Problems with framerate - only in browser

Question

I'm seeing an odd problem with my framerate in Flash, and I'm wondering if anyone here has seen something similar.  (Sorry if this is a duplicate post - This feels significant enough that I'm positive I'm not the first one to ask about it, but checking the search, all I was able to find were threads over 2 years old, which didn't look related.)  So here goes:
I'm working on a fairly interactive swf, and am noticing that the framerate appears FAR more choppy when I view it in a browser window than I do if I run it through the debug environment or as a stand alone player.
Here's my situation:
My movie's framerate is 30 fps.
Running it in the Dev environment, the flash player, or in a standalone player all runs fine.  Perfectly smooth.
Running it in a web page, it looks very choppy.
According to the MOVIE, it is running at full speed.  (I have a framerate counter in the corner, and even in a web browser, it never wavers.)
(Here's where it gets weird) If you move the mouse over the movie.... just move it, doesn't have to click or anything....then as long as you are actually MOVING the mouse...  the framerate turns normal.  So if you're willing to sit and constantly move the mouse, it plays normally.
So.  What does this mean?  Well, the short term answer is that my swf runs choppy unless someone sits and keeps the mouse moving at all times.  But beyond that, it looks like it means that the flash player in a browser window behaves very oddly.  the CPU can obviously keep up with my movie, since when I move the mouse around, it goes at the intended speed.  It seems like it just isn't updating as fast as it is telling Flash it is updating.  Or rather, it is letting the Flash virtual machine hum along at whatever speed it wants to think it is running at, but is only bothering to actually update the window on its own schedule, or when it receives a mouse event?
I've uploaded a simple test file (and html page) as an attachment here.  On my machine, at least, there is a very noticable difference in how smooth the box's movement is, depending on if you are moving the mouse or not.  All of my tests are being performed under the latest version of FireFox (3.0.11) and using the latest flash player plugin.  (10,0,22,87)  The swf was built using CS4, etc.
Does anyone have any experience with this?  Has anyone seen this before?
Part two of my question of course is "how do I fix it?"  Is there something I can do in my html file to force the plugin to update more frequently, so that none of my precious, precious frames are lost to the user?  Better still would be if there were something I could do in my swf file to make this happen?
Anyone know of such a thing I could do?
Thanks

Answer 1

Hi Mathonwy,
As you probably know, the swf speed will depend on many factors: the computer's strength, what browser is being used (some take up more juice than others), what else is running at the same time, etc. It is always slower than when swfs are ran from the stand alone player.
However, this thing you are experiencing with "moving the mouse" is indeed weird, since it should be the opposite, meaning that moving the mouse actualy takes up some juice, a tiny little bit.
It is sad I cannot load your attachment right now (????)
Could you also put a link?
Design Cyboïde
Création de sites web Montréal