dv4lstart(1) [debian man page]

DV4LSTART(1)						      General Commands Manual						      DV4LSTART(1)

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 facil-
       ity 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)

DC1394_VLOOPBACK(1)						   User Commands					       DC1394_VLOOPBACK(1)

NAME

       dc1394_vloopback - send format0 video to V4L vloopback device

SYNOPSIS

       dc1394_vloopback [--daemon] [--pipe] [--guid=camera-euid] [--video1394=/dev/video1394/x] [--vloopback=/dev/video0] [--palette=yuv422|rgb24]
       [--width=n] [--height=n]

DESCRIPTION

       Sends format0 640x480 RGB to the vloopback input device so that it can be consumed by V4L applications on the vloopback output device.

OPTIONS

       --daemon
	      run as a daemon, detached from console (optional).

       --pipe write images to vloopback device instead of using zero-copy mmap mode (optional).

       --guid select camera to use (optional). default is first camera on any port.

       --video1394
	      specifies video1394 device to use (optional). default is /dev/video1394/<port#>.

       --vloopback
	      specifies video4linux device to use (optional). default is to determine this automatically.

       --palette
	      specify the video palette to use (optional). yuv422 (default) or rgb24.

       --width
	      set the initial width (default=640)

       --height
	      set the initial height (default=480)

       --help print help message

BUGS

       This program is maintained by the DC1394 Package Mainteners' team <libdc1394-packaging@lists.sourceforge.net>.

       The bugs related to libdc1394 and current packaging can be submitted here:

       http://bugs.launchpad.net/~libdc1394-dev/

       For bugs related to library implementation, please submit to libdc1394 developers: <libdc1394-dev@lists.sourceforge.net>.

AUTHOR

       This manual page was originally written by Peter De Schrijver <p2@debian.org> for the Debian GNU/Linux system (but may be used by others).

COPYRIGHT

       This  manual  page is maintained by the DC1394 Package Mainteners' team. The team members and other information can  be	found  online  at:
       http://launchpad.net/~libdc1394-dev

       Permission  is  granted	to copy, distribute and/or modify  this  document  under the terms of the GNU General Public License, Version 3 or
       any later version published by the Free	Software  Foundation.

       On  Debian  systems (like Ubuntu), the complete text of the GNU General Public License can be found in /usr/share/common-licenses/GPL-3.

SEE ALSO

       dc1394_reset_bus(1)

dc1394_vloopback						   February 2008					       DC1394_VLOOPBACK(1)