CuVoodoo

The technical details are available on git. The README really explains it all. No need to copy it here again.

An explanation and demonstration is provided in this episode.

software:

• boblight, my choice to to send color data based on what is displayed. It's pretty good, and has even an XBMC/Kodi plugin
• list of software to send colour data based on what is displayed, and hardware compatibility table
• the original AtmoLight plugin
• DFAtmo, another nice AtmoLight controlling software
• WS2812b LED libraries: FastLED, NeoPixel, minimal WS2812B_control

similar projects:

• pretty much the same as I did and well documented (sadly I only found it after I finished): boblight+arduino+ws2812b
• combining lightpack hardware with boblight software (on openELEC/XBMC): link
• configure the SEDU-Board and configure boblight
• LiveLight: AmbiLight using RGB LEDs
• SCIMO: nice hardware which even parses the video signal by itself
• generic Arduino+ws2812b AmbiLight, using FastLED and Processing