diff --git a/inc/mpp_meta.h b/inc/mpp_meta.h
index 3f69c92a..0b70198f 100644
--- a/inc/mpp_meta.h
+++ b/inc/mpp_meta.h
@@ -127,6 +127,12 @@ typedef enum MppMetaKey_e {
      */
     KEY_NPU_OBJ_FLAG            = FOURCC_META('n', 'p', 'u', 'f'),
 
+    /*
+     * smart v4 encoder input key
+     */
+    KEY_BUFFER_UPSCALE          = FOURCC_META('u', 'b', 'u', 'f'),
+    KEY_BUFFER_DOWNSCALE        = FOURCC_META('d', 'b', 'u', 'f'),
+
     /* frame long-term reference frame operation */
     KEY_ENC_MARK_LTR            = FOURCC_META('m', 'l', 't', 'r'),
     KEY_ENC_USE_LTR             = FOURCC_META('u', 'l', 't', 'r'),
diff --git a/mpp/base/mpp_meta.c b/mpp/base/mpp_meta.c
index aa5dd9d5..87d135cf 100644
--- a/mpp/base/mpp_meta.c
+++ b/mpp/base/mpp_meta.c
@@ -128,6 +128,8 @@ static inline RK_U64 META_KEY_TO_U64(RK_U32 key, RK_U32 type)
     ENTRY(KEY_QPMAP0,               TYPE_SPTR) \
     /* buffer for super encode v3 */ \
     ENTRY(KEY_NPU_OBJ_FLAG,         TYPE_SPTR) \
+    ENTRY(KEY_BUFFER_UPSCALE,       TYPE_SPTR) \
+    ENTRY(KEY_BUFFER_DOWNSCALE,     TYPE_SPTR) \
     \
     ENTRY(KEY_LVL64_INTER_NUM,      TYPE_VAL_32) \
     ENTRY(KEY_LVL32_INTER_NUM,      TYPE_VAL_32) \