Drop DecryptConfig::data_offset_.

media/webm/webm_cluster_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_cluster_parser.h"
 
 #include <vector>
 
 #include "base/logging.h"
 #include "base/sys_byteorder.h"
@@ skipping 327 matching lines @@
 
   // The first bit of the flags is set when a SimpleBlock contains only
   // keyframes. If this is a Block, then inspection of the payload is
   // necessary to determine whether it contains a keyframe or not.
   // http://www.matroska.org/technical/specs/index.html
   bool is_keyframe =
       is_simple_block ? (flags & 0x80) != 0 : track->IsKeyframe(data, size);
 
   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(),
                  settings.begin(), settings.end(),
                  &side_data);
 
     buffer = StreamParserBuffer::CopyFrom(
         reinterpret_cast<const uint8*>(content.data()),
         content.length(),
         &side_data[0],
         side_data.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
-  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;
 
   if (block_duration >= 0) {
     buffer->set_duration(base::TimeDelta::FromMicroseconds(
         block_duration * timecode_multiplier_));
   }
 
   if (discard_padding != 0) {
@@ skipping 62 matching lines @@
 WebMClusterParser::FindTextTrack(int track_num) {
   const TextTrackMap::iterator it = text_track_map_.find(track_num);
 
   if (it == text_track_map_.end())
     return NULL;
 
   return &it->second;
 }
 
 }  // namespace media