PRESET_DARKER      83 libavfilter/vf_curves.c         { "darker",             NULL, 0, AV_OPT_TYPE_CONST, {.i64=PRESET_DARKER},               INT_MIN, INT_MAX, FLAGS, "preset_name" },
PRESET_DARKER     122 libavfilter/vf_curves.c     [PRESET_DARKER]             = { .master = "0.5/0.4" },