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) {

[damienv1, 2014/10/17 15:46:05]

Note: I was thinking about sth like:

::media::DecryptConifg* decrypt_config = buffer->decrypt_config();

// Handle the corner case:  
scoped_ptr<::media::DecryptConifg> equivalent_decrypt_config;
if (decrypt_config->subsamples().empty()) {
  std::vector<media::SubsampleEntry> subsamples(1);
  subsamples[0].clear_bytes = 0;
  subsamples[0].cypher_bytes = buffer->data_size();
  decrypt_config_alternate.reset(new ::media::DecryptConfig(key, iv,
subsamples);
}

[gunsch, 2014/10/17 16:04:02]

heh, I had something exactly like this earlier and rewrote it because I thought
this approach was preferable :)

+    if (buffer->decrypt_config()->subsamples().size() == 0)
+      DecryptConfigMarshaller::WriteFullSampleEncryption(
+          *buffer->decrypt_config(), buffer->data_size(), 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