Chromecast media pipeline: handle CENC "full sample encryption" case.

chromecast/media/cma/ipc_streamer/decrypt_config_marshaller.cc

 // Copyright 2014 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 "chromecast/media/cma/ipc_streamer/decrypt_config_marshaller.h"
 
 #include "base/logging.h"
 #include "chromecast/media/cma/ipc/media_message.h"
 #include "media/base/decrypt_config.h"
 
 namespace chromecast {
 namespace media {
 
 namespace {
 const size_t kMaxKeyIdSize = 256;
 const size_t kMaxIvSize = 256;
 const size_t kMaxSubsampleCount = 1024;
+
+void WriteDecryptConfigHeader(
+    const ::media::DecryptConfig& config, MediaMessage* msg) {
+  CHECK_GT(config.key_id().size(), 0);
+  CHECK_GT(config.iv().size(), 0);
+
+  CHECK(msg->WritePod(config.key_id().size()));
+  CHECK(msg->WriteBuffer(config.key_id().data(), config.key_id().size()));
+  CHECK(msg->WritePod(config.iv().size()));
+  CHECK(msg->WriteBuffer(config.iv().data(), config.iv().size()));
+}
+
 }
 
 // static
 void DecryptConfigMarshaller::Write(
     const ::media::DecryptConfig& config, MediaMessage* msg) {
-  CHECK_GT(config.key_id().size(), 0);
-  CHECK_GT(config.iv().size(), 0);
   CHECK_GT(config.subsamples().size(), 0);
+  WriteDecryptConfigHeader(config, msg);
 
-  CHECK(msg->WritePod(config.key_id().size()));
-  CHECK(msg->WriteBuffer(config.key_id().data(), config.key_id().size()));
-  CHECK(msg->WritePod(config.iv().size()));
-  CHECK(msg->WriteBuffer(config.iv().data(), config.iv().size()));
   CHECK(msg->WritePod(config.subsamples().size()));
   for (size_t k = 0; k < config.subsamples().size(); k++) {
     CHECK(msg->WritePod(config.subsamples()[k].clear_bytes));
     CHECK(msg->WritePod(config.subsamples()[k].cypher_bytes));
   }
 }
 
 // static
+void DecryptConfigMarshaller::WriteFullSampleEncryption(
+    const ::media::DecryptConfig& config, int data_size, MediaMessage* msg) {
+  WriteDecryptConfigHeader(config, msg);
+  CHECK_EQ(config.subsamples().size(), 0);
+
+  // Write exactly one subsample with zero clear bytes, |data_size| cypher bytes
+  CHECK(msg->WritePod(1));
+  CHECK(msg->WritePod(0));
+  CHECK(msg->WritePod(data_size));
+}
+
+// static
 scoped_ptr< ::media::DecryptConfig> DecryptConfigMarshaller::Read(
     MediaMessage* msg) {
   size_t key_id_size = 0;
   CHECK(msg->ReadPod(&key_id_size));
   CHECK_GT(key_id_size, 0);
   CHECK_LT(key_id_size, kMaxKeyIdSize);
   scoped_ptr<char[]> key_id(new char[key_id_size]);
   CHECK(msg->ReadBuffer(key_id.get(), key_id_size));
 
   size_t iv_size = 0;
@@ skipping 17 matching lines @@
 
   return scoped_ptr< ::media::DecryptConfig>(
       new ::media::DecryptConfig(
           std::string(key_id.get(), key_id_size),
           std::string(iv.get(), iv_size),
           subsamples));
 }
 
 }  // namespace media
 }  // namespace chromecast