Function parse_primary

libavcodec/eval.c:175–282

}

static AVExpr * parse_primary(Parser *p) {
    AVExpr * d = av_mallocz(sizeof(AVExpr));
    char *next= p->s;
    int i;

    if (!d)
        return NULL;

    /* number */
    d->value = av_strtod(p->s, &next);
    if(next != p->s){
        d->type = e_value;
        p->s= next;
        return d;
    }
    d->value = 1;

    /* named constants */
    for(i=0; p->const_name && p->const_name[i]; i++){
        if(strmatch(p->s, p->const_name[i])){
            p->s+= strlen(p->const_name[i]);
            d->type = e_const;
            d->a.const_index = i;
            return d;
        }
    }

    p->s= strchr(p->s, '(');
    if(p->s==NULL){
        *p->error = "undefined constant or missing (";
        p->s= next;
        ff_free_expr(d);
        return NULL;
    }
    p->s++; // "("
    if (*next == '(') { // special case do-nothing
        av_freep(&d);
        d = parse_expr(p);
        if(p->s[0] != ')'){
            *p->error = "missing )";
            ff_free_expr(d);
            return NULL;
        }
        p->s++; // ")"
        return d;
    }
    d->param[0] = parse_expr(p);
    if(p->s[0]== ','){
        p->s++; // ","
        d->param[1] = parse_expr(p);
    }
    if(p->s[0] != ')'){
        *p->error = "missing )";
        ff_free_expr(d);
        return NULL;
    }
    p->s++; // ")"