MultiGIF is a cross-platform utilty for creating animated GIF images. Given an initial set of GIF images, you can use MultiGIF to combine them into a single multi-image GIF file. When viewed with a web browser such as Netscape Navigator V2.0+, these images will appear sequentially as frames of an animation.
For further information on GIF animations, check out Royal Frazier's excellent information and tutorial pages.
PC executable, source code archives and samples are available from the download page.
MultiGIF is shareware for personal use. Individuals may use MultiGIF free of charge for an unlimited period. If you find you are using it a lot, enjoy it, find it useful or of any other value, you may wish to make a donation to the author to show your appreciation. If you find yourself using MultiGIF in anything that makes you money (such as web design), then you should make a donation if only to keep your conscience in check. An amount of 20 UK Pounds or equivalent is suggested, but any amount, large or small would be appreciated.
Commercial, government or institutional users must register MultiGIF for 20 UK Pounds or equivalent per copy in use. Site licenses are available for multiple users. Contact the author for more information.
Source code for MultiGIF is available and may be distributed freely for non-commerical purposes. You may compile, and distribute freely, unmodified versions of MultiGIF. You may not make any charge for MultiGIF (except for a small copying fee) without the express consent of the author.
You may modify MultiGIF for your own use but you may not distribute modified versions of the source code, or modified binaries, without the express permission of the author. However, you may reuse source code from MultiGIF into your own programs, providing this stays within the realms of "reasonable use" with the following conditions:
"Reasonable use" is admittedly a fuzzy term but you should be able to realise where the boundary is. If you want to reuse the GIF input/output routines or the command-line parser, for example, then that's fine as long as the conditions above are followed. If you find yourself doing more cutting and pasting that actual coding, then perhaps it's time to stop and have a little re-think.
In the spirit of sharing, I would like to see people get the most they can from the source code and hopefully pass something on for others to benefit from. I don't want to see someone benefit (either financially or by taking undue credit) for something that essentially isn't their own work. The little recognition we get for our work is often all there is.
If you have any questions or requests, just ask. Details at the end.
MultiGIF is invoked as a command line utility. You can specify options as command line parameters or create a command file and pass the option "@filename" to MultiGIF. You can freely mix commmand line parameters and command files.
For example, if you have a file called "prm" with the following contents:
-b 0 -c "This is a comment"
-g 4
then running MultiGIF as follows:
multigif @prm
is exactly the same as if you had typed:
multigif -b 0 -c "This is a comment" -g 4
You can also add further options to the command line:
multigif -o outfile.gif @prm -v foo.gif bar.gif baz.gif
Command line options may, or may not, have spaces between the command letter and value. i.e. "-ooutfile.gif" is the same as "-o outfile.gif". Options specified in a command file may appear on the same, or on different lines. Options may be stated in any order.
Be warned that some parameters will need to be quoted ("") to avoid problems. For example, a comment with spaces will need to be quoted to prevent the parser from thinking that the seperate words are additional paramaters:
-c "This is a comment" NOT -c This is a comment
Also note that parameters containing certain characters (e.g. '*' and '?') may need to be quoted to prevent the shell interpreting them.
The basic usage of MultiGIF is as follows:
multigif [options] files (or multigif @paramfile)
This will create a multi-image GIF from the files specified, using all default parameters. e.g.
multigif foo.gif bar.gif baz.gif
The following options are available. This table can be reproduced by invoking MultiGIF with the help (-h) option:
-b colour Background colour index (default: 0)
-c "comment" Add comment to output GIF file
-g frame Use palette from as a global palette (default: 1)
-n count Add a Netscape loop of iterations
-o file Output file name (default: multigif.gif)
-d "n:n:n..." Delays (1/100s) for each frame. Frame repetions may be
specified as "d*r" - delay for frames
-r "n:n:n..." Replace modes for each frame, specified as above
0/1 - None, 2 - Background, 3 - Restore
-x "n:n:n..." X position of frame (default: 0), specified as above
-y "n:n:n..." Y position of frame (default: 0), specified as above
-l "f,f,f..." List of frames to have a local palette. Range: "a-b"
-u "f,f,f..." List of frames to require user input
-v Verbose mode
-h This help
e.g.
multigif -b 5
e.g.
multigif -c "Cool Fire (C) 1996 Andy Wardley"
e.g.
multigif -g 2 a.gif b.gif c.gif
In this example, MultiGIF will use the global palette (or local palette if it has one) from image 2 (b.gif).
MultiGIF, when invoked with the -n option will add a Netscape specific Application Extension Block to the output GIF file which tells Netscape Navigator to repeat the animation a number of times. Note that Navigator version 2.0 ignores this value and loops indefinately but the repetition count is supported in versions 3.0+. A loop count of 0 indicates an indefinite loop, although this is not recommended.
Note also that Netscape Navigator only repeats the image if the cache is enabled (Options|Network Preferences|Cache) to avoid reloading the image across the network.
e.g.
multigif -n 25
e.g.
multigif -o coolfire.gif
Delays should be specified for each frame, seperated by colons (:). Empty values, or values for frames not specified will default to 0. To specify the same value for a number of frames, use the "delay*rep" syntax. For example, to indicate a delay of 0.25s for 5 frames, you would specify "25*5".
e.g.
multigif -d "100:25*3:200" a.gif b.gif c.gif d.gif e.gif
The image a.gif (frame 1) will have a 1s delay, b.gif (2), c.gif (3) and d.gif (4) will all have delays of 0.25s and e.gif (5) will have a 2s delay.
The replace modes are specified as a number in the range 0-3. These numbers indicate the following modes:
| 0 | Not Specified | No action (image is left on screen) |
| 1 | None | No action (image is left on screen) |
| 2 | Background | Image is replaced with background colour or image. |
| 4 | Restore | Image is replaced with previous contents of the image area. |
Note that option 3 (Restore) where the image is replaced with the saved contents of whatever it was displayed over, is not yet supported on any known web browser. Images with transparent colours may have problems when displaying over previous images if the image underneath can be seen through the transparent areas. Until this is supported in browsers, the only solution is to use Background mode, or insert a frame restoring the previous screen contents.
e.g.
multigif -r "0:2*3:0" a.gif b.gif c.gif d.gif e.gif.
In this example, images a.gif and e.gif (frames 1 and 5) will be left on screen and b.gif (2), c.gif (3) and d.gif (4) will be replaced with the background colour or image.
Note that the total image size will be as large as is required to place all images in their entirety. This avoids a bug in Netscape which occurs when an image, or part of an image, is positioned outside the "global" GIF area specified in the image header.
e.g.
multigif -x "0:48*3:50" -y "0:24*3:60" a.gif b.gif c.gif d.gif e.gif
In this example, a.gif (frame 1) is positioned at XY 0,0, b.gif (2), c.gif (3) and d.gif (4) are all positioned at XY 48,24, and e.gif (5) is positioned at XY 50,60.
e.g.
multigif -l "1,3-5" a.gif b.gif c.gif d.gif e.gif
Local palettes would be used for the frames built from files a.gif (frame 1), c.gif (3), d.gif (4) and e.gif (5). The image b.gif (2) would use the global palette which would, by default, be the palette taken from the first frame (a.gif).
e.g.
multigif -u "1,3-5"
MultiGIF maintains the transparency and interlace conditions of source files as is incorporates them.
The image size of the resulting GIF file will be as large as is necessary to fully incorporate all source images.
Options specified for frames that do not exist (e.g. specify delay values for 5 frames, but only provide 3 source GIF filenames) will be ignored.
The use of the colon (:) and comma (,) to seperate frame flags and lists in command line parameters is interchangeable.
MultiGIF is written in portable C and should compile without problem with any ANSI-compliant C compiler. A Makefile is provided for your convenience. Edit the Makefile to set any options (see the comments in the Makefile) and then run "make".
If you experience any problems building MultiGIF, consult your local man pages first, C (or UNIX/PC/etc) guru next, and finally myself. If the problem is due to a bug in the code or an error on my part, please let me know.
The source archive for MultiGIF also contains a simple utility, GIFInfo, which reads and displays information about a GIF file, including multiple images. Simple run GIFInfo with the filename of the GIF file you wish to examine. e.g.
gifinfo coolfire.gif
MultiGIF was written with reference to the "Encyclopedia of Graphics File Formats" by James D. Murray and William vanRyper, 1994 O'Reilly and Associates, ISBN 1-56592-058-9.
Thanks to Royal Frazier for his GIF Animation tutorial pages.
MultiGIF was written by Andy Wardley.
Please contact me (preferably by email) if you have any comments, criticisms, suggestions or even praise!
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