VLPF_LIN           67 libavfilter/vf_tinterlace.c    { "lowpass",           "set vertical low-pass filter", OFFSET(lowpass), AV_OPT_TYPE_INT,   {.i64 = VLPF_LIN}, 0, 2, FLAGS, "lowpass" },
VLPF_LIN           69 libavfilter/vf_tinterlace.c    {     "linear",        "linear vertical low-pass filter",              0, AV_OPT_TYPE_CONST, {.i64 = VLPF_LIN}, INT_MIN, INT_MAX, FLAGS, "lowpass" },
VLPF_LIN          533 libavfilter/vf_tinterlace.c     if (tinterlace->lowpass == VLPF_LIN)