
   if (!cluster_parser_.get())
     return -1;
 
   int id;
   int64 element_size;
   int result = WebMParseElementHeader(data, size, &id, &element_size);
 
   if (result <= 0)
     return result;
 
-  if (id == kWebMIdCluster)
+  if (id == kWebMIdCluster) {
     waiting_for_buffers_ = true;
 
+    // Wait until the beginning of a new cluster to set the buffer timestamp
+    // offset.
+    cluster_parser_->SetTimestampOffset(timestamp_offset_);
+  }
+
   if (id == kWebMIdCues) {
     if (size < (result + element_size)) {
       // We don't have the whole element yet. Signal we need more data.
       return 0;
     }
     // Skip the element.
     return result + element_size;
   }
 
   if (id == kWebMIdEBMLHeader) {
@@ skipping 18 matching lines @@
   if (!audio_buffers.empty() && !audio_cb_.Run(audio_buffers))
     return -1;
 
   if (!video_buffers.empty() && !video_cb_.Run(video_buffers))
     return -1;
 
   return bytes_parsed;
 }
 
 }  // namespace media