Windows Media Video

Windows Media Video (term English usually shortened in WMV ) is the name of a family of codecs video owners developed by Microsoft. On Internet, it is frequent to meet this type of video files, whether it is in remote loading or Streaming.

Like the majority of the codecs video owners, this family was initially based on technologies resulting from international standards (ISO/IEC MPEG, ITU-T H.26x)

Microsoft, wishing to insert their codec owner in the majority of the products general public (telephones, readers DVD, decoders TV) others that the computers, tried to introduce their version 9 (WMV9) into industrial consortia (3GPP, DVB, ATSC, DVD-Forum, Blu-Ray)

Being on the one hand in competition with the standard MPEG-4 AVC/H.264, which was developed jointly by researchers of companies and universities of the whole world, and whose results in term of effectiveness of coding were shown in an independent way, and on the other hand being obliged, by the consortium industrialists, to present a codec necessarily standardized, Microsoft subjected codec WMV9 to the SMPTE (Society off Motion Picture and Television Engineers) to standardize it under the name of VC-1. In 2005, the codec VC-1 became stable and moved towards the statute of international standard.

Before that, 3GPP had not included codec VC-1 for the exchange of vidéos on mobile (streaming, videoconference, remote loading).

The consortia DVD-Forum and Blu-Ray had already retained VC-1 (as well as MPEG-2 and MPEG-4 AVC/H.264) in their specification before even as it is not standardized. That means that future readers DVD in High-definition will be able to read films with format VC-1.

For the diffusion of television, DVB is studying, initially commercially, if it is useful to include VC-1 whereas MPEG-4 AVC/H.264 seems better technically and that it will be deployed front.

One of the perverse effects of the opening by Microsoft of the specifications of their codec, is that the other companies of the field could realize that Microsoft had indeed plundered in the patents of existing standards like MPEG-2 and MPEG-4 AVC/H.264. Vis-a-vis the pressure exerted by the holders of patents, Microsoft had to ask MPEG it to open a program of licenses. In January 2006, no agreement was still found and the conditions of licenses of VC-1 remain always unknown.

Codecs

Windows Media Video v7 (FourCC: WMV1)
Windows Media Screen v7 (FourCC: Ms) - Optimized for captures of basic screen quality
Windows Media Video v8 (FourCC: WMV2)
Windows Media Video 9 (FourCC: WMV3)
Windows Media Video 9 Screen (FourCC: Ms)
Windows Media Video 9 Advanced Profiles (FourCC: WVC1)
Windows Media Video 9 Image
Windows Media Video 9.1 Image
→ and probably of others (see VC-1)

External bonds

the official page of the VC-1 (wmv9)

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