diff --git a/include/media/AudioTrack.h b/include/media/AudioTrack.h
index f1b26b5..61214ec 100644
--- a/include/media/AudioTrack.h
+++ b/include/media/AudioTrack.h
@@ -510,7 +510,9 @@
 
     float                   mVolume[2];
     float                   mSendLevel;
-    uint32_t                mFrameCount;
+    size_t                  mFrameCount;            // corresponds to current IAudioTrack
+    size_t                  mReqFrameCount;         // frame count to request the next time a new
+                                                    // IAudioTrack is needed
 
     audio_track_cblk_t*     mCblk;                  // re-load after mLock.unlock()