Package: matriz
Matriz is aNetworked Music Performancesoftware.
The intended use is allowing real time musical performance of artists in different locations through computer networks.
The name “matriz” is portuguese for “matrix” and is inspired on the light and sound matrixes used in music and theater settings.Why?Tools likejacktripare built
to work in high bandwidth academic networks like the internet2 or GEANT networks.
Matriz is built to offer the lowest latencies possible, while using the least bandwidth possible.
This allows musicians to have low latency high quality music streaming using regular network connections.For fun.FeaturesLow latency (using OPUS codec)Easy to use and extendTested in live performancesDocumentation:https://matriz.readthedocs.org.What?The software is composed of two components, the client and the configuration server.
The client connects to the server over websockets and receives a list of all connected clients.
After starting it’s own RTSP stream with audio from the sound card, it spawns an RTSP client for all connected clients, forming a P2P streaming network.
For all connection or disconnection events, the client list is broadcasted to all connected clients, which open or close new RTSP clients as necessary.
Audio is encoded with the OPUS codec, which allows for low bandwidth use and high quality sound, while keeping the latency to a minimum.The system was used several times in live peformances, with three three groups of musicians.
Distances between groups ranged from tens of meters (same building) to 150 to 400 km in the final performance.
The hardware used was a Raspberry pi 2 with a Focusrite Scarlet 2i2 USB sound card.
The resulting streams where broadcasted live athttp://stress.fm.
More information, including recordings of the performances, can be obtained at the project website:http://matriz.stress.fm.
For any inquiries concerning the software or the project, contact us atinfo@stress.fm.InstallationPrerequisitesIn both cases external dependencies must be installed for the program to work. For the client:JackGStreamer, including the gst-rtsp-server package and Pyhton bindingsPython bindings for gobject-introspection librariesThese can be installed in Debian or Rapsbian whith the following command:$ echo "deb http://matriz.stress.fm/deb_repo jessie main" | sudo tee /etc/apt/sources.list.d/matriz.list
$ curl http://matriz.stress.fm/deb_repo/matriz_deb.gpg.asc | sudo apt-key add -
$ sudo apt-get update

$ sudo apt-get install -y python-pip\
                     jackd2 \
                     python-gst-1.0 \
                     python-gi \
                     libgstrtspserver-1.0-0 \
                     gstreamer1.0-plugins-bad \
                     libgstreamer-plugins-bad1.0 \
                     gir1.2-gst-rtsp-server-1.0 \
                     python-dev \
                     libffi-dev

# For the PI

$ curl https://raw.githubusercontent.com/stressfm/matriz/master/config/etc-dbus-1-system.d-matriz_jackd.conf | sudo tee /etc/dbus-1/system.d/matriz_jackd.conf >/dev/null
$ curl https://raw.githubusercontent.com/stressfm/matriz/master/config/boot-config.txt | sudo tee /boot/config.txt > /dev/null
$ curl https://raw.githubusercontent.com/stressfm/matriz/master/config/boot-cmdline.txt | sudo tee /boot/cmdline.txt >/dev/null
$ curl https://raw.githubusercontent.com/stressfm/matriz/master/config/supervisord.conf | sudo tee /etc/supervisord.conf >/dev/null
$ for cpu in /sys/devices/system/cpu/cpu[0-9]*; do echo -n performance | sudo tee $cpu/cpufreq/scaling_governor; done
$ sed -i "$(wc -l /etc/rc.local | cut -d' ' -f1)i for cpu in /sys/devices/system/cpu/cpu[0-9]*; do echo -n performance > $cpu/cpufreq/scaling_governor; done" /etc/rc.local
$ sed -i "$(wc -l /etc/rc.local | cut -d' ' -f1)i sudo mount -o remount,size=256M /dev/shm" /etc/rc.local
$ sudo pip install supervisor
$ sed -i "$(wc -l /etc/rc.local | cut -d' ' -f1)i supervisord -c /etc/supervisord.conf" /etc/rc.local
$ sudo rebootFor the server, if you want to stream the performance, you might want to install and configure:liquidsoap (to receive and combine client streams)icecast2 (to stream the combined audio from all clients)GStreamer (to decode client streams)Using PyPiTo install the program just to use the client:$ pip install matrizIn the machine where the server will run, server dependencies must be explicitly installed:$ pip install matriz[server]Install Script for Raspberry PiOr simply run the following command which performs all the steps above (Raspberry Pi specificDO NOTuse on other OS):curl https://raw.githubusercontent.com/stressfm/matriz/master/scripts/install.sh | sudo bash -UsageClientTo use the client open a shell and just type:$ matrizwithout arguments, to start the client. The program will try to read configuration options from a file
called client.json in the same directory where the program was invoked.
If you want to use another filename, just give that as an argumento to the program:$ matriz <filename>An example configuration file is in config/client.json:{"key":"key1","name":"porto","url":"ws://localhost:5000/config","interface":"eth0","port":8554,"client_pem":"fake_client.pem","client_crt":"fake_client.crt","ca_crt":"fake_ca.crt"}key:supposed to be unique id for clientname:some label  identifying the clienturl:the configuration server urlinterface:network card to start de emitter onport:port for emitter to listen onclient_pem:openssl key for secure websocketsclient_crt:openssl client certificateca_crt:openssl server certificateTo get a list of command line arguments type:$ matriz -hServerThe configuration server is just a single file Flask app (matriz/config_server.py). For deployment instructions consult the Flask documentation athttp://flask.pocoo.org. The server will try to read configuration options from the file given in the
MATRIZ_CONFIG_FILE environment variable or, if not set, from a file called clients.json in the same directory
where the program was invoked. An example configuration file can be found in config/clients.json:{"client_keys":[{"name":"porto","key":"key1"},{"name":"montemor","key":"key2"},{"name":"lisboa","key":"key3"},{"name":"marte","key":"key666"}],"monitor_key":{"name":"monitor","key":"monitorkey"}}MiscFor the software to work ports 8554 (TCP) and 8600-8700 (UDP) must be able accept incoming connections. This means you have to configure the gateways if you intend to use the software across the internet.PartnersOficinas do ConventoSonoscopiaOssoTrienal de Arquitectura de LisboaDigitópia - Casa da MúsicaCâmara Municipal de Montemor-o-Novo.FundingDireção Geral das Artes.History0.1.0 (2016-05-19)First release.