Subject: Re: [linux-audio-user] Re: Re: rosegarden silent
From: tim hall (tech_AT_glastonburymusic.org.uk)
Date: Tue Jun 22 2004 - 16:55:22 EEST
Last Tuesday 22 June 2004 04:07, David Corkill was like:
> Starting Jack with Qjackctl gives an error message: ...
>
> JACK: unable to mlock() port buffers: Operation not permitted
> cannot set thread to real-time priority (FIFO/20) (1: Operation not
> permitted)
> cannot use real-time scheduling (FIFO/10) (1: Operation not permitted)
> 12:24:50.512 Could not connect to JACK server as client.
Are you running a kernel with realtime capabilities? The stock Mandrake kernel
probably does not have this. I'm not an expert on this matter. You need a
kernel patched for low-latency, realtime operation and which hopefully allows
you to do this as an ordinary user.
> Starting Jack from the command line < jackd -d alsa -d hw:0 > results in:
>
> loading driver ..
> creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|rt|32bit
> control device hw:0
> configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
> Couldn't open hw:0 for 32bit samples trying 24bit instead
> Couldn't open hw:0 for 24bit samples trying 16bit instead
> Couldn't open hw:0 for 32bit samples trying 24bit instead
> Couldn't open hw:0 for 24bit samples trying 16bit instead
Try messing with the Setup options too. 'Force 16bit' will stop it trying to
do this. JACK _will_ balk at some options. I run with Realtime and Soft Mode
enabled and a 5s timeout, which seems to work for most things.
cheers
tim hall
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