ffmpeg -i vid1.wmv -i vid2.wmv -filter_complex '[0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a]' -map '[v]' -map '[a]' -vcodec libx264 -preset veryfast -tune film -x264opts level=41:deblock=-2,-2 -crf 18 test.mp4
ffmpeg version git-2013-02-14-33d6330 Copyright (c) 2000-2013 the FFmpeg developers
  built on Feb 14 2013 21:28:48 with gcc 4.4.5 (Debian 4.4.5-8)
  configuration: --enable-gpl --enable-libfaac --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
  libavutil      52. 17.101 / 52. 17.101
  libavcodec     54. 91.103 / 54. 91.103
  libavformat    54. 63.100 / 54. 63.100
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 37.101 /  3. 37.101
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
Guessed Channel Layout for  Input Stream #0.0 : stereo
Input #0, asf, from 'vid1.wmv':
  Metadata:
    WMFSDKNeeded    : 0.0.0.0000
    DeviceConformanceTemplate: MP@ML
    WM/WMADRCPeakReference: 327
    WM/WMADRCAverageReference: 236
    WMFSDKVersion   : 10.00.00.3802
    IsVBR           : 0
  Duration: 00:11:08.56, start: 0.000000, bitrate: 2640 kb/s
    Stream #0:0(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, stereo, fltp, 64 kb/s
    Stream #0:1(eng): Video: wmv3 (Main) (WMV3 / 0x33564D57), yuv420p, 720x432, 2567 kb/s, SAR 16:15 DAR 16:9, 25 tbr, 1k tbn, 1k tbc
Guessed Channel Layout for  Input Stream #1.0 : stereo
Input #1, asf, from 'vid2.wmv':
  Metadata:
    WMFSDKNeeded    : 0.0.0.0000
    DeviceConformanceTemplate: MP@ML
    WM/WMADRCPeakReference: 327
    WM/WMADRCAverageReference: 242
    WMFSDKVersion   : 10.00.00.3802
    IsVBR           : 0
  Duration: 00:09:51.84, start: 0.000000, bitrate: 2643 kb/s
    Stream #1:0(eng): Audio: wmav2 (a[1][0][0] / 0x0161), 44100 Hz, stereo, fltp, 64 kb/s
    Stream #1:1(eng): Video: wmv3 (Main) (WMV3 / 0x33564D57), yuv420p, 720x432, 2567 kb/s, SAR 16:15 DAR 16:9, 25 tbr, 1k tbn, 1k tbc
Stream specifier ':0' in filtergraph description [0:0] [0:1] [1:0] [1:1] concat=n=2:v=1:a=1 [v] [a] matches no streams.