media: Allow config change between clear and encrypted streams

content/renderer/pepper/content_decryptor_delegate.cc

Index: content/renderer/pepper/content_decryptor_delegate.cc
diff --git a/content/renderer/pepper/content_decryptor_delegate.cc b/content/renderer/pepper/content_decryptor_delegate.cc
index 88126db91a94887c7eaed102879cec97e80d40a8..6765331376f851243f56d0fd37b41d039827486f 100644
--- a/content/renderer/pepper/content_decryptor_delegate.cc
+++ b/content/renderer/pepper/content_decryptor_delegate.cc
@@ -95,32 +95,30 @@ bool CopyStringToArray(const std::string& str, uint8_t(&array)[array_size]) {
   return true;
 }
 
-// Fills the |block_info| with information from |encrypted_buffer|.
+// Fills the |block_info| with information from |buffer|.
 //
 // Returns true if |block_info| is successfully filled. Returns false
 // otherwise.
-bool MakeEncryptedBlockInfo(
-    const scoped_refptr<media::DecoderBuffer>& encrypted_buffer,
-    uint32_t request_id,
-    PP_EncryptedBlockInfo* block_info) {
+bool MakeEncryptedBlockInfo(const scoped_refptr<media::DecoderBuffer>& buffer,
+                            uint32_t request_id,
+                            PP_EncryptedBlockInfo* block_info) {
   // TODO(xhwang): Fix initialization of PP_EncryptedBlockInfo here and
   // anywhere else.
   memset(block_info, 0, sizeof(*block_info));
   block_info->tracking_info.request_id = request_id;
 
   // EOS buffers need a request ID and nothing more.
-  if (encrypted_buffer->end_of_stream())
+  if (buffer->end_of_stream())
     return true;
 
-  DCHECK(encrypted_buffer->data_size())
-      << "DecryptConfig is set on an empty buffer";
+  DCHECK(buffer->data_size()) << "DecryptConfig is set on an empty buffer";
 
-  block_info->tracking_info.timestamp =
-      encrypted_buffer->timestamp().InMicroseconds();
-  block_info->data_size = encrypted_buffer->data_size();
+  block_info->tracking_info.timestamp = buffer->timestamp().InMicroseconds();
+  block_info->data_size = buffer->data_size();
 
-  const media::DecryptConfig* decrypt_config =
-      encrypted_buffer->decrypt_config();
+  const media::DecryptConfig* decrypt_config = buffer->decrypt_config();
+  if (!decrypt_config)
+    return true;

[bbudge, 2017/02/15 15:46:13]

It seems strange to return true here, if the block info hasn't been filled in.

[xhwang, 2017/02/15 17:30:20]

The struct is initialized at line 107. Then when the buffer is not encrypted,
there's no need to fill any of the fields below as they are only used for
decryption.

I added a comment to make this more clear.

 
   if (!CopyStringToArray(decrypt_config->key_id(), block_info->key_id) ||
       !CopyStringToArray(decrypt_config->iv(), block_info->iv))
@@ -529,7 +527,6 @@ bool ContentDecryptorDelegate::Decrypt(
   DVLOG(2) << "Decrypt() - request_id " << request_id;
 
   PP_EncryptedBlockInfo block_info = {};
-  DCHECK(encrypted_buffer->decrypt_config());
   if (!MakeEncryptedBlockInfo(encrypted_buffer, request_id, &block_info)) {
     return false;
   }
@@ -1113,12 +1110,12 @@ void ContentDecryptorDelegate::CancelDecode(Decryptor::StreamType stream_type) {
 
 bool ContentDecryptorDelegate::MakeMediaBufferResource(
     Decryptor::StreamType stream_type,
-    const scoped_refptr<media::DecoderBuffer>& encrypted_buffer,
+    const scoped_refptr<media::DecoderBuffer>& buffer,
     scoped_refptr<PPB_Buffer_Impl>* resource) {
   TRACE_EVENT0("media", "ContentDecryptorDelegate::MakeMediaBufferResource");
 
   // End of stream buffers are represented as null resources.
-  if (encrypted_buffer->end_of_stream()) {
+  if (buffer->end_of_stream()) {
     *resource = NULL;
     return true;
   }
@@ -1128,7 +1125,7 @@ bool ContentDecryptorDelegate::MakeMediaBufferResource(
       (stream_type == Decryptor::kAudio) ? audio_input_resource_
                                          : video_input_resource_;
 
-  const size_t data_size = static_cast<size_t>(encrypted_buffer->data_size());
+  const size_t data_size = static_cast<size_t>(buffer->data_size());
   if (!media_resource.get() || media_resource->size() < data_size) {
     // Either the buffer hasn't been created yet, or we have one that isn't big
     // enough to fit |size| bytes.
@@ -1159,7 +1156,7 @@ bool ContentDecryptorDelegate::MakeMediaBufferResource(
     media_resource = NULL;
     return false;
   }
-  memcpy(mapper.data(), encrypted_buffer->data(), data_size);
+  memcpy(mapper.data(), buffer->data(), data_size);
 
   *resource = media_resource;
   return true;