Linux-audio-dev September 2018

linux-audio-dev@lists.linuxaudio.org

32 participants
16 discussions

by Jonathan E. Brickman

I have set up and run a number of tests now. Mido under python2, uses 5-7% of two different 2.4GHz+ cores for a one-way midi2tcp --> tcp2midi link based on the sample code using blocking waits on both MIDI and TCP ports. I ran into minor difficulty getting Mido into python2, and difficulty considerably beyond my knowledge getting Mido into python3, into this up-to-date Manjaro, so my next tests were midi2udp --> udp2midi using just Python3 and libraries JACK-Client and 'socket'; this is quite promising, just 2% CPU total, and the test is a bit crude. So now I'm working on designing an algorithm which models a hardwired MIDI cable over a UDP connection. Specific goals are: - MIDI over IP. Using UDP right now, will use TCP if a reason to do so emerges. - Simplicity. I want this implementable in dedicated hardware as easily and inexpensively as possible. I want $20 boxes where I can dial the src/dest IPs using dip switches. Dreaming? Maybe... - Very well-suited for live performance. This means absolutely no MIDI event dropouts without being unaware, and using MIDI resends and reset in emergency to handle packet loss. - Solid LAN immediately. Very slightly lossy LAN/WLAN next. WAN if there is call for it. - Reliability and predictability at MIDI standard speeds -- 31.5 kHz -- not bandwidth availability. Once this works it may be doubled or quadrupled, or brought to HD-MIDI's clock once someone decides on one. The current software thought is to have both sides have two threads: one thread running callback to JACK, the other handling UDP/TCP, the threads communicating by Python FIFO queues, the UDP/TCP thread being constrained by 31.5kHz wait-state loop of some sort. Any suggestions, abridgements, et cetera? Also any thoughts on the best way to build that UDP/TCP thread wait-state loop? I'm beginning to imagine that TCP might have the advantage of being able to build up the buffering...but all of this has been fairly far from my practical programming, and I know that so many of you live here, so I thought I might ask :-) -- Jonathan E. Brickman jeb(a)ponderworthy.com (785)233-9977 Hear us at ponderworthy.com -- CDs and MP3 available! Music of compassion; fire, and life!!!

5 years, 7 months

Reminder: Call for Participation - ALMAT Workshop @ Impuls, Academy 2019

by IOhannes m zmoelnig

ALMAT - "Algorithms That Matter" Workshop at the impuls 11th International Ensemble and Composers Academy for Contemporary Music 2019 Special workshop for computer music practitioners, sound artists and composers Call for Participation Deadline: October 1st, 2018 with Robin Minard, David Pirrò, Hanns Holger Rutz http://www.impuls.cc/academy-2019/special-programs.html#c5169 [please distribute] Algorithms that Matter (ALMAT) focuses on the experimentation with algorithms and their embedding in sound works. Rather than conceiving algorithms as established building blocks or the a priori formalisation of a compositional idea, we look at them as performing entities whose consequences are irreducible to models. Algorithms “matter” in the sense that matter and meaning cannot be distinguished, neither can artists and their computational tools. Algorithms actively produce spaces and temporalities which become entangled with their physical embeddings. The 2019 edition of the workshop focuses on the development of a site-specific sound installation. The installation will explore the interactions of algorithmic and physical spaces and their dynamic and mutable properties. Participants will work on the premise that spaces and our perception of them change depending on presence, absence, the movement of visitors, the time of the day, the rhythm of the surroundings as well as the sonic and algorithmic interventions we bring into them. This workshop seeks to attract computer music practitioners, sound artists and composers by offering a platform for exchange and reflection about their personal approaches towards algorithmic experimentation. The participants are invited to develop their various approaches within an atmosphere of collaboration, where special emphasis will be given to the translation of environmental data (such as sensor input from the surroundings and visitors) through computer music systems developed and assembled by the participants and tutors. One question we want to pursue is how behaviours can be composed that transition from "technical and artificial" to "organic and alive", particularly through the articulation of spatiality. The workshop starts with an internal presentation of the participants for the other participants and tutors. An initial sound situation using a large number of small reconfigurable speakers forms the starting point for in-situ work. This structure will then be available for decomposition and rearrangement by the participants. The space will become a public exhibition halfway through the workshop, making it possible to observe and adapt to the interactions with the audience, a central question in the making of sound installations. The workshop will be held with technical infrastructure provided by the Institute for Electronic Music and Acoustics (IEM), including an 48-channel sound system and a selection of sensors. The workshop ALMAT was developed by David Pirrò and Hanns Holger Rutz (both IEM Graz) and will be held together with the special support by Robin Minard. How to apply: 1.) First, you must register and be accepted as a participant of the impuls Academy 2019. 2.) Along with your application, you must submit a statement concerning your specific interest in participating in the ALMAT Workshop or send this by e-mail to office(at)impuls(dot)cc. 3.) In addition, please send a description of your personal work in relation to the workshop's theme stating your previous experiences and describing employed computational approaches, their aesthetic

5 years, 7 months

[ANN] Qtractor 0.9.2 - The Summer'18 Release

by Rui Nuno Capela

At last! Qtractor 0.9.2 (summer'18 beta) is released! Not much has changed but here's the change-log: - AppData/AppStream metadata is now settled under an all permisssive license (FSFAP); also updated to be the most compliant with latest freedesktop.org specification and recommendation. - Fix build for Qt >= 5.11.0 (by David Geiger, thanks); also for some g++ >= 8.1.1 warnings and quietness. Description: Qtractor [1] is an audio/MIDI multi-track sequencer application written in C++ with the Qt framework [2]. Target platform is Linux, where the Jack Audio Connection Kit (JACK [3]) for audio and the Advanced Linux Sound Architecture (ALSA [4]) for MIDI are the main infrastructures to evolve as a fairly-featured Linux desktop audio workstation GUI, specially dedicated to the personal home-studio. Website: http://qtractor.org http://qtractor.sourceforge.net https://qtractor.sourceforge.io Project page: http://sourceforge.net/projects/qtractor Downloads: http://sourceforge.net/projects/qtractor/files - source tarball: http://download.sf.net/qtractor/qtractor-0.9.2.tar.gz - source package (openSUSE Tubleweed): http://download.sf.net/qtractor/qtractor-0.9.2-37.rncbc.suse.src.rpm - binary package (openSUSE Tubleweed): http://download.sf.net/qtractor/qtractor-0.9.2-37.rncbc.suse.x86_64.rpm - AppImage [7] packages: http://download.sf.net/qtractor/qtractor-0.9.2-7.x86_64.AppImage Git repos: https://git.code.sf.net/p/qtractor/code https://github.com/rncbc/qtractor.git https://gitlab.com/rncbc/qtractor.git https://bitbucket.org/rncbc/qtractor.git Wiki (help wanted!): http://sourceforge.net/p/qtractor/wiki/ - static rendering: http://qtractor.org/doc http://qtractor.sourceforge.net/doc https://qtractor.sourceforge.io/doc - user manual & how-to's: http://download.sf.net/qtractor/qtractor-manual-and-howtos.epub http://download.sf.net/qtractor/qtractor-manual-and-howtos.pdf License: Qtractor [1] is free, open-source Linux Audio [5] software, distributed under the terms of the GNU General Public License (GPL [6]) version 2 or later. References: [1] Qtractor - An audio/MIDI multi-track sequencer http://qtractor.org http://qtractor.sourceforge.net https://qtractor.sourceforge.io [2] Qt framework, C++ class library and tools for cross-platform application and UI development http://qt.io/ [3] JACK Audio Connection Kit http://jackaudio.org [4] ALSA, Advanced Linux Sound Architecture http://www.alsa-project.org/ [5] Linux Audio consortium of libre software for audio-related work http://linuxaudio.org [6] GPL - GNU General Public License http://www.gnu.org/copyleft/gpl.html [7] AppImage, Linux apps that run anywhere http://appimage.org/ See also: http://www.rncbc.org/drupal/node/1933 Enjoy && Have fun. -- rncbc aka Rui Nuno Capela

5 years, 7 months

midi2tcp and tcp2midi, working prototype

by Jonathan E. Brickman

It is working as here: https://github.com/ponderworthy/midi2tcp and quite well. Haven't come up with a single reason to make it more complicated, beyond much more careful timeout handling. It will need to be able to destroy its own socket and recreate et cetera, to be durable with marginal wifi. And performance is not very good, midi2tcp takes 3-5% of one core and tcp2midi takes 6-8% of another on this i3- 3110 at 2.4GHz. Am not sure what best to do about the performance. Will probably try converting Python to binary, but have read over and over again that that doesn't do so very much. I also had to rename it back to TCP after re-reading the Mido library docs yet again, it is using rtpmidi backend but it says it's TCP, not UDP, and it is using a connected socket which means TCP I do believe. I had thought RTP-MIDI was UDP? I wonder if judicious use of UDP would improve performance by a substantial amount? -- Jonathan E. Brickman jeb(a)ponderworthy.com (785)233-9977 Hear us at ponderworthy.com -- CDs and MP3 available! Music of compassion; fire, and life!!!

5 years, 7 months

MIDI-2-TCP, TCP-2-MIDI

by Jonathan E. Brickman

I need lossless JACK MIDI networking outside of JACK's built-in networking, and not multicast unless someone can tell me straightforwardly how to get multicast (qmidinet) to run within localhost as well as outside it. Thus I am thinking of trying my hand at using the Mido library to bridge JACK MIDI and TCP. I have never done this sort of coding before, programmatorially I am mostly a deep scripting guy, Python-heavy with a bunch of Bash on Linux, Powershell- heavy on Windows of late, with a pile of history on back in Perl on both and VBA on Windows. Anyone have hints...suggestions...alternatives...a best or better starting place? Right now I don't want the applets to do GUI at all, I just want them to sit quietly in xterms, on JACK servers, keeping connection, and passing MIDI data to and fro, as other processes and devices bring it. -- Jonathan E. Brickman jeb(a)ponderworthy.com (785)233-9977 Hear us at ponderworthy.com -- CDs and MP3 available! Music of compassion; fire, and life!!!

5 years, 7 months

Berlin Linux Audio meeting @ c-base 2018-09-11

by Daniel Swärd

Hi all. Next meeting at c-base is on Tuesday 2018-09-11. To avoid cross-posting too much on the mailing lists I'd like the follow-up discussion to happen in the thread to the invitation mail I sent to the linux- audio-user list. There's also a bit more content in that mail than a redirect... ;-) Cheers /Daniel

5 years, 7 months

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Linux-audio-dev September 2018