I was handed a batch of videos from a client’s video shoot recently from a client’s video shoot. MXF (Material exchange format) is a container format much like MOV, AVI and MKV but there’s little info about it. Quicktime derps on it.
VLC and MplayerX plays MXF without hitches.
Apple’s Compressor ($49.99) works great as well as ffMPEG based apps like iffMPEG ($19).