InterVideo WinDVD: lots of dropped/scrambled frames, occassional outright time jumps
Windows Media Player: video freezes for long periods
RealPlayer: no video
VLC media player: video plays well, but is pixelated. Attempting to choose a different display method gives smooth video at about 2 frames per second.
Media Player Classic: much the same as WinDVD. Edit: it seems to have better timekeeping.
Conclusion: playing MPEG-2 videos using a computer is stupidly hard. Strange that my actual TV manages to handle the live stream with few problems.