GIF Animation - what affects speed?

[tedster]

I'm having a frustrating time with a new animated banner I'm designing. It seems to run very slow on some systems, even new ones. Yet it runs fine on an old 133. The whole file is only 5kb, but it does contain about 70 separate frames with inconsistent timing -- ranging from 3/100 of a second to 3 seconds.

I remember that older browsers used to freak at any speed under 10/100 of a second per frame, but that went away a while ago, I thought. I also think I've seen that Macs tend to run faster than PCs, but I'm not really sure on that one.

So what kinds of things do affect the running speed of animated GIFs?

[mivox]

I would think, once the animation has finished downloading, it would have to be a combination of the browser and operating system... You'd have to have a really old, *slow* computer for processor speed to be an issue, I'd think.

Anyone familiar with how browsers are programmed to handle animations?

[Air]

This [members.aol.com] link might be helpful (although it is getting a little dated), there is a lot of info on GIF89a there.

One possibility Tedster is the cache of the browser, if it has been set to always retrieve new page (or image) and therefore doesn't cache, it could affect the speed of the frames (just a guess).

[tedster]

Thanks for the link, Air. What trip down memory lane -- all those old inconsistencies with looping, first frame, final frames, etc. That page brought up the issue of browser overhead -- mayube that's it.

Although I haven't struggled with that one for a few years, it just might be the problem here. The total file size is small, but there are enough separate frames to cause problems in some browsers.

Well, at least that's my theory -- but I still don't really understand what I'm up against. Maybe I've discovered why I never see this particular effect in banner ads. I thought I was being innovative, but the results just don't work.

Oh well, back to the drawing board.

[mivox]

I hate it when that happens... you get the coolest idea, and because of technology limitations, it just won't work.

As far as animation/banner design goes, I think Flash has serious potential, as soon as banner programs and browsers universally support embedding small Flash objects in HTML pages.

Would Flash be a possibility for the banner you're working on?

[tedster]

Yes, I thought about using Flash here. But I'm still a novice with it, and the file size became too big using the techniques I know.

I'll probably study up a bit and give it one more try in Flash. Thanks for mentioning the idea.

[tedster]

A little update: it seems that this animated gif banner ad was only problematic on laptops -- and the only way I can make sense of that fact is assuming that graphics cards for LCD screens have trouble handling either a high frame count or lots of timing changes in an animated GIF. Does that make any sense?

Anyway, I experimented and found a way to cut the total frame count from 70 to 50 and eliminate most of the timing changes. Now everyone is happy with the results -- the new version runs at normal speed on both laptops and desktops.

This was a strange one and I'm still far from certain I understand what I ran into. Sometimes you can't figure out what's wrong, you just have to make it work.

[mivox]

I would assume it must be the LCD... you figure that a CRT screen has more or less constant movement/refresh with the color guns, but the LCD screen only redraws the image when it actually changes... if only one small part of the image was changing, it could possibly cause a hiccup.

Thanks for the accidental tip, Tedster! Next time I have to design a banner, I won't assume that my CRT is the last word in rendering.

(One more good excuse for buying a new Mac titanium laptop... :) )