I have the same problem, pix_video doesn't work and none of the pix_ family on my macbook pro retina...
Got this msg: [pix_video]: no valid video backend found
could not make new SG channnel error -9405

Anyone have any idea? I tried to reinstall already...nothing.

I'm using a MACBookPRO RETINA, 2.3 GHz Intel Core i7, 16GB 1600 MHz DDR3, OSX 10.9.5

Thanks anyway.