Failed to detect capture video standard

Hi

   Using VPIF,I want to run loopback copy demo to capture camera data.

   And the device file: /dev/Video0 is existed.

  But after run command:

             ./video_loopback_copy_omapl138.x470MV -r 720x576

  I got error:

            Failed to detect capture video standard

   What problem about this?

   Thanks very much!