On 10/12/05, Matt Garman <[EMAIL PROTECTED]> wrote: > On Wed, Oct 12, 2005 at 06:48:48PM -0700, Mark Knecht wrote: > > ...alsaplayer requires that you say you want to use realtime > > capabilities: > > alsaplayer -r -o jack > > ... > > Yeah, just the -r most likely. Also, depending on your sound card > > 128/2 might be a bit tight, but let's try for it and see what happens. > > Unfortunately, adding the -r had no effect as far as I can tell. > > According to the alsaplayer manpage, > > -r, --realtime > Enable realtime scheduling. To use this as a normal > user, alsaplayer must be SUID root. > > So I tried setting alsaplayer SUID root: > > # chmod u+s `which alsaplayer` > > Then as a regular (non-root) user: > > # alsaplayer -r -o jack & > 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+. > [2] + exit 1 alsaplayer -r -o jack > > I'm guessing that most folks don't have to worry about the whole > SUID root thing (or creating a "help program")?
No. None of that is required for me on any kernel - Gentoo or Vanilla. I just set up realtime-lsm and then run with realtime capabilites. I would suggest that you use QJackCtl to run Jack as it will save your settings nicely for you and give you patch bay access to hooking Jack apps up to the server. Note that I use pretty expensive RME cards. They work exceedingly well for me. There are a lot of people out there that report they never go faster than 128/2 or 256/2. 256/2 is about as good as any of my Windows systems have every worked, and better then Pro Tools worked when I owned it. You should not think that going a bit slower is necessarily a problem. If you cannot hear the latency it doesn't matte, and even if you can hear it, you can nudge recorded tracks after recording to get a better sound if you can lay down a good track. > > Any more thoughts? Yes, but not sure you're going to like them... ;-) The first one is easy. Try some different Jack settings. Instead of 128/2 try 64/4, or 128/3, etc., and see if some other setting works. You might get the same latency, or you might have to go a bit slower. The only time I actually use low latency is when recording. It's never needed for playback only. Most of the time I run 512/2 just to ensure no xruns causing clicks in my work. On my 32-bit machines I've always been able to run Jack the standard Gentoo-sources kernel and get good realtime results. I have had to be careful about what options I choose, and on a couple of machines different kernel options have caused xruns (such as networking) but I've always managed to get it to work and work well. Sometimes it has taken some time, but it has worked. Maybe we need to look at how you are configuring the kernel. Possibly send your config file off list or I'll send you one of mine. That said, on my new AMD64 machine gentoo-sources just doesn't cut it. I had to go to a custom kernel to get realtime to work. I first tried ck-sources, which lots of people report as working for them, but that did not work for me, so I went with Ingo's realtime preempt patches and I'm getting pretty good results. I get a few xruns/day at 64/2, none so far at 128/2 running 20 track sessions in Ardour. I'm using 2.6.14-rc4-rt1. Here's the patches required to do that, should you choose to go there: http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.13.tar.bz2 http://kernel.org/pub/linux/kernel/v2.6/testing/patch-2.6.14-rc4.bz2 http://redhat.com/~mingo/realtime-preempt/patch-2.6.14-rc4-rt1 (This one is VERY new. There are more stable, tested versions out there based on 2.6.13. I needed this due to AMD64) Once this is up and running you get access to setting priorities for all devices and things work pretty well. (I.e. - don't be disappointed if it doesn't do any better the first time you boot it.) Unfortunately, since Gentoo doesn't support an 'audio kernel' yet you and I would have to manage updates on our own. That said, this is the way most people interested in good realtime performance have gone. Maybe I've just been excessively lucky up until now. It's probably worth it to review how you've set up realtime-lsm one more time, just in case, and possibly to look at your hardware setup a bit. lspci lsmod cat /proc/asound/cards > > Thank you for all your help! Wish it was more successful. We should just keep plugging away. What audio stuff are you going to use this machine for, BTW? - Mark -- gentoo-user@gentoo.org mailing list
