+ { "format", "set output format", OFFSET(format), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "format" },
+ { "color", "", 0, AV_OPT_TYPE_CONST, {.i64=0}, .flags = FLAGS, .unit = "format" },
+ { "gray", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, .flags = FLAGS, .unit = "format" },
+ { "fill", "set the color of the unmapped pixels", OFFSET(fill_rgba), AV_OPT_TYPE_COLOR, {.str="black"}, .flags = FLAGS },