Windows Media Video
Encyclopedia
'Windows Media Video is a video compression
format
for several proprietary
codecs developed by Microsoft
. The original video format, known as WMV, was originally designed for Internet streaming applications, as a competitor to RealVideo
. The other formats, such as WMV Screen and WMV Image, cater for specialized content. Through standardization from the Society of Motion Picture and Television Engineers
(SMPTE), WMV 9 has gained adoption for physical-delivery formats such as HD DVD
and Blu-ray Disc
.
, thus making the WMV 9 format an open standard. Since then, VC-1 has become one of the three mandatory video formats for the BD-ROM specifications.
in the Advanced Systems Format
(ASF) container format. The file extension .WMV typically describes ASF files that use Windows Media Video codecs. The audio codec 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 codec. Microsoft recommends that ASF files containing non-Windows Media codecs use the generic .ASF file extension.
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
or AVI
container format. The resulting files have the .MKV and .AVI file extensions, respectively. One common way to store WMV in an AVI file is to use the WMV 9 Video Compression Manager (VCM)
codec implementation.
Windows Media Video (WMV) is the most recognized video format within the WMV family. Usage of the term WMV often refers to the Microsoft Windows Media Video codec
only. Its main competitors are MPEG-4 AVC, AVS
, RealVideo
, and MPEG-4 ASP
. The first version of the codec, WMV 7, was introduced in 1999, and was built upon Microsoft's implementation of MPEG-4 Part 2
. Continued proprietary development led to newer versions of the codec, but the bit stream syntax was not frozen until WMV 9. 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. 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., 528x576, 640×480 or 768x432 and beyond) and the bitrate 1000 kbit/s. 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. The Advanced Profile in VC-1 is implemented in a new WMV codec called Windows Media Video 9 Advanced Profile. It improves compressions 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 codec is not compatible with previous WMV 9 codecs, however.
WMV is a mandatory video codec 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 codec. WMV HD
mandates the use of WMV 9 for its certification program, at quality levels specified by Microsoft. WMV used to be the only supported video codec for the Microsoft Silverlight
platform, but H.264 codec is now also supported starting with version 3.
codec. It can capture live screen content, or convert video from third-party screen-capture programs into WMV 9 Screen files. It works best when the source material is mainly static and contains a small color palette. Depending on the complexity of the source material, the codec may switch between lossy
and lossless
encoding to enhance compression efficiency.
One of the uses for the codec is computer step-by-step demonstration videos. The first version of the codec was WMV 7 Screen, The second and current version, WMV 9 Screen, supports VBR encoding in addition to CBR.
codec. The codec works by applying timing, panning
and transition effects to a series of images during playback. 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 codec 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 × 768 resolution) requires heavy computer processing. The latest version of the codec, WMV 9.1 Image, used by Photo Story
3, features additional transformation effects, but is not compatible with the original WMV 9 Image codec.
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).
, RealPlayer
, MPlayer
, The KMPlayer, Media Player Classic
and VLC Media Player
. The Microsoft Zune media management software supports the WMV codec, 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 codecs.
On the Macintosh
platform, Microsoft released a PowerPC
version of Windows Media Player for Mac OS X
in 2003, but further development of the software has ceased. Microsoft currently endorses the 3rd party Flip4Mac
WMV, a QuickTime
Component which allows Macintosh users to play WMV files in any player that uses the QuickTime framework, free of charge to view files but chargeable to convert formats. The WMV installer is bundled with Microsoft Silverlight by default, installation without Silverlight can be accomplished with a "Custom" install. According to the Flip4Mac website, WMV files with DRM encryption are not compatible with the component.
users can rely on FFmpeg
based software like MPlayer
, MEncoder
.
For Mac
or Windows
users who wish to convert non-DRM WMV to MP4, HandBrake
is Free Software
that will do the job.
(PC Version),
Windows Movie Maker
, Windows Media Encoder
, Microsoft Expression Encoder
,
Sorenson Squeeze
, Sony Vegas Pro, Adobe Premiere Pro
, Adobe After Effects
, Telestream Episode, Total video converter
and Telestream FlipFactory.
Programs that encode using the WMV Image codec include Windows Media Encoder
and Photo Story
.
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
. 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.
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
for several proprietary
Proprietary software
Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...
codecs developed by Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...
. The original video format, known as WMV, was originally designed for Internet streaming applications, as a competitor to RealVideo
RealVideo
RealVideo is a suite of proprietary video compression formats developed by RealNetworks – the specific format changes with the version. It was first released in 1997 and is at version 10. RealVideo is supported on many platforms, including Windows, Mac, Linux, Solaris, and several mobile...
. The other formats, such as WMV Screen and WMV Image, cater for specialized content. Through standardization from the Society of Motion Picture and Television Engineers
Society of Motion Picture and Television Engineers
The Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers The Society of Motion Picture and Television Engineers (SMPTE , founded in 1916 as the Society of Motion Picture Engineers or SMPE, is an international professional association, based in...
(SMPTE), WMV 9 has gained adoption for physical-delivery formats such as HD DVD
HD DVD
HD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...
and Blu-ray Disc
Blu-ray Disc
Blu-ray Disc is an optical disc storage medium designed to supersede the DVD format. The plastic disc is 120 mm in diameter and 1.2 mm thick, the same size as DVDs and CDs. Blu-ray Discs contain 25 GB per layer, with dual layer discs being the norm for feature-length video discs...
.
History
In 2003, Microsoft drafted a video codec specification based on its WMV 9 codec and submitted it to SMPTE for standardization. The standard was officially approved in March 2006 as SMPTE 421M, better known as VC-1VC-1
VC-1 is the informal name of the SMPTE 421M video codec standard, which was initially developed as a proprietary video format by Microsoft before it was released as a formal SMPTE standard video format on April 3, 2006...
, thus making the WMV 9 format an open standard. Since then, VC-1 has become one of the three mandatory video formats for the BD-ROM specifications.
Container format
A WMV file is in most circumstances encapsulatedInformation hiding
In computer science, information hiding is the principle of segregation of the design decisions in a computer program that are most likely to change, thus protecting other parts of the program from extensive modification if the design decision is changed...
in the Advanced Systems Format
Advanced Systems Format
Advanced Systems Format is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media...
(ASF) container format. The file extension .WMV typically describes ASF files that use Windows Media Video codecs. The audio codec used in conjunction with Windows Media Video is typically some version of Windows Media Audio
Windows Media Audio
Windows Media Audio is an audio data compression technology developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs...
, or in rarer cases, the deprecated Sipro ACELP.net
ACELP
Algebraic code-excited linear prediction is a patented speech coding algorithm by VoiceAge Corporation in which a limited set of pulses is distributed as excitation to linear prediction filter....
audio codec. Microsoft recommends that ASF files containing non-Windows Media codecs use the generic .ASF file extension.
The ASF container can optionally support digital rights management
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
using a combination of elliptic curve cryptography
Elliptic curve cryptography
Elliptic curve cryptography is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. The use of elliptic curves in cryptography was suggested independently by Neal Koblitz and Victor S...
key exchange, DES
Data Encryption Standard
The Data Encryption Standard is a block cipher that uses shared secret encryption. It was selected by the National Bureau of Standards as an official Federal Information Processing Standard for the United States in 1976 and which has subsequently enjoyed widespread use internationally. It is...
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
Matroska
The Matroska Multimedia Container is an open standard free container format, a file format that can hold an unlimited number of video, audio, picture or subtitle tracks in one file. It is intended to serve as a universal format for storing common multimedia content, like movies or TV shows...
or AVI
Audio Video Interleave
Audio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
container format. The resulting files have the .MKV and .AVI file extensions, respectively. One common way to store WMV in an AVI file is to use the WMV 9 Video Compression Manager (VCM)
Video for Windows
Video for Windows was a multimedia framework developed by Microsoft that allowed Microsoft Windows to play digital video.-Overview:...
codec implementation.
Windows Media Video
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
only. Its main competitors are MPEG-4 AVC, AVS
Audio Video Standard
Audio Video Standard is a compression standard for digital audio and video, and is competing with H.264/AAC to potentially replace MPEG-2. Chinese companies own 90% of AVS patents. The audio and video files have an .avs extension as a container format.-Overview:Development of AVS was initiated by...
, RealVideo
RealVideo
RealVideo is a suite of proprietary video compression formats developed by RealNetworks – the specific format changes with the version. It was first released in 1997 and is at version 10. RealVideo is supported on many platforms, including Windows, Mac, Linux, Solaris, and several mobile...
, and MPEG-4 ASP
MPEG-4 Part 2
MPEG-4 Part 2, MPEG-4 Visual is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. It is a discrete cosine transform compression standard, similar to previous standards such as MPEG-1 and MPEG-2...
. The first version of the codec, WMV 7, was introduced in 1999, and was built upon Microsoft's implementation of MPEG-4 Part 2
MPEG-4 Part 2
MPEG-4 Part 2, MPEG-4 Visual is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. It is a discrete cosine transform compression standard, similar to previous standards such as MPEG-1 and MPEG-2...
. Continued proprietary development led to newer versions of the codec, but the bit stream syntax was not frozen until WMV 9. 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. 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., 528x576, 640×480 or 768x432 and beyond) and the bitrate 1000 kbit/s. It is targeted towards high-definition video content, at resolutions such as 720p
720p
720p is the shorthand name for 1280x720, a category of High-definition television video modes having a resolution of 1080 or 720p and a progressive scan...
and 1080p
1080p
1080p is the shorthand identification for a set of HDTV high-definition video modes that are characterized by 1080 horizontal lines of resolution and progressive scan, meaning the image is not interlaced as is the case with the 1080i display standard....
.
The Simple and Main profile levels in WMV 9 are compliant with the same profile levels in the VC-1
VC-1
VC-1 is the informal name of the SMPTE 421M video codec standard, which was initially developed as a proprietary video format by Microsoft before it was released as a formal SMPTE standard video format on April 3, 2006...
specification. The Advanced Profile in VC-1 is implemented in a new WMV codec called Windows Media Video 9 Advanced Profile. It improves compressions efficiency for interlaced content and is made transport-independent, making it able to be encapsulated in an MPEG transport stream or RTP
Real-time Transport Protocol
The Real-time Transport Protocol defines a standardized packet format for delivering audio and video over IP networks. RTP is used extensively in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applications, television services and...
packet format. The codec is not compatible with previous WMV 9 codecs, however.
WMV is a mandatory video codec for PlaysForSure-certified online stores and devices, as well as Portable Media Center
Portable Media Center
Portable Media Center is a defunct hard drive-based portable media player platform developed by Microsoft. Announced at the 2003 Consumer Electronics Show , and released in early 2004, it was originally positioned as a competitor to Apple's iPod.The platform was conceived in line with Microsoft's...
devices. The Microsoft Zune, Xbox 360
Xbox 360
The Xbox 360 is the second video game console produced by Microsoft and the successor to the Xbox. The Xbox 360 competes with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of video game consoles...
, Windows Mobile
Windows Mobile
Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and Pocket PCs, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone, which does not run Windows Mobile software.Windows Mobile is...
-powered devices with Windows Media Player, as well as many uncertified devices, support the codec. WMV HD
WMV HD
Windows Media High Definition Video is the marketing name for high definition videos encoded using Microsoft Windows Media Video 9 codecs...
mandates the use of WMV 9 for its certification program, at quality levels specified by Microsoft. WMV used to be the only supported video codec for the Microsoft Silverlight
Microsoft Silverlight
Microsoft Silverlight is an application framework for writing and running rich Internet applications, with features and purposes similar to those of Adobe Flash. The run-time environment for Silverlight is available as a plug-in for web browsers running under Microsoft Windows and Mac OS X...
platform, but H.264 codec is now also supported starting with version 3.
Windows Media Video Screen
Windows Media Video Screen (WMV Screen) is a screencastScreencast
A screencast is a digital recording of computer screen output, also known as a video screen capture, often containing audio narration. The term screencast compares with the related term screenshot; whereas screenshot is a picture of a computer screen, a screencast is essentially a movie of the...
codec. It can capture live screen content, or convert video from third-party screen-capture programs into WMV 9 Screen files. It works best when the source material is mainly static and contains a small color palette. Depending on the complexity of the source material, the codec may switch between lossy
Lossy data compression
In information technology, "lossy" compression is a data encoding method that compresses data by discarding some of it. The procedure aims to minimize the amount of data that need to be held, handled, and/or transmitted by a computer...
and lossless
Lossless data compression
Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
encoding to enhance compression efficiency.
One of the uses for the codec is computer step-by-step demonstration videos. The first version of the codec was WMV 7 Screen, The second and current version, WMV 9 Screen, supports VBR encoding in addition to CBR.
Windows Media Video Image
Windows Media Video Image (WMV Image) is a video slideshowSlideshow
A slide show is a display of a series of chosen information or pictures, done for artistic or instructional purposes. Slide shows are conducted by a presenter using an apparatus, such as a carousel slide projector, an overhead projector or in more recent years, a computer running presentation...
codec. The codec works by applying timing, panning
Panning (camera)
In photography, panning refers to the horizontal movement or rotation of a still or video camera, or the scanning of a subject horizontally on video or a display device...
and transition effects to a series of images during playback. 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 codec 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 × 768 resolution) requires heavy computer processing. The latest version of the codec, WMV 9.1 Image, used by Photo Story
Photo Story
Microsoft Photo Story is a free application that allows users to create a visual story from their digital photos. The software uses the Ken Burns Effect on digital photos and allows adding narration, effects, transitions and background music to create a Windows Media Video movie file with pan and...
3, features additional transformation effects, but is not compatible with the original WMV 9 Image codec.
Hardware support for WMV Image is available from Portable Media Centers, Windows Mobile
Windows Mobile
Windows Mobile is a mobile operating system developed by Microsoft that was used in smartphones and Pocket PCs, but by 2011 was rarely supplied on new phones. The last version is "Windows Mobile 6.5.5"; it is superseded by Windows Phone, which does not run Windows Mobile software.Windows Mobile is...
-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
MPEG-2
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...
before burning a DVD (average file sizes in MPEG-2 are 5 to 6 times the .wmv file).
Video quality
While Windows Media Video 7 and 8 codecs were comparable to MPEG-4 ASP in terms of visual quality, Windows Media Video 9 (especially the later SMPTE-compliant VC-1 implementations) is comparable to H.264 Main and High Profile. While WMV9/VC-1 does have certain advantages over H.264 such as support for non-square integer transforms, H.264 is more consistently able to yield better picture quality because it supports multiple reference frames, reference B-frames, context-adaptive binary arithmetic coding (CABAC) and stronger in-loop filtering. H.264's quality advantage is typically more evident at low bitrates.Players
Software that can play WMV files include Windows Media PlayerWindows Media Player
Windows Media Player is a media player and media library application developed by Microsoft that is used for playing audio, video and viewing images on personal computers running the Microsoft Windows operating system, as well as on Pocket PC and Windows Mobile-based devices...
, RealPlayer
RealPlayer
RealPlayer is a cross-platform media player by RealNetworks that plays a number of multimedia formats including MP3, MPEG-4, QuickTime, Windows Media, and multiple versions of proprietary RealAudio and RealVideo formats.-History:...
, MPlayer
MPlayer
MPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...
, The KMPlayer, Media Player Classic
Media Player Classic
Media Player Classic is a compact media player for 32-bit and 64-bit Microsoft Windows. The application mimics the look and feel of the old, lightweight Windows Media Player 6.4 but integrates most options and features found in modern media players...
and VLC Media Player
VLC media player
VLC media player is a free and open source media player and multimedia framework written by the VideoLAN project.VLC is a portable multimedia player, encoder, and streamer supporting many audio and video codecs and file formats as well as DVDs, VCDs, and various streaming protocols. It is able to...
. The Microsoft Zune media management software supports the WMV codec, but uses a Zune-specific variation of Windows Media DRM
Windows Media DRM
Windows Media DRM is a Digital Rights Management service for the Windows Media platform. It is designed to provide delivery of audio and/or video content over an IP network to a PC or other playback device in such a way that the distributor can control how that content is used.WMDRM includes the...
which is used by PlaysForSure. Many third-party players exist for various platforms such as Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
that use the FFmpeg
FFmpeg
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
implementation of the WMV codecs.
On the Macintosh
Macintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
platform, Microsoft released a PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
version of Windows Media Player for Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
in 2003, but further development of the software has ceased. Microsoft currently endorses the 3rd party Flip4Mac
Flip4Mac
Flip4Mac is a trademarked brand name for Telestream, Inc.'s proprietary digital media tools for the Macintosh. It is particularly known for being the only QuickTime component for Mac OS X that supports Windows Media Video, although there is non-QuickTime OS X software that supports WMV...
WMV, a QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
Component which allows Macintosh users to play WMV files in any player that uses the QuickTime framework, free of charge to view files but chargeable to convert formats. The WMV installer is bundled with Microsoft Silverlight by default, installation without Silverlight can be accomplished with a "Custom" install. According to the Flip4Mac website, WMV files with DRM encryption are not compatible with the component.
Decoders / Transcoders
LinuxLinux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
users can rely on FFmpeg
FFmpeg
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
based software like MPlayer
MPlayer
MPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...
, MEncoder
MEncoder
MEncoder is a free command line video decoding, encoding and filtering tool released under the GNU General Public License. It is a close sibling to MPlayer and can convert all the formats that MPlayer understands into a variety of compressed and uncompressed formats using different codecs.MEncoder...
.
For Mac
Macintosh
The Macintosh , or Mac, is a series of several lines of personal computers designed, developed, and marketed by Apple Inc. The first Macintosh was introduced by Apple's then-chairman Steve Jobs on January 24, 1984; it was the first commercially successful personal computer to feature a mouse and a...
or Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
users who wish to convert non-DRM WMV to MP4, HandBrake
HandBrake
HandBrake is a general-purpose, open-source, cross-platform, multithreaded video transcoder software application. HandBrake was originally developed by titer in 2003 as a general-purpose video transcoder to make ripping a film from a DVD to a data storage device easier...
is Free Software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
that will do the job.
Encoders
Software that exports video in WMV format include AvidAVID
AVID stands for:* Advancement Via Individual Determination, a college-readiness system designed to increase the number of students who enroll in four-year colleges in the U.S....
(PC Version),
Windows Movie Maker
Windows Movie Maker
Windows Movie Maker is a video creating/editing software application, included in Microsoft Windows Me, XP, and Vista. It contains features such as effects, transitions, titles/credits, audio track, timeline narration, and Auto Movie. New effects and transitions can be made and existing ones can be...
, Windows Media Encoder
Windows Media Encoder
Windows Media Encoder is a freely downloadable trial version media encoder developed by Microsoft which enables content developers to convert or capture both live and prerecorded audio, video, and computer screen images to Windows Media formats for live and on-demand delivery. It is the successor...
, Microsoft Expression Encoder
Microsoft Expression Encoder
Microsoft Expression Encoder is a Windows-based program for encoding digital video for web-based video. Expression Encoder can be used to create video compressed VC-1 as well as H.264 for distribution via Microsoft Silverlight. Expression Encoder features a WPF-based modern graphical user...
,
Sorenson Squeeze
Sorenson Squeeze
Sorenson Squeeze is a compression suite for video. It encodes to multiple formats including QuickTime, Windows Media, Flash Video, Silverlight, WebM & WMV. It uses multiple codecs, including the Sorenson codecs SV3 Pro and Spark, H.264, H.263, VP6, VC1, MPEG2, and many others. Squeeze operates on...
, Sony Vegas Pro, Adobe Premiere Pro
Adobe Premiere Pro
Adobe Premiere Pro is a timeline-based video editing software application. It is part of the Adobe Creative Suite, a suite of graphic design, video editing, and web development applications developed by Adobe Systems, though it can also be purchased separately. When purchased separately, it comes...
, Adobe After Effects
Adobe After Effects
Adobe After Effects is a digital motion graphics and compositing software published by Adobe Systems, used in the post-production process of filmmaking and television production. Its main uses are the origination of 2D and 2.5D animation, visual effects compositing and finishing...
, Telestream Episode, Total video converter
Total video converter
Total Video Converter is a shareware video and audio converter utility from EffectMatrix. It is commonly used to convert most fashionable video formats for various video players as well as show photos slide and burn the converted video to DVD/SVCD/VCD. Started from version 2.21, Total Video...
and Telestream FlipFactory.
Programs that encode using the WMV Image codec include Windows Media Encoder
Windows Media Encoder
Windows Media Encoder is a freely downloadable trial version media encoder developed by Microsoft which enables content developers to convert or capture both live and prerecorded audio, video, and computer screen images to Windows Media formats for live and on-demand delivery. It is the successor...
and Photo Story
Photo Story
Microsoft Photo Story is a free application that allows users to create a visual story from their digital photos. The software uses the Ken Burns Effect on digital photos and allows adding narration, effects, transitions and background music to create a Windows Media Video movie file with pan and...
.
Digital rights management
While none of the WMV codecs themselves contain any digital rights managementDigital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
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
CinemaNow
CinemaNow is an Internet-based digital video distribution company founded in 1999.The CinemaNow library contains approximately 14,000 feature-length films, shorts, music concerts and television programs from more than 250 licensors, including 20th Century Fox, ABC News, Disney, Endemol, MGM,...
. Windows Media DRM, a component of PlaysForSure and Windows Media Connect
Windows Media Connect
Windows Media Connect is a UPnP AV server from Microsoft for Windows XP and later Windows operating systems, to share and stream media on a Windows computer to WMC clients. The first two releases of WMC were made available as stand-alone software, and included a client as well...
, is supported on many modern portable video devices and streaming media clients such as the Xbox 360.
Criticism
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. The loss of the ability to restore licenses for WMV files in the Windows Media Player 11 was not positively received. In addition, the Microsoft Zune does not support the standard Windows Media DRM system, rendering protected WMV files unplayable.Versions
| Public Name | FourCC FourCC A FourCC is a sequence of four bytes used to uniquely identify data formats.The concept originated in the OSType scheme used in the Macintosh system software and was adopted for the Amiga/Electronic Arts Interchange File Format and derivatives... |
Description |
|---|---|---|
| Microsoft MPEG-4 version 1 | MPG4 | Video for Windows Video for Windows Video for Windows was a multimedia framework developed by Microsoft that allowed Microsoft Windows to play digital video.-Overview:... -based codec. Non-standard MPEG-4 codec incompatible with the later standardized version of MPEG-4 Part 2 MPEG-4 Part 2 MPEG-4 Part 2, MPEG-4 Visual is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standards. It is a discrete cosine transform compression standard, similar to previous standards such as MPEG-1 and MPEG-2... . |
| Microsoft MPEG-4 version 2 | MP42 | VfW-based codec. Non-compliant with finalized MPEG-4 part 2 standard. |
| Microsoft MPEG-4 version 3 | MP43 | VfW-based codec. Non-compliant with finalized MPEG-4 part 2 standard. Eventually locked for encoding only with ASF files (build 3688 and earlier could also encode to AVI). |
| Microsoft ISO MPEG-4 version 1 | MP4S | DirectX Media Objects (DMO)-based codec. MPEG-4 Simple Profile compliant. |
| Microsoft ISO MPEG-4 version 1.1 | M4S2 | MPEG-4 Advanced Simple Profile compliant. |
| Windows Media Video 7 | WMV1 | DMO-based codec. |
| Windows Media Screen 7 | MSS1 | DMO-based codec. Optimized for low-bitrate sequential screen captures or screencasts. Deprecated in favor of Windows Media 9 Screen codec. |
| Windows Media Video 8 | WMV2 | DMO-based codec. |
| Windows Media Video 9 | WMV3 | DMO-based codec. Video for Windows (VfW/VCM) version also available. http://www.microsoft.com/DOWNLOADS/details.aspx?FamilyID=0c99c648-5800-4aa3-a2fe-3de948689db8 |
| Windows Media Video 9 Screen | MSS2 | DMO-based codec. Optimized for low-bitrate sequential screen captures or screencasts. |
| Windows Media Video 9.1 Image | WMVP | DMO-based codec. Optimized for encoding video from sequential bitmap images. Used, for instance, by Photo Story. |
| Windows Media Video 9.1 Image V2 | WVP2 | DMO-based codec. Optimized for encoding video from sequential bitmap images. Used, for instance, by Photo Story. |
| Windows Media Video 9 Advanced Profile | WMVA | DMO-based codec. Deprecated as non-VC-1-compliant. |
| Windows Media Video 9 Advanced Profile | WVC1 | DMO-based codec. VC-1 compliant format. |
See also
- CodecCodecA codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
– The technical term for compressor and decompressor - VC-1VC-1VC-1 is the informal name of the SMPTE 421M video codec standard, which was initially developed as a proprietary video format by Microsoft before it was released as a formal SMPTE standard video format on April 3, 2006...
– The SMPTE codec standard based on WMV 9 that supports additional broadcast industry requirements - WMV HDWMV HDWindows Media High Definition Video is the marketing name for high definition videos encoded using Microsoft Windows Media Video 9 codecs...
– The marketing name for high definition videos encoded using WMV 9 codecs - Windows Media DRMWindows Media DRMWindows Media DRM is a Digital Rights Management service for the Windows Media platform. It is designed to provide delivery of audio and/or video content over an IP network to a PC or other playback device in such a way that the distributor can control how that content is used.WMDRM includes the...
– A digital rights management component of Windows Media that controls how content can be used - Windows Media AudioWindows Media AudioWindows Media Audio is an audio data compression technology developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs...
– An audio file format and codec developed by Microsoft - Photo StoryPhoto StoryMicrosoft Photo Story is a free application that allows users to create a visual story from their digital photos. The software uses the Ken Burns Effect on digital photos and allows adding narration, effects, transitions and background music to create a Windows Media Video movie file with pan and...
- Microsoft slide-show movie maker generating wmv image sub-set - JPEG XR / HD Photo – An image file format and codec developed by Microsoft
- Windows Movie MakerWindows Movie MakerWindows Movie Maker is a video creating/editing software application, included in Microsoft Windows Me, XP, and Vista. It contains features such as effects, transitions, titles/credits, audio track, timeline narration, and Auto Movie. New effects and transitions can be made and existing ones can be...
– A video editing tool included with the Microsoft Windows operating system that allows conversion of WMV format files into .avi (DV/AVI) - MPlayerMPlayerMPlayer is a free and open source media player. The program is available for all major operating systems, including Linux and other Unix-like systems, Microsoft Windows and Mac OS X. Versions for OS/2, Syllable, AmigaOS and MorphOS are also available. The Windows version works, with some minor...
– A third-party, open source, cross-platform media player capable of playing many WMV files using FFmpeg - FFmpegFFmpegFFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
– A third-party cross-platform free software codec library which partially implements WMV decoding and VC-1 decoding among other formats - WMV Player – A third-party, commercial codec which allows viewing of WMV files in QuickTime for Mac OS X
- Flip4MacFlip4MacFlip4Mac is a trademarked brand name for Telestream, Inc.'s proprietary digital media tools for the Macintosh. It is particularly known for being the only QuickTime component for Mac OS X that supports Windows Media Video, although there is non-QuickTime OS X software that supports WMV...
– QuickTime component to play and encode Windows Media files in QuickTime - Lossy data compressionLossy data compressionIn information technology, "lossy" compression is a data encoding method that compresses data by discarding some of it. The procedure aims to minimize the amount of data that need to be held, handled, and/or transmitted by a computer...
– Data compression with loss of information - Lossless data compressionLossless data compressionLossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
– Data compression without loss of information - Comparison of video codecsComparison of video codecsA video codec is software or a device that provides encoding and decoding which may or may not include the use of video compression and/or decompression for digital video....