(High-definition MPEG) and M2TS
files to preview.
MTS: High-definition MPEG Transport Stream video format, commonly
called "AVCHD" (Advanced Video Codec High Definition)used by
Sony, Panasonic, and other HD camcorders; based on the MPEG-2
transport stream and supports 720p and 1080i HD video formats.
M2TS: Video file saved in the high-definition Blu-ray BDAV format;
used for saving video data on Blu-ray discs; based on the MPEG-2
transport stream and supports 720p and 1080i formats. BDAV
stands for "Blu-ray Disc Audio/Visual," while the M2TS extension
refers to "MPEG-2 Transport Stream."
As always you just need the codec on your system to actually be able
to preview above file types. The shell will generate thumbnails for
these files if the appropriate extensions are installed.