Re: [Stella-main] Sound problems with stella.x11 & .sdl, stella 1.3

[Stephen A. <ste...@ro...>]

On March 20, 2004 09:14 pm, Thomas Boutell wrote:

> > Sound seems to be broken for some people with the 1.3 release.  I'm
> > in the process of rewriting it for Stella 1.4.  Other than that,
> > I'm sorry that there is no immediate solution.  I know the problem
> > (somewhat), but the solution is harder to fix that I originally
> > thought.
>
> Interesting. I just tried 1.2. The game runs at proper speed,
> but stella-sound has trouble; the sound is intermittent and
> not really usable as it doesn't sync with the game. Oh well,
> back to 1.3 without sound.

Yes, the problem has always been with the sound synchronization, not the 
actual generation.  In Stella 1.2, the sound code was external 
(stella-sound).  This made sound sync impossible.  The idea with Stella 
1.3 was to make the sound internal.  That is, we integrated the sound 
into the core code.  But since this was basically a first try, it 
didn't work out so well.  Also, the sound code isn't tied closely to 
the framerate, so if the computer is too slow and the framerate drops, 
the sound will become scratchy, instead of simply slowing down.

My plan is to make the sound scanline accurate, which will then work at 
whatever framerate is used.  And since the sound will be tied to 
scanline generation, it will be as synchronized as is technically 
possible.

The initial plan was to release Stella 1.4 with the sound partially 
broken, and fix it for Stella 1.5.  But since the 1.3 release actually 
is *worse* on Linux kernel 2.6.x as compared to 2.4.x, I decided to 
hold off until I get it working right.

> Maybe my sound card is just too awful for your needs? It does
> work fine with two other games (Ur-Quan Masters, and one
> of my own which is using SDL sound).

No, it's only emulating a 31400 Hz signal in mono mode, and even an 
ancient ISA card could do that.  The emulation itself only uses 4-5% of 
total CPU, so it's not CPU-bound either.  As I said above, this is 
strictly a _timing_ issue.  

> > > USB trackballs attached as game controllers
> >
> > I'd be interested in getting this patch, as multiple paddle
> > controllers are something that quite a few people have requested...
>
> I'll be sure to share it. Not sure you'll want it in the
> form I've got it: I'm reading directly from /dev/mouse*
> devices, which turns out to be well-documented and easy
> to do, whereas extra pointer devices in X itself are
> a pain at best.

Any form is fine, as I would use it for ideas moreso than code (unless 
it can be dropped into place with minimal work).  One question though; 
are you using it with the X11 or SDL version?  The next (and all 
future) releases of Stella will use SDL only.  The DirectX and X11 
ports have been discontinued due to lack of developers (Windows users 
needn't worry, as the SDL version will work there as well).

Is it possible to adapt this code to work in SDL?  Are the trackballs 
'seen' by SDL?  That is, do they show up if you call 'SDL_NumJoysticks' 
and later open them with 'SDL_JoystickOpen'?  If they are seen, then it 
becomes quite easy to add multi-platform support for them.  If not, 
then it becomes much harder :)

Steve