$ avconv -i concat:20160218_183945.mp4\|20160218_184228.mp4\|20160218_184459.mp4\|20160218_184556.mp4\|20160218_185026.mp4 -c copy 20160218.mkv
avconv version 9.18-6:9.18-0ubuntu0.14.04.1, Copyright (c) 2000-2014 the Libav developers
  built on Mar 16 2015 13:19:10 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
[h264 @ 0x23957c0] AVC: nal size 210031
[h264 @ 0x23957c0] AVC: nal size 1105338511
[h264 @ 0x23957c0] no frame!
[h264 @ 0x23ca420] AVC: nal size 296023
[h264 @ 0x23ca420] no frame!
[h264 @ 0x23cea20] AVC: nal size 210031
[h264 @ 0x23cea20] AVC: nal size 1105338511
[h264 @ 0x23cea20] no frame!
[h264 @ 0x23d0600] AVC: nal size 210031
[h264 @ 0x23d0600] AVC: nal size 1105338511
[h264 @ 0x23d0600] no frame!
[h264 @ 0x23ca420] AVC: nal size 1047611040
[h264 @ 0x23ca420] no frame!
[h264 @ 0x23cea20] AVC: nal size 1042858674
[h264 @ 0x23cea20] no frame!
[h264 @ 0x23d0600] AVC: nal size 2120473518
[h264 @ 0x23d0600] no frame!
[h264 @ 0x23957c0] AVC: nal size -1923890410
[h264 @ 0x23957c0] no frame!
[h264 @ 0x23ca420] AVC: nal size -1135083373
[h264 @ 0x23ca420] no frame!
[h264 @ 0x23cea20] AVC: nal size 164875298
[h264 @ 0x23cea20] no frame!
[h264 @ 0x23d0600] AVC: nal size 525657522
[h264 @ 0x23d0600] no frame!
[h264 @ 0x23957c0] AVC: nal size 880589675
[h264 @ 0x23957c0] no frame!
[h264 @ 0x23ca420] AVC: nal size -583746231
[h264 @ 0x23ca420] no frame!
[h264 @ 0x23cea20] AVC: nal size -1262368908
[h264 @ 0x23cea20] no frame!
[h264 @ 0x23ca420] AVC: nal size 91104893
[h264 @ 0x23ca420] no frame!
[h264 @ 0x23d0600] AVC: nal size -1452652290
[h264 @ 0x23957c0] AVC: nal size 1042939748
[h264 @ 0x23957c0] no frame!
[h264 @ 0x23ca420] AVC: nal size 1118567250
[h264 @ 0x23ca420] no frame!
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'concat:20160218_183945.mp4|20160218_184228.mp4|20160218_184459.mp4|20160218_184556.mp4|20160218_185026.mp4':
  Metadata:
    compatible_brands: isommp42
    major_brand     : mp42
    minor_version   : 0
    creation_time   : 2016-02-18 23:53:33
  Duration: 00:02:51.86, start: 0.000000, bitrate: 63321 kb/s
    Stream #0.0(eng): Video: h264 (High), yuv420p, 1920x1080, 19993 kb/s, PAR 65536:65536 DAR 16:9, 29.45 fps, 90k tbn
    Metadata:
      creation_time   : 2016-02-18 23:41:11
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, fltp, 156 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:41:11
    Stream #0.2(eng): Video: h264 (High), yuv420p, 1920x1080, 19990 kb/s, PAR 65536:65536 DAR 16:9, 29.45 fps, 90k tbn
    Metadata:
      creation_time   : 2016-02-18 23:44:27
    Stream #0.3(eng): Audio: aac, 48000 Hz, stereo, fltp, 155 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:44:27
    Stream #0.4(eng): Video: h264, 1920x1080, 19975 kb/s, PAR 65536:65536 DAR 16:9, 29.44 fps, 90k tbn
    Metadata:
      creation_time   : 2016-02-18 23:45:33
    Stream #0.5(eng): Audio: aac, 48000 Hz, stereo, fltp, 156 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:45:33
    Stream #0.6(eng): Video: h264 (High), yuv420p, 1920x1080, 19998 kb/s, PAR 65536:65536 DAR 16:9, 29.45 fps, 90k tbn
    Metadata:
      creation_time   : 2016-02-18 23:48:50
    Stream #0.7(eng): Audio: aac, 48000 Hz, stereo, fltp, 156 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:48:50
    Stream #0.8(eng): Video: h264 (High), yuv420p, 1920x1080, 20009 kb/s, PAR 65536:65536 DAR 16:9, 29.45 fps, 90k tbn
    Metadata:
      creation_time   : 2016-02-18 23:53:33
    Stream #0.9(eng): Audio: aac, 48000 Hz, stereo, fltp, 155 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:53:33
File '20160218.mkv' already exists. Overwrite ? [y/N] y
Output #0, matroska, to '20160218.mkv':
  Metadata:
    compatible_brands: isommp42
    major_brand     : mp42
    minor_version   : 0
    creation_time   : 2016-02-18 23:53:33
    encoder         : Lavf54.20.4
    Stream #0.0(eng): Video: libx264, yuv420p, 1920x1080 [PAR 65536:65536 DAR 16:9], q=2-31, 19993 kb/s, 1k tbn, 90k tbc
    Metadata:
      creation_time   : 2016-02-18 23:41:11
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, 156 kb/s
    Metadata:
      creation_time   : 2016-02-18 23:41:11
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press ctrl-c to stop encoding
frame= 2469 fps=858 q=-1.0 Lsize=  206274kB time=83.81 bitrate=20162.5kbits/s
video:204625kB audio:1599kB global headers:0kB muxing overhead 0.024125%