I have made a program which is to be run on a dedicated computer,
equipped only with a multichannel soundcard (hammerfall), a small LCD
and a remote control. This forms a dedicated surround processor (if
interested in the software, look at
http://www.ludd.luth.se/users/torger/almusvcu.html) for use in
multichannel HiFi systems.
In some configurations, a 64 sample processing block is relevant,
leaving a total IO-delay of 128 samples, which in 44.1 kHz is about 3
ms.
With such a configuration, I have got the system going for a few hours
at most before underflow. Of course the relevant processes are realtime
scheduled, I have even used tricks with sched_yield to get the
processes yield in the right order (I will probably have to pay for
that sooner or later though) for the most safe operation.
So, my question to this list is if someone has run a similar system for
days without underflows, and if there is some guide or tips on how to
put together the for the moment best low-latency kernel, if there are
kernel features that should be avoided, some bad driver or filesystem
perhaps, and if there are some hardware setting tricks (apart from
giving the sound card the highest interrupt priority). Perhaps tips on
which user space processes that should not run (I have no syslogd or
cron, but sshd is running)
Is it even possible today to build an embedded system with 1.5 ms
processing block based on Linux, which runs until hardware or power
failure? Oh, my software does not necessarily need to access any
filesystem while it is processing, although it would be good if it
could (to continuously save volume settings and similar if changed
through the remote control). So it can be seen as a strict
soundcard-to-the-cpu-and-back problem.
/Anders Torger
Hi,
Autocomp is an automatic accompaniment generator for Perl and Csound,
developed on Linux. It's an attempt at a practice utility for musicians.
Freshmeat project page is here:
http://freshmeat.net/projects/autocomp/
Download it or read more here:
http://www.waz.easynet.co.uk/software.html
Currently there is only one style of output, which is a pastiche of a
'swing' style with a walking bassline. The output is heavily on the
gorgonzola side of cheesy, but it's already at a stage where you can
practice with it if you don't mind the cheese level.
All comments/suggestions etc gratefully received.
Cheers etc.,
Wayne
--
Wayne Myers
http://www.waz.easynet.co.uk/
>Actually I'm just asking because I want to see how good jack is and
how >it works before we start to add jack support to glame.
Works well for me.
Having jack support increases the liklihood of more people using glame too.
--
Patrick Shirkey - Boost Hardware Ltd.
For the discerning hardware connoisseur
Http://www.boosthardware.comHttp://www.djcj.org - The Linux Audio Users guide
========================================
Being on stage with the band in front of crowds shouting, "Get off! No!
We want normal music!", I think that was more like acting than anything
I've ever done.
Goldie, 8 Nov, 2002
The Scotsman
Mmm.. releases :)
Biggest thing is that it now listens to changes in alsa and
automatically refreshes.
* made a nice dlopen() system for GUIs and drivers
* ladcca support
* major amounts of code cleaning up and seperating (eg apb.h -> 6 .h's:)
* bug fixes
* compilation fixes
* listens to alsa changes in a thread
* gtk gui now uses a proper toolbar with stock buttons
http://pkl.net/~node/alsa-patch-bay.html
Bob
Hi all,
I'm just curious about the software setup people use here to
play around to make music. Furthermore I'd be interested what
software setup people use to use jack. I was recently wanted
to try out jack so I just installed the debian packages of jack
and the alsaplayer with jack out, but wasn't really successfull.
So before I start building lots of apps, I just wanted to know what
is worth being tried out.
Cheers, Alex
from electronic musician (dec/2002):
"Polish developer Professional Sound Projects (PSP) has introduced a
plug-in emulation of Lexicon's PCM 42 hardware, and it bears
investigation. But first, I must make a disclosure. I designed the
Lexicon PCM 42, so this won't be your usual review. I can't claim
total objectivity, but I hope that I can offer some insight.
..."
(actually, its a very, very normal EM-style review. too bad, after
such a great start).
--p
from the gtk+ 2.2 announcement:
----------------------------------------------------------------------
Support for new X extensions, standards, and libraries:
GTK+-2.2 adds support for the RANDR extension for screen
size changes and for startup notification via a draft
freedesktop.org protocol. Interoperability with Qt for
inter-application embedding via the XEMBED protocol has
been improved. With support for version 2 of the Xft library,
antialiased text can be displayed even on older X servers.
----------------------------------------------------------------------
Hi folks,
First of all a happy x-mas
and newyear :)
I was just wondering if some of you
had considered using / implementing /
testing the new x-dnd (X Drag and
Drop) specification ?
http://www.newplanetsoftware.com/xdnd/
It seems very useful. It would be great
if we could just drag and drop audio
parts, pieces of midi, control settings ...
from one audio app to another.
Probably the protocol needs to be made aware
of the existence of these types and then
the audio apps should be able to handle
incoming data of that type.
I'm by no means a xdnd guru :)
I just thought I'd throw it in the group.
best regards,
Vincent
Hi all,
This is just an intermediate release to fix some things (and add LADCCA
support of course :)
* jack_set_server_dir is optional
* LADCCA support
* fixed bug dealing with LADSPA_PATH
http://pkl.net/~node/jack-rack.html
Bob
ZynAddSubFX is a opensource software synthesizer for
Linux.
It is available at :
http://zynaddsubfx.sourceforge.net
or
http://sourceforge.net/projects/zynaddsubfx
News:
1.0.3 - small bugfixes: "Bypass Global Filter" from
ADnoteUI dissapears sometimes ;
removed the low amplitude noise produced by the
reverb;
if you "acconect" zynaddsubfx with aseqview no note
was processed a long time.
- added Notch Filter
- added the option to randomize the ressonance
function
- added VU-Meter
- Change the Insertion effect modes behaves (it
sounds a bit louder)
- Added to the project an external program
called Spliter that splits the
keyboard and alows you to play two instruments same
time. You can use this
program with ZynAddSubFX or any other synthesizer.
- Added a new function to OscilGen
Paul.
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