1 Aug
2010
1 Aug
'10
8:37 p.m.
Thanks to Julien and Rui Capela. Being a musician and engineer, this seems
to be a great place to land in and learn new stuff in this world
of Linux audio. Currently, I am still not able to find document that I need
to solve 2 existing problems:
*Question on using JDelay:*
I have only one web source that has some details about using this tool:
http://www.kokkinizita.net/linuxaudio/ and this reads: "It uses a phase
measurements on a set of tones to measure the delay from the output to the
input".
How do I use these phase measurements and how do I pass in these tones? Are
they special tones? What kind of oscillator do I need to use to generate
these special tones? How do I pass in an audio tick or click? How do I do
other settings?
$ jack_delay -h --help does not show me the help menu
*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.
Your reply in this regard will be greatly appreciated.
Kind regards,
-F
Arvind V
On Sat, Jul 31, 2010 at 7:01 PM, Rui Nuno Capela <rncbc(a)rncbc.org> wrote:
On 07/31/2010 11:23 PM, Arvind Venkatasubramanian
wrote:
Hello:
I am very much new to Linux and Linux audio. I am trying to measure
audio IO latency for my system.
Jdelay seems to be the right tool but when I run it on the terminal, I
am getting message "Signal below threshold..." which probably might be
because Jack is trying to capture audio and ends up getting the low
noise floor because I do not have meaningful signal source connected.
But then I tried to patch the this App to the qJACKctl app but the
settings console is not straight forward to interpret. as it involved
many parameters.
I guess there are # of frames per period that may eventually be used
to calculate the target latency but *is there a step-by step document
description for Jdelay and any other JACK tools and also using JACK
audio server in an effective manner*? Also, qJACKctl console does not
offer options for very low sampling rates like 8 KHz. With ALSA, this
should be possible but may be this particular tool does not support it.
Can anyone help here?
re. qjackctl settings you can actually write whatever sample-rate you
want. you're not limited to the options given in the drop-down list.
however, that doesn't mean that the soundcard will stick to it, ever :)
cheers
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org
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1 Aug
1 Aug
9:08 p.m.
New subject: [LAD] Document on using Jack Apps
On 1 August 2010 19:37, Arvind Venkatasubramanian <mdu.arvind(a)gmail.com> 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.
2 Aug
2 Aug
4:53 a.m.
New subject: [LAD] Document on using Jack Apps
On Sun, Aug 1, 2010 at 3:08 PM, James Morris <james(a)jwm-art.net> wrote:
On 1 August 2010 19:37, Arvind Venkatasubramanian
<mdu.arvind(a)gmail.com>
wrote:
*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@laspr-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@laspr-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@laspr-01 ~]$
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.
_______________________________________________
6:48 a.m.
New subject: [LAD] Document on using Jack Apps
On Sun, Aug 1, 2010 at 3:08 PM, James Morris <james(a)jwm-art.net> wrote:
On 1 August 2010 19:37, Arvind Venkatasubramanian
<mdu.arvind(a)gmail.com>
wrote:
James:
I finally got a detailed document at:
http://linux.die.net/man/1/jackd
<http://linux.die.net/man/1/jackd>This will help me get started with Jack
scripting. Thanks for your patient answers.
-Arvind V
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.
_______________________________________________
3 Aug
3 Aug
11:28 a.m.
New subject: [LAD] Document on using Jack Apps
On 01/08/10 19:37, Arvind Venkatasubramanian wrote:
Thanks to Julien and Rui Capela. Being a musician and
engineer, this
seems to be a great place to land in and learn new stuff in this world
of Linux audio. Currently, I am still not able to find document that
I need to solve 2 existing problems:
*Question on using JDelay:*
I have only one web source that has some details about using this tool:
http://www.kokkinizita.net/linuxaudio/ and this reads: "It uses a
phase measurements on a set of tones to measure the delay from the
output to the input".
How do I use these phase measurements and how do I pass in these
tones? Are they special tones? What kind of oscillator do I need to
use to generate these special tones? How do I pass in an audio tick
or click? How do I do other settings?
$ jack_delay -h --help does not show me the help menu
http://wiki.linuxproaudio.org/index.php/Howto:latency_measurement
1:02 p.m.
New subject: [LAD] Document on using Jack Apps
Hi
Actually, there is some info that can be found here and there on some forums
(see below)
JDelay is, from what I've understood, a command-line tool that allows you to
determine your sound card latency.
#1 : start jack
#2 : type jdelay in a terminal
#3 : patch connections in jack : input -> jdelay, jdelay -> output, you
should get a tone in your speakers
#4 : latency is calculated, using phase difference between input and output
#5 : in the terminal, the latency is printed in msec.
It never worked on my soundcard, "signal below threshold" was all that was
printed in my terminal.
You can find info here :
http://old.nabble.com/using-jdelay-td22843924.html
<http://old.nabble.com/using-jdelay-td22843924.html>
https://help.ubuntu.com/community/UbuntuStudio/FireWire_Recording in
Preconditions/measure your latency
http://wiki.linuxproaudio.org/index.php/Howto:latency_measurement
<http://wiki.linuxproaudio.org/index.php/Howto:latency_measurement>jy
2010/8/3 rob <rob(a)curates-egg.org>
On 01/08/10 19:37, Arvind Venkatasubramanian wrote:
Thanks to Julien and Rui Capela. Being a musician and engineer, this seems
to be a great place to land in and learn new stuff in this world
of Linux audio. Currently, I am still not able to find document that I need
to solve 2 existing problems:
*Question on using JDelay:*
I have only one web source that has some details about using this tool:
http://www.kokkinizita.net/linuxaudio/ and this reads: "It uses a
phase measurements on a set of tones to measure the delay from the output to
the input".
How do I use these phase measurements and how do I pass in these tones?
Are they special tones? What kind of oscillator do I need to use to
generate these special tones? How do I pass in an audio tick or click? How
do I do other settings?
$ jack_delay -h --help does not show me the help menu
http://wiki.linuxproaudio.org/index.php/Howto:latency_measurement
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/listinfo/linux-audio-user
3:54 p.m.
New subject: [LAD] Document on using Jack Apps
On Tue, Aug 3, 2010 at 7:02 AM, Jean-Yves Poilleux <jypllx(a)gmail.com> wrote:
Hi
Actually, there is some info that can be found here and there on some forums
(see below)
JDelay is, from what I've understood, a command-line tool that allows you to
determine your sound card latency.
#1 : start jack
#2 : type jdelay in a terminal
#3 : patch connections in jack : input -> jdelay, jdelay -> output, you
should get a tone in your speakers
this is totally and utterly wrong. you have to patch the PHYSICAL
output connector of your soundcard to the PHYSICAL input of your
soundcard.
#4 : latency is calculated, using phase difference
between input and output
#5 : in the terminal, the latency is printed in msec.
It never worked on my soundcard, "signal below threshold"
yes, because jdelay is sending a signal out of the soundcard expecting
it to come back, but you have not connected it so that it can.
4:23 p.m.
New subject: [LAD] Document on using Jack Apps
Yes of course ! physical input/output should be patched. Thanks. How could
I've missed that !
Just to make sure : when you say that the following sentence is wrong :
"#3 : patch connections in jack : input -> jdelay, jdelay -> output, you
should
get a tone in your speakers"
you were refering to the tone part, right ? you mean that physical
connections should ALSO be made, i guess. Because if there are no
connections in jack such as I discribed signal won't get in or out, and thus
Jdelay won't be able to calculate latency.
2010/8/3 Paul Davis <paul(a)linuxaudiosystems.com>
On Tue, Aug 3, 2010 at 7:02 AM, Jean-Yves Poilleux
<jypllx(a)gmail.com>
wrote:
Hi
Actually, there is some info that can be found here and there on some
forums
(see below)
JDelay is, from what I've understood, a command-line tool that allows you
to
determine your sound card latency.
#1 : start jack
#2 : type jdelay in a terminal
#3 : patch connections in jack : input -> jdelay, jdelay -> output, you
should get a tone in your speakers
this is totally and utterly wrong. you have to patch the PHYSICAL
output connector of your soundcard to the PHYSICAL input of your
soundcard.
#4 : latency is calculated, using phase
difference between input and
output
#5 : in the terminal, the latency is printed in
msec.
It never worked on my soundcard, "signal below threshold"
yes, because jdelay is sending a signal out of the soundcard expecting
it to come back, but you have not connected it so that it can.
5019
days inactive
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days old
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7 comments
5 participants
participants (5)
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Arvind Venkatasubramanian -
James Morris -
Jean-Yves Poilleux -
Paul Davis -
rob