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

chromecast/media/cma/ipc_streamer/decoder_buffer_base_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/decoder_buffer_base_marshaller.h"
 
 #include "base/logging.h"
 #include "chromecast/media/cma/base/decoder_buffer_base.h"
 #include "chromecast/media/cma/ipc/media_message.h"
 #include "chromecast/media/cma/ipc/media_message_type.h"
@@ skipping 123 matching lines @@
   CHECK(msg->WritePod(buffer->end_of_stream()));
   if (buffer->end_of_stream())
     return;
 
   CHECK(msg->WritePod(buffer->timestamp().ToInternalValue()));
 
   bool has_decrypt_config =
       (buffer->decrypt_config() != NULL &&
        buffer->decrypt_config()->iv().size() > 0);
   CHECK(msg->WritePod(has_decrypt_config));
-  if (has_decrypt_config)
-    DecryptConfigMarshaller::Write(*buffer->decrypt_config(), msg);
+
+  if (has_decrypt_config) {
+    // DecryptConfig may contain 0 subsamples if all content is encrypted.
+    // Map this case to a single fully-encrypted "subsample" for more consistent
+    // backend handling.
+    if (buffer->decrypt_config()->subsamples().empty()) {
+      std::vector< ::media::SubsampleEntry> encrypted_subsample_list(1);
+      encrypted_subsample_list[0].clear_bytes = 0;
+      encrypted_subsample_list[0].cypher_bytes = buffer->data_size();
+      ::media::DecryptConfig full_sample_config(
+          buffer->decrypt_config()->key_id(),
+          buffer->decrypt_config()->iv(),
+          encrypted_subsample_list);
+      DecryptConfigMarshaller::Write(full_sample_config, msg);
+    } else {
+      DecryptConfigMarshaller::Write(*buffer->decrypt_config(), msg);
+    }
+  }
 
   CHECK(msg->WritePod(buffer->data_size()));
   CHECK(msg->WriteBuffer(buffer->data(), buffer->data_size()));
 }
 
 // static
 scoped_refptr<DecoderBufferBase> DecoderBufferBaseMarshaller::Read(
     scoped_ptr<MediaMessage> msg) {
   scoped_refptr<DecoderBufferFromMsg> buffer(
       new DecoderBufferFromMsg(msg.Pass()));
   buffer->Initialize();
   return buffer;
 }
 
 }  // namespace media
 }  // namespace chromecast