2 Jun
2010
2 Jun
'10
10:24 a.m.
Hello all!
I just got back into asterisk, the big telephony pbx system. It has a JACK
module, which is very helpful to me, as it allows me to use asterisk with its
cLI to be my telephone. Since I found no other commandline telephone
supporting JACK, this is the only way to get there.
So asterisk has a small module (1025 lines, including comments), that allows
to use JACK. But unfortunitely the programmer of that module has no more time
to develop it. So he wrote on the list today.
Now I was wondering if anyone of you might be willing to help out here.
There are a few people how like to use this module and I'm not the only one,
who ends up frustrated. :-(
So here are a few links:
I uploaded app_jack.c to my site:
http://juliencoder.de/app_jack.c
I also uploaded libresample - which I think it relies upon:
http://juliencoder.de/libresample-310510.tar.bz2
The latest asterisk can be downloaded here:
http://downloads.asterisk.org/pub/telephony/asterisk/asterisk-1.6.2.9-rc1.t…
Basic Developer resources (coding guidelines, etc.) can be found here:
http://www.asterisk.org/developer/resources
The author of the JACK module has written an article, on how to write a
module for asterisk, so one can understand the basic structure. It can be
found through this link:
http://www.venturevoip.com/news.php?rssid=2024
(If you're in a hurry, directly search for "part 1").
That's the best I could find for a starter. I think app_jack relies on
libresample, which is somehow connected with asterisk. Beyond that I suppose
it's pure JACK and asterisk basic structure.
Is anyone here willing to help in some way? Please?
Kindest regards
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
2 Jun
2 Jun
1:37 p.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
Hello everyone!
I've just scanned the code of app_jack.c as best I could. It seems, that the
functionality is rather simple:
create a jack_client, if demanded, connect it to somewhere.
Get Audioframes from a telephone channel (8kHz, signed 16 bit - I believe)
If necessary resample them to jack_sampl_rate
Get input from JACK, if necessary resample them to 8kHz
Write 20ms frames back to the telephone channel.
all the JACK code gets to see of the asterisk system, is the audio frames,
simple buffers.
As far as I could determine, there seems to be nothing wrong. The code is
quite nicely commented and I compared snippets of it to some of the jackd
example-clients' source code.
Perhaps I overlooked something. I'm not too good with reading other people's
code. Well, not even my own. :-(
Kindly yours
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
3 Jun
3 Jun
1:05 a.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
On Wed, Jun 02, 2010 at 01:37:40PM +0200, Julien Claassen wrote:
Hello everyone!
I've just scanned the code of app_jack.c as best I could. It
seems, that the functionality is rather simple:
create a jack_client, if demanded, connect it to somewhere.
Get Audioframes from a telephone channel (8kHz, signed 16 bit - I believe)
If necessary resample them to jack_sampl_rate
Get input from JACK, if necessary resample them to 8kHz
Write 20ms frames back to the telephone channel.
One problem I can imagine is that the two sample clocks -
the one used by Jack and and the 8 kHz one used by the
telephone interface) are independent and resampling
will have to adapt to any errors. But you mentioned
a resampling library before, maybe this takes care of
this. The same problem would exist with any audio
interface (ALSA, OSS) used by Asterisk.
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
1:18 a.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
Hello fons!
I'm not even using a real phone. I use googletalk, well I try to. :-)
It worked a few years ago, but even with the old version of Asterisk I had
then, I wasn't able to get it back to that state.
I have now discovered, that JACK frequently doesn't read/write as many bytes
as it would like to do.
Kind regards
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
1:38 a.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
On Thu, Jun 03, 2010 at 01:18:18AM +0200, Julien Claassen wrote:
I have now discovered, that JACK frequently
doesn't read/write as
many bytes as it would like to do.
??? You mean Jack as we know it, or the Jack interface
to Asterisk ???
As far as I know, each Jack cycle handles period_size
samples, I've not seen any exceptions to that...
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
8:30 a.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
Morning Fons!
I meant the JACK interface to Asterisk. Ihas a function to handle input and
one to handle output. There audio gets resampled if necessary and then written
to a ringbuffer. Or vice versa for soundcard input to Asterisk channel output.
Kindly yours
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
10:33 p.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
On Thu, Jun 03, 2010 at 08:30:48AM +0200, Julien Claassen wrote:
I meant the JACK interface to Asterisk. Ihas a
function to handle
input and one to handle output. There audio gets resampled if
necessary and then written to a ringbuffer. Or vice versa for
soundcard input to Asterisk channel output.
So what is the problem if all of this works ?
Ciao,
--
FA
O tu, che porte, correndo si ?
E guerra e morte !
4 Jun
4 Jun
7:24 p.m.
New subject: Help, someone interested in taking over a small orphaned jack-module
HelloFons!
Sorry, for the late reply, I wasn't home.
So the problem is, that it doesn't really work. And I can't find the source
of that. I don't know about rules for buffering and how much to read or write,
especially, since the audio must interface with a different system. Realtime
is not reallythe problem. Of course too much latency is a hinderance, but
beyond that, a rather steady stream of speech is enough.
So because I don't know, how to write a proper JACK application, let alone
the pitfalls in that, I wanted to ask, if an experienced programmer would be
so kind as to take a look at the code, to see, if a pitfall or partly
deprecated code or practise of coding could be spotted.
As I mentioned, the original programmer has given up his work, due to work
and maybe other projects. I'm afraid JACK isn't the most popular interface.
I've heard, that some people got it working, but they can't reallyremember
what exactly they did to do so. If it's a question of configuration, then it
must be one of a VERY special setup (including JACK startup options and other
things, you would usually consider, with a reasonably stardard setup).
Sunny regards (yes, it's showing and shining)
Julien
--------
Music was my first love and it will be my last (John Miles)
======== FIND MY WEB-PROJECT AT: ========
http://ltsb.sourceforge.net
the Linux TextBased Studio guide
======= AND MY PERSONAL PAGES AT: =======
http://www.juliencoder.de
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Julien Claassen