What is WMV

Rob Parsons Updated on Apr 15, 2022 4:21 PM

WMV, shorted for Windows Media Video, is a format developed by Microsoft for video codecs and its corresponding video coding formats. Being a part of Windows media frames of Microsoft, WMV has three different codecs. As a competitor to RealVideo, WMV was first developed to compress some original videos to meet the needs of Internet streaming applications. Other compression technologies like WMV Screen and WMV Image, are supplying for the specialized content. After the standardization of SMPTE( Society of Motion Picture and Television Engineers ), WMV version 9 was accepted by physical delivery as a format, such as HD digital and Blu-ray Disc, known as VC-1 as well. ASF(Advanced Systems Format), another digital container format, was also developed by Microsoft to store video encoded by WMV. With the same video effect, the WMV format video may both download and play at the same time. It is perfect format for users to play video online and transfer data.

History

In 2003, Microsoft proposed bills based on WMV9 format and submitted it to SMPTE for standardization. WMV9 became a more standard format when was official approved in SMPTE 421M standard in March 2006, better known as VC-1. VC-1, H.264 and MPEG-4 AVC soon become the three video formats of the Blu-ray video disc. And we strongly believed that as the development of WMV9, it is more than a codec since Microsoft is also a member of the sixteen shared patents industries using VC-1.

Container format

WMV files use ASF(Advanced Systems Format)to encapsulate the encoded media content. Because ASF can also use other codes to encapsulate media content, the ASF files are usually used .ASF as filename rather than the .WMV file extension. Although WMV is normally packed into the ASF container format, it may be packed into Matroska or AVI as well. The file extensions of this file type are .MKV or .AVI. One formal way of storing WMV to AVI is to use VCM(Video Compress Manager) of WMV9 for encoding.

Video compression formats

WMV is the most recognized one in WMV video format family. The term of WMV often refers to the Windows video format of Microsoft merely. The main competitors of WMV are MPEG-4 AVC, AVS, RealVideo and MPEG-4 ASP. In the first version WMV7, was introduced in 1999 and based on MPEG-4 Part 2. Although there are continuously new versions emerged, the bit stream syntax was not frozen until the WMV9. For every version of WMV9 can support changeable bit rate, average bit rate, and steady bit rate, WMV accepted some key features, such as supporting for interlaced video, non-square pixels, and frame interpolation. It also introduced a new profile called Windows Media Video 9 Professional. Whenever the resolution over 300,000 pixels (e.g., 528 px × 576 px, 640 px × 480 px or 768 px × 432 px and beyond), the bitrate 1000 kbit/s would come into effect automatically. The target resolution towards WMV is 720p and 1080p.

As an identified online recording, movable media device, WMV is a mandatory video format. WMV supports various formats for Zune, Xbox 360, Windows Mobile and other uncertified devices in Windows media player of Microsoft. WMV HD authorized WMV9 as its certification program and the quality level is certified by Microsoft. Developed by Microsoft, WMV-HD is another version of video compressing technology based on WMV9 standard , using .wmv as a filename. The compression rate of WMV is higher than MPEG-2, which means with the same HDTV program, MPEG-2 may compress it into 30GB, while WMV-HD can compress it into 15GB with no visual quality loss.

Although WMV-HD is the unique standard of Microsoft, it became popularized rapidly in desktop for its use of WMV format series. In terms of functions, the data compression rate of WMV-HD remains basically the same with H.264. In a fight of mainstream of video encoding, both WMV-HD and H.264 are focusing on the next disc standard" HD DVD"and Digital Microwave for Broadcasting Television.

Audio compression formats

In general, WMV may include both video and audio files. For video part, it uses Windows Media Video for encoding while audio uses Windows Media Audio. WMV used to be the only supported video format of Silverlight, but later it supports H.264 format after its version 3.

Players

Programs that can support WMV includes Windows Media Player, RealPlayer, MPlayer, Media Player Classic, VLC Media Player and K-Multimedia Player. Others players such as Linux, may use FFmpeg format.

As Macintosh, Microsoft developed a Windows media player of PowerPC version for Mac OS X in 2003, but the further development of it has ceased. Microsoft now supports the 3rd party Flip4Mac WMV, a QuickTime Component that allows all Macintosh users to play WMV files used QuickTime framework. See more how to play .wmv files on Mac. WMV is bundle with Silverlight, but it may also be accomplished with install even without it. From the Flip4Mac website, WMV is incompatible with the QT component.