The video shows two videos running contemporarily on Pi 2, with QML animations applied to the videos and with audio fading from one to the other. The videos are 720p h264 main and high profile. UI is written in QML in 1080p with 24 bit color depth. As you can see, load on the CPU is very low. The demo also shows the same QML file running on Mac OS X.
To get this performance you'll need to properly overclock your Pi 2, otherwise the achievable frame rate is lower.
NOTE: Code for this is not yet on github.