Multi-Screen Video Synchronization

3 min readSep 3, 2018

Ethan Kurzrock | Lisa Müller-Trede

University of Southern California |
Division of Media Arts and Practice

Approach

In this document, we overview the process of running multiple synchronized video players over a wired network with the OMXPlayer-Sync program. This system utilizes video file timecode to maintain sequencing across a group of connected micro-computers. Documentation from multiple video installation projects provides tested procedures for multi-screen synchronization using OMXPlayer-Sync.

**Seedy knockout in preparation**, 4 screens (Lisa Müller-Trede, 2018)

Materials

This process was tested on two microcomputers via an ethernet crossover cable, and three and six screen arrangements over an eight port ethernet hub.

2x+ Displays & HDMI adapters
2x+ Raspberry PIs & AC adapters
2x+ Bluetooth Keyboards
2x+ Ethernet Cables
2x+ Ethernet Hub

Phase 1: Export Media

Export .mp4 files formatted for all five displays at the appropriate resolutions.
Load exported files on USB drive for media transfer.
Name files consistently for each Raspberry PI (ex: filename.mp4).
Place video files in directory “/home/pi/Videos”.

Phase 2: Prep Raspberry PIs (1)

Launch terminal and run following command line:

sudo su
sudo apt-get remove omxplayer
sudo rm -rf /usr/bin/omxplayer /usr/bin/omxplayer.bin /usr/lib/omxplayer
sudo apt-get install libpcre3 fonts-freefont-ttf fbset libssh-4 python3-dbus
sudo wget http://omxplayer.sconde.net/builds/omxplayer_0.3.7~git20170130~62fb580_armhf.deb
(note: on Windows and Mac keyboards f5 and f6 keys function as “~” key)
sudo dpkg -i omxplayer_0.3.7~git20170130~62fb580_armhf.deb

If libssl is not installed, run following commands and re-attempt install (check libbssl version number):

sudo wget security.debian.org/debian-security/pool/updates/main/o/openssl/libssl1.0.0_1.0.1t-1+deb8u9_armhf.deb
sudo dpkg -i libssl1.0.0_1.0.1t-1+deb8u9_armhf.deb

Phase 2: Prep Raspberry PIs (2)

sudo wget -O /usr/bin/omxplayer-sync https://github.com/turingmachine/omxplayer-sync/raw/master/omxplayer-sync
(note: sudo wget dash capitalized O, not 0)
sudo chmod 0755 /usr/bin/omxplayer-sync
sudo apt-get install omxplayer

Phase 3: Test video player

sudo wget https://github.com/turingmachine/omxplayer-sync/raw/master/synctest.mp4
sudo omxplayer-sync -muv synctest.mp4
(hit control + C to exit player)

Phase 4: Run video file

Use “-muv” command for the primary driver unit and “-luv” for all other PIs to follow:

cd /home/pi/Videos
sudo ls -l
sudo omxplayer-sync -muv [filename]

Phase 5: Connect network

Operate numbered Raspberry PI units with respective wireless keyboard.
Connect Ethernet cable between each Raspberry PI unit and the associated port on ethernet hub.

Run following commands to establish network connection through local ethernet network:

cd /etc/
sudo cp dhcpcd.conf dhcpcd.conf.old
sudo vi dhcpcd.conf
interface eth0
(note: 0 is zero)
static ip-address = 192.168.0.[unique address]/24
static routers = 192.168.0.1
static domain_name_servers = 192.168.0.1