Animated GIFs Play Differently in Versions of PowerPoint

 

An animated GIF has two settings in its header, a "loop flag" and an "iteration setting". The loop flag can have a value of 0 or 1, and a 1 indicates that the GIF should be looped. The iteration setting indicates how many times the GIF should be looped.

If loop=1 and iteration=0, the GIF will loop endlessly. In most software, if loop=0 the GIF will play the number of times indicated in the iteration setting. However, in PowerPoint 2003 a loop value of 0 will cause the GIF  to not animate at all, regardless of a non-zero value in the iteration setting.  In PowerPoint 2002 a loop value of 0 will result in the GIF animating once, regardless of the value in the iteration setting.  In PowerPoint 2000, all animated GIFs loop continuously, regardless of the loop and iteration settings.
 

If your animated GIF won't play in PowerPoint 2003 it may be that the loop flag is set to zero.  You can easily correct this.  Download and install the trial version of GIF Construction Set and open your GIF file in it.  Double click on the first "block", 1:HEADER.  At the bottom of the dialog check the Loop box and set the number of iterations to your choice (1-99).  Save the file with a new name.  Insert it in your presentation and test it in Slide Show mode.
 
The problem in PowerPoint 2003 was discovered as the result of extensive testing.  If you would like to see and understand my test results, read on:
 
  I created 8 versions of the same animated GIF, varying the values of the loop flag and the iteration setting.  Then I played each of them in PowerPoint 2002 and 2003 presentations and opened the GIF files in Internet Explorer and Netscape.  The results of my testing are summarized in an Excel table and each of the test files are available below for your own testing.

See Test Results

(depending on your browser, you may need to right click and select "Save Target As".
 

See what the files look like in your browser:

(Click on the image on the pages below to download and test in the file PowerPoint or other software)
 

Loop = yes, Iterations = 0 (loops continuously in all applications)
Loop = yes, Iterations = 1
Loop = yes, Iterations = 2
Loop = yes, Iterations = 5
Loop = no, Iterations = 0
Loop = no, Iterations = 1
Loop = no, Iterations = 2
Loop = no, Iterations = 5
 



All contents Copyrighted by Sonia Coleman 1998 - 2004