A long lasting idea (first occurence was during residency of the Metahub Nuit Blanche in Brussels) trying to come to life out of necessity.

Concept: use the Raspberry Pi as a VJ plateform

Sure, why not. It's cheap, light weight, small, has RCA or HDMI output, can play h264 HD videos, works already well as a media center,…

A lot of credit has to be given to PocketVJ which has opened my eyes on the web interface to control the videos and by showing the way to do things.

The setup involve a custom application developped in openFrameworks. It uses ofxOMXPlayer addon to display two video as a textures (this provides the ability to crossfade between the two textures and have seamless loop) and ofxOsc for communication with the web interface.

A webserver pushed by nodejs with modules:

• express
• socket.io
• osc

Projects that already exist and other related tools.

A full featured VJ software by the great Pikilipita

• http://www.pikilipita.com/superpikixpi/
• Free, but not open source
• Own codec (kouky .k19) and converter for Win or Mac only
• Clips limited to 250 frames @ 25fps, 640×360
• Playlist based, some overlay effects,…

• http://pocketvj.com/
• Can sync multiple Raspis
• Web interface
• Can play HD videos
• Can play from usb key

The oF toolbox ported to Raspberry Pi and its addon to use the OpenMAX video capabilities with it.

• http://www.openframeworks.cc/setup/raspberrypi/Raspberry-Pi-Getting-Started.html
• https://github.com/jvcleave/ofxOMXPlayer

ofxOMXPlayer works best with h264 videos with sound. Since I don't need sound, here's a command to add silence to a video. The parameters have to be in that order (especially for the mapping). If you already have an audio channel in your source video, it's better to not do any compression on the video codec (-vcodec copy) while swapping the existing audio channel with the silent one. If you don't have any prior sound, you can do video and audio compression at the same time.

ffmpeg -ar 48000 -ac 2 -f s16le -i /dev/zero -i video.mp4 -shortest \
    -vcodec copy -acodec pcm_s16le -map 1:v -map 0:a output.mov

ffmpeg -ar 48000 -ac 2 -f s16le -i /dev/zero -i video.mp4 -shortest \
    -s 1024x768 -vcodec libx264 -b 2000k -acodec pcm_s16le \
    --map 1:v -map 0:a output.mov

ffmpeg -i video.avi -s 1024x768 -vcodec libx264 -b 2000k \
    -acodec pcm_s16le output.mov

It's /dev/zero that produces silence.

Python wrapper module around OMXPlayer for the Raspberry Pi.

• https://github.com/jbaiter/pyomxplayer (pexpect)
• https://github.com/KenT2/pyomxplayer (FIFO)

To install the latest version of NodeJS:

wget http://node-arm.herokuapp.com/node_latest_armhf.deb
sudo dpkg -i node_latest_armhf.deb

A NodeJS framework. Requires Mongodb

• Install Mongodb without compiling

• hostapd set up
• This link has complementary information