I just tried the new Beta 1 and have no video image output. Sound is playing, interface is working, just a black screen.
Running Ubuntu 14.04 with lts-xenial packages on an Intel J1900 platform.
Disabling vaapi and playing on CPU works.
Using VAAPI with "Normal Shaders" shows a red flash before audio starts.
Using VAAPI with "Enhanced Shaders" shows a green flash before audio starts.
19:07:29 T:140684811880448 ERROR: Previous line repeats 4 times.
19:07:30 T:140684811880448 ERROR: Previous line repeats 1 times.
We require mesa 11 or later.
For reference: I was missing this ppa.