The MKV is a video format container very similar to the MOV and AVI formats that support several different types of video compression algorithms and video codecs as well as a range of audio compression formats. It can play SSA, USF as well as SRT subtitles and also VobSub subtitles for the DVDs.
As to MKV codec, it is video codec that is used to decode and encode MKV file. Here we will recommend you several popular codecs for playing MKV files.
1. Matroska Pack Full
The famous full pack, not only for playing matroska media files, but it will also allow playback of most modern video formats on any DirectShow player, even with Windows Mediaplayer 6.4/7/8/9/10.
2. Lazy Man's MKV 1.0.1 alpha 8
This is a Matroska Playback Pack for minimalists who hate bloated Codec Packs. It will install only 3 DirectShow filters (kudos to Gabest and his project guliverkli).
3. Real Alternative Lite
Real Alternative will allow you to play RealMedia files without having to install RealPlayer. All RealMedia formats (.ra, .rm, .rmvb, .ram, .rpm, .rv, .rp, .rt, .rnx, .smi, .smil etc.) are supported, including streaming content and RealMedia content that is embedded in webpages.
Other frequently-used codecs
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