Add DecryptingAudioDecoder.

webkit/media/filter_helpers.cc

Index: webkit/media/filter_helpers.cc
diff --git a/webkit/media/filter_helpers.cc b/webkit/media/filter_helpers.cc
index d34cf52408cdd97e7af6042f22d78b8a59b9a724..b18a1bdec382c262cbde40064f61da050802c729 100644
--- a/webkit/media/filter_helpers.cc
+++ b/webkit/media/filter_helpers.cc
@@ -7,6 +7,7 @@
 #include "base/bind.h"
 #include "media/base/filter_collection.h"
 #include "media/base/message_loop_factory.h"
+#include "media/filters/decrypting_audio_decoder.h"
 #include "media/filters/decrypting_video_decoder.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/dummy_demuxer.h"
@@ -36,6 +37,17 @@ static void AddDefaultDecodersToCollection(
                      base::Unretained(message_loop_factory),
                      media::MessageLoopFactory::kDecoder));
 
+  scoped_refptr<media::DecryptingAudioDecoder> decrypting_audio_decoder =
+      new media::DecryptingAudioDecoder(
+          base::Bind(&media::MessageLoopFactory::GetMessageLoop,
+                     base::Unretained(message_loop_factory),
+                     media::MessageLoopFactory::kDecoder),
+          base::Bind(&ProxyDecryptor::RequestDecryptorNotification,
+                     base::Unretained(proxy_decryptor)));
+
+  filter_collection->GetAudioDecoders()->push_back(ffmpeg_audio_decoder);
+  filter_collection->GetAudioDecoders()->push_back(decrypting_audio_decoder);

[scherkus (not reviewing), 2012/10/19 02:12:58]

here we have ffmpeg > decrypting for audio, but for video the order is reversed


intentional?

[xhwang, 2012/10/19 02:19:45]

Nothing happens by chance :) This is intentional.
Ideally I'd like decrypting decoders to be after normal decoders because in the
real world most videos will not be encrypted. But for video, FFVD can also do
decryption. If both decrypt-only and decrypt-and-decode are supported, we'd like
to choose decrypt-and-decode. That's why DVD comes before FFVD. WDYT?

[scherkus (not reviewing), 2012/10/19 02:23:05]

...but FFVD doing decryption is temporary, right?

[xhwang, 2012/10/19 02:40:35]

Yes. But if I move FFVD up now, then decrypt-and-decode (D&D) will not be
chosen. For decrypt-only, we don't have the mechanism to ask a CDM "if you
support decrypt-only". Decrypt-only can only succeed or fail. So it should
always be tried after the D&D path. We'll change the order here when we remove
decryption out of FFVD.

[scherkus (not reviewing), 2012/10/19 02:51:48]

Sounds good to me -- can you TODOify it w/ a comment?

[xhwang, 2012/10/19 07:28:28]

Done.

+
   scoped_refptr<media::DecryptingVideoDecoder> decrypting_video_decoder =
       new media::DecryptingVideoDecoder(
           base::Bind(&media::MessageLoopFactory::GetMessageLoop,
@@ -51,7 +63,6 @@ static void AddDefaultDecodersToCollection(
                      media::MessageLoopFactory::kDecoder),
           proxy_decryptor);
 
-  filter_collection->GetAudioDecoders()->push_back(ffmpeg_audio_decoder);
   filter_collection->GetVideoDecoders()->push_back(decrypting_video_decoder);
   filter_collection->GetVideoDecoders()->push_back(ffmpeg_video_decoder);
 }