I've recently been conscripted into the role of backup to our primary
phone system admin with an eye towards leveraging my network admin
background in our coming VoIP deployment. Due to this I've been cramming
as much telephony information as I can into my brain over the past 3-4
weeks. Our PBX (private branch exchange, i.e. the switch for our office
phone system for those unfamiliar with the term) is a proprietary system
from NEC. Having to deal with systems like this is contrary to my
nature.
To sooth the irritation of being rubbed the wrong way by this
proprietary technology I've signed on to the asterisk users and dev
lists with a few aims. First, as I expected, I've found the members of
the asterisk community to really know their stuff when it comes to the
standards and protocols that make phone systems work. In a few days of
reading the lists I've already learned much that I haven't gotten out of
the NEC manuals, but that helps me to better understand their closed
system. Second, I'm hoping that down the road I can get an asterisk
system into this operation to provide additional services and
functionality that would be more expensive to purchase from NEC.
I'm writing to LAU to get some feedback on a number of possiblities that
come to mind for cross fertilization between this community and the
asterisk community. Also I'm hoping there are some here who have
experiences with asterisk they would be willing to share.
As I understand it asterisk can use ALSA supported full-duplex cards to
provide voice i/o. An asterisk server with a number of connections to
the phone network and several RME HDSP or other such high channel count
multi-channel cards would seem to be a very useful, cost effective and
high quality solution for supporting call-in shows and telephone
interviews for a radio station. Such a settup could also provide a nice
platform for an intercom system for a business or even a home. Is anyone
here doing such things?
Apropos my recent inquiry regarding bats, telephony has traditionally
saved bandwidth by limiting the frequencies transmitted to a roughly
4kHz band since the information important to intelligible speech can be
conveyed without the sounds outside that band. Are the concepts used to
capture bandlimitted audio for speech the same, or similar to, what
would be used to capture the interesting information from sounds
produced by animals who hear above the human hearing range?
There are a variety of audio data compression and synthesis/resynthesis
schemes in use in the telephony world. Have any of these been repurposed
for use as effects, perhaps wrapped up in LADSPA plugins?
Are there similarities between jack and asterisk in what they need to do
to provide audio routing and scheduling? Perhaps this has already
occured or perhaps their needs are too different, but could the two
projects benefit from sharing ideas or even code? If these are naive
questions and the two domains are orthogonal I'm interested in knowing
why. Hmm ... as I write I realize a big difference is that many phone
conversations happen at once and have no need for synchronization.
jack's typical application space involves keeping many channels of audio
in sync. So, I guess I've largely answered this one for myself. But,
still input from the system programming gurus like Paul and Jack would
be most welcome and surely enlightening and educational.
I had a few other ideas and questions, but they've slipped away from me.
Anyway, this has gotten long enough.
Thanks in advance for reading and for any feedback.
-Eric Rz.
Well, as far as info about audio goes, for newbies their best bet is to
use Suse Linux, it comes with support, so you have a live human to call if
you have problems.
Greetings listers.
I thought I'd share some things I discovered last night.
After spending an inordinate amount of time (not all at one sitting)
trying to figure out how to solve this problem...
~/test-alsa/ arecord -D pdaudiocf -f cd foo.wav
Recording WAVE 'foo.wav' : Signed 16 bit Little Endian, Rate 44100 Hz,
Stereo
arecord: pcm_read:1196: read error: Input/output error
...I made some discoveries. This started happening to me after coming
fresh to the laptop one evening, ready to transfer an old concert tape.
The PDAudio-CF having worked like a champ before, I was starting to get
nervous that something odd had happened. Turns out, after going to the
#alsa group on freenode and getting a huge amount of attention from one
kind soul, who eventually pointed me to one of the alsa list archives,
combined with something I seemed to recall reading somewhere, that the
tape was at 48k, and the PDAudio-CF doesn't do hardware sample rate
conversion.
So why I am I telling you this?
Well, for one thing, if my notes ever get deleted, I can always check
this archive. :)
But I hope to save someone else the problem.
WHAT TO DO:
So, if you get this error, and it seems out of the blue (like the thing
was *just* working!!!),
Check what the card thinks the incoming sample rate is. You can do this:
amixer -c <card#> contents.
In there somewhere you'll see something about "IEC958 External Rate",
and the next line will be the incoming sample rate (in samples/sec).
you'll want to make sure that the incoming sample rate and outgoing
sample rate are the same. So in my case for last night, I needed to do
the following with the 48k tape:
arecord -c hw:1,0 -r 48000 -f dat foo.wav
BUT WAIT, THERE'S MORE:
Before I got to that solution, I found this nifty shell script in the
alsa archives that let's you specify optical/coax input. It
automagically figures out which hardware slot the PDAudio-CF occupies.
Here's a link the alsa archives message containing the script:
http://sourceforge.net/mailarchive/message.php?msg_id=7502478
That's it for today. I'm looking forward to recording my first live
convert this weekend using this device (backed up with DAT just in case...)!
Regards,
Daniel Zuckerman
Hi
I think some people may be interested in this
best
Jake
-------------------------------------------------------
CALL FOR AUDIO SUBMISSIONS
Linux Open Source Sound CD (L.O.S.S.)
[Planned release date - April 2005]
Deadline for submissions: 07-Jan-05
Access Space, Sheffield's lowtech digital arts organisation, is currently calling for submissions for a CD of audio produced with open source software, and the Linux operating system.
There is no specific theme for the curated works, as the concept behind the project is freedom of all elements of music manufacture, encapsulating style, production software and distribution techniques. We hope to receive submissions covering a broad and eclectic range of styles, to represent the dynamic nature of contemporary open source audio culture. Therefore, contributions are invited from musicians of all types, programmers, sound artists or artists who use sound.
The LOSS CD is to be released under a Creative Commons 'Sampling Plus' license, so as well as being produced with free software, the CD will also extend the ethos of the open source movement into its method of distribution. For more information about this license, please visit http://creativecommons.org.
Please do not submit tracks if you are not willing to release your work in this manner.
The LOSS project will develop not only through the CD release, but also through a website, aimed at being an ongoing portal for producers of open source music to showcase their work. This will also offer the works for redistribution under the Creative Commons licensing mentioned above. This website will be online later in the year at http://www.access-space.org/loss.
How to submit your proposal:
[A maximum of 2 tracks per artist, each between 20 seconds and 8 minutes in length.]
Send a DATA CD containing the following files:
- Your audio track(s) in .wav format, 16bit, 44.1khz in either mono or stereo.
- A text document stating your name, contact details (email and mailing address), track title, track length, the software and operating system used for producing the track, and a declaration that your track does not infringe any copyrights or use any unlicensed material.
- An optional screenshot (in .jpg or .png format) of your software setup - which may be used for artwork purposes.
For more information, or to mail your submission:
Linux Open Source Sound CD
Access Space
1a Sidney Street
Sheffield
S1 4RG
0114 2495522
www.access-space.org
loss(a)access-space.org
Access Space is UK registered charity no: 1103837
Funded by Arts Council England, Yorkshire and Digital South Yorkshire.
Are there any affordable journals/magazines out there that people
recommend, for computer music in general? I'd love to subscribe to the
CMJ but the cost is way out of reach...
--
De gustibus non disputandum est.
Hi all,
I guess the title says it all. I was wondering if there was a button or
something that would enable this using perhaps a hdspmixer or something
similar or perhaps passing appropriate setting via alsa mixer?
On my setup jack always fails with anything above 48KHz.
Best wishes,
Ivica Ico Bukvic, composer & multimedia sculptor
http://meowing.ccm.uc.edu/~ico/
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Ive played around with .config settings, and I get an error
I can do something with:
rhgb: 1578 Bug: lock held at task time
my kernel like from grub.conf looks like:
kernel /bzImage-2.6.10-rc1-mm3-RT-V0.7.18 ro root=LABEL=/ rhgb quiet
If I remove rhgb as a kernel flag I get another error that I
cannot see the origin of, but I catch that it tells me that
something like \"deadlock\" has been stoped and that I should
report this. I think its \"deadlock\"...
What is the problem with my .config?
Thanks for the help! I cant wait to get capabilities working!
I had 2.6.9-rc3-mm3-VP-T3 working, but without capabilities.
-thewade
Hi all,
Would it be possible to connect my IMic USB soundcard capture port to the
onboard AC97 soundcard using JACK? I'm able to connect ports of a single
soundcard to each other, however I would like to be able to listen via the
onboard card what I'm recording on the external USB soundcard.
It seems that I have to start the JACK daemon in such a way that it can talk
to both soundcards at the same time.
jackd -V:0.94.0
best,
Jeroen
--
Kile - an Integrated LaTeX Environment for KDE
http://kile.sourceforge.net
Hi all,
I just wanted to share with you a quick report from the ICMC. The conference
was much fun although many events were overlapping and therefore it was
impossible to attend everything.
A number of new open-source audio-oriented software was demoed many of which
are also available for the Linux platform.
My Linux demo went relatively well (apart from the 2 consecutive X-server
crashes, courtesy of the crappy binary-only ATI's driver, and an odd issue
where disconnect of hdsp pcmcia did not yield acknowledgment from the 2.6.7
kernel and therefore subsequent reconnect did not recognize the card's
presence). There were ~20+ people in the audience at any given time
throughout the presentation (some of them were there only for a portion of
the presentation, so people kept coming and going).
Stuff I demoed (in no particular order):
*Jack
*Freqtweak
*Jamin
*Pd/Gem
*Latency tests
*Ardour
*Sweep
*Rezound
*Audacity
*gAlan
*Rosegarden
*Qsynth/fluidsynth
*ZynAddSubFX
*VKeybd
*Cinelerra
*Blender
*Xine/DVD playback
*Spiral Synth Modular
*KDE productivity
Stuff I wanted to demo but ran out of time:
*Hdsp latency/performance
*RTcmix synthesis language
*Supercollider
*Csound
Etc.
Stuff I observed preparing and doing this demo (please understand that I
have no idea whether these problems are result of my own setup or are
justifiable bugs -- nonetheless I am including them here in hope they may
shed some light towards their resolution):
*ZynAddSubFx crashes when a lot of polyphony is created even though the cpu
utilization is not topped-off
*Jamin crashes when pushing limiters to the extereme (not consistently)
*fluidsynth has some weird looping problems (I am trying to track this one
down as apparently this is specific to my setup)
*Ardour's real-time preview via sliding the timing bar does not work (I do
have one release prior to the latest, though)
*Spiral Synth Modular crackles a bit even with large buffer sizes when using
OSS (haven't had the time to do exhaustive tests nor did I try using Jack
object as of yet)
*Audacity has some instabilities when used in conjunction with Jack
*There is a real need for Jack to be able to restart (should a need for its
restarting ever arise) without losing all of the connections
Stuff that really rocked:
*I was able to run Jack on my via82xx laptop soundcard using rt mode with
64x4 buffers (5.33ms at 44.1KHz) *almost* rock solid (there is still some
issues due to crappy ATI driver and obviously 2.6.7 kernel that is still
sub-par to the 2.4.x kernel series performance, but that mainly amounted to
perhaps a 1 xrun/minute).
*I was able (although after the demo) to run hdsp with 64x2 (2.9ms at
44.1KHz) *almost* rock solid (random occasional xruns but no xruns when
adding new connections and/or apps to the Jack session).
*I tested the PD with the hdsp's 64x2 buffer size and used the latency test
patch by connecting audio out with audio in on the multiface and got ~6ms
:-).
The general reaction from the audience was quite positive as many of the
users who even were familiar with the Linux Audio scene were impressed by
the diversity and quality of the software offering as well as the
flexibility of the Jack's framework and the overall user-friendliness of the
UI/desktop environment.
I would like to therefore use this opportunity to once more thank all of you
for being such active and generous contributors to this great community.
Without you none of this would have been possible!
----------------------
The panel on the "Standards from the Computer Music Community" was very much
interesting as it covered many of the important facets of today's computer
music scene, but also more importantly revealed some of the greatest
strengths of Linux, including (but not limited to):
*openness of the standards and therefore ability to generate umbrella
meta-standards (i.e. LASH)
*longevity
*ability for a new standard to supersede the reigning old standard solely
based on its merit (i.e. Alsa vs. OSS), and not due to its commercial PR
and/or widespread use
*Minimization of the misrepresentation of the standard's features and/or
abilities
Having had this wonderful opportunity to be a part of such panel (many
thanks to Matt Wright for inviting me!) has truly reinforced and clearly
defined the advantages as well as strong reasons for being a part of this
community.
Many thanks go to all of you who have generously offered your insight in
these issues.
Time permitting, I will post a more in-depth list of the ideas I've covered
during the panel. Matt Wright should also have slides ready on his site
sometime soon.
Best wishes,
Ivica Ico Bukvic, composer & multimedia sculptor
http://meowing.ccm.uc.edu/~ico/
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