Hi,
In the spirit of organizing a well executed Awards ceremony and due to
lack of interest from the business community in sponsoring the inaugural
Linux Audio Awards for 2009 I have decided to withdraw from organising
the event and will postpone the inaugural event to the next Linux Audio
Conference in 2010.
Hopefully conditions will be more suitable for sponsors to get involved
next year.
Cheers.
//
--
Patrick Shirkey
Boost Hardware Ltd.
Hi everyone,
Fons, thanks to your essay "Using a DLL to filter time" [1], that you mentionned
in a discussion we had in August, I've put together a small library, named
Pendule, for accurate timing within a real time context. It's a tiny piece of
code, but offers a very easy to use replacement for gettimeofday().
Plus, it includes some benchmarking/measuring tools, that produce that sort of
fancy graphics (this one using a PCI hda intel card):
http://www.samalyse.com/code/pendule/shortgraph.png
Usage is very simple. first create an instance:
#include <pendule.h>
Pendule *pendule = pendule_new(buffer_size / sample_rate, bandwidth);
Then, in the realtime thread, update the loop every process cycle:
pendule_cycle(pendule);
And use pendule_gettime() instead of gettimeofday():
double current_time_in_seconds = pendule_gettime(pendule);
As expected, looking at the graph above, the obtained time doesn't drift as the
audio time, and has a lower jitter than the system time. Well, at least, it
works for me.
However, although my measures are pretty encouraging, I am not 100% sure of my
DLL implementation. Could you please review it ? It's there:
http://svn.samalyse.com/pendule/trunk/src/pendule.c
You can grab everything using svn:
svn co http://svn.samalyse.com/pendule/trunk pendule
I'd like to know how it works for others. You can easily test your
hardware/system and make graphs with:
./waf configure
./waf build
./measure
./graph
Check the README for more.
[1] http://www.kokkinizita.net/papers/usingdll.pdf
Best regards,
--
Olivier
On Mon, Feb 02, 2009 at 12:49:32PM -0800, Ken Restivo wrote:
> Wow, it's in Italia! I'd love to go. Alas, I can't;
> the airfare alone from SFO to Milano would be around
> US$1000... there's no way I can come up with that kind
> of money.
You're not the first US resident to deplore this...
What happened to all those cheap transatlantic
flights ? Petrol prices are down...
> Also I've never been to Italy myself (sono io
> cento-per-cento italiano, ma nato a New York),
> and I'm a bit afraid to go, since if I do,
> I might not ever want to come back. *sigh*
I'm not so sure of that... The US finally have a
respectable president, we still have Berlusconi.
Italy is in crisis - and not only the economy.
Last weekend some kids (youngest was 17, and all
from 'respectable' families) set fire to a homeless
Indian sleeping outdours, just 'per divertirsi'...
Ciao,
--
FA
Laboratorio di Acustica ed Elettroacustica
Parma, Italia
O tu, che porte, correndo si ?
E guerra e morte !
Hello all,
Some quick LAC2009 news.
The LAC2009 website now has some info on
travelling to and staying in Parma.
<http://lac.linuxaudio.org/2009/>
In the bed & breakfast category there is
one more which will be added soon:
DUCALE, Via Costituente 11, 43100 Parma
<http://digilander.libero.it/bbducale/>
If you look at the map on this website
(click on the foto), the CdM is very
near to the place marked 'Duomo'.
10-15 min from the conference site,
depending on your walking speed.
La Casa della Musica on Google maps:
<http://maps.google.it/maps?f=q&hl=it&geocode=&q=piazzale+san+francesco+parma>
Robin Gareus and Christoph Haag are working
on getting the registration page on line.
Ciao,
--
FA
Laboratorio di Acustica ed Elettroacustica
Parma, Italia
O tu, che porte, correndo si ?
E guerra e morte !
Hello all,
On popular demand (which means Joern Nettingsmeier
has been prodding me) there's an update of the
Ambisonic LADSPA plugins.
Version 0.4.0 adds a 2nd order periphonic panner and
horizontal rotator (i.e. 9-ch output).
Have a look at the README - channel orders of the
existing 2,1 plugins and the new 2,2 ones are not
the same.
As always
<http://www.kokkinizita.net/linuxaudio/downloads>
The fa-plugins.rdf has been updated as well.
Ciao,
--
FA
Laboratorio di Acustica ed Elettroacustica
Parma, Italia
O tu, che porte, correndo si ?
E guerra e morte !
J?rn Nettingsmeier <nettings(a)folkwang-hochschule.de> sez:
>
> true, for this particular case it would do (and that's what i'm using
> atm). but i have this idea for a plugin that takes actual mic distance,
> temperature, humidity and desired distance as parameters and will do
> something that is reasonably correct (not taking into account sound
> diffraction or reflection at temperature boundary layers, obviously).
> would be kind of cool, but i need to get a deeper understanding of the
> physics involved... especially the dependance on humidity is a very
> tricky and quite non-linear issue.
>
> fons is probably right that it doesn't make all that much of a
> difference, but since such a plugin could be a nice learning tool for
> sound engineers, i'd want it to be as precise as reasonably possible.
This sounds like a really interesting project to me, and I wish you
all the best in completing it! Aside from being a nice learning tool,
I'm sure it will be a *very* nice creative tool, as well.
I can't wait to hear what it sounds like to modulate humidity with a sine wave!
~Maitland
hi everybody!
does anyone know a way to compute filters that simulate air dissipation
for a given temperature and humidity?
so far, all i've found is an online calculator at
http://www.sengpielaudio.com/calculator-air.htm, but the javascript in
there is not exactly fit for citation :)
plus i know there is a standard (ISO 9613-1:1993) that deals with sound
attenuation, but i don't have access to a standards library and don't
feel like buying it...
a rough calculation at 18°C and 85% relative humidity (using sengpiel's
tool) yields:
f[Hz] dp[dBSPL/m]
----------------------
20 0
40 0
80 0
160 0
320 0.001
640 0.003
1280 0.006
2560 0.011
5120 0.032
10240 0.112
20480 0.404
which indicates that for my usecase (close-miked sounds that need to be
placed at distances between 10 and 45 m), the air-damping non-linearity
is really important.
question is: how do i design a filter to simulate this? would make a
cool ladspa tool eventually...
pointers to related papers or maybe even filters are most welcome.
best,
jörn
On Wed, 28 Jan 2009, hermann meyer wrote:
> Hello
>
> Thanks for the new version, build and run fine here (debian/sid).
> I would ask could you add the $(DESTDIR) variable to the Makefile
> INSTALLPATH to make Pakeage building a little easier, :)
>
>
Hi,
Sure, but I'm not familiar with the use of DESTDIR. How do you want
the makefile to look?
Downloads:
http://archive.notam02.no/arkiv/src/?C=M;O=Dhttp://folk.uio.no/ksvalast/arkiv/src/?C=M;O=D
jack_capture
============
jack_capture is a program for recording soundfiles with jack. Its default
operation is to capture whatever sound is going out to your speakers into
a file, but it can do a number of other operations as well.
0.9.31 -> 0.9.32:
*Changed default format for from wav to wavex for files with more
than two channels. Thanks to Fons Adriaensen for the suggestion.
*Added fix for 64 bit mode. Thanks to Andras Simon for helping
to find the bug and Dominique Fober for fixing the bug.
*Added the "-verbose" option for easier debugging in case program
crashes or freezes.
*Checks whether sndfile.h exists before generating setformat.c.
Good news.
I found out last week that I'll receive sponsorship for my LAC trip. That
means there will be a LASH presentation, and I think a LASH workshop is also
in order.
The amount I'm getting isn't all that much but it will cover my travel costs.
That means I'm on the lookout for _cheap_ accommodation near the conference
site during 15.-20. April. Is there some place there specifically for LAC
visitors?
Now, I need to write that paper before the 29th...
Juuso
PS: Dave, how's ticket #321 going?