Diagnosing a toslink bitrate

Hi,
I have a Samsung Bd-f9800 Blu-ray player the only audio output for audio is optical toslink. I've also got a few Blu-ray audio disks. I can't find out anywhere what the max bitrate of the toslink is. Does anyone know how I can test it? I'm thinking it might be downsampling my disks to 44.1
A thought did occur, I've got an old XP laptop somewhere with a toslink input. If I connected that up to the Samsung, is there a free program that might tell me what bit rate is being received from the disk in the Samsung?
Tia