[linux-audio-user] [ANN] jack_oscrolloscope 0.1

[Fons Adriaensen]

On Tue, Nov 21, 2006 at 09:01:53PM +0100, Dominic Sacré wrote:

> On Tuesday 21 November 2006 18:50, Fons Adriaensen wrote:
>
> > It comsumes a lot of CPU if you use many channels.
> > On my 2 Ghz P4, 16 channels take 94%. Almost all of this
> > is taken by X11, which indicates that there's something
> > strange.
> 
> I assume you're using SDL. If you can, try OpenGL, that should take most 
> of the work off the CPU.

Rather the opposite, see below.
 
> Another thing you could try is to change both occurences of SDL_HWSURFACE 
> in video.h to SDL_SWSURFACE. Does it make any difference? On my machine 
> it doesn't, so I wasn't sure what to use.

It does help a bit, but not with -g:

       |           -g
    ---------------------
    HW |   33%     94%
    SW |   22%     93%
 
> Also note that currently, even in non-scrolling mode, jack_oscrolloscope 
> redraws the whole window on every frame, because was easier to implement. 
> Changing that is somewhere on my todo list :)

Probably something you should do. I've got an almost identical app
(Yass - not yet released). With 100 updates per second, 32 channels,
and the maximum scrolling speed it takes less than 1% of available CPU.
So it's definitely not X11 taking all the time.

-- 
FA

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