The latest fpp code (Falcon Pi Player), has the beta release of video sync. Video is coming out all of the slaves besides the master. There is a thread describing testing Pat Delaney did: http://falconchristmas.com/forum/index.php/topic,1316.15.html#lastPost. Pat made a video of 4 pi players running the same sequence, each pi player is producing hdmi video. all are synced up. You will see the first 3 perfectly synced, the 4th one slightly ahead. The official release of this video syncing is scheduled for mid October. The fpp team is in beta testing now so I expect them to fix the 4th fpp soon. Here is the video of the four fpp's each playing videos in sync. http://nutcracker123.com/nutcracker/videos/patdelaney_fpps.mp4 i also made an image of the 4 fpp's. There were two Model B's and two Model B+'s in the test. Each fpp can drive 64K channels of lights so these 4 could be driving 256K channels along with the 4 video streams.