ffmpeg -f video4linux2 -i /dev/video2 -vcodec libx264 -b 3000k -r 15 -crf 16 -pix_fmt yuv420p http://localhost:8090/cam3.ffm
ffmpeg version git-2012-08-13-ed8d827 Copyright (c) 2000-2012 the FFmpeg developers
  built on Aug 12 2012 23:13:28 with gcc 4.4.5 (Debian 4.4.5-8)
  configuration: --enable-gpl --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libx264 --enable-nonfree --enable-version3
  libavutil      51. 69.100 / 51. 69.100
  libavcodec     54. 52.100 / 54. 52.100
  libavformat    54. 23.100 / 54. 23.100
  libavdevice    54.  2.100 / 54.  2.100
  libavfilter     3.  8.100 /  3.  8.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[video4linux2,v4l2 @ 0x9735580] Estimating duration from bitrate, this may be inaccurate
Input #0, video4linux2,v4l2, from '/dev/video2':
  Duration: N/A, start: 1345070683.916738, bitrate: 62145 kb/s
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 480x360, 62145 kb/s, 29.97 tbr, 1000k tbn, 29.97 tbc
Please use -b:a or -b:v, -b is ambiguous
[libx264 @ 0x9734f40] broken ffmpeg default settings detected
[libx264 @ 0x9734f40] use an encoding preset (e.g. -vpre medium)
[libx264 @ 0x9734f40] preset usage: -vpre <speed> -vpre <profile>
[libx264 @ 0x9734f40] speed presets are listed in x264 --help
[libx264 @ 0x9734f40] profile is optional; x264 defaults to high
Output #0, ffm, to 'http://localhost:8090/cam3.ffm':
    Stream #0:0: Video: h264, yuv420p, 320x240, q=2-31, 3000 kb/s, 1000k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> libx264)
Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height