Linux-audio-user April 2009

linux-audio-user@lists.linuxaudio.org

112 participants
101 discussions

Steinway_IMIS2.2 soundfont (no loops fix)

by Roberto Gordo Saez

This is Steinway_IMIS soundfont, version 2.2. ftp://musix.ourproject.org/pub/musix/sf2/Steinway_IMIS2.2 This version fixes the issue with loops. I hope this is the good one and there are no more remaining major bugs. Marcos is a little busy right now, so he asked me to make this fix. He is thinking to make other improvements, so expect more updates soon.

1 year, 3 months

[linux-audio-user] Sub-harmonic generator? (LADSPA or VST)

by Tim Howard

Hello, Does anyone know of a good plugin that will generate subharmonics? I would like to put a little more low frequency "oomph" into my bass track. Preferrable LADSPA, but VST would work, too. Thanks for any help! -TimH

7 years, 10 months

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

by Kjetil S. Matheussen

Olivier Guilyardi: > > Ken Restivo wrote: >> It has been over 7 years since I last messed around with writing Pthreads applications. >> >> I recall it as a painful, ugly, brain-numbing task. I located an exercise I did back then to address the consumer/producer problem in Pthreads, and just the sight of it is giving me a headache. >> >> I'm being lazy, so instead of researching everything that's out there, I'll ask here: can anyone recommend a relatively simple and painless abstraction library (GPL or LGPL of course) that will give me functions to create a thread in which I can stuff things into a ring buffer, and another thread in which I can pull stuff out of it? >> >> By the way, I know that JACK has a very nice event buffer which is insanely easy to use (and I have), and makes multithreading almost transparent, but this isn't a JACK app. > > I don't know of any abstraction library, but creating/terminating a normal > thread with pthread is really an easy task IMO. It's about 10 lines in C. > > For inter-thread communication there's Portaudio's ring buffer: > http://portaudio.com/trac/browser/portaudio/trunk/src/common/pa_ringbuffer.h > > It can easily be used out of Portaudio (I'm currently doing that), and it > features memory barriers [1] which AFAIK Jack's ringbuffer doesn't. > > One problem with everything Portaudio is this heavy naming scheme. For a simpler > API, you might like my little wrapper: > http://jackbeat.samalyse.org/browser/jackbeat/trunk/src/core/ringbuffer.h > Nice. It's probably quicker to copy the jack_ringbuffer.c file out of jack though. > Portaudio actually also offers a callback mechanism (with hidden thread > creation), so if you're coding an non-JACK audio app, you might want to check it > out. > > For thread synchronization, semaphores (man semaphore.h) are really easy to use. > However, if you need a lock-free equivalent (for realtime, ...) phtread mutex > and especially pthread_mutex_trylock are your friends. > Those friends can be really cranky sometimes though. By using atomic operations instead, it's possible to avoid a lot of headache by not having to synchronize at all. Performance might be better too. Midishare has lockfree atomic functions for lifo and fifi queues: http://midishare.cvs.sourceforge.net/viewvc/midishare/midishare/src/common/…

12 years, 6 months

Seq24 and jack-transport with Jack-1.9

by go music

This is for all those who might have tried seq24 with jack2. Attached is a patch containing modifications made by Stéphane Letz, the developer of jack2 who was so kind to have a look into the seq24 code yesterday. In the original setting, seq24 was not able to do a proper client connection and failed working with jack2 transport. It also fixes the deprecated call to jack_client_new. It applies to src/perform.cpp , hope it works as a patch... Thanks very much Stéphane. Cheers Frank

15 years

Audio Hardware Recommendations

by Christopher Stamper

Hello all, I'm thinking about finally upgrading from my cheap soundblaster+mic to something of a little higher quality. I'm thinking along the lines of an external firewire/usb box and some kind of low-cost mic. I'd use it primarely for vocals, but I'd like the recording interface to support 2-channel, for possible some piano recordings/etc. I also don't want to spend very much, and would plan to get it used, on ebay. What do you guys use or recommend? Thanks! -- Christopher Stamper Email: christopherstamper(a)gmail.com Web: http://tinyurl.com/2ooncg gTalk: http://tinyurl.com/6e359r Skype: cdstamper

15 years

Goed nieuws! Especially for the Dutch speaking: special linux audio forum part on homerecording.be !

by rosea grammostola

(Nederlandstalig linux forum gedeelte op homerecording.be >>> http://www.homerecording.be/forum/f43/ !) Hi, Thanks to the LAU mailinglist, I've discovered the possibilities of Linux for producing music in the last two years. But it seems I'm a bit of a special case in The Netherlands... most people seems to use Mac or Windows for music production, even people who prefer Linux as their main OS... To change it a bit, I helped people on Linux forums and wrote a dutch tutorial for Qjackctl and Ardour. I also posted my enthusiasm and knowledge on 'not-linux' forums... got a lot negative reactions, but not on www.homerecording.be. The had a open mind for opensource software... and after posting some posts there, they have decided to open a special subforum for making music on Linux! :) (Windows and Mac can't say that...) It would be cool if dutch speaking people will support this forum part by taking a look at it reguarly and to post some messages, moreover to help people with making music on GNU/Linux! You can find the forum here: http://www.homerecording.be/forum/f43/ CU there! \r

15 years, 1 month

alsa midi to jack midi

by andy baxter

hello, I've been looking at ingen ( http://drobilla.net/software/ingen/ ). Had some problems getting it to build, but the trick turns out to be to install liblo and libsoup bfore you configure the build. It's a really nice bit of software - a GUI modular synth that lets you design and save simple patches which can then be used as building blocks for more complex ones. The main problem I'm having with it so far is that it doesn't seem to understand alsa midi - only jack midi. This is difficult as I don't have or know of any midi programs (particularly a virtual keyboard) which produce jack midi signals. Does anyone know of an easy way to convert alsa midi into jack midi and vice versa? andy

15 years, 1 month

using jdelay

by Atte André Jensen

Hi I tried measuring my latency with jdelay. Started in on the commandline, first it said Signal below threshold... Then I connected it's input to the output of system:capture_1 with my microphone connected and it output to the input of system:playback_1+2. Now I get a squareish tone and when "singing" into the microphone I get reading like these: 22442.483 Inv 58010.411 ?? 43602.390 ?? Inv 43474.474 43474.474 ?? Inv Signal below threshold... Signal below threshold... Signal below threshold... 25549.731 ?? 25549.731 ?? Inv 37749.225 ?? 37749.225 ?? Inv 37749.225 ?? 24653.357 ?? 24653.228 ?? Inv 25677.165 ?? 11013.134 ?? Inv 25677.153 ?? 2821.046 ?? Inv 2821.046 ?? The man page says the values are in samples, so for instance a value of 37749.225 should be 0.77 seconds at 48000, right? This seems bogus (qjackctl reports 10 ms). What am I doing wrong? -- Atte http://atte.dk http://modlys.dk

15 years, 2 months

suspending with realtime kernel

by Robert Persson

Hello I've been having a problem which isn't directly to do with audio—it's to do with the Ubuntu realtime kernel—but I haven't got any answers from the Ubuntu forums and this is a real showstopper as far as doing audio work goes. I hadn't done any audio work for quite a while, and therefore had been running the 64 bit Intrepid generic kernel on my Thinkpad R61i without too much problem (but not entirely without problems either). Yesterday I booted the realtime kernel. When I tried to suspend the machine I got a message "Freezing of tasks failed after 20.00 seconds (2 tasks refusing to freeze):" At this point the interface had frozen completely and I had to force a shutdown by holding down the power button. There was however some intermittent flickering from the disk activity indicator, so something was still working. The tasks that were refusing to freeze were NetworkManager and wpa_supplicant. This happened one or two more times. Then I tried it again and found that 4 tasks this time were refusing to freeze: NetworkManager, wpa_supplicant, avahi-daemon and gnome-do. After this I returned to the generic kernel, which is working as well as it always did. Any ideas what's going on here? Unfortunately upgrading to Jaunty is not a viable workaround yet because of its broken Intel graphics driver. Many thanks Robert

15 years, 2 months

[ANN] Nama agile recorder-mixer version 0.98

by Joel Roth

Another version of Ecasound/Nama is available at CPAN for your multitrack recording pleasure. We are approaching a 1.0 release! Here are the newest changes: - Track soloing - Documentation rewrite - Pager for long text listings - Many bug fixes - Simplified build script (preprocessing really) facilitates source browsing/tinkering And a feature list: - Based on Ecasound, a stable, full-featured audio processing engine. - Very flexible template-based signal routing allows for multiple buses. Possible to simultaneously record and mixdown a live performance. - Tracks + can be mono, stereo or any desired width + volume/pan with any number of effects + signal sources from soundcard or JACK clients + multiple WAV versions per track + playat, reverse, select, audioloop - Tk based GUI + main window and effects window + auto-hinting of LADSPA plugin parameters range and linear/log + stable, lightweight + no dialog boxes considered a feature - Full-featured text UI + Executes Ecasound commands, Nama commands, shell commands and perl code + multiple commands per line + help for commands and plugins - Automated connection to JACK clients - Marks - Looping over entire chain setup between designated marks - Full diagnostics with dumping of all data structures - Persistent settings stored as browsable YAML - Per-project configuration files - Small codebase compared to other projects, ~7K lines - Active development - Hackable, extensible Caveat! We're having some difficulties compiling Audio::Ecasound, on which Nama depends, for x86-64. The easiest way to install Nama is from CPAN: cpan Audio::Ecasound::Multitrack If you'd prefer to install from sources, you can copy the repository thus: git clone git://github.com/bolangi/nama.git Build instructions are found in the README. I'm interested in any comments, bug reports, feature requests, etc. you may have. Regards, -- Joel Roth

15 years, 2 months

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Linux-audio-user April 2009