The file extension M2TS indicates a file containing data according to the BDAV standard. This can be both video and audio.
The format is mainly used on BluRay discs. It was partially designed to be compatible with the AVCHD standard. AVCHD files, which are still on the storage medium of the recording device (eg camcorder) are usually the extension mts. After importing to the computer, however, the extension M2TS is often used as well.
The files include a transport stream in an MPEG-2 TS based container, video data with a resolution between 720x480 (SD) and 1920x1080 (FullHD) and audio data as PCM (Pulse Code Modulation), AC3 or TrueHD (Dolby Digital) or DTS or DTS-HD (Digital Theater System). In addition, other data streams or multiple video streams may be included. For the compression of the video data usually MPEG 2, VC1 or H.264 is used.
On BluRays, the M2TS files are protected by a digital rights management (DRM) method, usually AACS encrypted.