They can capture live screen content, or convert video from third-party screen-capture programs into WMV 9 Screen files. Windows Media Video Screen (WMV Screen) are video formats that specialise in screencast content. WMV used to be the only supported video format for the Microsoft Silverlight platform, but the H.264 format is now also supported starting with version 3. WMV HD mandates the use of WMV 9 for its certification program, at quality levels specified by Microsoft. The Microsoft Zune, Xbox 360, Windows Mobile-powered devices with Windows Media Player, as well as many uncertified devices, support the format. WMV is a mandatory video format for PlaysForSure-certified online stores and devices, as well as Portable Media Center devices. The format is not compatible with previous WMV 9 formats, however. It improves compression efficiency for interlaced content and is made transport-independent, making it able to be encapsulated in an MPEG transport stream or RTP packet format. The Advanced Profile in VC-1 is implemented in a new WMV format called Windows Media Video 9 Advanced Profile. The Simple and Main profile levels in WMV 9 are compliant with the same profile levels in the VC-1 specification. 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. Diagram illustrating the relative frame sizes of several common video resolutions targeted by Windows Media Video 9 Professional, starting with 480p.
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