#Trim Commmand
ffmpeg -i part1_final.mkv -vcodec copy -acodec copy -ss 00:00:00 -to 01:45:39 part1_trimmed.mkv

#output is normal and file is successful

#Ffprobe of trimmed file
ffprobe version N-66005-g3efc174 Copyright (c) 2007-2014 the FFmpeg developers
  built on Aug 31 2014 16:19:25 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  configuration: --enable-gpl --enable-libmp3lame --enable-libvorbis --enable-libvpx --enable-libx264 --extra-libs=-ldl
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  3.100 / 56.  3.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  0.103 /  5.  0.103
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
[matroska,webm @ 0x38ab020] Could not find codec parameters for stream 0 (Video: h264, 1920x1080): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, matroska,webm, from 'part1_trimmed.mkv':
  Metadata:
    ENCODER         : Lavf56.3.100
  Duration: 01:45:39.12, start: 0.000000, bitrate: 11540 kb/s
    Stream #0:0: Video: h264, 1920x1080, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 2k tbc (default)
    Metadata:
      ENCODER         : Lavc56.1.100 libx264
    Stream #0:1: Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)
    Metadata:
      ENCODER         : Lavc56.1.100 dca



#Command to concat with second part of video
ffmpeg -i part1_trimmed.mkv -i part2_final.mkv -filter_complex "[0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a]" -map "[v]" -map "[a]" FINAL.mkv


#Outpt of concat
ffmpeg version N-66005-g3efc174 Copyright (c) 2000-2014 the FFmpeg developers
  built on Aug 31 2014 16:19:25 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-4)
  configuration: --enable-gpl --enable-libmp3lame --enable-libvorbis --enable-libvpx --enable-libx264 --extra-libs=-ldl
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  3.100 / 56.  3.100
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  0.103 /  5.  0.103
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
[matroska,webm @ 0x3960e40] Could not find codec parameters for stream 0 (Video: h264, 1920x1080): unspecified pixel format
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, matroska,webm, from 'part1_trimmed.mkv':
  Metadata:
    ENCODER         : Lavf56.3.100
  Duration: 01:45:39.12, start: 0.000000, bitrate: 11540 kb/s
    Stream #0:0: Video: h264, 1920x1080, SAR 1:1 DAR 16:9, 23.98 fps, 23.98 tbr, 1k tbn, 2k tbc (default)
    Metadata:
      ENCODER         : Lavc56.1.100 libx264
    Stream #0:1: Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)
    Metadata:
      ENCODER         : Lavc56.1.100 dca
Input #1, matroska,webm, from 'part2_final.mkv':
  Metadata:
    ENCODER         : Lavf56.3.100
  Duration: 01:45:43.46, start: 0.083000, bitrate: 11543 kb/s
    Stream #1:0: Video: h264 (High), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Metadata:
      ENCODER         : Lavc56.1.100 libx264
    Stream #1:1: Audio: dts (DTS), 48000 Hz, 5.1(side), fltp, 1536 kb/s (default)
    Metadata:
      ENCODER         : Lavc56.1.100 dca
[buffer @ 0x3a30560] Unable to parse option value "-1" as pixel format
    Last message repeated 1 times
[buffer @ 0x3a30560] Error setting option pix_fmt to value -1.
[graph 0 input from stream 0:0 @ 0x3992680] Error applying options to the filter.
Error configuring filters.