[mythtv] [mythtv-commits] Ticket #7525: Optimize Pulse handling in MythUI

[Gavin Hurlbut]

On Thu, Aug 26, 2010 at 3:05 PM, Jim Stichnoth <stichnot at gmail.com> wrote:

> One could globally reduce the pulse rate from 70Hz and get a
>
proportional drop in CPU use, but then some transition effects will
> look strange.
>

I'm not sure how 70Hz was ever decided on, but really, we only need to
refresh effects at most at the same rate (or maybe slightly faster?) that we
refresh the display.  When running at 1080i output, we are only refreshing
the screen 29.97 times a second.  Why on earth are we refreshing the screen
contents over twice as fast as we are displaying it?  That's just wasted CPU
spin.

I would suggest that we change the pulsing (assuming this is even
technically possible) to happen at 24fps at the fastest (film rate).  I
don't see any particular purpose to making it faster than that.  I'm sure
the average user wouldn't even be able to tell the difference visually.

One could also patch alphapulse to update only every few ticks, which
> would make alphapulse less smooth but not affect anything else.


It would be no less smooth, I would expect... if you updated every other
tick at 70Hz.  It may not even be noticably different at 1080i as BOTH are
refreshing faster than screen updates anyways.

Or am I missing something here?

Anyways, I don't know if I'll have time to mess with it much before 0.24
release anyways, but I may just resort to locally disabling alphapulse
completely if I can't find a better way.
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