clipped from: www.mtsconverterdownload.com 
.MTS is the raw file of AVCHD video, which can't be recognized by most devices. You need MTS Converter to convert .mts files to AVI, FLV, MP4, MOV, 3GP, MP3, WMA, etc. So you can playback MTS file on computer or on iPod, Pocket PC, even share the videos on Internet
As a professional MTS file converter, MTS Converter can convert MTS video file at fastest speed with least quality loss. Besides converting MTS files, the MTS Converter also can convert *.M2TS files , *.M2T files, etc. Further more, MTS Converter is also a good .mts file editor. You can customize video quality, size and other thing by editing and trimming.