1 files changed, 10 insertions, 0 deletions
diff --git a/libs/vr/libdvr/dvr_internal.h b/libs/vr/libdvr/dvr_internal.h
index 28b6c28e9f..de8bb96aec 100644
--- a/libs/vr/libdvr/dvr_internal.h
+++ b/libs/vr/libdvr/dvr_internal.h
@@ -34,10 +34,20 @@ DvrWriteBuffer* CreateDvrWriteBufferFromBufferProducer(
 extern "C" {
 
 struct DvrWriteBuffer {
+  // The slot nubmer of the buffer, a valid slot number must be in the range of
+  // [0, android::BufferQueueDefs::NUM_BUFFER_SLOTS). This is only valid for
+  // DvrWriteBuffer acquired from a DvrWriteBufferQueue.
+  int32_t slot = -1;
+
   std::shared_ptr<android::dvr::BufferProducer> write_buffer;
 };
 
 struct DvrReadBuffer {
+  // The slot nubmer of the buffer, a valid slot number must be in the range of
+  // [0, android::BufferQueueDefs::NUM_BUFFER_SLOTS). This is only valid for
+  // DvrReadBuffer acquired from a DvrReadBufferQueue.
+  int32_t slot = -1;
+
   std::shared_ptr<android::dvr::BufferConsumer> read_buffer;
 };