diff --git a/libavcodec/mpeg12enc.c b/libavcodec/mpeg12enc.c
index 5dedabd268..26d26c7217 100644
--- a/libavcodec/mpeg12enc.c
+++ b/libavcodec/mpeg12enc.c
@@ -74,6 +74,8 @@ static void init_uni_ac_vlc(RLTable *rl, uint8_t *uni_ac_vlc_len){
     for(i=0; i<128; i++){
         int level= i-64;
         int run;
+        if (!level)
+            continue;
         for(run=0; run<64; run++){
             int len, bits, code;