VLC media player is a free and open source cross-platform multimedia player that plays most multimedia files as well as discs, devices, and network streaming protocols. After much delay, it is now available for Windows RT devices including Surface RT and Surface 2.
VLC for Windows 8.1 plays most local video and audio files, and network streams.
The app has a media library for audio and video files, a complete audio library, with metadata fetching.
VLC supports multi-track audio and subtitles, speed control.
VLC supports all formats of video, including, FLAC, MKV, MOV, TS and Ogg.
Download it here from Windows Store.