ffmpeg -y -i E:\input.avs -sws_flags spline -sn -s 1920x1080 -c:v libx264 -preset slow -profile:v high -level 4.1 -refs:v 5 -crf 18 -r 24000/1001 -x264opts force-cfr=1:colormatrix=bt709 E:\out.mkv

The Above line gives me the below output

Frame rate mode                          : Variable
Original frame rate                      : 23.976 FPS

Log

ffmpeg version N-86482-gbc40674 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 7.1.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconf
ig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc -
-enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --
enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --
enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-zlib
  libavutil      55. 66.100 / 55. 66.100
  libavcodec     57. 99.100 / 57. 99.100
  libavformat    57. 73.100 / 57. 73.100
  libavdevice    57.  7.100 / 57.  7.100
  libavfilter     6. 92.100 /  6. 92.100
  libswscale      4.  7.101 /  4.  7.101
  libswresample   2.  8.100 /  2.  8.100
  libpostproc    54.  6.100 / 54.  6.100
Input #0, avisynth, from 'E:\input.avs':
  Duration: 00:22:54.65, start: 0.000000, bitrate: 0 kb/s
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1920x1080, 19.18 fps, 19.18 tbr, 19.18 tbn, 19.18 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 04a74a40] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 04a74a40] profile High, level 3.1
[libx264 @ 04a74a40] 264 - core 150 r2833 df79067 - H.264/MPEG-4 AVC codec - Copyleft 2003-2017 - http://www.videolan.org/x264.html - options: cabac=1 ref=5 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=2 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=crf mbtree=1 crf=19.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, matroska, to 'E:\out.mkv':
  Metadata:
    encoder         : Lavf57.73.100
    Stream #0:0: Video: h264 (libx264) (H264 / 0x34363248), yuv420p, 720x400, q=-1--1, 23.98 fps, 1k tbn, 23.98 tbc
    Metadata:
      encoder         : Lavc57.99.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame=  635 fps= 96 q=24.0 size=    1500kB time=00:00:29.57 bitrate= 415.6kbits/s speed=4.47x
video:95570kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.200804%
[libx264 @ 04a74a40] frame I:367   Avg QP:13.30  size: 34647
[libx264 @ 04a74a40] frame P:7807  Avg QP:17.22  size:  6918
[libx264 @ 04a74a40] frame B:18193 Avg QP:21.29  size:  1712
[libx264 @ 04a74a40] consecutive B-frames:  5.4%  5.9%  5.9% 82.8%
[libx264 @ 04a74a40] mb I  I16..4: 16.8% 49.5% 33.7%
[libx264 @ 04a74a40] mb P  I16..4:  2.4%  5.4%  2.1%  P16..4: 28.7% 10.9%  7.4%  0.0%  0.0%    skip:43.2%
[libx264 @ 04a74a40] mb B  I16..4:  0.2%  0.4%  0.2%  B16..8: 21.0%  2.7%  0.9%  direct: 2.7%  skip:71.9%  L0:44.9% L1:47.4% BI: 7.7%
[libx264 @ 04a74a40] 8x8 transform intra:52.9% inter:56.5%
[libx264 @ 04a74a40] direct mvs  spatial:100.0% temporal:0.0%
[libx264 @ 04a74a40] coded y,uvDC,uvAC intra: 61.5% 64.0% 43.0% inter: 8.9% 9.9% 2.5%
[libx264 @ 04a74a40] i16 v,h,dc,p: 34% 21%  5% 40%
[libx264 @ 04a74a40] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 14% 10% 16%  8% 11% 11% 10% 10% 11%
[libx264 @ 04a74a40] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 16%  9%  9% 10% 13% 13% 10% 10% 11%
[libx264 @ 04a74a40] i8c dc,h,v,p: 44% 25% 19% 13%
[libx264 @ 04a74a40] Weighted P-Frames: Y:11.0% UV:8.0%
[libx264 @ 04a74a40] ref P L0: 58.2%  9.2% 16.1%  8.5%  6.5%  1.2%  0.2%
[libx264 @ 04a74a40] ref B L0: 78.4% 13.3%  6.7%  1.6%
[libx264 @ 04a74a40] ref B L1: 95.0%  5.0%
[libx264 @ 04a74a40] kb/s:711.91