Add Common Encryption support to BMFF, including subsample decryption.

media/mp4/avc.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/mp4/avc.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "media/mp4/box_definitions.h"
@@ skipping 14 matching lines @@
     nal_size = (nal_size << 8) + (*buf)[pos+2];
     nal_size = (nal_size << 8) + (*buf)[pos+3];
     std::copy(kAnnexBStartCode, kAnnexBStartCode + kAnnexBStartCodeSize,
               buf->begin() + pos);
     pos += kLengthSize + nal_size;
   }
   return pos == buf->size();
 }
 
 // static
-bool AVC::ConvertToAnnexB(int length_size, std::vector<uint8>* buffer) {
+bool AVC::ConvertFrameToAnnexB(int length_size, std::vector<uint8>* buffer) {
   RCHECK(length_size == 1 || length_size == 2 || length_size == 4);
 
   if (length_size == 4)
     return ConvertAVCToAnnexBInPlaceForLengthSize4(buffer);
 
   std::vector<uint8> temp;
   temp.swap(*buffer);
   buffer->reserve(temp.size() + 32);
 
   size_t pos = 0;
   while (pos + length_size < temp.size()) {
     int nal_size = temp[pos];
     if (length_size == 2) nal_size = (nal_size << 8) + temp[pos+1];
     pos += length_size;
 
     RCHECK(pos + nal_size <= temp.size());
     buffer->insert(buffer->end(), kAnnexBStartCode,
                    kAnnexBStartCode + kAnnexBStartCodeSize);
     buffer->insert(buffer->end(), temp.begin() + pos,
                    temp.begin() + pos + nal_size);
     pos += nal_size;
   }
   return pos == temp.size();
 }
 
 // static
-bool AVC::InsertParameterSets(const AVCDecoderConfigurationRecord& avc_config,
-                         std::vector<uint8>* buffer) {
+bool AVC::ConvertParameterSetsToAnnexB(
+    const AVCDecoderConfigurationRecord& avc_config,
+    std::vector<uint8>* buffer) {
+  DCHECK(buffer->empty());
+  buffer->clear();
   int total_size = 0;
   for (size_t i = 0; i < avc_config.sps_list.size(); i++)
     total_size += avc_config.sps_list[i].size() + kAnnexBStartCodeSize;
   for (size_t i = 0; i < avc_config.pps_list.size(); i++)
     total_size += avc_config.pps_list[i].size() + kAnnexBStartCodeSize;
-
-  std::vector<uint8> temp;
-  temp.reserve(total_size);
+  buffer->reserve(total_size);
 
   for (size_t i = 0; i < avc_config.sps_list.size(); i++) {
-    temp.insert(temp.end(), kAnnexBStartCode,
+    buffer->insert(buffer->end(), kAnnexBStartCode,
                 kAnnexBStartCode + kAnnexBStartCodeSize);
-    temp.insert(temp.end(), avc_config.sps_list[i].begin(),
+    buffer->insert(buffer->end(), avc_config.sps_list[i].begin(),
                 avc_config.sps_list[i].end());
   }
 
   for (size_t i = 0; i < avc_config.pps_list.size(); i++) {
-    temp.insert(temp.end(), kAnnexBStartCode,
-                kAnnexBStartCode + kAnnexBStartCodeSize);
-    temp.insert(temp.end(), avc_config.pps_list[i].begin(),
-                avc_config.pps_list[i].end());
+    buffer->insert(buffer->end(), kAnnexBStartCode,
+                   kAnnexBStartCode + kAnnexBStartCodeSize);
+    buffer->insert(buffer->end(), avc_config.pps_list[i].begin(),
+                   avc_config.pps_list[i].end());
   }
-
-  buffer->insert(buffer->begin(), temp.begin(), temp.end());
   return true;
 }
 
 }  // namespace mp4
 }  // namespace media