M2TS is a video file format that contains Blu-ray BDAV high-definition HD video. This is video from Blu-ray discs and digital camcorders. The .m2ts extension means “MPEG-2 Transport Stream”. However, it is associated as the narrower container format BDAV, which is the standard Blu-ray format for consumer video discs. The original name for the file type is Blu-ray BDAV Video File. The format was developed by Sony. It arose after the introduction of new Blu-ray media. The audio and video transmission protocol M2TS, i.e., MPEG-2 Transport Stream, was created based on MPEG-2. In fact, this is his advanced modification. The protocol supports error correction if partial data loss occurs. A .m2ts file is a BDAV container that contains digital multimedia data that is compressed by one of the videos available in the H.262, H.264, VC-1 format. And some audio codecs, too. This is Dolby AC3, PCM. There are several video and audio streams in one M2TS file. There are also subtitle tracks that can be selected during playback. Most modern video players support .M2TS format. For smooth playback, you need a powerful computer. Such a video can be edited using the professional program Sony Vegas Pro.
M4V is a video file format that has been downloaded from the Apple iTunes store. The format contains TV shows, videos, films, music. It looks like a .MP4 file, but it sometimes has copy protection when Apple's FairPlay DRM is used (technical copyright protection). The M4V format, i.e., MPEG-4 iTunes Video File, was developed by Apple. MP4 is a container format. Like the same formats as MOV, AVI, MKV, it provides the ability to combine a variety of multimedia streams into one file. Mostly it is audio and video. In order to play the protected M4V file, the computer must be authorized using the iTunes account from which the videos were purchased. In this case, it can be used in order to buy video. Unprotected M4V files can be played by other video players if the extension is changed from .M4v to .Mp4. Files with the M4V extension contain both sound and video data. You can convert M4V files to MP4 format. In this case, it will be possible to play them on other computers, since the M4V files are protected by DRM. MP4 files, compared to the M4V format, do not allow you to specify partition information.