[PlanetCCRMA] network support in the low lat. kernel

[Zacharias Enochsson]

Hi Fernando!

Thanks for the helpful input!  I'll try to be a bit more specific. Since 
you further down imply that my hardware should do just fine for the 
software you provide, I am getting pretty excited about being able to 
mix som music soon!

I also thought I should let you know that planet ccrma is the reason I 
recently switched from Mandrake to RedHat.  Thanks!


 >> I had some troubles though:  After using the low lat kernel, it seems I
 >> couldn't get online anymore.  I could browse samba shares on the LAN,
 >> but couldn't find any servers with ping or anyhting ("unknown host
 >> name").

 >If it is the same connection the fact that you are able to access samba
 >shares through it means the driver is loaded and the interface properly
 >configured.



Yes it would seem so.  At least RH made no complaints when using the 
network setup gui tool.



 >So it would seem you were having problems with name
 >resolution. To confirm that you could try pinging to a numerical >address
 >instead of the computer's name. If you can ping then the problem is >name
 >resolution (ie: translation of names to ip addresses). Are you getting
 >your ip address through dhcp? From where? Check the contents of
 >/etc/resolv.conf, it should contain the name of the name server you
 >should be using.




I do use dhcp, so you're probably right.  I'll look into the resolv.conf 
.  I am just a bit surprised that this would change after installing 
your kernel, i didn't get the impression that it would change any of 
those settings.  Perhaps I messed it up myself?




 >>programs (audacity in particular) >>will
 >> occasionally while playing back sound make a loud "scribbly" noise 
 >>and
 >> hang for a while.  Why is this?

 >It would seem you are describing an underrun but I can't be sure. The
 >system is not able to deliver samples to the soundcard in time and >there
 >is a gap in the sound, most of the time accompained with clicks at the
 >beginning and end of the gap. Check that you have low latency turned on
 >(see instructions in the Planet CCRMA pages on optimizing for low
 >latency) and that the disk is optimized (at least using dma).



yup, pretty sure I did that, but I could have messed up I suppose.



 >When you
 >say "hangs for a while", how long is that? A fraction of a second?




Not really.  In audacity, while playing back a wav-file, there will be a 
screech for about half - quarter of a second, and then nothing (the 
cursor doesn't move) but the play button is still pressed down.  Then if 
I press the stop button, it will remain pressed together with the play 
button for perhaps 5-7 seconds, during which time the program will be 
completely unresponsive.  Then it just returns to normal, the cursor at 
the beginning of the waveform, the program responsive and ready to try 
again.

In soundtracker playback will occasionally stop after about half a 
second of playback and the quick scribbly-screech.  Restarting the 
playback works fine, but the same thing will happen for about 4-5 tries 
then it'll work like a charm all of the sudden.  (this screech-hang 
seems quite random)

The gnome soundrecorder sometimes screeches and hangs (has to be killed 
with xkill) after playing about 4-5 seconds.



 >> Also when recording in audacity, with
 >> simultaneous playback of previously recorded tracks, everything thats
 >> recorded has a really looooow tone (timing ok thoug).

 >Low tone means transposed down and lasting longer than the original (as
 >if you were turning down the speed of a tape recorder?)




Yes, by low tone I mean transposed down, but no, I cant say I've noticed 
the recording being longer, but perhaps my recordings are to short to 
really tell (approx 10 seconds).
The shift down must have been about two octaves (tonewise) but the fact 
that the recordings seemed not to grow drastically longer has me confused.


Anyway, like you say, ther IS the possibility that I forgot to turn on 
the low latency, so I suppose

 >> My setup:  fujitsu-siemens lifebook s-4510, cpu: pentium II 450 MHz, 
 >>128
 >> sdram, soundcard: intel 810 ac97 (I know - its embarrasing), RedHat 9

 >Sounds ok to me.



Good to know that it's not entirely out of the question for me to be 
messing with the ccrma packages! Out of curiosity do you think that once 
you get the rpms for ardour, I would be able to use that on my hardware? 
  I would probably be recording vocals or instrumental solos to 
simultaneous playback of at most three or four tracks and mixing it. 
(sort of what I was hoping to do in audacity).




THANKS A MILLION for your help!


+Zach