When using a Sony HD camera always set the camera to save video to the SD card instead of internal memory. It is extremely important that you pull the video directly from the card and NOT use the USB connection to the camera. Doing so will convert the native .MTS files to an unsupported format, so always use the SD or Sony Card.
Once the video is on the system you can convert it to a .MP4 or .WMV using the AISEESOFT MTS Converter, that way you can write the video. The .MTS files will work and play for analysis, however the .MP4 or .WMV conversion is superior for playback and creating videos.