Re: [LAU] [LAD] Document on using Jack Apps

On Sun, Aug 1, 2010 at 3:08 PM, James Morris <james@email-addr-hidden-art.net> wrote:

> On 1 August 2010 19:37, Arvind Venkatasubramanian <mdu.arvind@email-addr-hidden>
> wrote:
>
> > Question on using QJACKctl:
> > I was able to create some basic setting, load and read latency that gets
> > printed on the terminal. But what do the parameters on the setting tab
> of
> > console pop up mean? No soft mode, monitor, priority, time out etc and
> the
> > options tab. How do I use these options and tine tune them in order to
> set
> > the minimum feasible latency for the application that I intend to
> develop?
> > Above all, if the drop down menu options does not allow me to choose
> lower
> > sampling rates, what command do I use on the CLI to do the setting. Or
> Do I
> > need to edit QJACKctl's .conf file to set lower sampling rates manually.
> > My Intel sound card supports sampling rates of 8kHz and 16 kHz. I
> confirmed
> > this by looking into Audacity device ID setting. I know that I am asking
> > some basic stuff but my problem is that I do not find the right
> > documentation for solving my problems.
>
> Typing in the console:
>
> man jackd
>
> will help you identify the nature of some of the command line options
> for jack, as well as give you some clues for matching them to the tabs
> within QjackCTL.
>
> I'm no expert, and all I've ever tried for getting the best (lowest)
> latency is by experimenting with seeing how low I can go with the
> Frames/Period setting in QjackCTL which is the -p or --period setting
> on the command line. If it works and no x-runs occur, then...
> ...it works :-)
>
> A method of identifying which command line option to Jack relates to
> which setting in QjackCTL is by changing a setting in qjackctl and
> stop/starting Jack through qjackCTL while watching the messages log.
>
> James.
> _______________________________________________
>

*James:*

These are the responses I get from the program upon pinging the commands. I
am trying to set a time out: 500 ms and I do not get a successful return
flag. I also get some info about sys config which probably comes from
SElinux which I have forced it to permissive mode. What would you comment
on this?

[Arvind@email-addr-hidden-01 ~]$ jackd -r -t 500
jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and
others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and
others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

usage: jackd [ --no-realtime OR -r ]
             [ --realtime OR -R [ --realtime-priority OR -P priority ] ]
      (the two previous arguments are mutually exclusive. The default is
--realtime)
             [ --name OR -n server-name ]
             [ --no-mlock OR -m ]
             [ --unlock OR -u ]
             [ --timeout OR -t client-timeout-in-msecs ]
             [ --port-max OR -p maximum-number-of-ports]
             [ --debug-timer OR -D ]
             [ --no-sanity-checks OR -N ]
             [ --verbose OR -v ]
             [ --clocksource OR -c [ c(ycle) | h(pet) | s(ystem) ]
             [ --replace-registry ]
             [ --silent OR -s ]
             [ --version OR -V ]
             [ --nozombies OR -Z ]
         -d backend [ ... backend args ... ]
             Available backends may include: alsa, dummy, freebob, firewire,
net, oss, sun, or portaudio.

       jackd -d backend --help
             to display options for each backend

[Arvind@email-addr-hidden-01 ~]$ jackd -t 500
jackd 0.118.0
Copyright 2001-2009 Paul Davis, Stephane Letz, Jack O'Quinn, Torben Hohn and
others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

JACK is running in realtime mode, but you are not allowed to use realtime
scheduling.

After applying these changes, please re-login in order for them to take
effect.

*You don't appear to have a sane system configuration.* It is very likely
that you
encounter xruns. Please apply all the above mentioned changes and start jack
again!
[Arvind@email-addr-hidden-01 ~]$

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Received on Mon Aug 2 08:15:02 2010