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You've had the idea, you've built your emotes, you've put them all together in an animated GIF which you upload for the world to enjoy. The comments start coming in; "Sweet", "Cute", Love it", "Why is it so slow?". All well and good, apart from that last one.
So you take a closer look and either:
So what's the problem? The answer is Stupid Browsers. Simple as that. Our browsers are just rubbish at rendering fast animated GIFs.
An animated GIF file consists of a number of image blocks, each with it's own control block. The control block includes how long (in 1/100s of a second) the image should be displayed before moving on to the next image.
The GIF Programming Reference[1] has this to say about the frame delay:
and
All very simple, the rendering engine should simply wait for the specified delay before moving on to the next image. No exceptions! A delay of 0 should be interpreted as instantly displaying the next image and is of no practical use for creating animations. Some programs, JASC Animation Shop for example, will not allow a 0 delay. As each frame in a GIF can have it's own local colour map, some programs have even used the 0 delay to create static GIFs with more that 265 colours[2].
Imagine a series of animated GIFs that all show a progress bar. These GIFs are identical except for the frame delay. The first has a delay of 1/100 seconds, the next has 2/100, the next has 3/100, etc. When the first bar has finished the second should be half finished, the next only one third finished, etc. If you took a screenshot you should see this:
Sorry, image not available in this news article
So that's the theory. After a number of people had mentioned problems with their animations being slower than they had build them, I decided to investigate and put together a test page containing the GIF progress bars described above. I then loaded this test page into a number of browser/OS combinations to see what happened. What I found was a remarkable example of piss poor programming.
The figures below show screenshots of the test page displayed by various browsers on different platforms (this test page is available here - you may find this test works best if you download it and run it locally).
Sorry, images not available in this news article
If all the browsers followed Safari's example and just stopped making the delays faster then there would not be too much of a problem. If you ask Safari for a delay of 1/100 seconds and it delivers 3/100 then the animation might not be as fast as you wanted, but it will probably be fast enough. However, asking Internet Explorer and the Mozilla browsers for 1/100 and getting 10/100 is a significant problem.
So what delays should you use when animating GIFs? Well never 1/100 or 0; imagine what would happen if one of the popular browsers decided to honour the 0 delay! As over 2/3 of visitors[3] are using Internet Explorer I'd suggest not dropping below 6/100. If you really need to go faster than that (and I have seen a few emotes that were stunning at 2/100 in Firefox) then make it clear on your description what browsers it is suitable for. If you're feeling generous then you could always provide an alternative IE version.
Never, never, never use delays of 0 or 1. Avoid 2 - 5 if possible.
1. GRAPHICS INTERCHANGE FORMAT Version 89a www.w3.org/Graphics/GIF/spec-g…
2. Wikipedia's GIF entry describes True Colour GIFs en.wikipedia.org/wiki/Gif
3. Browser share data provided by leSicilien
The Problem
You've had the idea, you've built your emotes, you've put them all together in an animated GIF which you upload for the world to enjoy. The comments start coming in; "Sweet", "Cute", Love it", "Why is it so slow?". All well and good, apart from that last one.
So you take a closer look and either:
a) you scratch your head and think "it wasn't that slow when I built it"
b) you think it looks fine but other people are still saying it's slow
So what's the problem? The answer is Stupid Browsers. Simple as that. Our browsers are just rubbish at rendering fast animated GIFs.
The Theory
An animated GIF file consists of a number of image blocks, each with it's own control block. The control block includes how long (in 1/100s of a second) the image should be displayed before moving on to the next image.
The GIF Programming Reference[1] has this to say about the frame delay:
Process each graphic in the Data Stream in sequence, without delays other than those specified in the control information.
and
Delay Time - If not 0, this field specifies the number of hundredths (1/100) of a second to wait before continuing with the processing of the Data Stream. The clock starts ticking immediately after the graphic is rendered.
All very simple, the rendering engine should simply wait for the specified delay before moving on to the next image. No exceptions! A delay of 0 should be interpreted as instantly displaying the next image and is of no practical use for creating animations. Some programs, JASC Animation Shop for example, will not allow a 0 delay. As each frame in a GIF can have it's own local colour map, some programs have even used the 0 delay to create static GIFs with more that 265 colours[2].
Imagine a series of animated GIFs that all show a progress bar. These GIFs are identical except for the frame delay. The first has a delay of 1/100 seconds, the next has 2/100, the next has 3/100, etc. When the first bar has finished the second should be half finished, the next only one third finished, etc. If you took a screenshot you should see this:
Sorry, image not available in this news article
The Truth
So that's the theory. After a number of people had mentioned problems with their animations being slower than they had build them, I decided to investigate and put together a test page containing the GIF progress bars described above. I then loaded this test page into a number of browser/OS combinations to see what happened. What I found was a remarkable example of piss poor programming.
- Mozilla's rendering engine seems to have taken the line that, as screens cannot refresh faster than 90Hz, no one will ever use a delay of 1/100. So a 1/100 delay is changed to 10/100. Not what you asked for. Mozilla's answer to the 0 delay is to ignore the specification and use a delay of 10/100.
- Internet Explorer is even worse. Any delay less than 6/100 is changed to 10/100. This is probably based upon the assumption that if 15fps is good enough for cartoons then it's good enough for animated GIFs.
- Opera is the worst of all. Every delay below 10/100 is displayed at 10/100.
- Safari is the best as far as delay cropping is concerned. It does crop below 3/100, but it crops to 3/100, not back to 10/100.
The figures below show screenshots of the test page displayed by various browsers on different platforms (this test page is available here - you may find this test works best if you download it and run it locally).
Sorry, images not available in this news article
Conclusions and Recommendations
If all the browsers followed Safari's example and just stopped making the delays faster then there would not be too much of a problem. If you ask Safari for a delay of 1/100 seconds and it delivers 3/100 then the animation might not be as fast as you wanted, but it will probably be fast enough. However, asking Internet Explorer and the Mozilla browsers for 1/100 and getting 10/100 is a significant problem.
So what delays should you use when animating GIFs? Well never 1/100 or 0; imagine what would happen if one of the popular browsers decided to honour the 0 delay! As over 2/3 of visitors[3] are using Internet Explorer I'd suggest not dropping below 6/100. If you really need to go faster than that (and I have seen a few emotes that were stunning at 2/100 in Firefox) then make it clear on your description what browsers it is suitable for. If you're feeling generous then you could always provide an alternative IE version.
Summary
Never, never, never use delays of 0 or 1. Avoid 2 - 5 if possible.
References
1. GRAPHICS INTERCHANGE FORMAT Version 89a www.w3.org/Graphics/GIF/spec-g…
2. Wikipedia's GIF entry describes True Colour GIFs en.wikipedia.org/wiki/Gif
3. Browser share data provided by leSicilien
).
but I suspect I would have had to shave my head to match the riders 
.
). Some software does not seem to support comments at all (I'm looking at you, Fireworks 
).
Like my new avatar? 
Anyone able to verify that?
I tried 0.01 and was getting the same result. After reading your thread I tried 0.03, so at least people with safari will get the full effect..and guess what. Mozilla Firefox 2.0.0.4 renders 0.03 second delays!!!
mytest [link]
offtopic: if anyone knows the author of the original sexy robot girl picture, please let me know!
How about artists like =sereneworx though? His emoticons seem to be utilizing a fast animation speed without too many problems on Firefox (and perhaps Internet Explorer). Is it a similar situation with the Peacock Display emote?
In any case, great job *humpy77, yet another great article!
If you let me know which of your animations you're having this problem with (and what browser you're using) then I'll see if I can spot any problems.
I have noticed, however, that when I use Adobe ImageReady, my uploaded emotes move as fast as they do when I optimize and save them as GIFs, which is the speed I want them to be.
I've watched both your GIFs in FireFox 2, IE7 and Jasc Animation Shop and they all ran at similar times (with the browsers running a little slower than JAS).
It sounds as if Fireworks may be running slower than it should. You could try a little test by building an animation that has something like 100 frames with a 0.10 second delay. This should loop every 10 seconds so you could time how long it takes in Fireworks. You could also try asking some people who use Fireworks if they've seen the same problem.
Hope this helps
I really appreciate the help and advice! Thanks!
and also its worth noting that older versions of internet explorer play all gifs on the same page at the same framerate (I dont know how it decides what framerate, but its usally pretty crap)
I'll bet those older IE versions were chopping at 0.10.
Anyway, stuff it all! I'm starting to think that Flash is needed for anything that wants fast, accurate timing.
this is as most animations and stuff in flash is rendered in realtime, so the performance between differnent computers can vary much more than gifs in browsers.
like all things you just have to balance it all out, if you want to be really sly though you make the animation first, and just put the frames in flash, but then you have to play with your compression...
hmmm, one day you think they will make something that is surefire?
Well, animation rendering engines aren't exactly a competitive field so I'd guess there's not much development happening. For example, the MNG specs have been out for 6 years and got nowhere. The GIF format should be fine (for small scale work) if the developers bothered to follow the standard. Flash is probably the way forward as it's come from one source that produces it's own (reasonably consistent) implementations.
Good investigative work.
So the rule would be;
Never, never, never "no delay" or 0.01. Avoid 0.02 - 0.05 if possible
The alternative option would be to use swf. Adobe are claiming that 98% of web users have Flash Played installed ([link]) so this is now a viable option. You just have to have a look at something like Bertie ([link]) to see how good flash can be.