real time sound

[thedogfarted]

S. Gongola wrote:
> 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?

I had similar issue when i switched from oss to alsa (via mobo with 
onboard sound, 2.4.22-1.2174.nptl kernel). Look at the logs, there sould 
be a few lines at the sound card initialization that asks you to set an 
option for the driver. I tried one and now there are no more delays. 
(I'm not at my box now so i can't tell you exact name and value of the 
option)

> 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
>>
>>--
>>	T o m  M i t c h e l l
>>	/dev/null the ultimate in secure storage.
> 
> 
> 

-- 
thedogfarted *

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