FBGrab

Introduction

FBGrab is a framebuffer screenshot program, capturing the Linux framebuffer and converting it to a png-picture.

Installation

[host] $ make menuconfig 

• then choose fbgrab in:

Usage

• Just do:

# fbgrab toto.png

• Here is the full man page:

NAME
      fbgrab - takes screenshots using the framebuffer device

SYNOPSIS
       fbgrab [options] filename

DESCRIPTION
      fbgrab  reads  the framebuffer device (/dev/fb*) or a dump thereof and saves a PNG image file. You can use it for making screen‐
      shots of of virtually any application, from traditional test applications to your X-windows  desktop,  as  well  as  framebuffer
      applications.

OPTIONS
      -?     print usage information.

      -b bitdepth
             the number of bits per pixel used, optional when reading from device.

      -c console
             specifies  which  console (or virtual terminal - like other people call this feature) to grab. Sometimes this changing is
             faster then the framebuffer is refreshed (especially when grabbing framebuffer apps). If so, you should  use  -C  console
             ... This waits some time before grabbing. You can’t use -s in this case.

      -d device
             specifies  which  framebuffer  device you want to read. If you do not use this option, it takes the value from the FRAME‐
             BUFFER environment variable. If no FRAMEBUFFER environment variable is given or if its value is NULL, then DEFAULT_FB  is
             taken. (see source code), which usually is /dev/fb0.

      -f filename
             Read from from file instead of device, requires that -w (width), -h (height) and -b (bitdepth) are specified.

      -h height
             the height of the frambeuffer in pixels, optional when reading from device.

      -i     turns off interlacing. If you do not want ADAM7 interlacing, you should use the -i option.

      -s seconds
             specifies  how  many  seconds to wait before grabbing. fbgrab does not lock console switching, so you can switch it while
             waiting, if you cannot use -c requires normally that fbgrab is run as root.

      -w width
             the width of the frambeuffer in pixels, optional when reading from device.

TODO
      * Low-end bit depths, eg 1, 2, 4 & 8 bits.

      * Grab just part of framebuffer/file.

      * Companion program fbput that would display a picture in the frambuffer.

      * Better utilization of the PNG-lib, all formats are first converted to 32 bitdepth and then stored as PNG -  hardly  the  right
      approach.

BUGS
      Some framebuffer seams to store the data for one fixed resolution even if the resolution is set to  something  lower.  In  these
      cases the fixed size has to be specified and the picture has to be cut in a separate program afterwards.

EXAMPLES
      fbgrab fb.png

      will take a framebuffer snapshot, or if you don’t have fbgrab at your machine, you can do

      cat /dev/fb0 > framebuffer.dump

      and then

      fbgrab -w 1024 -h 768 -b 16 -f framebuffer.dump fb.png

      to convert it to a picture.

AUTHOR
      Written by Gunnar Monell <gmo@linux.nu>.  Basically a rewrite of fbshot by Stephan Beyer <fbshot@s-beyer.de>

COPYRIGHT (C)
      (C) 2002 Gunnar Monell <gmo@linux.nu>

      (C) 2000 Stephan Beyer <fbshot@s-beyer.de>

      This  program  is  free  software; you can redistribute it and/or modify it under the terms of the GNU General Public License as
      published by the Free Software Foundation; either version 2 of the License.

      This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied  warranty  of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

      You  should  have  received a copy of the GNU General Public License along with this program; if not, write to the Free Software
      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Links

• FBGrab HomePage