It is targeted towards high-definition video content, at resolutions such as 720p and 1080p. WMV 9 also introduced a new profile titled Windows Media Video 9 Professional, which is activated automatically whenever the video resolution exceeds 300,000 pixels (e.g., 528 px × 576 px, 640 px × 480 px or 768 px × 432 px and beyond) and the bitrate 1000 kbit/s. While all versions of WMV support variable bit rate, average bit rate, and constant bit rate, WMV 9 introduced several important features including native support for interlaced video, non-square pixels, and frame interpolation.
Continued proprietary development led to newer versions of the format, but the bit stream syntax was not frozen until WMV 9. The first version of the format, WMV 7, was introduced in 1999, and was built upon Microsoft's implementation of MPEG-4 Part 2. Its main competitors are MPEG-4 AVC, AVS, RealVideo, and MPEG-4 ASP. Usage of the term WMV often refers to the Microsoft Windows Media Video format only.
Windows Media Video (WMV) is the most recognized video compression format within the WMV family. Container format ĭiagram illustrating the relative frame sizes of several common video resolutions targeted by Windows Media Video 9 Professional, starting with 480p. VC-1 became one of the three video formats for the Blu-ray video disc, along with H.262/MPEG-2 Part 2 and H.264/MPEG-4 AVC. The standard was officially approved in March 2006 as SMPTE 421M, better known as VC-1, thus making the WMV 9 format an open standard. In 2003, Microsoft drafted a video compression specification based on its WMV 9 format and submitted it to SMPTE for standardization. Microsoft also developed a digital container format called Advanced Systems Format to store video encoded by Windows Media Video. After standardization by the Society of Motion Picture and Television Engineers (SMPTE), WMV version 9 was adapted for physical-delivery formats such as HD DVD and Blu-ray Disc and became known as VC-1. The other compression technologies, WMV Screen and WMV Image, cater for specialized content. WMV consists of three distinct codecs: The original video compression technology known as WMV, was originally designed for Internet streaming applications, as a competitor to RealVideo. It is part of the Windows Media framework. Windows Media Video ( WMV) is a series of video codecs and their corresponding video coding formats developed by Microsoft. This article is about video encoding and decoding software.
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