Provided by: vgrabbj_0.9.6-5build1_amd64 bug


       vgrabbj - grab images from a v4l-compatible webcam


       vgrabbj [options]


       This manual page documents briefly the vgrabbj command.

       vgrabbj  is a program that will grab images from any v4l-capable device which supports one
       of the rgb24, rgb32, yuv420, yuv420p, yuyv, or yuv422 palettes and saves the  image  as  a
       .jpg, .png, or .pnm file.

       Optional,  it  can  timestamp  the  resulting  image,  and/or  upload  it to a ftp-server.
       Additionally, a daemon-mode is available to do the above regularly.

       On startup, the default configuration file /etc/vgrabbj.conf is read and evaluated.  If  a
       configuration  file  is  specified via the -c parameter (see below), that file is read and
       parsed. Values which are present in the default config file keep their  values.   Finally,
       the  commandline  is  evaluated. If an option is presented more than once, the last in the
       commandline is taken.  If no options given, vgrabbj tries to open the  default  v4l-device
       /dev/video, grab an image and return it on /dev/stdout.  So be aware.


       All  options  are  either  numeric values, strings, or booleans. If it is a boolean switch
       (e.g. no value/string shown after the switch), it plainly switches the current setting  of
       that  particular option.  Remember, vgrabbj.conf is read first, so any option set to on or
       off there will be toggled by the commandline switch.

       -h     Show summary of options and version number.  -c <filename>  Specifies  filename  as
              alternative configuration file.

       -l <seconds>
              Daemonize & loop with seconds intervals (min. 1).

       -L <microseconds>
              Daemonize & loop microseconds intervals (min. 1). Same as -l except you can control
              it more precisely.

       -a     Enable vgrabbj's  brightness  adjustment  (default:  disabled).  To  use  vgrabbj's
              brightness  adjustment,  RGB24  support of the device is necessary. You may have to
              provide it to your device via the -F parameter (see below).  If  your  device  does
              not support RGB24, this setting is silently ignored.

       -q <quality>
              Sets the quality of a jpeg output to quality (1-100, default: 75).

       -i <imagesize>
              Sets the imagesize of input device, where imagesize is one of:

               sqcif= 128x96,     qsif = 160x120,
               qcif = 176x144,    sif  = 320x240,
               cif  = 352x288,    vga  = 640x480,
               svga = 800x600,    xga  = 1024x768,
               sxga = 1280x1024,  uxga = 1600x1200,

              (default: cif)

       -w <width>
              Sets  the width of the image to width. Needs -H.  The v4l-device has to support the
              image width you set with this option.

       -H <height>
              Sets the height of the image to height. Needs -w.  The v4l-device  has  to  support
              the image height you set with this option.

       -o <format>
              Sets the output to format (either jpeg, png, or pnm, default: jpeg)

       -f <filename>
              Output is written to filename (default: /dev/stdout)

       -A <path+filename>
              Additional  to the output of -f another file is written to the named path+filename,
              whereas the whole may be formatted  according  to  strftime(2).  This  enables  the
              creation  of  an  archive of images. Currently, the output is only supported on the
              same filesystem as the original output.

       -E <value>
              Defines how many images shall be read until a copy for the archive is made. E.g.  1
              means  each image taken is also put in the archive.  5 would mean every fifth image
              taken is put in the archive.

       -M <value>
              Sets the maximum number of images kept in the archive. If you defined 5 seconds for
              daemon  mode, archive every image, you collect 720 images per hour. If you set this
              switch to 720 you would keep an hour of images in the archive.

       -d <device>
              Sets the input device to device (default: /dev/video)

       -s <device>
              This flag causes vgrabbj to print the v4l capabilities of <device> and exit.

       -C     Causes vgrabbj to open the device only  while  image  data  is  grabbed.   This  is
              helpful  if  you need access to the device besides vgrabbj. It's use is discouraged
              due to possible problems with memory fragmentation.  Default is to  keep  the  v4l-
              device open while vgrabbj is running.

       -g     Disables  setting of the image size (see -i, -H, and -w. Necessary for certain v4l-
              devices which do not support to be set to a particular image  size  (e.g.  IBM-usb-
              cam, QuickCam). For these devices you have to specify the size at module load time.

       -S     Switches colormap from BGR to RGB (or vice versa). Use if you have odd colors.

       -R     Swaps left and right of the image like a mirror.

       -U     Swaps  top  and  bottom of the image like a mirror (e.g. for upside-down montage of
              the cam).

       -G     Turns off use of mmap'ed memory. see vgrabbj.conf(5) for details.

       -D <value>
              Sets the loglevel of vgrabbj. Valid for value are 0, 2, 3, 4, 6, 7 (default: 4).  0
              means  no  messages  at  all, 7 is debug. Don't use 7 if you are running vgrabbj in
              daemon mode, it'll surely fill your syslog. Be aware, that  loglevel  7  will  also
              write your ftp-password (if defined in vgrabbj.conf(5)) in the logfile!

       -n     Disable  the  use of the temporary outputfile and write directly to the output-file
              specified with -f. Output to /dev/stdout is always written directly without the use
              of a temporary file.

              If  a  filename different from /dev/stdout was given with the -f parameter, vgrabbj
              defaults to use a temporary file called filename.tmp to write the image. This  file
              is  then  renamed  to  filename to shorten the time period corrupt data may be read
              from filename.

       -F <palette>
              Force the usage of the specified palette. If palette is  not  supported  by  either
              vgrabbj  or the v4l-device, fallback to a palette supported by both is provided. If
              no common denominator is available, vgrabbj exits. See DESCRIPTION for  details  on
              palettes supported by vgrabbj. Possible values are (copy from videodev.h):

               1  VIDEO_PALETTE_GREY      Linear greyscale
               2  VIDEO_PALETTE_HI240     High 240 cube (BT848)
               3  VIDEO_PALETTE_RGB565    565 16 bit RGB
               4  VIDEO_PALETTE_RGB24     24bit RGB
               5  VIDEO_PALETTE_RGB32     32bit RGB
               6  VIDEO_PALETTE_RGB555    555 15bit RGB
               7  VIDEO_PALETTE_YUV422    YUV422 capture
               8  VIDEO_PALETTE_YUYV
               9  VIDEO_PALETTE_UYVY
               10 VIDEO_PALETTE_YUV420
               10 VIDEO_PALETTE_YUV411    YUV411 capture
               11 VIDEO_PALETTE_RAW       RAW capture (BT848)
               12 VIDEO_PALETTE_YUV422P   YUV 4:2:2 Planar
               13 VIDEO_PALETTE_YUV411P   YUV 4:1:1 Planar
               14 VIDEO_PALETTE_YUV420P   YUV 4:2:0 Planar
               15 VIDEO_PALETTE_YUV410P   YUV 4:1:0 Planar
               16 VIDEO_PALETTE_PLANAR

              (no default, depends on v4l-device)

       -z <value>
              value  images are grabbed and immediately discarded. Only the last image is written
              to the output. This might be helpful if your v4l-device needs to take a  couple  of
              images to auto-adjust to the current light.

       -X     Does  not  fork  daemon  process  and  keeps  vgrabbj in daemon mode in foreground,
              attached to the terminal. Useful for debugging purpose.  Not  available  in  config


       With  the  following  options you can control the hardware settings of your cam - if it is
       supported by your cam. Be aware that these options might break your hardware, as there  is
       no check on what values are available, allowed, and supported by your hardware.

       -W <value>
              Whiteness definition.

       -r <value>
              Color definition.

       -x <value>
              Contrast definition.

       -b <value>
              Brightness definition.

       -u <value>
              Hue definition.


       The following options are available only if vgrabbj was compiled with the freetype library
       available. If you set any one of these  options  on  the  commandline  timestamp  will  be
       enabled with default values for all other options.

       -e     Switches  timestamp  to  be  used  or not. Default is off, but may be overridden by
              config-file, so just try to enable this switch if there  is  no  timestamp  in  the
              resulting image.

       -t <filename>
              The     TrueType    font    to    be    used    for    the    timestamp    (default

       -T <size>
              Set the fontsize to size for timestamp (3-100, default: 12).

       -p "<format-str>"
              Defines the timestamp. format-str can be plain text or any strftime format and  has
              to  be  enclosed  with  '""'  (default: "%a, %e.  %B %Y - %T" - see strftime(3) for

       -P <value>
              Alignment of the timestamp in the image. Possible value:

              0 = upper left,    1 = upper right,
              2 = lower left,    3 = lower right,
              4 = upper center,  5 = lower center

              (default: 1).

       -m <value>
              Defines the blend between font background and image (1-100, default: 60).

       -B <value>
              value pixels will be used as border around the timestamp  string  (1-255,  default:


       There  are  no  options  for  ftp-upload  on  the command line. This is due to the need to
       provide a password which would be visible via the  ps(1)  command.  See  vgrabbj.conf  for
       details  on how to set-up the ftp-upload option.  Additionally, vgrabbj has to be compiled
       with libftp support.


       %F in the archive time-string (year with century) causes memory corruption at  a  pentium-
       machine running vgrabbj (not validated). No further bugs are known at this time.


       vgrabbj.conf(4), strftime(3), ps(1)


       This  manual page was originally written by Michael Janssen <>, for the
       Debian GNU/Linux system and enhanced by Jens Gecius <>.

                                        February  24, 2002                             VGRABBJ(1)