diff --git a/media/libmediaplayerservice/include/MediaPlayerInterface.h b/media/libmediaplayerservice/include/MediaPlayerInterface.h
index c21ef42..0ef3809 100644
--- a/media/libmediaplayerservice/include/MediaPlayerInterface.h
+++ b/media/libmediaplayerservice/include/MediaPlayerInterface.h
@@ -66,14 +66,17 @@
 // duration below which we do not allow deep audio buffering
 #define AUDIO_SINK_MIN_DEEP_BUFFER_DURATION_US 5000000
 
-// callback mechanism for passing messages to MediaPlayer object
-typedef void (*notify_callback_f)(const wp<IMediaPlayer> &listener,
-        int msg, int ext1, int ext2, const Parcel *obj);
-
 // abstract base class - use MediaPlayerInterface
 class MediaPlayerBase : public RefBase
 {
 public:
+    // callback mechanism for passing messages to MediaPlayer object
+    class Listener : public RefBase {
+    public:
+        virtual void notify(int msg, int ext1, int ext2, const Parcel *obj) = 0;
+        virtual ~Listener() {}
+    };
+
     // AudioSink: abstraction layer for audio output
     class AudioSink : public RefBase {
     public:
@@ -152,7 +155,7 @@
         virtual sp<VolumeShaper::State> getVolumeShaperState(int id);
     };
 
-                        MediaPlayerBase() : mClient(0), mNotify(0) {}
+                        MediaPlayerBase() {}
     virtual             ~MediaPlayerBase() {}
     virtual status_t    initCheck() = 0;
     virtual bool        hardwareOutput() = 0;
@@ -263,22 +266,22 @@
     };
 
     void        setNotifyCallback(
-            const wp<IMediaPlayer> &client, notify_callback_f notifyFunc) {
+            const sp<Listener> &listener) {
         Mutex::Autolock autoLock(mNotifyLock);
-        mClient = client; mNotify = notifyFunc;
+        mListener = listener;
     }
 
     void        sendEvent(int msg, int ext1=0, int ext2=0,
                           const Parcel *obj=NULL) {
-        notify_callback_f notifyCB;
-        wp<IMediaPlayer> client;
+        sp<Listener> listener;
         {
             Mutex::Autolock autoLock(mNotifyLock);
-            notifyCB = mNotify;
-            client = mClient;
+            listener = mListener;
         }
 
-        if (notifyCB) notifyCB(client, msg, ext1, ext2, obj);
+        if (listener != NULL) {
+            listener->notify(msg, ext1, ext2, obj);
+        }
     }
 
     virtual status_t dump(int /* fd */, const Vector<String16>& /* args */) const {
@@ -297,8 +300,7 @@
     friend class MediaPlayerService;
 
     Mutex               mNotifyLock;
-    wp<IMediaPlayer>    mClient;
-    notify_callback_f   mNotify;
+    sp<Listener>        mListener;
 };
 
 // Implement this class for media players that use the AudioFlinger software mixer