diff --git a/include/private/media/AudioTrackShared.h b/include/private/media/AudioTrackShared.h
index ea8a78e..24784ea 100644
--- a/include/private/media/AudioTrackShared.h
+++ b/include/private/media/AudioTrackShared.h
@@ -177,6 +177,10 @@
                 // server write-only, client read
                 ExtendedTimestampQueue::Shared mExtendedTimestampQueue;
 
+                // This is set by AudioTrack.setBufferSizeInFrames().
+                // A write will not fill the buffer above this limit.
+    volatile    uint32_t   mBufferSizeInFrames;  // effective size of the buffer
+
 public:
 
     volatile    int32_t     mFlags;         // combinations of CBLK_*
@@ -312,9 +316,9 @@
         return mEpoch;
     }
 
-    size_t      getBufferSizeInFrames() const { return mBufferSizeInFrames; }
-    // See documentation for AudioTrack.setBufferSizeInFrames()
-    size_t      setBufferSizeInFrames(size_t requestedSize);
+    uint32_t      getBufferSizeInFrames() const { return mBufferSizeInFrames; }
+    // See documentation for AudioTrack::setBufferSizeInFrames()
+    uint32_t      setBufferSizeInFrames(uint32_t requestedSize);
 
     status_t    getTimestamp(ExtendedTimestamp *timestamp) {
         if (timestamp == nullptr) {
@@ -329,12 +333,10 @@
         mTimestamp.clear();
     }
 
-protected:
-    // This is set by AudioTrack.setBufferSizeInFrames().
-    // A write will not fill the buffer above this limit.
-    size_t      mBufferSizeInFrames;      // effective size of the buffer
-
 private:
+    // This is a copy of mCblk->mBufferSizeInFrames
+    uint32_t   mBufferSizeInFrames;  // effective size of the buffer
+
     Modulo<uint32_t> mEpoch;
 
     // The shared buffer contents referred to by the timestamp observer
@@ -518,6 +520,11 @@
         mTimestampMutator.push(timestamp);
     }
 
+    // Get dynamic buffer size from the shared control block.
+    uint32_t            getBufferSizeInFrames() const {
+        return android_atomic_acquire_load((int32_t *)&mCblk->mBufferSizeInFrames);
+    }
+
 protected:
     size_t      mAvailToClient; // estimated frames available to client prior to releaseBuffer()
     int32_t     mFlush;         // our copy of cblk->u.mStreaming.mFlush, for streaming output only