add definition to enforce both reflist not empty

it is a suppliment of https://github.com/intel/libva/pull/220
to distinguish P frame and low delay B frame

Signed-off-by: Carl Zhang <carl.zhang@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/va/va.h b/va/va.h
index 4d93582..4c170c3 100755
--- a/va/va.h
+++ b/va/va.h
@@ -1024,6 +1024,8 @@ typedef union _VAConfigAttribValEncJPEG {
 #define VA_PREDICTION_DIRECTION_PREVIOUS                0x00000001
 /** \brief Driver support backward prediction frame/slice */
 #define VA_PREDICTION_DIRECTION_FUTURE                  0x00000002
+/** \brief Dirver require both reference list must be not empty for inter frame */
+#define VA_PREDICTION_DIRECTION_BI_NOT_EMPTY            0x00000004
 /**@}*/
 
 /** @name Attribute values for VAConfigAttribEncIntraRefresh */