Windows Media Video
Windows Media Video | |
---|---|
File extension : |
.wmv
|
MIME type : | video / x-ms-wmv |
Developed by: | Microsoft |
Windows Media Video ( WMV ) is a series of proprietary video formats from Microsoft and part of the Windows Media platform.
In addition to Windows Media Player and many other software players, some standalone hardware players can also decode WMV files.
Files that contain WMV-encoded video streams are usually embedded in Microsoft's Advanced Streaming Format (ASF) container format . These files usually have the extension .asf , but in the case of a video file they can also have the extension .wmv .
A new variant of WMV is the Windows Media Video High Definition (WMVHD) format .
The Windows Media Format also supports the integration of Digital Rights Management (DRM), which should enable owners of exploitation rights to regulate the access rights to sound and video material. In practice, this technology is often used as a copy protection measure.
There are currently three versions of WMV, all of which are similar in structure to MPEG-4 . These versions each have the FourCCs WMV1 to WMV3, but are often referred to as WMV7 to WMV9 because they were released together with version 7.0 to 9.0 of Windows Media Player. An expanded version of WMV3 was submitted to SMPTE as VC-1 and was approved as an open (but nonetheless proprietary) standard in 2006. VC-1 is used on Blu-ray Disc and HD DVD as one of three mandatory video formats.
A disadvantage of this format is that standard DVD players do not recognize this format. Even Apple's QuickTime required under Mac OS to WMV playback in web browsers a QuickTime extension such as Flip4Mac or separate WMV players such as MPlayer or VLC media player .
More than 50% of the patents for Codec VC-1 have expired by the end of 2018.
Web links
Individual evidence
- ↑ Flip4Mac 3.2 Brings Dramatically Improved Load Times for WMV and ASF Video. iClarified, May 2, 2013, accessed October 3, 2016 .
- ↑ http://www.mpegla.com/main/programs/VC1/Documents/vc-1-att1.pdf