Leonardo Gabrielli | 16 Apr 22:06 2014
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smallest embedded platform for Jack

Hi all,
I'm trying to see whether I can fit Jack into a rather simple ARM 
processor, and I was wondering the smallest embedded system people 
managed to compile and run Jack into.

My hypothetical platform is an armel (no floating point unit) with 64MB 
RAM, low speed (4-500MHz).
So far the biggest issue is RAM: my target system only has 64MB and Jack 
asks for 80-90MB usually.
The lack of a floating point unit may be another issue: converting fixed 
and floating may eat a lot of CPU, I guess.

Cheers

--

-- 

Dr. Leonardo Gabrielli, PhD student
A3Lab - Dept. Information Engineering
Università Politecnica delle Marche
via Brecce Bianche 12, 60131, Ancona, Italy
Skype: leonardo.gabrielli
Web: a3lab.dii.univpm.it/people/leonardo-gabrielli 
<http://a3lab.dii.univpm.it/people/leonardo-gabrielli>
Noel O'Leary | 16 Apr 12:14 2014

Contract

I am looking for an Linux Jack Audio expert for a 3 to 6 month contract in the Uk.

Anybody available

 

Regards

 

 

 

Noel O´Leary 

 

 

Capitol International Services Ltd

Tel. +34963943500

Fax +34961475886

noelo <at> capitolinternational.com

 

Registered Office: New Derwent House, 69-73 Theobalds Road, London WC1X 8TA, United Kingdom

European Sales Office: Avenida de las Cortes Valencianas 58, Sorolla Center 711, 46015 Valencia, Spain

 

This message (including any attachments) contains confidential information intended for a specific individual and purpose, and is protected by law. If you are not the intended recipient please contact the sender and delete this message; you are hereby notified that any disclosure, copying or distribution of this message, or the taking of any action based on it, is strictly prohibited. Any views or opinions presented are solely those of the author and do not necessarily represent those of CiS unless specifically stated. Capitol International Services Limited, registered in England and Wales, registration number 4571996, registered office 69 - 73Theobalds Road, London WC1X 8TA, United Kingdom

 

 

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Athanasios Silis | 16 Apr 08:48 2014
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low latency . what does it mean? how is it achieved?

Hi all,
I find myself wondering again and again what makes a difference between a simple AC '97 audio chip and a professional sound card...

I mean the chips are different, sure, but I always hear about "professional equipement, does not go through the normal application execution path", or something in those lines.

both ac97 and professional chips go through ALSA (in linux at least). what gives an edge to the professional chip then? Why can I not run an ac97 with a latency of 10msec or so (and a low latency kernel) ? I mean, the processing power of a core i7 should be enough to run audio, right?

I am looking for the big, but also the detailed picture here . Is there some book / presentation / blog / academic paper that I could read to figure out what makes the difference?

thank you for your help.
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Paul Davis | 15 Apr 19:22 2014

[jackaudio/jack1] 61ffb4: submodule upate

  Branch: refs/heads/master
  Home:   https://github.com/jackaudio/jack1
  Commit: 61ffb488c684b53db1f5f8b47554772809d57a04
      https://github.com/jackaudio/jack1/commit/61ffb488c684b53db1f5f8b47554772809d57a04
  Author: Paul Davis <paul <at> linuxaudiosystems.com>
  Date:   2014-04-15 (Tue, 15 Apr 2014)

  Changed paths:
    M jack

  Log Message:
  -----------
  submodule upate

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Paul Davis | 15 Apr 19:22 2014

[jackaudio/headers] 198407: remove unusued, leftover <uuid/uuid.h> include fro...

  Branch: refs/heads/master
  Home:   https://github.com/jackaudio/headers
  Commit: 198407e95611938375ce87cb5ba924d8cff4eb09
      https://github.com/jackaudio/headers/commit/198407e95611938375ce87cb5ba924d8cff4eb09
  Author: Paul Davis <paul <at> linuxaudiosystems.com>
  Date:   2014-04-15 (Tue, 15 Apr 2014)

  Changed paths:
    M types.h

  Log Message:
  -----------
  remove unusued, leftover <uuid/uuid.h> include from types.h

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Leonardo Gabrielli | 11 Apr 18:42 2014
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jackd + /dev/inputevent sounds bad

Dear devels,
I am facing a strange issue with jackd.

I'm running a debian armhf board with the latest jackd2 from git. By 
default I loopback the capture and playback ports, the audio sounds good 
at low period size and everything runs smooth when I startup jackd and 
connect the ports using a custom script (called jackaudio). Now, the 
sound is crippled if an init script I recently made is running in 
background. The guilty init script is called read_usrbutton and reads a 
gpio line for button press (BeagleBoard xM rev.C).
What it does mainly

   BUTTONPATH="/dev/input/event0"
   cat $BUTTONPATH > /tmp/dump 2>1&
   THIS_VALUE=`tail -n1 /tmp/dump`

Then THIS_VALUE is checked for changes in a while loop every 50ms.

Why could this be? For crippled audio I mean that buffers are scrambled 
up. Neither read_usrbutton nor 'cat' use much CPU so it's not a problem 
of XRUNS.

FYI, jackaudio looks like

   killall jackd
   # setup McBSP2
   echo threshold | tee /sys/devices/68000000.ocp/49022000.mcbsp/dma_op_mode
   echo 320 | tee /sys/devices/68000000.ocp/49022000.mcbsp/max_rx_thres
   echo 320 | tee /sys/devices/68000000.ocp/49022000.mcbsp/max_tx_thres
   # enable max CPU freq
   echo -n performance | tee 
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
   # start jack
   sudo -u debian jackd -P62 -t2000 -dalsa -dhw:0 -r44100 -p64 -n2 -s 
-i4 -o4 > /var/log/jackaudio.log 2>&1 &
   sleep 8
   sudo -u debian jack_connect system:capture_1 system:playback_1 > 
/dev/null
   sudo -u debian jack_connect system:capture_3 system:playback_3 > 
/dev/null

Ideas?
Cheers
--

-- 

Dr. Leonardo Gabrielli, PhD student
A3Lab - Dept. Information Engineering
Università Politecnica delle Marche
via Brecce Bianche 12, 60131, Ancona, Italy
Skype: leonardo.gabrielli
Web: a3lab.dii.univpm.it/people/leonardo-gabrielli 
<http://a3lab.dii.univpm.it/people/leonardo-gabrielli>
Kjetil Matheussen | 8 Apr 10:50 2014
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Wrong subject line (Re: N.E.)

Sorry about inserting your name into the subect line Niko, that's
an unfortunate mistake.

I meant to paste "diasabling stderr" into the subject line, but
something must have gone wrong.

On Tue, Apr 8, 2014 at 9:03 AM, Kjetil Matheussen
<k.s.matheussen <at> gmail.com> wrote:
> Niko Efthymiou:
>>
>> Hi all,
>>
>> I am currently working on an output plug in for a curses based app
>> (cmus). When an error happens, like when jackd is killed, jack dumps
>> some error messages on stderr, when it was auto started by the jack API.
>> This corrupts the curses ui, which is ugly. Is there a way to disable
>> the stderr output of the auto started server?
>>
>
> Besides Dominique's suggestion, perhaps an option is
> to specify the JackNoStartServer flag to jack_client_open?
>
> Personally, I think this flag should be on by default, but
> I guess it's too late to change that now.
Kjetil Matheussen | 8 Apr 09:03 2014
Picon

Re: Niko Efthymiou

Niko Efthymiou:
>
> Hi all,
>
> I am currently working on an output plug in for a curses based app
> (cmus). When an error happens, like when jackd is killed, jack dumps
> some error messages on stderr, when it was auto started by the jack API.
> This corrupts the curses ui, which is ugly. Is there a way to disable
> the stderr output of the auto started server?
>

Besides Dominique's suggestion, perhaps an option is
to specify the JackNoStartServer flag to jack_client_open?

Personally, I think this flag should be on by default, but
I guess it's too late to change that now.
Niko Efthymiou | 7 Apr 20:00 2014
Picon

dias

Hi all,

I am currently working on an output plug in for a curses based app
(cmus). When an error happens, like when jackd is killed, jack dumps
some error messages on stderr, when it was auto started by the jack API.
This corrupts the curses ui, which is ugly. Is there a way to disable
the stderr output of the auto started server?

Thanks Niko
김정연 | 6 Apr 08:16 2014
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Suggest to auto build service for jack.

Dear all,

I suggest that jack support auto-build service via Travis https://travis-ci.org/, so I did pull request to upload .travis.yml script file to use it.
Any forked branch able to make own build service also, for example, please refer https://travis-ci.org/KimJeongYeon/jack2.

I think it seems very useful for maintaining master branch on GitHub.

Thanks,
KimJeongYeon
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brad | 6 Apr 00:59 2014
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Why the syntax error?

I get "the syntax of the command is incorrect" when I try to manually 
register the dll in the 64 bit folder.
After I right click and run as administrator:

c:\windows\system32>cd\

c:\>cd progam files <x86>
the syntax of the command is incorrect

What i'm I doing wrong here? Thank You

Gmane