Linux-audio-dev

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7539 discussions

[linux-audio-dev] latency and P4 hyperthreading?

by Fernando Pablo Lopez-Lezcano

Hi all, has anyone tested latency on a P4 machine with Hyperthreading support? (HT simulates two processors on one processor using - I guess - the spare time available in the cpu when it is waiting for, for example, memory accesses). Anyway, on a: P4 2.4G 800MHz fsb, 875P chipset, 1G ram, Seagate Barracuda V 60G drive: Booting into an smp kernel with HT enabled in the bios (kernel based on 2.4.21-rc6 with the usual low latency, preemptive and full acpi kernel patches) I see both processors, but the latency in the disk tests (using latencytest 0.42) has spikes that go up to 10/15 msecs, specially in the read/write test. If I boot into a up kernel, or if I boot with acpi=off I see only one processor and the latency for the disk tests is fine. Same kernel, same alsa on a dual Athlon MP 1800+ machine does not show any abnormal latency behavior so this seems to be confined to HT machines... :-( I guess "made up" processors are not as good as real ones :-) -- Fernando

22 years, 9 months

[linux-audio-dev] Presentation & New project.

by ListBox

Hi to everybody... I'd like to introduce myself to you and to present you my new project. I'm a 26 year old programmer living on the Canary Islands. Unfortunately I'm new to Linux and I've been specializing on Pascar rather than on C. I'm a hobby musician and that's where my idea started. I seek people like me who'd like to help me to assemble a really good studio system with existing aAPIs and peaces of code. Today I uploaded my initial page which explains the project. Please have a look at http://laudio.freehomepage.com/index.html (my page) where I describe the project in detail. Comments are welcome. Thank you & greetz Merlin

22 years, 9 months

[linux-audio-dev] Horgand v0.90

by holborn

Hi! First Release. This program is released GNU/GPL version 2. Horgand is a organ, is my first attempt to do something with sound, generates sound like a FM synthesizer in real time. And i try to add some DSP effects, rotary, chorus, tremolo, delay ... Is Jack capable and recognizes MIDI Program Change (1-32), Volume, Modulation... Horgand is tested on a PIII 966 (Debian Sid ) and PII 300 (Gentoo). REQUERIMENTS: * FAST COMPUTER * LINUX * ALSA * JACK * FLTK 1.1 I'm musicien, not programer i do this only for fun. Take a look in http://personal.telefonica.terra.es/web/soudfontcombi/ Comments and patches will be apeciatted Josep

22 years, 9 months

[linux-audio-dev] A "best" event delegation strategy?

by Lukas Degener

Hi list, Here is a propblem that is propably already solved in another context, so i would like to know some opinions on it: I am trying to implement a (hopefully:-) ) simple general-purpose event delegation architecture. The actual application will propably be something like a network of modules that can do arbitrary filtering, generation and manipulation of midi events in real time. As propably different kinds of external event sources, like several midi ports, maybe joystick device and of course a gui, are involved, how would one efficiently organize the delegation of events passed between the modules, so that the everything is still thread-safe? The three main ideas i can currently think of are: A: don't do it at all, that is, everything is implemented as simple subject/observer patterns, so that the communication is a pure module-to-module thing. Mutexes et al, would have to be managed by each individual plugin. B: use a global, mutexed event queue. This could be a priority queue for time-stamped events, or a simple FIFO. C: use local queues. As above, but for each individual module. Each of the above aproaches seems to have its advantages and disatvantages. E.g. if queues are used, this would as far as i an judge, make it easy to have feedback cycles. OTOH this would propably introduce some overhead which aproach A wouldn't have. C would propably involve a single thread for each module, or a global "clock" thread that periodicaly calls an "process_queue" method on each module. Is there a general "best" way to do this? Kind regards, Lukas

22 years, 9 months

[linux-audio-dev] [ANN] tuneroid 0.9.3

by Jozef Kosoru

tuneroid 0.9.3 tuneroid is a tuner for variety of musical instruments. It is designed to tune musical instruments on PC using a microphone or directly connecting the instrument to the PC's sound card. http://www.uid0.sk/zyzstar/?tuneroid -- jozef kosoru http://www.uid0.sk/zyzstar

22 years, 9 months

[linux-audio-dev] [ANN] swh-plugins 0.4.2

by Steve Harris

http://plugin.org.uk/releases/0.4.2/ Highly recomended upgrade for 0.4.x users. Changes: * Great new set of filter plugins from Alexander Ehlert * Applied patch from Anand Kumria to make it build with gcc 3.3 * Rewrote the flanger modulation code - its not optimised, but should work * Added support for FFTW3 * Added denormal killer to l/c/r delay - hopefully works better on PIV * Fixed serious peak detection bug in lookahead limiter * Things I forgot Thanks to Nick T. and Anand K. for bug reports and Alexander E. for the new plugins. FFTW3 is much better than old versions, but if youre going to upgrade make sure you tell it to build the 32bit library, and optimise it right for your CPU. The SIMD optimisations (SSE etc.) make a lot of difference. FFTW2 will be supported for the near future anyway. - Steve

22 years, 9 months

[linux-audio-dev] FIFOs vs. sockets

by Hans Fugal

On linux, which is faster, pipe, FIFO, or socket? What about shared memory - is it faster, and if so is it faster enough to warrant the extra programming overhead? -- Hans Fugal | De gustibus non disputandum est. http://hans.fugal.net/ | Debian, vim, mutt, ruby, text, gpg http://gdmxml.fugal.net/ | WindowMaker, gaim, UTF-8, RISC, JS Bach --------------------------------------------------------------------- GnuPG Fingerprint: 6940 87C5 6610 567F 1E95 CB5E FC98 E8CD E0AA D460

22 years, 9 months

[linux-audio-dev] [OT] Analog circuit design?

by Paul Winkler

Sort of off-topic, except that i want to do it on linux and it does have to do with audio :) I've been wanting to tinker a bit with analog audio circuit design. I've built a few boxes from schematics but I've never actually designed a circuit. What I'd REALLY like is some GUI software in which I can construct a circuit diagram and then feed in a test audio signal and through some DSP magic, hear (more or less) what the result would sound like before I start using my big clunky hands to ruin physical objects :) Does such a thing exist? Or some combination of software that would do the above? I've been looking at some SPICE resources online but I can't tell if you can feed an arbitrary digitized audio signal into a SPICE simulation. -- Paul Winkler http://www.slinkp.com Look! Up in the sky! It's PURPLE KABUKI WARRIOR BOOMERANG! (random hero from isometric.spaceninja.com)

22 years, 9 months

[linux-audio-dev] [OT] Linux Music & Sound Software site updated

by Dave Phillips

Greetings: As of May 30 2003 the Linux Music & Sound Applications sites have been updated. The site may be reached here: http://linux-sound.org (USA) Here: http://www.linuxsound.at (Europe) And here: http://linuxsound.jp (Japan) Best regards, == Dave Phillips The Book Of Linux Music & Sound at http://www.nostarch.com/lms.htm The Linux Soundapps Site at http://linux-sound.org

22 years, 9 months

[linux-audio-dev] high-res time measurement?

by jacob robbins

I'm a little green at time measurement facilities available in linux, In my host, I would like to be able to measure how much time each individual LADPSA plugin takes. Assuming I do realtime work with the smallest buffer sizes my system can handle, what options are available to me to measure time on this small scale? I know that the typical system calls time and gettimeofday have resolution of 10 ms, which is too big for this purpose. Is there any way to do this? Is there a high-res time howto? -jacob robbins.....

22 years, 9 months

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Linux-audio-dev