Linux-audio-dev

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7520 discussions

Any introductory material for sound programming?

by Carl-Erik Kopseng

Having searched the net for hours, I still cannot find any tutorials or intro-material for someone new to sound programming in Linux. Can anyone tip me of such a place? Things that would be valuable for a newbie: - Introduction to various ways of storing audio; float vs integer representation, bit depth issues, etc. - Introduction to using standard libraries such as libsndfile and libsamplerate. - How to programatically convert 24 bit sound files to 16 bit files The *only* audio programming introductions I could find was about ALSA and OSS. Trying to directly use the APIs is very frustrating when one doesn't have a high-level understanding of what goes on ... -- Carl-Erik Kopseng

17 years, 2 months

[OT] DIY Trigger - Piezo to MIDI to PC

by Ray Rashif

Sorry for the very random subject, but I figured I'd need all the help I can get. I've read about this for a _little_ while (time constraints..arghhh) on the WWW, and I've posted on www.edrum.info too. In case anyone here has better/fast/helpful suggestions/advice/shizznit, I'm sort of cross-posting: I just want one trigger, which I'll use for the kick drum. As such, I'm interested to know if there are premade boards for the MIDI conversion. Basically all I need is something which can take the vibrations and convert them to electrical signals (piezo), and then fed to something else that will convert that electrical signal to a MIDI-ON message, after which I can plug it into the MIDI input of an audio interface or use a MIDI-USB adapter to plug in to a USB port. And regarding MIDI, if I want to take into consideration dynamics, and let the piezo trigger MIDI messages with varying attack information, how would it be done? So depending on the voltage generated, it'd be a MIDI-ON but the final message to the computer (audio interface) would be a "MIDI-ON && ATTACK == 75" sort of logic. Sorry for the noobish description, have just started to dabble into (audio/midi) electronics. I understand the concept and design roughly and I can move on by reading the construction manual (refering to edrum's DIY guide), but at the moment I'm looking for a quick way to build a trigger as I need it asap (and no $$ for a real trigger kit/module).

17 years, 2 months

Re: [LAD] [LAU] Simple, easy multithreaded circular buffer library for Linux?

by Joern Nettingsmeier

Olivier Guilyardi wrote: > Here's how to run the test: > > svn co http://svn.samalyse.com/misc/rbtest > cd rbtest > make test on a pentium-m 32bit notebook: nettings@hoppetosse:/local/rbtest> make test gcc -Wall -I. -I./jack -lpthread -o test-int-array-jack \ test-int-array.c jack/ringbuffer.c gcc -Wall -I. -I./portaudio -lpthread -o test-int-array-portaudio \ test-int-array.c portaudio/ringbuffer.c portaudio/pa_ringbuffer.c gcc -Wall -I. -I./portaudio -lpthread -o test-int-array-portaudio-nobarrier \ -DNO_MEMORY_BARRIER \ test-int-array.c portaudio/ringbuffer.c portaudio/pa_ringbuffer.c ./alltests.sh Starting ringbuffer tests (buffer size: 512) === Jack ringbuffer test === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 Success === Portaudio ringbuffer test === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 Success === Portaudio ringbuffer test (without memory barriers) === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 Success nettings@hoppetosse:/local/rbtest> -- jörn nettingsmeier home://germany/45128 essen/lortzingstr. 11/ http://spunk.dnsalias.org phone://+49/201/491621 Kurt is up in Heaven now.

17 years, 2 months

Re: [LAD] [LAU] Simple, easy multithreaded circular buffer library for Linux?

by Joern Nettingsmeier

Olivier Guilyardi wrote: > To figure whether memory barriers are needed or not, we need to run the test on > various architectures. > > For this purpose, I've set up a small svn repo with everything to run the test > easily. There's no dependency, you just need pthread, gcc and sh. > > Here's how to run the test: > > svn co http://svn.samalyse.com/misc/rbtest > cd rbtest > make test i don't really understand the finer points of this discussion, but hey it's always great to join a technical thread. my favourite bikeshed color is yellow :-D ok, here comes the result for a single-cpu athlon64 4000+ in 64bit mode. nettings@kleineronkel:/build/rbtest> make test gcc -Wall -I. -I./jack -lpthread -o test-int-array-jack \ test-int-array.c jack/ringbuffer.c test-int-array.c: In function ‘main’: test-int-array.c:101: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’ gcc -Wall -I. -I./portaudio -lpthread -o test-int-array-portaudio \ test-int-array.c portaudio/ringbuffer.c portaudio/pa_ringbuffer.c test-int-array.c: In function ‘main’: test-int-array.c:101: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’ gcc -Wall -I. -I./portaudio -lpthread -o test-int-array-portaudio-nobarrier \ -DNO_MEMORY_BARRIER \ test-int-array.c portaudio/ringbuffer.c portaudio/pa_ringbuffer.c test-int-array.c: In function ‘main’: test-int-array.c:101: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long unsigned int’ ./alltests.sh Starting ringbuffer tests (buffer size: 512) === Jack ringbuffer test === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 49536 != 49408 at offset 0 failure in chunk 330502 === Portaudio ringbuffer test === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 Success === Portaudio ringbuffer test (without memory barriers) === starting ringbuffer stress test (2 minutes max) buffer size (bytes): 512 array size (bytes): 256 reader started on cpu 0 writer started on cpu: 0 Success -- jörn nettingsmeier home://germany/45128 essen/lortzingstr. 11/ http://spunk.dnsalias.org phone://+49/201/491621 Kurt is up in Heaven now.

17 years, 2 months

ALSA sequencer question

by Julien Claassen

Hello! If I want to output a MIDI note to all channels, what do I have to assign to snd_seq_event_t *ev; ev->data.note.channel Is there a possibility to do so in one strike, or do I ave to iterate through all 16 channels? 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

17 years, 2 months

RME PCI Express card drivers

by Fons Adriaensen

Hello all, Could someone confirm / deny the availability of fully working drivers for the following: http://www.rme-audio.de/en_products_hdspe_madiface.php http://www.rme-audio.de/en_products_hdspe_expresscard.php I hear rumours that these are / may be available but would like to be 100% sure before planning to use them in a future project. TIA, -- FA Follie! Follie! Delirio vano e' questo!

17 years, 2 months

Re: [LAD] [Lash-dev] Re: LASH - some questions & comments

by Nedko Arnaudov

schoappied <schoappied(a)gmail.com> writes: > There is posted a message for testers here: > http://linuxmusicians.com/viewtopic.php?f=24&t=622 > and a discussion about lash here: > http://linuxmusicians.com/viewtopic.php?f=28&t=609 > > If you need testers in the future maybe good to left a message there > or/ and on the LAU mailinglist? Thank you for your forum post about rc1. Posting announce of rc1 to dev-only lists only was intetional. The reason is to avoid user frustration that can be caused by "unpolished" software. Also devs are supposed to be able to give better feedback for crashing software. If everything goes as I expect, rc2 announce will probably be posted in laa and lau mailing lists too. -- Nedko Arnaudov <GnuPG KeyID: DE1716B0>

17 years, 2 months

[ANN] lash-0.6.0 release candidate 1

by Nedko Arnaudov

I would like to ask LASH beleivers and other interested parties to test the first release candidate for 0.6.0. Juuso Alasuutari and me have been doing some major changes to the lash code. We have done lot of work, we've fixed several big implementation issues and we need stable point before doing more changes (0.6.1 and 1.0 milestones). In the tarball there is simple lash_control script. One can also control LASH through patchage-0.4.2 and through lpatchage (availabe through git). User visible changes since 0.5.4: * Use jack D-Bus interface instead of libjack, enabled by default, can be disabled. Ticket #1 * Allow controlling LASH through D-Bus. Ticket #2 * Use D-Bus autolaunching instead of old mechanism. Ticket #3 * Log file (~/.log/lash/lash.log) for LASH daemon. Ticket #4 * Client stdout/stderr are logged to lash.log, when clients are launched by LASH daemon (project restore). Ticket #5 * Improved handling of misbehaved clients. Ticket #45 * Projects now can have comment and notes associated. Ticket #13 Download: http://download.savannah.gnu.org/releases/lash/lash-0.6.0~rc1.tar.bz2 http://download.savannah.gnu.org/releases/lash/lash-0.6.0~rc1.tar.bz2.sig -- Nedko Arnaudov <GnuPG KeyID: DE1716B0>

17 years, 2 months

[IDEA] Amp and effects modeling software for guitar

by almbfsek＠turk.net

Hello, Few days ago I came up with an idea about an open source guitar modeling software. But because of my lack of knowledge on both electronics and audio engineering I couldn't decide if it worths something. Here it is directly quoted from linuxmusicians.com **QUOTE** Okay! My idea is to use GNUCAP or SPICE to process the guitar signal. These are the top open source analog circuit simulators that are also widely used in the industry for general purpose circuit simulation (not audio specific). You basically feed them the schematics of a circuit and wait for magic to happen. I believe they may be hacked to accept a guitar signal as a varying voltage source. Now there are 3 questions: Is that even possible? If yes, is it possible in real-time? If yes, would results be satisfying (quality and accuracy wise) **END_QUOTE** thanks very much, and sorry in advance if I missed something obvious and this is a completely useless idea

17 years, 2 months

Re: [LAD] [IDEA] Amp and effects modeling software for guitar

by almbfsek＠turk.net

It would be great though since it would take a minimal amount of effort to make it work with a guitar signal but no real-time means the end of this idea thanks very much for the quick answers

17 years, 2 months

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Linux-audio-dev