Windows Media Video#Windows Media Video

In 2003, Microsoft drafted a video compression specification based on its WMV 9 format and submitted it to SMPTE for standardization. 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. 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.

{{Main|Advanced Systems Format}}

File:WindowsMediaVideo.jpg of what a WMV file may contain.]]

A WMV file uses the Advanced Systems Format (ASF) container format to encapsulate the encoded multimedia content. While the ASF can encapsulate multimedia in other encodings than those the WMV file standard specifies, those ASF files should use the {{mono|.asf}} file extension and not the {{mono|.wmv}} file extension.{{cite web|date=November 17, 2003|title=The Difference Between ASF and WMV/WMA Files|url=http://support.microsoft.com/kb/284094|url-status=dead|archive-url=https://web.archive.org/web/20070819113435/http://support.microsoft.com/kb/284094|archive-date=2007-08-19}}{{failed verification|date=August 2019}}

The ASF container can optionally support digital rights management using a combination of elliptic curve cryptography key exchange, DES block cipher, a custom block cipher, RC4 stream cipher and the SHA-1 hashing function.

Although WMV is generally packed into the ASF container format, it can also be put into the Matroska{{cite web|date=2003-06-19|title=Archives {{pipe}} Matroska|url=http://matroska.org/news/archives.html|url-status=dead|archive-url=https://web.archive.org/web/20111011142432/http://matroska.org/news/archives.html|archive-date=2011-10-11|access-date=2011-10-12|quote=As a sidenote, his muxer filter will also allow transmuxing of Microsoft WMV9 video files ( ASF/WMV container ) fine into matroska files, from Graphedit, and with WMV9 VCM installed on your PC you can even open and edit the files in latest VirtualdubMod}} container format (with file extension {{mono|.mkv}}), or AVI container format (extension {{mono|.avi}}). One common way to store WMV in an AVI file is to use the WMV 9 Video Compression Manager (VCM) codec implementation.Microsoft Corporation (2003-07-07) [http://www.microsoft.com/downloads/details.aspx?FamilyID=0c99c648-5800-4aa3-a2fe-3de948689db8&DisplayLang=en Windows Media Video 9 VCM] {{webarchive|url=https://web.archive.org/web/20090810203658/http://www.microsoft.com/downloads/details.aspx?FamilyID=0c99c648-5800-4aa3-a2fe-3de948689db8&displaylang=en |date=2009-08-10 }}, Retrieved on 2009-08-07{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9VCM|url-status=dead|archive-url=https://web.archive.org/web/20171101052328/http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9VCM|archive-date=1 November 2017|access-date=3 May 2018|website=www.microsoft.com}}

Image:Common Video Resolutions 2.svg]]

Windows Media Video (WMV) is the most recognized video compression format within the WMV family. Usage of the term WMV often refers to the Microsoft Windows Media Video format only. Its main competitors are MPEG-4 AVC, AVS, RealVideo, and MPEG-4 ASP. The first version of the format, WMV 7, was introduced in 1999, and was built upon Microsoft's implementation of MPEG-4 Part 2.{{cite web|title=News, Features, Reviews, Forums and Resources for the Professional Content Creator - Creative Planet Network|url=http://digitalcontentproducer.com/mag/video_mpeg_makes_scene/|url-status=dead|archive-url=https://web.archive.org/web/20090222024150/http://digitalcontentproducer.com/mag/video_mpeg_makes_scene/|archive-date=22 February 2009|access-date=3 May 2018|website=Creative Planet Network}} Continued proprietary development led to newer versions of the format, but the bit stream syntax was not frozen until WMV 9.{{cite web|title=Windows Media Audio & Video 9 Series|url=http://download.microsoft.com/download/6/f/c/6fc03c60-5d5b-42c0-bcce-5e184fa56741/2_Audio_Video.ppt|url-status=dead|archive-url=https://web.archive.org/web/20070928022926/http://download.microsoft.com/download/6/f/c/6fc03c60-5d5b-42c0-bcce-5e184fa56741/2_Audio_Video.ppt|archive-date=28 September 2007|access-date=3 May 2018|website=microsoft.com}} 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.{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.microsoft.com/windows/windowsmedia/demos/video_quality_demos.aspx|url-status=dead|archive-url=https://web.archive.org/web/20100821235549/http://www.microsoft.com/windows/windowsmedia/demos/video_quality_demos.aspx|archive-date=21 August 2010|access-date=3 May 2018|website=www.microsoft.com}} WMV 9 also introduced a new profile titled Windows Media Video 9 Professional,{{Cite web|url=http://www.elims.org/downloads/sample_content/9Series_RevGuide.pdf|archive-url=https://web.archive.org/web/20070928023100/http://www.elims.org/downloads/sample_content/9Series_RevGuide.pdf|url-status=dead|title=Windows Media 9 Series Beta Reviewer's Guide|archive-date=September 28, 2007}} 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 1 Mbit/s{{Citation needed|reason=where did this info come from, and why such a weird example rez originally? it's not anywhere in the linked document(s)|date=July 2009}}. It is targeted towards high-definition video content, at resolutions such as 720p and 1080p.

The Simple and Main profile levels in WMV 9 are compliant with the same profile levels in the VC-1 specification.{{Cite web|url=http://www.microsoft.com/windows/windowsmedia/howto/articles/codecadvancedsettings.aspx|archive-url=https://web.archive.org/web/20070811040550/http://www.microsoft.com/windows/windowsmedia/howto/articles/codecadvancedsettings.aspx|url-status=dead|title=Using the Advanced Settings of the Windows Media Video 9 Advanced Profile Codec|website=Microsoft |archive-date=August 11, 2007}} The Advanced Profile in VC-1 is implemented in a new WMV format called Windows Media Video 9 Advanced Profile. 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 format is not compatible with previous WMV 9 formats, however.{{cite web|url=http://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=64909|title=Best Practices for Windows Media Encoding|first1=Ben|last1=Waggoner|date=21 February 2007|website=Streaming Media Magazine|access-date=3 May 2018|url-status=live|archive-url=https://web.archive.org/web/20110726005854/http://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=64909|archive-date=26 July 2011}}

WMV is a mandatory video format for PlaysForSure-certified online stores and devices, as well as Portable Media Center devices. The Microsoft Zune, Xbox 360, Windows Mobile-powered devices with Windows Media Player, as well as many uncertified devices, support the format.{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.microsoft.com/windows/windowsmedia/player/windowsmobile/faq.aspx|url-status=dead|archive-url=https://web.archive.org/web/20070914112132/http://www.microsoft.com/windows/windowsmedia/player/windowsmobile/faq.aspx|archive-date=14 September 2007|access-date=3 May 2018|website=www.microsoft.com}} WMV HD mandates the use of WMV 9 for its certification program, at quality levels specified by Microsoft.{{cite web|title=MSN - Outlook, Office, Skype, Bing, Breaking News, and Latest Videos|url=http://go.microsoft.com/fwlink/?LinkId=41932|url-status=dead|archive-url=https://web.archive.org/web/20051020113823/http://download.microsoft.com/download/0/7/e/07e701c3-2875-46be-9418-9c6591c46eb8/wmvhdencoding.DOC|archive-date=October 20, 2005|access-date=3 May 2018|website=go.microsoft.com}} 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.{{cite web|title=Microsoft Silverlight Developer Server Audio Video Streaming FAQ|url=http://www.microsoft.com/silverlight/faq.aspx|url-status=dead|archive-url=https://web.archive.org/web/20070904060106/http://www.microsoft.com/silverlight/faq.aspx|archive-date=4 September 2007|access-date=3 May 2018|website=microsoft.com}}

Windows Media Video Screen (WMV Screen) are video formats that specialise in screencast content. They can capture live screen content, or convert video from third-party screen-capture programs into WMV 9 Screen files. They work best when the source material is mainly static and contains a small color palette.{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9Screen|url-status=dead|archive-url=https://web.archive.org/web/20171101052328/http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9Screen|archive-date=1 November 2017|access-date=3 May 2018|website=www.microsoft.com}}

One of the uses for the format is computer step-by-step demonstration videos. The first version of the format was WMV 7 Screen. The second version, WMV 9 Screen, supports VBR encoding in addition to CBR. Additionally there is MSA1 (aka “MS ATC Screen codec” or “MSS3”) which is used in Live Meeting 2007. FourCCs for the formats are MSS1, MSS2 and MSA1.{{cite web|url=http://wiki.multimedia.cx/?title=Microsoft_Screen_Codec|title=Microsoft Screen Codec - MultimediaWiki|website=wiki.multimedia.cx|access-date=3 May 2018|url-status=live|archive-url=https://web.archive.org/web/20130515053029/http://wiki.multimedia.cx/?title=Microsoft_Screen_Codec|archive-date=15 May 2013}}

Windows Media Video Image (WMV Image) is a video slideshow format. The format works by applying timing, panning and transition effects to a series of images during playback.{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9ImageVersion2|url-status=dead|archive-url=https://web.archive.org/web/20171101052328/http://www.microsoft.com/windows/windowsmedia/forpros/codecs/video.aspx#WindowsMediaVideo9ImageVersion2|archive-date=1 November 2017|access-date=3 May 2018|website=www.microsoft.com}} The codec achieves a higher compression ratio and image quality than WMV 9 for still images as files encoded with WMV Image store static images rather than full-motion video.

Since the format relies on the decoder (player) to generate video frames in real-time, playing WMV Image files even at moderate resolutions (e.g. 30 frames per second at 1024 px × 768 px resolution) requires heavy computer processing. The latest version of the format, WMV 9.1 Image, used by Photo Story 3, features additional transformation effects, but is not compatible with the original WMV 9 Image format.

Hardware support for WMV Image is available from Portable Media Centers, Windows Mobile-powered devices with Windows Media Player 10 Mobile.

Since no known domestic DVD player supports this format, users of Photo Story 3 wishing to generate material capable of being played in a DVD player will first have to convert to MPEG-2 before burning a DVD (average file sizes in MPEG-2 are 5 to 6 times the .wmv file).

The audio format used in conjunction with Windows Media Video is typically some version of Windows Media Audio, or in rarer cases, the deprecated Sipro ACELP.net audio format. Microsoft recommends that ASF files containing non-Windows Media formats use the generic {{mono|.ASF}} file extension.

Software that can play WMV files includes Windows Media Player, RealPlayer, MPlayer, Media Player Classic, VLC Media Player and K-Multimedia Player. The Microsoft Zune media management software supports the WMV format, but uses a Zune-specific variation of Windows Media DRM which is used by PlaysForSure. Many third-party players exist for various platforms such as Linux that use the FFmpeg implementation of the WMV format.

On the Macintosh platform, Microsoft released a PowerPC version of Windows Media Player for Mac OS X in 2003,{{cite web|title=Office 365 for Mac, Office 2016 for Mac|url=https://products.office.com/en-US/mac?pid=download&location=/mac/download/misc/winmp_osx.xml&secid=80&ssid=8&flgnosysreq=True|url-status=dead|archive-url=https://web.archive.org/web/20180503013327/https://products.office.com/en-US/mac?pid=download&location=%2Fmac%2Fdownload%2Fmisc%2Fwinmp_osx.xml&secid=80&ssid=8&flgnosysreq=True|archive-date=3 May 2018|access-date=3 May 2018|website=office.com}} but further development of the software ceased. From January 2006 to May 2014, Microsoft endorsed and distributed the 3rd party Flip4Mac, a QuickTime Component developed by Telestream that allowed Macintosh users to play WMV files in any player that used the QuickTime framework.{{cite web|title=Telestream Press Release|url=http://www.telestream.net/news/06_01_10.htm|url-status=dead|archive-url=https://web.archive.org/web/20060910194332/http://www.telestream.net/news/06_01_10.htm|archive-date=10 September 2006|access-date=10 September 2006|website=telestream.net}}{{cite web|title=Knowledge Article: Flip4Mac Player: Why is Telestream charging for Flip4Mac Player|url=https://telestream.secure.force.com/kb/articles/Knowledge_Article/Why-isTelestream-charging-for-Flip4Mac-Player/?l=en_US&fs=RelatedArticle|url-status=live|archive-url=https://web.archive.org/web/20210822181814/https://telestream.secure.force.com/kb/articles/Knowledge_Article/Why-isTelestream-charging-for-Flip4Mac-Player/?l=en_US&fs=RelatedArticle|archive-date=22 August 2021|access-date=22 August 2021}} Telestream ended sales of Flip4Mac on 1 July 2019 and officially ended support on 28 June 2020.{{cite web|title=Knowledge Article: Flip4Mac retired as of July 1, 2019|url=https://telestream.secure.force.com/kb/articles/Knowledge_Article/Flip4Mac-retired-as-of-July-1-2019|url-status=live|archive-url=https://web.archive.org/web/20210822180145/https://telestream.secure.force.com/kb/articles/Knowledge_Article/Flip4Mac-retired-as-of-July-1-2019|archive-date=22 August 2021|access-date=22 August 2021}} The Elmedia player, which can play WMV files on Macintosh computers, is still available.

Many programs can export video in WMV format; a few examples are Windows Movie Maker, Windows Media Encoder, Microsoft Expression Encoder, Sorenson Squeeze,{{cite web|title=Sorenson Media - Next Generation Television Starts Here|url=http://sorensonmedia.com|url-status=dead|archive-url=https://web.archive.org/web/20180323052423/https://www.sorensonmedia.com/|archive-date=23 March 2018|access-date=3 May 2018|website=Sorenson Media}} Vegas Pro,{{cite web|title=Sony Creative Software - Vegas Pro 8 - Technical Specifications|url=http://www.sonycreativesoftware.com/products/product.asp?PID=457&PageID=107|url-status=dead|archive-url=https://web.archive.org/web/20080302001832/http://www.sonycreativesoftware.com/products/product.asp?PID=457&PageID=107|archive-date=2 March 2008|access-date=3 May 2018|website=sonycreativesoftware.com}} AVS Video Editor, VSDC Free Video Editor, Telestream Episode, Telestream FlipFactory,{{cite web|title=Supported file formats in Adobe Premiere Pro 2.0|url=http://kb.adobe.com/selfservice/viewContent.do?externalId=332612|url-status=dead|archive-url=https://web.archive.org/web/20071013122312/http://kb.adobe.com/selfservice/viewContent.do?externalId=332612|archive-date=13 October 2007|access-date=3 May 2018|website=adobe.com}}{{cite web|url=http://www.easymediasuite.com|title=EMS - PLAYOUT - CG - MAM - INGEST - ENCODER - IP MULTIVIEWER|website=www.easymediasuite.com|access-date=3 May 2018|url-status=live|archive-url=https://web.archive.org/web/20170930085002/http://www.easymediasuite.com/|archive-date=30 September 2017}} and FFmpeg.

Programs that encode using the WMV Image format include Windows Media Encoder, AVS Video Editor, and Photo Story.

{{Main|Windows Media DRM}}

While none of the WMV formats themselves contain any digital rights management facilities, the ASF container format, in which a WMV stream may be encapsulated, can. Windows Media DRM, which can be used in conjunction with WMV, supports time-limited subscription video services such as those offered by CinemaNow.{{cite web|title=Windows - Official Site for Microsoft Windows 10 Home & Pro OS, laptops, PCs, tablets & more|url=http://www.playsforsure.com/ItemDetail.aspx?id=26|url-status=dead|archive-url=https://web.archive.org/web/20070822181259/http://www.playsforsure.com/ItemDetail.aspx?id=26|archive-date=22 August 2007|access-date=3 May 2018|website=www.playsforsure.com}} Windows Media DRM, a component of PlaysForSure and Windows Media Connect, is supported on many modern portable video devices and streaming media clients such as the Xbox 360.

WMV has been the subject of numerous complaints from users and the press. Users dislike the digital rights management system which is sometimes attached to WMV files.{{cite web|url=https://www.theinquirer.net/default.aspx?article=34523|title=Microsoft Media Player shreds your rights|website=theinquirer.net|access-date=3 May 2018|url-status=unfit|archive-url=https://web.archive.org/web/20070907023902/http://www.theinquirer.net/default.aspx?article=34523|archive-date=7 September 2007}} In 2007, the loss of the ability to restore licenses for WMV files in the Windows Media Player 11 was not positively received.

• JPEG XR/HDHD, an image file format and format developed by Microsoft

{{reflist|colwidth=30em}}

{{Commons category}}

• [http://www.spinnaker.com/crypt/drm/freeme/Technical Description of the algorithm used for Windows Media encryption] {{Webarchive|url=https://web.archive.org/web/20130210012154/http://www.spinnaker.com/crypt/drm/freeme/Technical |date=2013-02-10 }}
• [http://on10.net/Blogs/benwagg/elephants-dream-720p--2-mbps/ Demonstration of WMV 9 delivering 720p video at 1.8 Mbit/s ABR] {{Webarchive|url=https://web.archive.org/web/20100322203116/http://on10.net/Blogs/benwagg/elephants-dream-720p--2-mbps/ |date=2010-03-22 }}
• [https://web.archive.org/web/20071224194356/http://on10.net/Blogs/benwagg/elephants-dream-sample/Default.aspx Demonstration of WMV 9 delivering 1080p video at 10 Mbit/s ABR]
• [https://web.archive.org/web/20090418134328/http://software-history.org/?p=3 History of Windows Media Player] (archived 2009)

{{Compression formats}}

{{Compression Software Implementations}}

Category:Video codecs

Category:Microsoft proprietary codecs

Category:Microsoft Windows multimedia technology

Category:Digital rights management systems