Everyone who is acquainted with running Windows will be familiar with the Windows Media Video or WMV video file format. Simply put, the WMV is a video format that uses lossy compression algorithm proprietary to the Windows operating platform. It is developed by Microsoft as a competitor to the RealVideo multimedia platform.

As a codec, the WMV is encapsulated or contained in the ASF (Advanced System Format) file container format. The file with extension .wmv is precisely an ASF file that contains a proprietary Microsoft video codec for Windows. Interestingly enough, WMV can also be contained in the AVI file container format.

A short history

The very first version of the format, WMV7 was released in 1999 based on the MPEG4 Part2 as implemented by Microsoft. It was among the first video codec that supported constant and variable video bitrates. Since then, newer versions have been developed to keep up with competition culminating in the WMV9 specification released.in 2003. It has adopted much of the specification of professional video formats with support for frame interpolation, interlaced video and non-square pixels.

In 2006, the SMPTE group adopted it as its standard SMPTE 421M or VC1 that became one of the mandatory video formats for the emerging high resolution HD DVD and Blu-Ray formats for Home Theater entertainment. It supports both 720p and 1080p video resolutions and multichannel audio.

One of its features that made movie studios accept it is its support for the Digital Rights Management or DRM . It does provide encryption protection that studios are adamant about when releasing titles from their catalogues as well as new ones. But while WMV video codec itself does not contain DRM, the ASF container file that encapsulates the WMV video stream does. Windows Media DRM is standard in Windows PCs using the new Windows Vista.

The Benefits of using WMV

The WMV codec is the most recognizable video codec format. Its competitors, apart from RM of RealVideo, include MPEG4 AVC, DivX and Xvid. The MPEG4 AVC is the other high resolution format developed for HD DVD and Blu-Ray.

Understandably, WMV is the mandatory video format for Portable Media Center devices that run special versions of the Windows operating system. They include the Microsoft Zune that competes with the Apple iPod, the Xbox 360 gaming console and mobile phones using the Windows Mobile platform. Needless to say, it is the default video format for the Windows Media Player that comes bundled with the Windows operating system.

Video player software that can play WMV files includes PowerDVD, Mplayer, VLC MediaPlayer and the Media Player Classic. Interestingly enough, RealPlayer against which the WMV file was meant to compete also plays WMV files.

Video quality of the WMV9 is claimed to be superior to MPEG4 and about three times better than MPEG2, the codec used for the home video standard DVD. That’s what Microsoft claims. But independent tests have not confirmed this.

Dislikes about WMV

The newer WMV9 and WMV HD which uses the WMV codec have received unwanted criticisms from the press and mostly from users. It has more to do with the issue of DRM which has never really grown on users. Restoring licenses for DRM protected WMV files in other PC is problematic and these same files can’t even be played when downloaded on Zune devices. The standard Windows Media DRM systems apparently are not supported in Zune.