[Ardour-users] WAV files, xruns

Anthony DiSante orders at nodivisions.com
Fri Feb 20 13:57:29 PST 2004


Anthony DiSante wrote:
>>>> causes these xruns from jackd, like this:
>>>>
>>>> **** alsa_pcm: xrun of at least 43.943 msecs
>>>>
>>>> Should I be concerned about this?  I don't think I've noticed it 
>>>> affecting
>>>> the recording at all, but then I'm only recording 2 channels, at the 
>>>> moment.
>>
>>
>>
>> Yes, you should be. It *will* affect recording. Make sure you are running
>> as root, lowlatency is enabled, and that jack is using a non-journaling
>> filesystem for shm. Make your latency as large as you can tolerate, in
>> fact I suggest choosing the -n and -p options as big as the device 
>> allows.
>> Make sure you don't have an autopoller checking the CD-rom drive.
> 
> 
> I'm running as root, lowlatency is enabled, and I don't have any 
> automounters for my cdrom drives.
> 
> I did do the shmfs thing when installing jack (I have "shmfs on /dev/shm 
> type shm"), but that was a while ago.  Is there a way I can make sure 
> jack is actually using it?
> 
> Also, how do I know what values to choose for -n and -p for my card?

OK, I can't set n to anything but 2.  However, I set p to 4096, and now 
there's no more xruns (so far)!  Thanks a lot.

How can I test the actual value of latency on my system?

Thanks again,
Anthony
http://nodivisions.com/



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