Answer:
I have many mts files transfered from my AVCHD camera, the files is difficult to use on mac, quicktime can not play them, fcp can not accept them, i just convert mts files to h.264 mov for quicktime player and fcp using Aunsoft Video Converter for mac, very ease, only three steps, this article can help you.
http://www.aunsoft.com/convert-deinterlace-mts-to-h264-mov-for-fcp-mac-sony-cx150-avchd-converter/
http://www.mtsconverter.org/convert-mts-to-h264.html