An MTS file is a video saved in the Advanced Video Coding High Definition (AVCHD) format. It is the standard video format used by many Sony and Panasonic HD camcorders. MTS files are also used for storing high definition video on Blu-ray discs.

MTS file open in Microsoft Windows Media Player 12 MTS is short for "MPEG Transport Stream." The file format uses MPEG-4 / H.264 video compression and supports 720p and 1080i HD video resolutions. The audio in an MTS file may be compressed using the Dolby AC-3 codec or saved as uncompressed linear PCM audio. Supported audio tracks include stereo (2-channel) and 5.1 (5-channel + subwoofer) surround sound. The AVCHD format was established by Sony and Panasonic in 2006. Therefore, most Sony and Panasonic HD camcorders come with software that can open and edit MTS files. Many third party programs can open and play MTS video files as well. NOTE: AVCHD files saved on a camcorder often have an .mts file extension. AVCHD files edited on a computer or imported from a Blu-ray disc are commonly saved with an .M2TS extension.