Linux-audio-dev September 2009

linux-audio-dev@lists.linuxaudio.org

61 participants
44 discussions

phasex-0.12.0-pre1

by William Weston

Announcing phasex-0.12.0-pre1: The pre-release is here. It's stable. It builds cleanly. No build errors or warnings. No runtime errors or crashes. No glitches. If no bugs are found in the next week, then this code (with the addition of some brand-new patches) will become the stable release. Changes since phasex-0.12.0-beta4: - Build system overhaul. GCC version detection for better arch- specific optimization (compiles clean with gcc-3.4.x or higher). Atom builds fall back to next-best optimizations for GCC < 4.5.x. New --enable-32bit and --cpu-power-level= flags and better user variable handling for ./configure. Missing -lpthread in link phase is fixed. - Velocity control for the amplifier. Better aftertouch handling. - Scheduling policy defaults to SCHED_RR, and can be changed in the settings at runtime. - Broken ringbuffer code has been fixed. No more glitches (unless you have actually run out of CPU). - Theme loading has been fixed. Now properly detects if the nodoka theme engine is installed, and quietly falls back to an engineless theme. - Fullscreen and Maximize interaction have been fixed. - New command line options: -m (--midi-channel=), -f (--fullscreen), and -M (--maximize). Loading a patch by name or by program number on the command line now finds the appropriate patch in the patchbank. - The lurking patch name corruption bug has been fixed! - And more. See the ChangeLog for details... Download phasex and hear for yourself... http://sysex.net/phasex/ Alternatively, you can utilize the git repositoty: git clone http://sysex.net/git/phasex.git Cheers, --ww

15 years

GIl, python, threading, and IPC

by Patrick Stinson

I wrote a scripting engine for a pro audio plugin by embedding a CPython interpreter. Since audio sequencing hosts use separate threads for each audio track, loading more than one instance of my plugin while running scripting code causes contention on Python's GIl and results in CPU spikes at low latencies. While CPython is more than capable of running fast enough in the audio thread for control-rate (MIDI) work, the GIL is killing us. Using process migration to move calls to CPython to daemon processes would take less code than forking python itself, but the scripting engine includes a python extension module that exposes pointers to the C++ classes in the audio engine. This complicates things quite a bit. The calls look like this: size = engine.getAudioBufferSize() engine.loadPatchFile(SOME_PATH) instrument.loadAudioFile(SOME_PATH_2) instrument.setVolume(.5) ...where 'engine' and 'instrument' are C++ classes in the audio engine that I wrapped in a python extension. I think that the biggest problem for me is tackling the complexity of managing new real time daemon processes for each audio track, finding an IPC method, and also implementing a middle-ware layer that would allow those synchronous calls to the engine be made back to the host. This is the sort of overhead that one can expect when trying to use process migration to work around the GIL. I consider myself an experienced coder, but just thinking about finding a clean, rock-solid daemon management and IPC mechanism that works on Mac and Windows freaks me out. Does anyone have any comments on this topic? cheers, -P

15 years, 1 month

Non-daw, non-sequencer

by Grammostola Rosea

Hi, I'm impressed by my recent discovery: non-daw and especially non-sequencer: http://non.tuxfamily.org/ I love the design of the sequencer, it's very intuitive, userfriendly and fast! Respect for that! But I couldn't contact the author. So I was wondering, maybe he is on this (lad) list? I really like to know what his plans are with the apps and if he needs support in some kind of way. Does he continue to work on it? (If not that would be a real pity, cause this is not just another sequencer... And then we might need some talented devs to fork it...) Ok, I hope I will get some sign of life from the author soon... Kind regards, \rooz

15 years, 2 months

FLTK vs GTKmm

by Christian

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I'm just curious what your long-time experiences with these gui-libraries are. Considering to use one of these two but can't really decide. But I do not want to switch in a year or two... Thanks for your advices! Christian -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkp/wE0ACgkQVC26eJ+o0+2UQACePLcVXkXSwPygZrC1sQnDUWC0 hk0AmgNmgru7KzOfYCkGppoqldsam5GH =BzmB -----END PGP SIGNATURE-----

15 years, 2 months

(Somewhat OT) Advice needed on distro choice

by Fons Adriaensen

Hello all, A number of system here, including the ones at the Casa del Suono are to be upgraded in the coming weeks. At the moment they all run Fedora 8, so the first choice would be to go for Fedora 11. But: * None of them will run Gnome or KDE. * Most will be headless anyaway. * I want access/privilege control to be based on user and group ID and nothing else. Privileges will never depend on the user having a local login or desktop session. * I'm prepared to have to spend some time configuring udev, pam, /etc/fstab etc. etc. etc. * What I certainly *do not want* is some parallel access control system that would interfere with the above, or that could modify/bypass/enhance in any way what has been configured there. * I'm *not* really prepared to have to waste any time reconfiguring the Kit family. Consequently I don't want to see any of them. So what distro should I go for ? Having to spend weeks compiling everything from source is not an option. Anyone able to point in the right direction will receive my eternal gratitude which could be expressed in quantities of fine Italian food and drinks if the occasion arises. Ciao, -- FA Io lo dico sempre: l'Italia è troppo stretta e lunga.

15 years, 3 months

Saving plugin presets

by Sebastian Moors

Hi, i would like to know if somebody has already thought about a (unified) way to save or export the settings of ladspa plugins (or vst,lv2..) I'm familiar with the idea of LASH, but i want to share plugin settings between different sessions. A typical use case: After recording songs with my drumset, the gate-plugin applied to basedrum and snare has most times (nearly) the same setting. At the moment this is a quite painful task: Ardour is able to save the settings, but you can't export these or exchange them between other applications. In addition, ardour's ladspa plugin dialog can just save the settings, changing an already saved settings is not possible. This results in a heap of saved settings and old revisions.. It would be great to export these settings, it could be implemented as a feature in applications like ardour2 ,jackrack or hydrogen. After exporting the setting to a plain text file (or xml), sharing the file with other people or between your computer would be no problem. What are your thoughts on this? What are the disadvantages? Thanks, Sebastian

15 years, 3 months

[ANN] QjackCtl 0.3.5 slipped away!

by Rui Nuno Capela

A classic needs no introduction. QjackCtl 0.3.5 slipped away! Website: http://qjackctl.sourceforge.net Project page: http://sourceforge.net/projects/qjackctl Downloads: - source tarball: http://downloads.sourceforge.net/qjackctl/qjackctl-0.3.5.tar.gz - source package (openSUSE 11.1): http://downloads.sourceforge.net/qjackctl/qjackctl-0.3.5-1.rncbc.suse111.sr… - binary packages (openSUSE 11.1): http://downloads.sourceforge.net/qjackctl/qjackctl-0.3.5-1.rncbc.suse111.i5… http://downloads.sourceforge.net/qjackctl/qjackctl-0.3.5-1.rncbc.suse111.x8… - binary packages (Ubuntu 8.04 LTS): http://downloads.sourceforge.net/qjackctl/qjackctl_0.3.5-1.rncbc.ubuntu804_… http://downloads.sourceforge.net/qjackctl/qjackctl_0.3.5-1.rncbc.ubuntu804_… - binary packages (Ubuntu 9.04): http://downloads.sourceforge.net/qjackctl/qjackctl_0.3.5-1.rncbc.ubuntu904_… http://downloads.sourceforge.net/qjackctl/qjackctl_0.3.5-1.rncbc.ubuntu904_… Weblog (upstream support): http://www.rncbc.org License: QjackCtl is free, open-source software, distributed under the terms of the GNU General Public License (GPL) version 2 or later. Change-log: - Late support for UTF-8 encoded client/port names. - Allow only one single patchbay connection to or from an exclusive socket (mitigating bug #2859119). - Automatic crash-dump reports, debugger stack-traces (gdb), back-traces, whatever, are being introduced as a brand new configure option (--enable-stacktrace) and default enabled on debug build targets (--enable-debug). - Probable fix on the audio connections with regard to client/port (re)name changes (an ancient bug reported by Fons Adriaensen). - Portaudio device selector is now available (after a patch handed by Torben Hohn and Stephane Letz). - A couple of primitive D-Bus interface slots have been introduced, giving the option to start/stop the jackd server from the system bus eg. via dbus-send --system / org.rncbc.qjackctl.start (.stop), (a nice addition supplied by Robin Gareus, thanks). - New command line option (-a, --active-patchbay=[path]) to specify and activate a given patchbay definition file (a simple patch sent by John Schneiderman, thanks). - Added one significant digit to DSP Load percentage status display. - Tentative support for netjack (slave) by adding the "net" driver to the existing backend driver options on the Setup/Settings section. - Converted obsolete QMessageBox forms to standard buttons. - New patchbay snapshot now raises the dirty flag and allows for the immediate salvage of patchbay definition profile. - Conditional build for JACK port aliases support (JACK >= 0.109.2). - Alternate icon sizes other than default 16x16, are now effective to the Connections widget (Setup/Dislay/Connections Window/Icon size). Enjoy, -- rncbc aka Rui Nuno Capela rncbc at rncbc dot org http://www.rncbc.org

15 years, 3 months

interesting blog post about syncing blender and ardour

by Jörn Nettingsmeier

http://www.jpbouza.com.ar/ESP2/tutoriales/gnulinux/blenderardour/id/en

15 years, 3 months

FFADO Contact Needed

by alex tinsley

Hi, I have tried the contact form on the FFADO website and through the email address provided in the contact pages at the SourceForge.net project page to no avail. I'm not sure where else to ask except here. Are any of the FFADO developers on this email group that can provide a contact email that will garner a response? Thanks, Alex -- When you gotta have it, you gotta have it. Lesson learned from days of record shopping.

15 years, 3 months

"Open midi-keyboard"

by Albin Stigo

Hi, I'm new to the list so I hope this is not the wrong forum! I've been working on a midi keyboard ("physical" hardware 88-keys "professional" = no toy) for a while for which I plan to release the schematics and source as open source. It's based around a Fatar keybed (they make Studiologic) and an Atmel AVR mcu. The code is all in C and is very portable. Current features are: - Velocity sensitivity. - Pedal support. - Custom velocity curves. - Only normal MIDI serial "current" link. No USB, yet... My questions are, Is there an interest in this sort of thing..? What features would you like to see, what are you missing from off-the-shelf products? Atb, Albin

15 years, 3 months

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Linux-audio-dev September 2009