Video file recorded by Windows Media Center, a program used to play multimedia content and record TV shows; encodes video using MPEG-2 compression and audio using MPEG-1 Layer II or Dolby Digital AC-3 compression; may also include descriptive metadata and digital rights management (DRM) information. The WTV Windows Media Center video format is successor of the DVR-MS Windows Media Center video format and was introduced in Windows 7
this is open lossless codecs, developed under the Ogg project. Lately it’s become quite popular: many users wishing to store audio with original quality choose FLAC. This is partly in connection with the fact that codecs uses IDv1 and IDv3 tags - this allows a user to sort an audio collection according to one’s particular tastes, changing the original metadata of the tracks.