Windows Essentials Codec Pack covers most of the codecs, filters, splitters and related tools needed to play video and music. 99% of all movies, music and flash files are guaranteed to work with this codec pack. Filters further improve video and audio quality. And you will definitely not miss any new release, as the updates work automatically.

Although it is not affiliated with Microsoft, it still provides reliability and security as it is an open source software free of spyware, adware and virus software that works alongside other codecs with no known conflicts.

The latest version comes with DTS-HD and Dolby TrueHD bit streaming support integrated into Media Player Classic, a player also included in this package.

• various compression methods
• all common encoding modes: constant bitrate, fixed quantizer, fixed quality, two-pass encoding (depends on the capabilities of the compressor) for libavcodec and XviD detailed choice of motion estimation method
• minimum and maximum I-frame spacing, quantizer selection, quantizer type, and trellis quantization selection for libavcodec
  
• adaptive quantization (aka masking) for libavcodec and XviD, one factor exclusion
• selectable compression of opening and closing credits
• two curve compression algorithms for the second pass of two-pass encoding – thanks to the developers of XviD
• Second pass simulation: although not very accurate, it is still useful for tweaking advanced curve compression options
• ability to use libavcodec internal two pass code
• image preprocessing with ffdshow image filters (must have the latest version of ffdshow installed)
  
• graph during encoding: if your encoding program does not provide
• B-frame support: One to eight consecutive B-frames
  
• MPEG4 support quarter-ball and GMC
• selectable interlacing encoding