V4L capturing

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There is several applications for continuous pictures capturing (e.g. for web, emailing)

  • webcam
  • streamer
  • videodog

Common configuration and control commands

1. Control the TV card (v4lctl is a part of the xawtv package)

  • v4lctl -c /dev/video0 list
  • v4lctl -c /dev/video0 bright "60%"
  • v4lctl -c /dev/video0 contrast "55%"

2. Capture the snaps (streamer is a part of the xawtv package)

  • streamer:
Usage:
streamer -i 1 -c /dev/video0 -s 320x240 -q -j 80 -f jpeg -n ntsc -b 24 -o /var/www/webcam.jpeg
streamer -i 1 -c /dev/video0 -s 320x240 -q -j 80 -f jpeg -n ntsc -b 24 -o /dev/stdout |uuencode thief.jpeg|sendmail alarm@foo.com
  • videodog:
Usage:
videodog -x 640 -y 480 -w 3 -b 1 -c 65535 -m PAL -q -d /dev/video0 -j -f /var/www/webcam.jpg
This useful tool supports continuously moving (ftp or scp - ssh copy) of jpeg output to remote server. Also allows put in additional text (date time, location), rotating of image.
Usage:
webcam /etc/webcamrc

Image format information

Good place to look is http://www.fourcc.org/

About philips webcam compression format good info and free decoders can be found on http://www.saillard.org/linux/pwc/