if (desc->idaver) fprintf(f, "%sidaver: %s\n", prefix, desc->idaver);
if (desc->width) fprintf(f, "%swidth: %d\n", prefix, desc->width);
if (desc->height) fprintf(f, "%sheight: %d\n", prefix, desc->height);
if (desc->idaver) fprintf(f, "%sidaver: %s\n", prefix, desc->idaver);
if (desc->width) fprintf(f, "%swidth: %d\n", prefix, desc->width);
if (desc->height) fprintf(f, "%sheight: %d\n", prefix, desc->height);