-
- emit_marker(cinfo, M_DAC);
-
- emit_2bytes(cinfo, length*2 + 2);
-
- for (i = 0; i < NUM_ARITH_TBLS; i++) {
- if (dc_in_use[i]) {
- emit_byte(cinfo, i);
- emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
- }
- if (ac_in_use[i]) {
- emit_byte(cinfo, i + 0x10);
- emit_byte(cinfo, cinfo->arith_ac_K[i]);
+
+ if (length) {
+ emit_marker(cinfo, M_DAC);
+
+ emit_2bytes(cinfo, length*2 + 2);
+
+ for (i = 0; i < NUM_ARITH_TBLS; i++) {
+ if (dc_in_use[i]) {
+ emit_byte(cinfo, i);
+ emit_byte(cinfo, cinfo->arith_dc_L[i] + (cinfo->arith_dc_U[i]<<4));
+ }
+ if (ac_in_use[i]) {
+ emit_byte(cinfo, i + 0x10);
+ emit_byte(cinfo, cinfo->arith_ac_K[i]);
+ }