Add comments for backward/forward reference to avoid confusion
diff --git a/va/va_vpp.h b/va/va_vpp.h
index 9096ea6..25eebdf 100644
--- a/va/va_vpp.h
+++ b/va/va_vpp.h
@@ -989,11 +989,11 @@
VABufferID *filters;
/** \brief Actual number of filters. */
uint32_t num_filters;
- /** \brief Array of forward reference frames. */
+ /** \brief Array of forward reference frames (past frames). */
VASurfaceID *forward_references;
/** \brief Number of forward reference frames that were supplied. */
uint32_t num_forward_references;
- /** \brief Array of backward reference frames. */
+ /** \brief Array of backward reference frames (future frames). */
VASurfaceID *backward_references;
/** \brief Number of backward reference frames that were supplied. */
uint32_t num_backward_references;
