[LAD] [LAA] announcing envy24control, mudita (*) edition.

[Niels Mayer]

On Wed, Jul 28, 2010 at 3:40 PM, James Morris <james at jwm-art.net> wrote:
>> Also, you mentioned there was a problem with CPU usage and sluggish
>> response. I haven't heard of any other complaints along these lines,
>> so i'm wondering if you did something to resolve the issue, or if you
>> might be able to do some more debugging:
>
> No, I've not resolved the issue. I could do some more debugging though.

No need....

> Yes, the CPU usage is from envy24control. Somehow, strange as it
> sounds... The higher the volume, the higher the CPU usage... Or, if
> the audio output is continually loud, it seems to overload the meters
> and CPU usages rockets.

I've reproduced and fixed this problem. It had to do with a strange
"Gtk-oscillation" in UI sizing that would happen whenever label
"0dBFS" would get drawn into the digital mixer meter pair (which would
of course occur with louder signals :-) ). Lesser (or at least more
computationally tractable) oscillations within the pane of
sliders&meters might also happen, but the "earthquake" caused by the
digital mixer panel on the LHS resizing had an interesting "feedback
loop" that would take quite a while to "settle out" event-wise.

I fixed by using the label "0.0dB" which is shorter and doesn't cause
resizing. The weird thing is that oscillation would somehow manage to
also do the equivalent of clicking "reset" -- allowing the jiggling to
recur repeatedly every time a new peak hit. Normally, if 0dB was hit,
and another 0dB peak came along, nothing would happen as nothing
needed to happen UI-wise. I'm pretty sure the only time I ever saw
that kind of behavior was a Gtk program that had written past some
important arrays (memory corruption -- and a particularly nasty way of
triggering it via Gtk).

Strangely, this problem was not visible  on a 4-core AMD Phenom II box
with on-board ATI graphics. But on a two-core AMD Opteron 1220, with
NVidia onboard graphics, it was reproducible.

It's kind of an interesting looking effect. Like when you start
hitting 0.0dB on the mixer, the entire UI starts shaking around like
it's having an earthquake. But only when it's loud.  Clearly an
extension of this feature should be added to window managers: shake
the window of your DAW whenever you clip inputs  or outputs on your
soundcard. :-)

Also, after seeing your snapshots with the "dark" background graphics,
I decided to let a gnome style pick a pair of contrasting colors for
me. so now I'm using the following foreeground/background pair:
	widget->style->text_aa[GTK_STATE_ACTIVE]
	widget->style->text_aa[GTK_STATE_PRELIGHT]
(the L/R meter pair for the digital mixer pair are the same color as
all the other meters)

Comments on this approach? The color choice is truly milquetoast now!
But also visible, soothing & functional:

http://nielsmayer.com/envy24control/Screenshot-Mudita24-rc0-MonInp.png

- Niels
http://nielsmayer.com