diff --git a/decoder/ih264d_api.c b/decoder/ih264d_api.c
index 4a54663..a63e09e 100644
--- a/decoder/ih264d_api.c
+++ b/decoder/ih264d_api.c
@@ -2126,8 +2126,9 @@
         WORD32 prev_slice_err;
         pocstruct_t temp_poc;
         WORD32 ret1;
-
-        num_mb_skipped = (ps_dec->u2_frm_ht_in_mbs * ps_dec->u2_frm_wd_in_mbs)
+        WORD32 ht_in_mbs;
+        ht_in_mbs = ps_dec->u2_pic_ht >> (4 + ps_dec->ps_cur_slice->u1_field_pic_flag);
+        num_mb_skipped = (ht_in_mbs * ps_dec->u2_frm_wd_in_mbs)
                             - ps_dec->u2_total_mbs_coded;
 
         if(ps_dec->u4_first_slice_in_pic && (ps_dec->u4_pic_buf_got == 0))