A multi USB webcam projection approach with open frameworks.

#Overview 'Madcam' is an open frameworks (http://www.openframeworks.cc) project for using multiple USB web cams (e.g. PS3 Eye) simultaneously for displaying live video material. Its controllable by MIDI and OSC! We wrote it as a Live VJ extension for the robotics media art installation project "Glitchrobot" by SonicRobots. #Description The goal is set up an VJ setup which is based on webcam material. So far we used 9-10 Web cams, but the amount can probably extended. The webcam content is displayed on one screen, in different tilings and with FX. Tiling and FX can be controlled by Midi and OSC. The system uses Open Frameworks. #Features

• Open Frameworks
• OpenGL shaders for filters and FX
• UVC Video Compatible (Linux Video driver) e.g. the very cheap and high frame rate USB Webcams "PS3 Eye"
• Different tilings: One cam full screen, 2-9 Cams tiling.
• Decay Filter: Apply Aan OpenGL Shader to create an "fade out" effect on a single cam image, whenever a certain Midi Note is triggered
• Midi and OSC Controls
  • Control and switch the tilings with midi notes!
  • Control the cam assignment with MIDI CC commands
  • Control the Decay time OSC
• Tested for PS3 Eye Cams running 640x480, 30 Fps

Requirements

The setup we build the system upon consists of the following parts, but may be build from different hard/ software as well. As the Amount of data of several USB Webcam is considerably big, care has to be taken when choosing the USB controllers.

Hardware

• System: standard CPU is sufficient. We used Amd 6 Core. 4GB Ram. SSD 128GB.
• USB: One MIDI Host controller (USB chain) can take data from 2 Webcams (PS 3Eye) running at 480x600 resolution at 30FPS. We added PCI USB cards so that one USB Host controller is in charge of 2 webcams.
• We used Xubuntu as a base system
• Shader FX
  • "Billboard" - https://www.shadertoy.com/view/Xlf3RS
  • "Pixelate" - https://www.shadertoy.com/view/MslXRl#
  • "Comic Print" - https://www.shadertoy.com/view/lsBXzV
  • "TV Signal" - https://www.shadertoy.com/view/MdjSRy
  • "ASCII ART" - https://www.shadertoy.com/view/4ll3RB
  • "Glitch" - https://www.shadertoy.com/view/MdXGWn
  • "VHS Style" - https://www.shadertoy.com/view/4ss3RX
  • "Filters" - https://www.shadertoy.com/view/XsX3z8

Midi Commands

NoteOn

• Ch. 9, Note 0 - 4 setLayout
• Ch. 9, All notes in settings.xml trigger resp. Camera
• Ch. 9, CC 20 - 29, set slot to Camera
• Ch. 9, CC 30, set decay
• Ch. 9, CC 32, value < 64 trigger mode off, value > 64 trigger mode on
• Ch. 9, CC 33, value < 64 fbo mode off, value > 64 fbo mode on
• Ch. 9, CC 34, set iterations (feedback mode)
• Ch. 9, CC 35, set alpha (feedback mode)
• Ch. 9, CC 36, set x-offset (feedback mode)
• Ch. 9, CC 37, set y-offset (feedback mode)
• Ch. 9, CC 40 - 49, set color mode for slot to value
• Ch. 9, CC 50, set global fx amount for X axis
• Ch. 9, CC 51, set global fx amount for Y axis
• Ch. 9, CC 52 - 69, set fx amount for x/y on camera
• Ch. 9, CC 70, set camera on all slots
• Ch. 9, CC 71 -79, set camera to slot
• Ch. 9, CC 80, set global color mode
• Ch. 9, CC 81 - 89, set global for slot/camera