NAME

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

SYNOPSIS

       dvlstart [options] command [argument ...]

DESCRIPTION

       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
       /dev/video0)

OPTIONS

       -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

EXAMPLES

       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.

LIMITATIONS

       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.

SEE ALSO

       dv4l(1)

                                                                                                    DV4LSTART(1)