How to Play .Mkv Files on a Mac. Most of the time, when you want to play a digital video on your computer, you just click on the file and it plays. On a Mac, most videos are played on the QuickTime Player. .Mkv files, however, are different. They can only play on certain players, but they are not associated with a single player like QuickTime .mov files are with QuickTime Player.
Obtain the Correct Codec and Player
Become familiar with the .mkv format. .Mkv is a container format developed by Matroska. It can hold different types of video and audio. For example, there might be an .avi file contained within the .mkv file.
Realize that there is no standard for distributable video. Companies can encode their videos however they want and require their own decoders and players for you to play it back. They do this to make money by forcing users to purchase a certain type of video player. Luckily, there are a few different players that will play .mkv files on the Mac.
Get ready for frustration. Not every codec (short for coder/decoder) will play .mkv files on your Mac. In fact, most of the time your Mac will not play them at all.
Get the proper player to play .mkv files on your Mac. Two codecs/players that are popular among Mac users are VLC and Mplayer (see Resources below). In fact, Matroska, who developed the .mkv format, lists them on its homepage as being able to open .mkv files on the Mac.
Use the VLC player. The VLC player contains a decoder to decode the .mkv files. It will also play many of the formats you will find inside the .mkv file. One it does not support is RealVideo. That is because RealVideo is proprietary and you must have RealPlayer to play its files.
Things You'll Need
.Mkv files to play
Codec and player to play the files on a Mac
MplayerOSX is open source software, which means that it is a collaborative effort and anyone who understands programming can work on it. It is a work in progress and you might find different versions of it around the Internet.