This reminds me of what VLC does sometimes when playing video through the network, sometimes if the network is a little slow or you try to skip forwards, for a few seconds it will display similar glitches to ones in your picture. Sorry I'm not sure why this happens and I can only speculated, but it might be the video tries to continue playing without sufficient data to complete the image or with corrupted data. Had you tried lowering the picture quality? Also how well is your internet working?