@@ -440,7 +440,8 @@ static void vp6_parse_coeff(VP56Context *s)

         model1 = model->coeff_dccv[pt];

         model2 = model->coeff_dcct[pt][ctx];

-        for (coeff_idx=0; coeff_idx<64; ) {

+        coeff_idx = 0;

+        for (;;) {

             if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {

                 /* parse a coeff */

                 if (vp56_rac_get_prob(c, model2[2])) {

@@ -481,8 +482,10 @@ static void vp6_parse_coeff(VP56Context *s)

                             run += vp56_rac_get_prob(c, model3[i+8]) << i;

                 }

             }

-

-            cg = vp6_coeff_groups[coeff_idx+=run];

+            coeff_idx += run;

+            if (coeff_idx >= 64)

+                break;

+            cg = vp6_coeff_groups[coeff_idx];

             model1 = model2 = model->coeff_ract[pt][ct][cg];

         }