Support for parsing encrypted WebM streams by src.

media/base/demuxer.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_DEMUXER_H_
 #define MEDIA_BASE_DEMUXER_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/time.h"
 #include "media/base/data_source.h"
@@ skipping 46 matching lines @@
   //
   // TODO(acolwell): Change to generic DisableStream(DemuxerStream::Type).
   virtual void OnAudioRendererDisabled();
 
   // Returns the given stream type, or NULL if that type is not present.
   virtual scoped_refptr<DemuxerStream> GetStream(DemuxerStream::Type type) = 0;
 
   // Returns the starting time for the media file.
   virtual base::TimeDelta GetStartTime() const = 0;
 
+  virtual void KeyAdded();

[ddorwin, 2012/08/22 23:20:29]

Comment.
Also, curious why this is needed now and wasn't before.

[fgalligan1, 2012/08/23 02:39:11]

I'm not sure I understand the question. Do you mean why did we not need this in
the first media source implementation? Because the javascript was controlling
when the encrypted data was passed in. And in the demo we didn't pass any data
until we gave media source the key. I'm guessing if the application didn't wait
the decoder would not have been happy.

[xhwang, 2012/08/23 19:04:53]

I removed the "waiting for key" part in the demo, so this is not necessary. If
the decryptor doesn't have a key when trying to decrypt an encrypted frame, the
media pipeline will wait until the key is added, or the pipeline is stopped.

In spec about this: section 5.1.9: Key Presense
The CL in chrome: http://codereview.chromium.org/10822026/

[fgalligan1, 2012/08/24 20:01:26]

Removed KeyAdded().

+
  protected:
   friend class base::RefCountedThreadSafe<Demuxer>;
   virtual ~Demuxer();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(Demuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_DEMUXER_H_