Add support for incremental cluster parsing.

media/webm/webm_cluster_parser.cc

 // Copyright (c) 2011 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_cluster_parser.h"
 
 #include "base/logging.h"
 #include "media/base/data_buffer.h"
 #include "media/webm/webm_constants.h"
 
@@ skipping 14 matching lines @@
       audio_track_num_(audio_track_num),
       audio_default_duration_(audio_default_duration),
       video_track_num_(video_track_num),
       video_default_duration_(video_default_duration),
       last_block_timecode_(-1),
       cluster_timecode_(-1) {
 }
 
 WebMClusterParser::~WebMClusterParser() {}
 
 int WebMClusterParser::Parse(const uint8* buf, int size) {

[scherkus (not reviewing), 2011/12/03 01:56:51]

perhaps the .h docs need to be updated because I'm not quite clear on what this
function is supposed to be doing

+  audio_buffers_.clear();
+  video_buffers_.clear();
+
+  int id;
+  int64 element_size;
+  int result = WebMParseElementHeader(buf, size, &id, &element_size);
+
+  if (result <= 0)
+    return result;
+
+  if (id == kWebMIdCues) {

[scherkus (not reviewing), 2011/12/03 01:56:51]

sanity check: this branch checks for a CUES section then skips it?

+    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;
+  } else if (id != kWebMIdCluster) {

[scherkus (not reviewing), 2011/12/03 01:56:51]

nit: no need for else

+    VLOG(1) << "Unexpected ID 0x" << std::hex << id;

[scherkus (not reviewing), 2011/12/03 01:56:51]

DVLOG

+    return -1;
+  }
+
   last_block_timecode_ = -1;
   cluster_timecode_ = -1;
-  audio_buffers_.clear();
-  video_buffers_.clear();
 
   return WebMParseListElement(buf, size, kWebMIdCluster, 1, this);
 }
 
 bool WebMClusterParser::OnListStart(int id) {
   if (id == kWebMIdCluster)
     cluster_timecode_ = -1;
 
   return true;
 }
@@ skipping 74 matching lines @@
     VLOG(1) << "Got SimpleBlock timecode is not strictly monotonically "
             << "increasing for track " << track_num;
     return false;
   }
 
   queue->push_back(buffer);
   return true;
 }
 
 }  // namespace media