Linux-audio-dev

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7516 discussions

by AlgoMantra

Geeks, tuxians and audioslaves! I need some help here. I got a bit freaked when I saw that the libsndfile example files contained a program nearly 1000 lines long to simply play a file. But perhaps it's intended for a higher level of geekery. My needs are very modest. My task: I just want to load a few samples(wav) which are represented on a GUI (using SDL) and when they knock about on the screen, sound (music) is generated using some rules.I need them to mix, of course. I was using SDL_mixer for this. But my problem was that I want to write to file (record) a whole session of the running program as a single wav. SDL_mixer does not seem to have writing options. Now is there a way I can do this in some reasonably efficient manner using libsndfile? I could load using libsndfile too, skipping SDL_mixer altogether. It's already installed. What to do? Any tips would be appreciated. Thanks, ------- -.- 1/f ))) --. ------- ... http://www.algomantra.com

17 years

Voice2Midi : or how to get the note names of songs you sing

by Eric David

Hi, I've just published a free software that can recognize notes recorded by an audio input device in real time. It's here : http://davidferaoun.free.fr/eric/zik/voice2midi.php This may interest users (it's can be used freely) and developers if they want to put it into a bigger audio program. There are 2 releases : signed applet and stand-alone. Both work on my PC, but sometimes it seems that the signed applet may cause a browser crash. The source code (in java) is available for download. ( Btw: I use a java FFT library from the online book http://www.cs.princeton.edu/introcs/97data/FFT.java.html but I don't know its license. Sorry ) Best regards, Eric

17 years

LASH - some questions & comments

by Fons Adriaensen

Some questions and comments regarding the LASH release candidate. 1. lahs_init() Would it be possible to document the contents of the first argument 'lash_args_t *args' ? I'd be happy to give lash all the info it needs but feel quite strongly that I should be able to provide this myself and not being forced to have liblash inspect/mangle my argv. See also 2. 2. lash_extract_args() The type of main()'s argv is char *argv[], so why is the second argument a triple pointer ? Re-arranging the elements of argv does not require access to the variable argv itself, only to its elements, and for this a double pointer is all you need. 3. The Restore_Data_Set event. How does a client know when all configs saved by a previous session have been received ? The client may be updated meanwhile and expect more configs than were saved. It should have defaults for these of course, but how long should it wait for data that may never arrive ? Ciao, -- FA Follie! Follie! Delirio vano e' questo!

17 years

soundcards and clocks

by Julien Claassen

Hello everyone! I have a couple of questions regarding this. 1. Does every soundcard have a clock? 2. Do other architectures than ALSA offer access to this clock? 3. Can the soundcard clock probably be accessed via simple device file access? I have looked into OSS, but didn't find anything there, directly reffering to clocks. If OSS or other unix sound drivers don't offer access to this resource, how would they take care of accuracy? Kindest regards and thanks in advance for any good advise 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

JACK transport timebase and its callback

by Julien Claassen

Hello! I just read through the JACK transport section in the JACK reference again. If you want to be timebase-master you can (or must) supply a callback function to update the time-info. Does my program need audio thread (a process function?) Which timing source is used to update the time? Does my program provide it or does JACK provide it and my program only really kicks in when I want to relocate (jump to another position)? I am correct in assuming, that my code doesn't have to be multithreaded (at least not look multithreaded) if I want to use the JACK transport interface (control and timebase)? 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

Denemo 0.8 Release -

by Nils Gey

Dear linux audio users and developers, Short version: ================== Denemo 0.8 is fresh, hot and avaible now! Grab your tarball @ http://download.savannah.gnu.org/releases/denemo/ (Windows binaries will join in later) and have a look at our newest features including full scripting support! If you are a programmer please help us to give Denemo JACKmidi/JACKtransport support so that its capable of blending with the rest of Linux-pro-audio. For contact, feature requests, bug reports and further information please visit http://www.denemo.org Interesting version: ================== Denemo is a music notation program for Linux and Windows (and MacOS some time ago) that lets you rapidly enter notation for typesetting via the LilyPond music engraver (because Lilypond is the reference and there is no sense in coding your own WYSIWYG notation apps). Its mainly controlled via your pc-keyboard with several edit-modes and shortcuts. Please note that we need help! Denemo has already many notation features build-in and if anything is not avaible you can enter Lilypond commandos and save them with your denemo file so that you can use the whole range of lilypond features. This means that Denemo is already capable of writing full, professional scores. But it lacks sequencer-features like advanced playback and routing via JACKmidi and support for JACKtransport. To really become the first usefull Linux notation-editor and notation-sequencer this is the last piece of the puzzle. Version 0.8 changelog: 1. A scripting interface to the Denemo commands has been created. 2. Example script-based commands are provided with the Denemo installation. 3. New scripts can be hand-written or "recorded" from a sequence of menu item clicks or by editing another script or a mixture of these. 4. New commands (scripts) can be installed in the menu system, given keyboard shortcuts, and generally used as other commands are. 5. The example scripts provided include a script showing the potential of Denemo for use in music education. In this example, random notes are generated and the user has to name the note. 6. Other examples include scripts for commands useful when generating scores with percussion, guitar fingerings, orchestral markings etc. 7. Various bugfixes and improvements to midi import have been made. greetings, Nils Gey www.denemo.org

17 years

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

[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

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

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

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Linux-audio-dev