http://www.videohelp.com/tools/LAV-Filters
Before Windows, or an app like a player can open a video file it has to know a bit about the type or format of video, & it has to be able to decode the video -- the LAV Filters can help in that regard. Both regular install & portable versions are available -- the portable versions use .bat files to install & uninstall the 3 filters individually, so it's not a big deal to right click a .bat file, & run as admin, & if it doesn't work for you uninstall the same way.
"LAV Filters (aka LAVFSplitter) is a multi-format media splitter/decoder that uses libavformat (the demuxing library from ffmpeg) to demux all sorts of media files. MKV/WebM, AVI, MP4/MOV, MPEG-TS, FLV, OGG are tested and will be registered for. Other formats can be tested using GraphStudio. H264, VC-1, MPEG4-ASP (Divx/Xvid), VP8 have been tested and are working well. DTS, AC3, TrueHD, MP3, Vorbis have been tested. Subtitle Support. Stream Switching. "
"Version history:
0.53 - 2012/11/05 - Release NotesLAV Splitter
- Added support for reading image files (tiff, png, jpeg, tga, bmp)
- Support for MPEG-4 ASP in MPEG-TS
- Support for reading metadata using the IAMMediaContent interface
- Fixed Aspect Ratio on some wmv/asf filesLAV Video
- Fixed a crash in the WMV9 DMO decoder on Windows 8
- DVD improvements
- Subtitles are properly cleared from the screen, and won't be shown forever on some discs
- Improved subtitle/menu positioning on some PAL discs
- Improved handling of still frame DVD menus
- Fixed a deadlock that caused the player to freeze in some DVD menus
- Improved quality of blending subtitles/menus
- QuickSync improvements
- Support using QuickSync in Fullscreen Exclusive mode (ie. in WMC)
- Improved fallback to software decoding if QuickSync is not available
- Support for DVD decoding
- Added support for Avid DV
- Properly indicate progressive video when YADIF deinterlacing is activatedLAV Audio
- Added proper DirectShow types and config options for AMR-NB, Nellymoser and various (AD)PCM variants"