Drop DecryptConfig::data_offset_.

media/webm/webm_cluster_parser.cc

Index: media/webm/webm_cluster_parser.cc
diff --git a/media/webm/webm_cluster_parser.cc b/media/webm/webm_cluster_parser.cc
index df9e4ce244bb17d3f7bda4b39d16bbc71dd33e18..4ac888df859d93acfb39f8f327e41140dccd9ad1 100644
--- a/media/webm/webm_cluster_parser.cc
+++ b/media/webm/webm_cluster_parser.cc
@@ -345,13 +345,30 @@ bool WebMClusterParser::OnBlock(bool is_simple_block, int track_num,
 
   scoped_refptr<StreamParserBuffer> buffer;
   if (!is_text) {
-    buffer = StreamParserBuffer::CopyFrom(data, size,
-                                          additional, additional_size,
-                                          is_keyframe);
+    // Every encrypted Block has a signal byte and IV prepended to it. Current
+    // encrypted WebM request for comments specification is here
+    // http://wiki.webmproject.org/encryption/webm-encryption-rfc
+    scoped_ptr<DecryptConfig> decrypt_config;
+    int data_offset = 0;
+    if (!encryption_key_id.empty() &&
+        !WebMCreateDecryptConfig(
+             data, size,
+             reinterpret_cast<const uint8*>(encryption_key_id.data()),
+             encryption_key_id.size(),
+             &decrypt_config, &data_offset)) {
+      return false;
+    }
+
+    buffer = StreamParserBuffer::CopyFrom(
+        data + data_offset, size - data_offset,
+        additional, additional_size,
+        is_keyframe);
+
+    if (decrypt_config)
+      buffer->set_decrypt_config(decrypt_config.Pass());
   } else {

[DaleCurtis, 2014/01/02 19:31:09]

Does this not need a DecryptConfig?  Presumably we're not encrypted text.

[xhwang, 2014/01/08 00:43:36]

As you can see from l.314-l.319, encryption_key_id is only set for audio/video.

For now only audio/video can be encrypted. We may add support for text, but I am
not sure what's the use case for that :) Even if we need to do it, I'd keep it
in another CL.

     std::string id, settings, content;
-    WebMWebVTTParser::Parse(data, size,
-                            &id, &settings, &content);
+    WebMWebVTTParser::Parse(data, size, &id, &settings, &content);
 
     std::vector<uint8> side_data;
     MakeSideData(id.begin(), id.end(),
@@ -366,19 +383,6 @@ bool WebMClusterParser::OnBlock(bool is_simple_block, int track_num,
         is_keyframe);
   }
 
-  // Every encrypted Block has a signal byte and IV prepended to it. Current
-  // encrypted WebM request for comments specification is here
-  // http://wiki.webmproject.org/encryption/webm-encryption-rfc
-  if (!encryption_key_id.empty()) {
-    scoped_ptr<DecryptConfig> config(WebMCreateDecryptConfig(
-        data, size,
-        reinterpret_cast<const uint8*>(encryption_key_id.data()),
-        encryption_key_id.size()));
-    if (!config)
-      return false;
-    buffer->set_decrypt_config(config.Pass());
-  }
-
   buffer->set_timestamp(timestamp);
   if (cluster_start_time_ == kNoTimestamp())
     cluster_start_time_ = timestamp;