K-Lite Codec Pack Standard is a collection of components needed for audio and video playback in DirectShow players such as Windows Media Player, Media Center, and Media Player Classic. This is the latest beta, the latest stable K-Lite Codec Pack Full can be downloaded here.
This Codec Pack is designed as a user-friendly solution for playing all your movie files.
It contains everything you need to play all common audio and video file formats. It also provides additional functionality such a thumbnail generation in Explorer.
There are four variants of the (stable) K-Lite Codec Pack:
K-Lite Codec Pack Basic contains everything you need to play all the common video file formats. Such as AVI, MKV, MP4, OGM, and FLV. This pack is for those who like a small, no-nonsense pack. It is small but powerful. K-Lite Codec Pack Standard contains a few additional features compared to the basic variant. It includes Media Player Classic, which is an excellent player for video files. This pack is recommended for the average user. K-Lite Codec Pack Full has some extras compared to the standard variant. It additionally GraphStudioNext, and a few extra DirectShow filters. K-Lite Codec Pack Mega is the complete pack. It additionally contains VFW/ACM codecs for video encoding/editing.
For detailed tables with comparisons of the abilities and contents of the different variants of the codec pack, have a look at the comparison of abilities and comparison of contents pages.