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       dv4lstart - redirect V4L API to access a camcorder from a V4L program


       dvlstart [options] command [argument ...]


       dv4lstart  enables  command  to access a dv1394 (Firewire) camcorder by
       using  the  video4linux  (V4L)  API.   dv4lstart  uses  the  LD_PRELOAD
       facility  to  intercept  calls  to the V4L API and make the camcorder’s
       videostream available.

       Check that LD_PRELOAD works in your environment by starting

         $ dv4lstart ls -l /dev/video0

       The resulting output should look like

       crw-rw---- 0 root video 81, 0 Jan  1  1970 /dev/video0

       Check your 1394 driver config by starting

         $ gst-launch-0.10 dv1394src \! dvdemux \! dvdec \!  xvimagesink

       from your shell. After turning on your camera, a  video  window  should
       appear. If this works, dv4lstart should work as well.

       Inside  command,  use /dev/video0.  Any existing, real V4L device named
       /dev/video0 can not  be  accessed  from  an  application  started  with
       dv4lstart   (applications   started   normally   can  access  the  real


       -c, --color-correction
              Set this option if red objects look blue.

       -n, --new-dev
              Tell dv4lstart to  simulate  a  new  video  device  rather  than
              overriding  /dev/video0.  Set  this  option  if your application
              needs to access other video devices.

       -r, --rgb-only
              Set this option to prevent V4L applications  from  choosing  YUV
              palettes. Try this option if you get low frame rates.

       -v, --verbose level
              Set  the  amount  of  debugging  messages. A level of 0 means no
              output at all, 1 is the default, 3 enables all messages.

       -h, --help
              displays a help message


       The command

         $ dv4lstart v4l-info

       outputs some information about the simulated V4L device.

         $ dv4lstart -c gqcam -v /dev/video0

       starts the gqcam webcam viewer, swapping red and blue colors.


       Programs using exotic ways to access the V4L API will not work.

       Some environments don’t  allow  the  use  of  LD_PRELOAD  for  security
       reasons.  dv4lstart will not work there.

       If dv4lstart does not work, try dv4l instead.