I'm not sure that all the changes Adobe has done for Flash 10.1 will leave
OpenLaszlo and LFC unaffected, since throttling down to 2 fps is quite a
change for the whole application. Has anyone done some testing?

On Sat, Sep 4, 2010 at 5:47 PM, Raju Bitter <
[email protected]> wrote:

> There has been major change in the way Flash handles timing for the 10.1
> release of Flash Player for desktop browsers as well:
> http://www.kaourantin.net/2010/03/timing-it-right.html
>
> In Flash Player 10.1 SWFs on hidden tabs are limited resource wise. Whereas
>> they would run at full speed in Flash Player 10.0 and before (note though
>> that we NEVER rendered, we only continued to run ActionScript, audio
>> decoding and video decoding), we now throttle the Flash Player when a SWF
>> instance is not visible. Doing this change was not easy as I had to add many
>> exceptions to avoid breaking old content. Here is a list of some of the new
>> rules:
>
>  Visible:
>
>
>>    - SWF frame rates are limited and aligned to jiffies, i.e. 60 frames a
>>    second. (Note that Flash Playe 10.1 Beta 3 still has an upper limit of 120
>>    which will be changed before the final release)
>>    - timers (AS2 Interval and AS3 Timers) are limited and aligned to
>>    jiffies.
>>    - local connections are limited and aligned to jiffies. That means a
>>    full round trip from one SWF to another will take at least 33 
>> milliseconds.
>>    Some reports we get say it can be up to 40ms.
>>    - video is NOT aligned to jiffies and can play at any frame rate. This
>>    increases video playback fidelity.
>>
>>   Invisible:
>
>
>>    - SWF frame rate is clocked down to 2 frames/sec. No rendering occurs
>>    unless the SWF becomes visible again.
>>    - timers (AS2 Interval and AS3 Timers) are clocked down to 2 a second.
>>    - local connections are clocked down to 2 a second.
>>    - video is decoded (not rendered or displayed) using idle CPU time
>>    only.
>>    - For backwards compatibility reasons we override the 2 frames/sec
>>    frame rate to 8 frames/sec when audio is playing.
>>
>>   Check the screenshots at the bottom of this blog post, where you see
> memory usage and cpu load or an SWF running in a visible and, and an
> invisible tab.
> CPU load goes down 13 from 42, memory usage goes down to 80mb from 250mb.
>
>
> On Sat, Sep 4, 2010 at 2:48 PM, P T Withington <[email protected]> wrote:
> > On 2010-09-04, at 06:45, Raju Bitter wrote:
> >
> >> Is there code inside the LFC which will run into problems with such a
> >> low framerate? Could objects be destroyed in such a case? How would
> >> you handle such a situation within an OL app?
> >
> > OL does expect to be able to set the player framerate for media playback;
> but from what you say, this is _not_ affected when media is playing and you
> are backgrounded.
> >
> > OL also has an abstract notion of framerate that corresponds to the idle
> polling rate, pretty much for legacy reasons.  Depending on how the player
> implements interval timers, it is possible that OL will defeat the attempt
> to lower the framerate when the applications is backgrounded (since it
> installs an interval timer callback at the canvas or default framerate).
>  Maybe the player takes the liberty of adding jitter to the interval timer
> when backgrounded automatically.  If not, then the OL kernel should take
> notice of these deactivate events and 're-nice' itself appropriately.
> >
> > [IWBRN if all players did this -- it drives me nuts when a window I have
> left open in my browser that is totally obscured still sucks up 30% of my
> CPU running an animated flash advert.]
>
>

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