USER_START_CODE  1229 libavcodec/cavsdec.c         case USER_START_CODE:
USER_START_CODE  2558 libavcodec/mpeg12dec.c         case USER_START_CODE:
USER_START_CODE   508 libavcodec/mpeg12enc.c         put_header(s, USER_START_CODE);
USER_START_CODE   537 libavcodec/mpeg12enc.c             put_header(s, USER_START_CODE);