[Mediawiki-l] Animated Gifs

[Dan Nessett]

On Sun, 24 Oct 2010 15:40:36 -0400, Tim Starling wrote:

> On 22/10/10 17:35, Dan Nessett wrote:
>> We are upgrading to 1.16. One of the things we would like to do is
>> support animated gifs. Unfortunately, there is a surfeit of information
>> about this issue, but nothing I have read so far gives a clear
>> guideline how to go about providing such support. The history of this
>> issue is found in at least the following places:
>> 
>> A Village Pump thread:
>> 
>> http://commons.wikimedia.org/wiki/Commons:Graphics_village_pump/
GIF_thread
>> 
>> Some bug tickets, specifically:
>> 
>> https://bugzilla.wikimedia.org/show_bug.cgi?id=22041
> 
> That is a Wikimedia sysadmin issue and does not apply to other
> installations.
> 
>> https://bugzilla.wikimedia.org/show_bug.cgi?id=23063
>> https://bugzilla.wikimedia.org/show_bug.cgi?id=23063
>> 
>> While the first ticket is marked resolved/fixed, the latter two (which
>> cover the same or at least a very similar issue) are marked new. The
>> last entry in the 3rd bug ticket is dated 2010-05-08.
> 
> That is two copies of the same link. See below for a discussion of it.
> 
>> So, I wonder if anyone is able (and is willing) to supply the following
>> information:
>> 
>> + The version of imagemagick that we should install for animated gif
>> support.
>> 
>> + Whether 1.16.0 is sufficient for non-buggy animated gif support.
>> 
>> + Is there any configuration required for animated gif support, other
>> than setting $wgMaxAnimatedGifArea?
>> 
>> + Is there anything else we need to do to support animated gifs?
> 
> MediaWiki and ImageMagick have both supported animated GIFs since
> forever. You don't need any special version.
> 
> The recent problems with animated GIFs at Wikimedia were related to
> changing usage patterns, specifically an increasing tendency to convert
> large videos into animated GIF format. ImageMagick handles large
> animated GIFs in a very inefficient way. This led to several new
> resource limit features being developed, in order to provide more useful
> and stable error messages, as opposed to letting ImageMagick hit a
> memory or time limit.
> 
> If your users stick to using animated GIF in its traditional
> applications, e.g. MySpace-style sparkling flourishes and looping
> diagram animations, then you should have no trouble. If your users wish
> to convert hours of MPEG video to animated GIF format and have it scaled
> by your servers, then your choice of MediaWiki version and resource
> limit configuration will determine what sort of error message the users
> see. Ideally, this should be an informative "image too large" error,
> rather than a browser timeout because the server has gone into swap and
> died.
> 
> -- Tim Starling

Thanks for the information. We are currently running 1.13.2 and have had 
to ask our users to stop uploading animated gifs, since they brought our 
servers to their knees. So, I think we are in a similar position to that 
Wikipedia found itself until recently.

Would you be willing to tell us what version of Imagemagick you use?

Dan Nessett


-- 
-- Dan Nessett