Sluggish playback MPEG4 video

Norwegian telecomcompany has recorded and released a 7 hour 720p MPEG4 (the file is about 20 GB and 720p HD).

Link for torrent file (legal torrent) is http://nrkbeta.no/2009/12/18/bergensbanen/

The camera is mounted in front of train from Bergen city to Oslo (celebration of 100 years since opening on railway) and the trip takes about 7 houres…

Problem : sluggish playback on Apple TV (native playbacb, XBMC and VLC)…

The file plays very nice on my Macbook Pro (4.1)…

Regrads,
Thomas