func: int show_formats(void *optctx,const char *opt,const char *arg) AVInputFormat * ifmt = ( ( void * ) 0 ) ; AVOutputFormat * ofmt = ( ( void * ) 0 ) ; const char * last_name ; last_name = "000"; const char * name = ( ( void * ) 0 ) ; while ( ofmt = av_oformat_next ( ofmt ) )  if ( ( name == ( ( void * ) 0 ) || strcmp ( ofmt -> name , name ) < 0 ) && strcmp ( ofmt -> name , last_name ) > 0 )  name = ofmt -> name; while ( ifmt = av_iformat_next ( ifmt ) )  if ( ( name == ( ( void * ) 0 ) || strcmp ( ifmt -> name , name ) < 0 ) && strcmp ( ifmt -> name , last_name ) > 0 )  name = ifmt -> name; if ( name == ( ( void * ) 0 ) )  last_name = name; 