ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8.3.1 (GCC) 20190414
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 00000000004ee340] Auto-inserting h264_mp4toannexb bitstream filter
[concat @ 00000000004e2cc0] Could not find codec parameters for stream 2 (Unknown: none): unknown codec
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, concat, from 'U:GoPro_concatconcat_video.txt':
  Duration: N/A, start: 0.000000, bitrate: 15110 kb/s
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1280x720 [SAR 1:1 DAR 16:9], 14982 kb/s, 59.94 fps, 59.94 tbr, 60k tbn, 119.88 tbc
    Metadata:
      creation_time   : 2019-04-16T13:18:14.000000Z
      handler_name    :  GoPro AVC
      encoder         : GoPro AVC encoder
      timecode        : 13:17:26:44
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s
    Metadata:
      creation_time   : 2019-04-16T13:18:14.000000Z
      handler_name    :  GoPro AAC
      timecode        : 13:17:26:44
    Stream #0:2: Unknown: none
Output #0, mp4, to 'U:GoPro_concatGoPro_concat.MP4':
  Metadata:
    encoder         : Lavf58.20.100
    Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1280x720 [SAR 1:1 DAR 16:9], q=2-31, 14982 kb/s, 0.02 fps, 59.94 tbr, 60k tbn, 60k tbc
    Metadata:
      creation_time   : 2019-04-16T13:18:14.000000Z
      handler_name    :  GoPro AVC
      encoder         : GoPro AVC encoder
      timecode        : 13:17:26:44
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s
    Metadata:
      creation_time   : 2019-04-16T13:18:14.000000Z
      handler_name    :  GoPro AAC
      timecode        : 13:17:26:44
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000000066703980] Auto-inserting h264_mp4toannexb bitstream filter
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000000066703980] Auto-inserting h264_mp4toannexb bitstream filter
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000000005b440c0] Auto-inserting h264_mp4toannexb bitstream filter
frame=268936 fps=1647 q=-1.0 Lsize= 8282945kB time=01:14:46.73 bitrate=15123.2kbits/s speed=27.5x
video:8205691kB audio:70105kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.086390%