diff --git a/decoder/ih264d_api.c b/decoder/ih264d_api.c
index 09c0d5e..fe9ea87 100644
--- a/decoder/ih264d_api.c
+++ b/decoder/ih264d_api.c
@@ -1417,7 +1417,7 @@
     ps_dec->pu4_mbaff_wt_mat = pv_buf;
 
     size = sizeof(UWORD32) * 2 * 3
-                        * (MAX_FRAMES * MAX_FRAMES);
+                        * ((MAX_FRAMES << 1) * (MAX_FRAMES << 1));
     pv_buf = pf_aligned_alloc(pv_mem_ctxt, 128, size);
     RETURN_IF((NULL == pv_buf), IV_FAIL);
     ps_dec->pu4_wts_ofsts_mat = pv_buf;