can't open file (codec AV1x, Linear PCM)

Hi, I have a client who sent me a video file that I can't play... I just get this message: The document “777 Air to Air sunset.mov” could not be opened. The movie is not in a format that QuickTime Player understands.

I'm a little new to using a bunch of different files that people send me, and feeling a bit overwhelmed. Can anybody help me? I'm using FCP 7. Here are the detail on the video file itself:

QuickTime movie
566.6 MB on disk
720 × 486
Codecs: AV1x, Linear PCM
duration: 00:26
audio channels: 2
total bit rate: 174, 378

Thanks,

Eric