$ ffmpeg -f concat -i list.txt -c copy output.mp4
ffmpeg version 2.0 Copyright (c) 2000-2013 the FFmpeg developers
  built on Jul 15 2013 07:09:57 with gcc 4.7 (Ubuntu/Linaro 4.7.3-1ubuntu1)
  configuration: --prefix=/opt/ffmpeg --libdir=/opt/ffmpeg/lib/ --enable-shared --disable-stripping --enable-gpl --enable-version3 --enable-runtime-cpudetect --enable-postproc --enable-x11grab --enable-libcdio --enable-vaapi --enable-vdpau --enable-bzlib --enable-gnutls --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libfaac --enable-nonfree --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libfdk_aac --enable-libopus --enable-pthreads --enable-zlib --enable-libvpx --enable-libfreetype --enable-libpulse
  libavutil      52. 38.100 / 52. 38.100
  libavcodec     55. 18.102 / 55. 18.102
  libavformat    55. 12.100 / 55. 12.100
  libavdevice    55.  3.100 / 55.  3.100
  libavfilter     3. 79.101 /  3. 79.101
  libswscale      2.  3.100 /  2.  3.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  3.100 / 52.  3.100
[concat @ 0x1b5fea0] Estimating duration from bitrate, this may be inaccurate
Input #0, concat, from 'list.txt':
  Duration: 00:00:00.00, start: 0.000000, bitrate: 1873 kb/s
    Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 1682 kb/s, 23.98 fps, 23.98 tbr, 48k tbn, 47.95 tbc
    Stream #0:1: Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 191 kb/s
Output #0, mp4, to 'output.mp4':
  Metadata:
    encoder         : Lavf55.12.100
    Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 1280x720, q=2-31, 1682 kb/s, 23.98 fps, 48k tbn, 48k tbc
    Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, 191 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press [q] to stop, [?] for help
frame= 7115 fps=0.0 q=-1.0 Lsize=   62730kB time=00:05:26.02 bitrate=1576.2kbits/s    
video:56472kB audio:6114kB subtitle:0 global headers:0kB muxing overhead 0.229482%