2015-04-30 11:24 GMT+02:00 ORL <orl@ammd.net>:
Hi!

I already told you about Sebkha-Chott several times on this list, usually speaking about our releases (always under GNU/Linux, from the beginning to the end).

Actually, Sebkha-Chott also uses GNU/Linux on stage to manage sound, lights and video of the whole show (see details below).
I usually don't post shows list or tour schedule here (maybe I should), but this time it's a big and international festival, so it might be that some of you will be interested in it.

So Sebkha-Chott will play at Brutal Assault Festival #20 in Jaromer (Cz), for the third time, but for the first time, we will use the GNU/Linux live setup they have on tour. The final schedule is not known yet, but it will be between 5th and 8th of August. If some of you live near Cz, are metalheads, that's the place you should be (if you ask me, this year's line-up is really great, the best I've known since I know this festival).

http://www.sebkhachott.net/15-years-of-sebkha-chott-kourt

Here it is (please note the video and lights part of the system won't probably play at Brutal Assault due to very tight changeover schedule).


Description of Sebkha-Chott's live setup

Distribution
All machines, including RPI, are running Debian systems, mostly Jessie.
http://www.debian.org

Session Handling
Session handling is managed through ladish and on some control machine small shell scripts.
http://ladish.org

Audio
Routing
All the routing is managed through ladish, jack is configured with the restrict self-connect option.

Mixing
The mixing/processing of any audio signals coming from the instruments on stage or from "virtual sources" inside the machines (synths, samplers) is done through a bunch of Non-Mixer (probably not uptodate) instances, running independently one from the other. All these Non-Mixers finally ends up in the FOH mix or on of the three monitors mix (which goes to in-ear monitors system). We highly recommend Non-Mixer for this type of setup, as you don't need a timeline, and Non-Mixer is really lightweighted, OSC controllable, and flexible. Ecasound might have done the job too, still.
http://non-mixer.tuxfamily.org/

Live Looping
The "instrumental line-up" contains 2 basses, 2 guitars, 3 vocals and a drumkit, each of them goes to a single looper (for the drums, we only loop a stereo submix). We use Sooperlooper (probably not uptodate, and (uglily) patched so that Jack Transport Synchronization with SL as a master works with it and is recalled when at session load).
http://essej.net/sooperlooper/

Synths
Additionnally to the physical instruments, 5 synths are running, 3 of them polyphonic, 2 of them monophonic. We use Alsa Modular Synth (probably no uptodate) for this. You might get the patches on github (see below)
http://alsamodular.sourceforge.net/

Samplers
A virtual drumkit is also used, with really-non-drumistic sounds. We use tapeutape (patched not uptodate version) for this purpose.
http://hitmuri.net/index.php/Software/Tapeutape

Clic
We use Klick to send clic in every monitor.
https://github.com/dsacre/klick

Lights
Lights are controlled using QLC+. We use four profiles projectors and 4 LED "barres", which are split into 8 RGB segments each, each segment mightbe controlled independently from the others.
http://qlcplus.sourceforge.net/

Videos
Videos and Moving images are displayed on three V-form screens. Those videos are displayed using a self-developped software called PytaVSL (derivating from VSL, a set of pd patches we used on a children show) and based on Pi3D. This runs on RPIs (old ones, not the big beasts you might get for 30$!!!).
This lays on a mapped-layers principle, each of them might be mapped with images or videos, the content can be changed with OSC control, and you can move or change properties (including visibility/inivisibility) of a layer using OSC too.
By now, PytaVSL is not recommended for anyone except us (or you will have to put your hands in it, and you'll see then we're no real devs!!!).
https://github.com/orlammd/pytaVSL
https://github.com/tipam/pi3d

Controls
MIDI/OSC Routing
The whole thing is controlled via a centralized OSC/Midi router. We use Mididings for this purpose, and we highly recommend it, it's a really good piece of software which makes everything possible in such a setup.
The version we used has been patched to be able to route/filter/manage OSC messages too. I propose this dirty patch to Dominic and I know he has worked on this, but I couldn't tell what's the current state of the software, as we do not use an uptodate version on this neither!

PedalBoards
We use DIY pedalboards to trig the sequencers, loopers, and to change instruments sounds (including synths). These pedalboards are made of a "règle de maçon", push-buttons and a Teensy2.0 programmation board. It basically sends an OSC message /pedalBoard/button #number when you press a button. These messages are then managed by Mididings. There are two pieces of software for this, one on the board, one on the receiving computer.
https://github.com/AMMD/Poly_PedalBoard

Touchscreen Interfaces
All the mixers, the LASDPA plugs, and in some case the synths are controlled using touchscreen interfaces. We've developped a programm for this purpose called Ghislame. Initially developped in C++/Fltk, we ported it to python/kivy and finally it now uses a JS engine. Initial versions controlled more things (loopers, synths, mixers, lights), but in a quite weighted way. Current version (JS) only controls Mixers and Plugs, but does it much more fluently.
One of these touchscreen interfaces is placed at FOH, so that mix of the show might be done from FOH. The other ones are sprayed on stage so that musicians might control their monitoring and some other things easily.
https://github.com/jean-emmanuel/oschtmlgui
https://github.com/AMMD/kvGhislame
https://github.com/AMMD/Ghislame

Visual Monitoring
Several small laptops are placed on stage with LiveDings (Mididings frontend) and slgui (SooperLooper GUI) running on them.

Sequencers
Midi Sequencing
seq24 in a really really patched version is used to sequence MIDI. It's used in matricial mode, and the patches we've done acts on many things: arbitrary number of beats in a measure, abitrary number of measures in a sequence, n-tuples, 16x13 matrix (instead of 8x2), play/stop controllable by Program Changes, and other crappy things. I really don't recommend our patched version which contains many bugs we learned to prevent! It's the very first software we've been patching, and.... wel.... seq24 is synced to Jack Transport as a slave. As far as I know this doesn't work anymore with more recent version of seq24, and as a result, our version is not uptodate. We will certainly change about this when we'll have time. We attend much from Non-Sequencer on that point! ;)

OSC Sequencing
Over the Midi Sequencing, OSC sequencers are running. One controls the lights, one controls the videos, another one might send messages to audio machines (including seq24), and one runs over them all and might send the BIG SEQUENCE messages!
We use a self-developped software called pyOSCseq. This sequencer can run looped sequence (as any other sequencer) but also can send on-shots sequence (many uses in theater context).
https://github.com/jean-emmanuel/pyOSCseq

Jack Transport
Jack Transport is used to synchronize every tempi/triggers and so on. Sooperlooper is Jack Timebase Master, and the other pieces of software that might be sync to are slaves. Considering that Sebkha-Chott'music is composed of many sequences in many metrics and tempis, with highly contrasted way of passing from one to the other, this point was a very critical point at the beginning of our work with machines (in 2008).

-- 
ORL
AMMD - Freak & Free Arts Coo[r]p
www.ammd.net - 095 234 72 48

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Really good and useful info for reference. Great to see real musician using FLOSS in production and in such kind of festivals.
Would be great to see some "behind the scenes" footage of your performance.

Thanks for sharing.

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