Objects which at the same time produce and receive shadows show some strange glitches.
http://playground.babylonjs.com/#1SGTPA#9
I tested it on Nvidia NVS3100M and Intel HD Graphics (1 st gen.) On each of those cards the the size of circles is different, but looks bad anyway.
When you comment lines 92,93:
// shadowGenerator.getShadowMap().renderList.push(plane);
// shadowGenerator.getShadowMap().renderList.push(videoPlane);
Planes start to look ok, but it is not a solution at all, in case of more complicated meshes/scenes selfshadowing is an important feature.
Only in very limited scenes it is possible to make it good by disabling some meshes shadows.