*var = b;
if (c->type == FF_OPT_TYPE_FLAG) { if (b) *var |= (int)c->min; else *var &= ~(int)c->min; } else *var = b;
static int parse_bool(const AVOption *c, char *s, int *var){    int b = 1; /* by default -on- when present */    if (s) {	if (!strcasecmp(s, "off") || !strcasecmp(s, "false")	    || !strcmp(s, "0"))	    b = 0;	else if (!strcasecmp(s, "on") || !strcasecmp(s, "true")		 || !strcmp(s, "1"))	    b = 1;	else	    return -1;    }    *var = b;    return 0;}