Windows 8 Codec Pack is a FREE software which allows you to play lots of file formats such as flv and mkv in your Windows Media Player.
The name of the software is misleading I think…it supports not only windows 8/8.1 but also 7, Vista, XP, 2000, 2008, & 2003.
The software is compatible with Microsoft Windows Media Player 9, 10, 11, & 12.
Now you can relax and play all your files in Windows Media Player. You don’t need any separate player for playing video files such as flv and mkv.
From the Windows 8 Codec Pack website:
Compression types that you will be able to play include:x265 | h.265 | HEVC | 10bit x264 | x264| h.264 | AVCHD | AVC | DivX | XviD | MP4 | MPEG4 | MPEG2 and many more.
File types you will be able to play include:.bdmv | .evo | .hevc | .mkv | .avi | .flv | .webm | .mp4 | .ts | .m4v | .m4a | .ogm | .ac3 | .dts | .flac | .ape | .aac | .ogg | .ofr | .mpc | .3gp and many more.
Codec's Explained:A codec is a piece of software on either a device or computer capable of encoding and/or decoding video and/or audio data from files, streams and broadcasts. The word Codec is a portmanteau of 'compressor-decompressor'
Official Website of Windows 8 Codec : http://www.windows8codecs.com