MPlayerX on OS X suddenly doesn't interpolate video anymore? (fullscreen = ugly pixelated output) I always favor MPlayerX as my video player, it works perfectly. However since a few days, when playing fullscreen, it seems to no longer interpolate the video content, resulting in a 'pixelated' output.

If I compare it with QuickTime or VLC for example, using the same video file, with MPlayerX I can see pixel blocks in the output, the typical jagged edges from image stretching, whereas it looks smooth in other players.

I already removed + reinstalled it, no difference. I checked all the settings, couldn't find anything related, I changed 'image enhancement' between None, Normal, and Advanced, no difference.

In case it's relevant: I upgraded to El Capitan earlier this week. Can't tell for sure but this problem started somewhere around the same time. Can it be related, and if yes, is there any El Capitan-specific setting involved that could fix this?
I had the same problem at my both devices, MacBook Air (mid 2011) and 5k Retina iMac (mid 2014) only after upgrading to El Capitan. I tried everything to solve the issue with MPlayerX (as it's my fav player and most used app) but no luck. Later i downgraded my MacBook Air to Yosemite and problem was solved.
Now I don't think it's a OS X related problem because other players are running smoothly so I guess it's high time for MPlayerX to release a new version.