Video playing low res in Safari
I've got a player embedded on my site here http://officeagenda.britishland.com/video/the-right-move
In Chrome the video is crisp and clear, and I can select which source to play from.
In Safari, the video looks like it's playing from the lowest quality source, and there is no option to chose another.
How can I force the player to use the best quality source in Safari?
Thanks in advance