Capture parts of your screen to single files for every frame. This could be used as input for e.g. a MPEG encoder. I use this package to grab frames of my running XtTV program, which uses the bttv video/TV card driver for bt848-based cards.

This program does not use a special hardware driver to access the video card. It just asks the X server about rectangular areas. This means you need a fast machine (>= 133 MHz) and a fast harddrive. Big frames (e.g. 384x288 = 1/2 PAL) at a high FPS rate are only possible with very very fast systems :-) but this program may also work on non-Linux systems.. try it.

Warning: this is an unstable beta release! Bug reports would be nice..

Features

• Different frame output formats: XWD, PPM, PNG, MNG and JPEG
• Supported visuals: TrueColor 15 bpp, 16 bpp, 24 bpp, and 32 bpp, StaticGray/8 bpp
• PseudoColor/8bpp and TrueColor/8bpp only for some output formats
• I don't know about DirectColor-visual, may be it works or not ..
• GT: QuickTime support (RGB, JPEG and PNG) for TrueColor 15, 16, 24 and 32bpp.
• Command line arguments could be set by X resources
• Define frames per second (fps) which should be recorded
• Frames could be saved compressed (.gz)
• Set the maximum number of frames which should be captured
• Set the maximum time in seconds to capture
• Usage of the X shared memory extension if the X Server supports it
• Step mode for capturing single frames

Download Source Code, Binary (Linux glibc) and Screen Dump

ftp://ftp.komm.hdk-berlin.de/pub/linux/X11/xvidcap-1.0.9.tar.gz
http://home.pages.de/~rasca/xvidcap/dump.png
http://home.pages.de/~rasca/xvidcap/xvidcap.gz (ldd output)

Additional programs / libraries

For compressed XWD and PPM files you need the zlib, for PNG support you need zlib and the PNG library (0.96 or newer), for JPEG support you need the jpeg library. For viewing the recorded frames as animation the animate program of the ImageMagick package is very handy.

Installation

• Create a Makefile, with xmkmf -a or use the included setup.tcl-tool (which in turn runs the 'configure' script)
• Compile the source code with make or via the setup.tcl-tool
• Install the program with make install or use setup.tcl

Todo

Support for other visuals/bit depths. Disable Shm if client and server are not running on the same host. Support for saving the settings in the options dialog window and fixes in Field.c. Support for Video4Linux, sound support.

Tips and hints

Disabling backing store (-bs) at the Xserver gives better (faster) results on my system. Don't ask me why, I don't know about X server internals. Perhaps it's only imagination :-)
I think the XWD output is the fastest one. If you use compression it will slow down the capturing. Compressed PPM seems to be faster as PNG with the same compression level and produces also smaler files.

A patch for xanim 27070 is included to make xanim happy to accept big movies created with xvidcap.

Documentation

Have a look at the man-page of xvidcap.

Resources

ImageMagick, this package contains the program 'animate'
XAnim, X11 animation program to play QT files
Berkeley's, MPEG2 encoder and decoder
zLib, the well know compression library
PNG, portable network graphics
bttv, a Linux driver for Bt848 based frame grabbers
JPEG, a free JPEG library

Related Projects

XMixer
XtTV
w3Cam

It's GnuTime

---

rasca, 05. Feb 1999 - 17:35