ffplay -f video4linux2  /dev/video0

ffplay version N-50554-gcada996 Copyright (c) 2003-2013 the FFmpeg developers
  built on Mar  7 2013 11:33:55 with gcc 4.7.2 (GCC) 20121109 (Red Hat 4.7.2-8)
  configuration: --prefix=/opt --enable-bzlib --enable-gnutls --enable-libx264 --enable-x11grab --enable-postproc --enable-pthreads --enable-gpl --enable-debug --disable-stripping --enable-pic --enable-libv4l2 --enable-libvpx
  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
[video4linux2,v4l2 @ 0x7f1e58004260] Estimating duration from bitrate, this may be inaccurate
Input #0, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 4992.416355, bitrate: 110592 kb/s
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 640x480, 110592 kb/s, 30 fps, 30 tbr, 1000k tbn, 1000k tbc