./ffmpeg -i input.mp4 -i forced.srt -i full.srt -map 0:0 -map 0:1 -map 0:2 -map 1:0 -map 2:0 -c:v copy -c:a copy -c:s:0 mov_text -c:s:1 mov_text -map_metadata -1 output.mp4
ffmpeg version N-94600-g661a9b274b-tessus  https://evermeet.cx/ffmpeg/  Copyright (c) 2000-2019 the FFmpeg developers
  built with Apple LLVM version 10.0.1 (clang-1001.0.46.4)
  configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libmysofa --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvmaf --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-version3 --pkg-config-flags=--static --disable-ffplay
  libavutil      56. 33.100 / 56. 33.100
  libavcodec     58. 55.100 / 58. 55.100
  libavformat    58. 31.101 / 58. 31.101
  libavdevice    58.  9.100 / 58.  9.100
  libavfilter     7. 58.100 /  7. 58.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.20.100
  Duration: 00:42:06.55, start: 0.000000, bitrate: 6722 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 5908 kb/s, 23.98 fps, 23.98 tbr, 16k tbn, 47.95 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 162 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
    Stream #0:2(und): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, 5.1(side), fltp, 640 kb/s
    Metadata:
      handler_name    : SoundHandler
    Side data:
      audio service type: main
Input #1, srt, from 'forced.srt':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Subtitle: subrip
Input #2, srt, from 'full.srt':
  Duration: N/A, bitrate: N/A
    Stream #2:0: Subtitle: subrip
[mp4 @ 0x7f93c0010c00] track 2: codec frame size is not set
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf58.31.101
    Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 5908 kb/s, 23.98 fps, 23.98 tbr, 16k tbn, 16k tbc (default)
    Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 162 kb/s (default)
    Stream #0:2: Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, 5.1(side), fltp, 640 kb/s
    Side data:
      audio service type: main
    Stream #0:3: Subtitle: mov_text (tx3g / 0x67337874)
    Metadata:
      encoder         : Lavc58.55.100 mov_text
    Stream #0:4: Subtitle: mov_text (tx3g / 0x67337874)
    Metadata:
      encoder         : Lavc58.55.100 mov_text
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
  Stream #0:2 -> #0:2 (copy)
  Stream #1:0 -> #0:3 (subrip (srt) -> mov_text (native))
  Stream #2:0 -> #0:4 (subrip (srt) -> mov_text (native))
Press [q] to stop, [?] for help
[mp4 @ 0x7f93c0010c00] Application provided duration: 2367156000 / timestamp: 2380504000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2376665999 / timestamp: 2391599000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2378917998 / timestamp: 2396645000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2379000997 / timestamp: 2398272000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2379083996 / timestamp: 2401150000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2379167995 / timestamp: 2403027000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2382796994 / timestamp: 2407907000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2389303993 / timestamp: 2417875000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
[mp4 @ 0x7f93c0010c00] Application provided duration: 2404610992 / timestamp: 2434183000 is out of range for mov/mp4 format
[mp4 @ 0x7f93c0010c00] pts has no value
frame=60576 fps=31973 q=-1.0 Lsize= 2073383kB time=00:42:06.50 bitrate=6722.8kbits/s speed=1.33e+03x
video:1822137kB audio:247475kB subtitle:16kB other streams:0kB global headers:0kB muxing overhead: 0.181433%