Best video format for playback on second screen

[MikeyC314]

I had one other question as a bonus if anyone knows as well, is there a specific video format that VLC handles best? I'm currently playing ProRes422 files from FCPX and I've noticed that if I skip around in the video a bit it freezes on the second screen and that would kind of ruin everything. I guess the files are just too big. I can use handbreak to convert to h264 at a lower bitrate but I want to get the best quality I can that VLC won't ever crash at.

Thanks again for reading
Michael