halexander9000@halexander9000-904HD:~/ffmpeg$ ffmpeg -f x11grab -s vga -r 16 -i :0.0 /tmp/out.mpg
ffmpeg version N-38318-g34210e8 Copyright (c) 2000-2012 the FFmpeg developers
  built on Mar  1 2012 03:10:57 with gcc 4.6.1
  configuration: --enable-gpl --enable-nonfree --enable-libx264 --enable-libtheora --enable-libvorbis --enable-x11grab
  libavutil      51. 41.100 / 51. 41.100
  libavcodec     54.  4.100 / 54.  4.100
  libavformat    54.  1.100 / 54.  1.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 62.101 /  2. 62.101
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  7.100 /  0.  7.100
  libpostproc    52.  0.100 / 52.  0.100
[x11grab @ 0x9c2ec00] device: :0.0 -> display: :0.0 x: 0 y: 0 width: 640 height: 480
[x11grab @ 0x9c2ec00] shared memory extension found
[x11grab @ 0x9c2ec00] Estimating duration from bitrate, this may be inaccurate
Input #0, x11grab, from ':0.0':
  Duration: N/A, start: 1330564669.863183, bitrate: 157286 kb/s
    Stream #0:0: Video: rawvideo (BGR[0] / 0x524742), bgr0, 640x480, 157286 kb/s, 16 tbr, 1000k tbn, 16 tbc
File '/tmp/out.mpg' already exists. Overwrite ? [y/N] y
Incompatible pixel format 'bgr0' for codec 'mpeg1video', auto-selecting format 'yuv420p'
[buffer @ 0x9c2f140] w:640 h:480 pixfmt:bgr0 tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0x9c2c540] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
[scale @ 0x9c2cac0] w:640 h:480 fmt:bgr0 -> w:640 h:480 fmt:yuv420p flags:0x4
[mpeg1video @ 0x9c29200] MPEG1/2 does not support 15/1 fps
Output #0, mpeg, to '/tmp/out.mpg':
    Stream #0:0: Video: mpeg1video, yuv420p, 640x480, q=2-31, 200 kb/s, 90k tbn, 15 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> mpeg1video)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height
halexander9000@halexander9000-904HD:~/ffmpeg$