Mirrored 360 video, google cardboard

Hey,
I'm making a simple 360 app based on the sample that comes in Google Cardboard asset (GVR v1.5).

In that sample, the video played is mirrored.
Does anyone know how to solve this? I tried an inverted sphere, but the video doesn't play at all on that, not sure why (all I see is white). I tried a custom shader but it doesn't play nice with the video player.

Any ideas?

Thanks.