# ffmpeg -video_size wxga -framerate 25 -f x11grab -i :0.0 output.avi
ffmpeg version N-57811-g2c4f573 Copyright (c) 2000-2013 the FFmpeg developers
  built on Nov  2 2013 16:34:43 with gcc 4.8 (Debian 4.8.2-1)
  configuration: --enable-gpl --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-x11grab --prefix=/usr --enable-libv4l2
  libavutil      52. 49.100 / 52. 49.100
  libavcodec     55. 40.101 / 55. 40.101
  libavformat    55. 21.100 / 55. 21.100
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
[x11grab @ 0xa6c1de0] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 1366 height: 768
[x11grab @ 0xa6c1de0] shared memory extension found
Input #0, x11grab, from ':0.0':
  Duration: N/A, start: 1383407104.886732, bitrate: 839270 kb/s
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 1366x768, 839270 kb/s, 25 tbr, 1000k tbn, 25 tbc
File 'output.flv' already exists. Overwrite ? [y/N] y
[swscaler @ 0xa6dfac0] deprecated pixel format used, make sure you did set range correctly
Output #0, flv, to 'output.flv':
  Metadata:
    encoder         : Lavf55.21.100
    Stream #0:0: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p, 1366x768, q=2-31, 200 kb/s, 1k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> flv)
Press [q] to stop, [?] for help
[swscaler @ 0xa6dfac0] Warning: data is not aligned! This can lead to a speedloss
frame=  123 fps= 22 q=31.0 Lsize=    1265kB time=00:00:06.84 bitrate=1514.5kbits/s
video:1262kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.168641%
Received signal 2: terminating.