real time sound

[S. Gongola]

I mostly pipe everything through SDL. mplayer works through SDL, and most 
games use SDL. Like when I'm playing a shooting game when I press fire, I 
hear the shooting sound about a second later. Can I do anything to SDL to 
give it realtime priority?
And what about artsd. When I click the run with realtime priority check-box it 
doesn't do much?


On Sun March 21 2004 05:59 am, Tom 'Needs A Hat' Mitchell wrote:
> On Sat, Mar 20, 2004 at 09:04:10PM -0500, S. Gongola wrote:
> > It seems like I can only get real time sound without a delay when I'm
> > logged in only as root. How can I get real time sound when I'm logged in
> > as a user. What device permissions do I need to change, or adding the
> > user to a certain group can solve the problem.
>
> If the delays are not an issue for 'root' and they are for you when
> you are a normal 'user' then the issue is real time scheduling (or are
> you doing more stuff).
>
> You did not indicate which player you are working with.
>
> For xmms there is a config option "Use realtime priority when
> available".  But "realtime priority" is restricted to root.  N.B. with
> real time scheduling it is possible to apparently lock up a system.
>
> Anyhow RTS it is not available to mortals.  So....
>
> First increase the buffer size.
>
> Next perhaps open a window for a "su/su -" shell and run it there.
>
> If 'root' is not an option the next trick is a bit more complicated.
> Since xmms can browse, read and write files there are risks!
>
> If you know, understand and trust xmms AND it's plugins build a
> helper...  If you try marking xmms SUID=root and run it from a shell
> prompt you will see this helpful hint that might apply to any player
> that has RTS system calls coded in it:
>
>     Gtk-WARNING **: This process is currently running setuid or setgid.
>     This is not a supported use of GTK+. You must create a helper
>     program instead. For further details, see:
>
> 	http://www.gtk.org/setuid.html
>
>     Refusing to initialize GTK+.
>
> Good luck.
> mitch
>
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