Windows Media Codecs. Microsoft has developed anumber of codecs, including: WMV7 and WMV8, which are early versions of theMicrosoft video codec. WMV9, which is the current version of the Microsoftvideo codec. VC-1, which is the Advanced Profile of the WMV9codec, and which is needed for support by both Blu-rayand HD-DVD players. WMA (Windows Media Audio), including WMA Pro,which is a multichannel audio codec. Dolby Digital. Dolby Digital forms the basis ofmultichannel audio coding in HDTV and DVD movies.Popular file containers AVI is a popular audio/video file format in PC systems. Itsupports multiple audio and video codecs, including DV andMPEG-1/2/4. MP4 file format is based on the Apple QuickTime file format,but is part of the MPEG-4 standard (MPEG-4, part 14). MP4files use the .mp4 extension and support a variety of codecs,including the AAC and MPEG-4 (part 2 or part 10) codecs. WMV (Windows Media Video) or ASF (AdvancedStreaming Format) are also popular Microsoft media filecontainers. They support mostly Microsoft-based codecs suchas WMV7/8/9, WMA, and VC-1. DVR-MS is a Microsoft file container for storing broadcastTV programming that is recorded by Media Center PCs. DivX is a file container developed by the DivX Corporation.It supports the DivX video codecs (versions 3.0 to 6) that arebased on the MPEG-4, part 2, video codec, and a variety ofaudio codecs, including MP2, MP3, Dolby Digital, and rawLPCM data. The divx file format can also support metadata,subtitle tracks, and DRM. QuickTime (.mov or .qt) is a file container developed byApple. It provides the basis for the MP4 file format that iscurrently used by iTunes and other media service providers.
