NationMaster - Encyclopedia: Advanced Systems Format

Advanced Systems Format (formerly Advanced Streaming Format, Active Streaming Format) is Microsoft's proprietary digital audio/digital video container format, especially meant for streaming media. ASF is part of the Windows Media framework. A filename extension is a suffix to the name of a computer file applied to show its format. ... For mime as an art form, see mime artist. ... A type code is a mechanism used in pre-Mac OS X versions of the Macintosh operating system to denote a files format, in a manner similar to file extensions in other operating systems. ... A Uniform Type Identifier (UTI) is a string that uniquely identifies the type of a class of items. ... In computer programming, a magic number is a constant used to identify the file or data type employed. ... Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... Windows Media Audio (WMA) is an audio data compression technology developed by Microsoft. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ... MPEG-4, introduced in 1998, is the designation for a group of audio and video coding standards agreed upon by the Moving Picture Experts Group (MPEG). ... Microsoft Corporation, (NASDAQ: MSFT, HKSE: 4338) is a multinational computer technology corporation with global annual revenue of US$44. ... It has been suggested that closed source be merged into this article or section. ... Digital audio comprises audio signals stored in a digital format. ... Digital video is a type of video recording system that works by using a digital, rather than analog, of the video signal. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... Streaming media is multimedia that is continuously received by, and normally displayed to, the end-user while it is being delivered by the provider. ... Windows Media is a multimedia framework for media creation and distribution for Microsoft Windows. ...

The format does not specify how (i.e. with which codec) the video or audio should be encoded; it just specifies the structure of the video/audio stream. This is similar to the function performed by the QuickTime, AVI, or Ogg container formats. One of the objectives of ASF was to support playback from digital media servers, HTTP servers, and local storage devices such as hard disk drives. A codec is a device or program capable of performing encoding and decoding on a digital data stream or signal. ... QuickTime is a multimedia framework developed by Apple Inc. ... AVI, an acronym for Audio Video Interleave, is a multimedia container format introduced by Microsoft in November 1992, as part of the Video for Windows technology. ... Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. ... Playback could mean: Playback singing, a practice in Bollywood musicals. ... Streaming media is multimedia that is continuously received by, and normally displayed to, the end-user while it is being delivered by the provider. ... The term web server can mean one of two things: a computer responsible for serving web pages, mostly HTML documents, via the HTTP protocol to clients, mostly web browsers; a software program that is working as a daemon serving web documents. ... A hard disk drive (HDD), commonly referred to as a hard drive, hard disk or fixed disk drive,[1] is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. ...

ASF is based on serialized objects which are essentially byte sequences identified by a GUID marker. In computer science, in the context of data storage and transmission, serialization is the process of saving an object onto a storage medium (such as a file, or a memory buffer) or to transmit it across a network connection link, either in binary form, or in some human-readable text... In computer science a byte (pronounced bite) is a unit of measurement of information storage, most often consisting of eight bits. ... A Globally Unique Identifier or GUID (IPA pronunciation: or ) is a pseudo-random number used in software applications. ...

The most common filetypes contained within an ASF file are Windows Media Audio (WMA) and Windows Media Video (WMV). Note that the file extension abbreviations are similar in name to the codecs of the same name but are different things. Windows Media Audio (WMA) is an audio data compression technology developed by Microsoft. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ...

ASF files can also contain objects representing metadata, such as the artist, title, album and genre for an audio track, or the director of a video track, much like the ID3 tags of MP3 files. Metadata is data about data. ... This article or section does not cite its references or sources. ... For other uses, see MP3 (disambiguation). ...

Files containing only WMA audio can be named using a .wma extension, and files of only audio and video content may have the extension .wmv. Both may use the .asf extension if desired. A filename extension is a suffix to the name of a computer file applied to show its format. ...

Certain error-correcting techniques related to ASF are patented in the United States (United States Patent 6,041,345 Levi, et al. March 21, 2000) by Microsoft. Although the format is publicly documented by Microsoft, its license limits implementations to closed-source development projects only. Apple's iTunes software (for Windows) now has the capability to convert WMA files to any iTunes-supported format.[1] It has been suggested that this article or section be merged with SEC-DED. (Discuss) In mathematics, computer science, telecommunication, and information theory, error detection and correction has great practical importance in maintaining data (information) integrity across noisy channels and less-than-reliable storage media. ... Apple Inc. ... This article is about the iTunes application. ...

The ASF container provides the framework for digital rights management in Windows Media Audio and Windows Media Video. An analysis of an older scheme used in WMA reveals that it is 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. Digital rights management (DRM) is an umbrella term that refers to access control technologies used by publishers and other copyright holders to limit usage of digital media or devices. ... Elliptic curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. ... The Data Encryption Standard (DES) is a cipher (a method for encrypting information) selected as an official Federal Information Processing Standard (FIPS) for the United States in 1976, and which has subsequently enjoyed widespread use internationally. ... For the Vietnam road named RC4, see Route Coloniale 4. ... The SHA (Secure Hash Algorithm) family is a set of related cryptographic hash functions designed by the National Security Agency (NSA) and published by the National Institute of Standards and Technology (NIST). ...

ASF files have MIME type application/vnd.ms-asf or video/x-ms-asf. (Advanced Stream Redirector (ASX) files also have MIME type video/x-ms-asf.) For mime as an art form, see mime artist. ... The Advanced Stream Redirector (ASX) format is a type of XML metafile designed to store a list of Windows Media files to play during a multimedia presentation. ...

ASF container-based media is usually streamed on the internet either through the MMS protocol or the RTSP protocol. Microsofts streaming server Microsoft Media Services (also called NetShow Services) uses the Microsoft Media Server (MMS) protocol to transfer unicast data. ... The Real Time Streaming Protocol (RTSP), developed by the IETF and created in 1998 as RFC 2326, is a protocol for use in streaming media systems which allows a client to remotely control a streaming media server, issuing VCR-like commands such as play and pause, and allowing time-based...

Codecs

Although the ASF container format can technically include any codec, Microsoft's encoding tools (including Windows Media Encoder and Windows Movie Maker) produce ASF/WMA/WMV files using the DirectX Media Objects (DMO) framework. So far, third-party DMO-based codecs remain almost non-existent or extremely rare. Microsoft has threatened legal action for patent violation against (at least) one free software project aiming to allow playback of the format^[1]. Windows Media Encoder is a production tool developed by Microsoft which enables content developers to convert both live and prerecorded audio, video, and computer screen images to Windows Media formats for live and on-demand delivery. ... â€œMovie makerâ€ redirects here. ... DirectX Media Objects (DMOs) are COM-based multimedia and data-streaming components. ...

See also

The Advanced Stream Redirector (ASX) format is a type of XML metafile designed to store a list of Windows Media files to play during a multimedia presentation. ... This table compares features of container formats. ...

References

External links

Categories: Container formats | Windows multimedia | Digital rights management Look up Multimedia in Wiktionary, the free dictionary. ... â€œSource codingâ€ redirects here. ... Video compression refers to making a digital video signal use less data, without noticeably reducing the quality of the picture. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... Motion JPEG, also known as M-JPEG, is a video file format consisting of a sequence of individual JPEG images; unlike other video compression algorithms, each frame is an image unto itself. ... MPEG-1 defines a group of Audio and Video (AV) coding and compression standards agreed upon by MPEG (Moving Picture Experts Group). ... MPEG-2 is a standard for the generic coding of moving pictures and associated audio information [1]. It is widely used around the world to specify the format of the digital television signals that are broadcast by terrestrial (over-the-air), cable, and direct broadcast satellite TV systems. ... MPEG-4 Part 2 is a video compression technology developed by MPEG. It belongs to the MPEG-4 ISO/IEC standard (ISO/IEC 14496-2). ... H.264 is a standard for video compression. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... H.261 is an 1990 ITU video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. ... H.262 is an ITU-T digital video coding standard. ... H.263 is a video codec designed by the ITU-T as a low-bitrate encoding solution for videoconferencing. ... H.264 is a standard for video compression. ... Audio Video Standard, or AVS, is a compression codec for digital audio and video, and a possible alternative to H.264/AAC/Vorbis [1], meant to potentially replace MPEG-2. ... Bink is a video file format (extension . ... Dirac is a prototype algorithm for the encoding and decoding (see codec) of raw video. ... Indeo Video (commonly known now simply as Indeo) is a video codec developed by Intel in 1992. ... Motion JPEG (M-JPEG) is an informal name for multimedia formats where each video frame or interlaced field of a digital video sequence is separately compressed as a JPEG image. ... Pixlet is a video codec created by Apple Computer and based on wavelets, designed to enable viewing of full resolution, high resolution movies in real time at low DV data rates. ... RealVideo is a proprietary video format developed by RealNetworks. ... RTVideo RTVideo is Microsofts default video codec for OCS. RTVideo is a proprietrary codec. ... Smacker video is a video file format (with the file extension) developed by RAD Game Tools and oftenly used in computer games. ... Theora is a video codec being developed by the Xiph. ... VC-1 is the informal name of the SMPTE 421M video codec standard initially developed by Microsoft. ... TrueMotion VP6 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3 and VP5. ... TrueMotion VP7 is a video codec developed by On2 Technologies as a successor to earlier efforts such as VP3, VP5 and TrueMotion VP6. ... Windows Media Video (WMV) is a generic name for the set of video codec technologies developed by Microsoft. ... This article is about a process which reduces the data rate or file size of digital audio signals. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... For other uses, see MP3 (disambiguation). ... MPEG-1 Audio Layer II (MP2, sometimes Musicam) is an audio codec defined by ISO/IEC 11172-3. ... MPEG-1 Audio Layer I, commonly abbreviated to MP1, is one of three audio codecs included in the MPEG-1 standard. ... MPEG-4 AAC DRM encoding as used in the iTunes Store Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... High Efficiency AAC (HE-AAC) is a lossy data compression scheme for digital audio. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... G.711 is an ITU-T standard for audio companding. ... G.722[1] is a ITU-T standard wideband speech codec operating at 48-64 kbit/s. ... G.722. ... Adaptive Multi Rate - WideBand or AMR-WB is a speech coding standard developed after the AMR using same technology like ACELP. The codec provides excellent speech quality due to wider speech bandwidth of 50 - 7000 Hz compared to narrowband speech codecs which in general are optimized for POTS wireline quality... This article is in need of attention from an expert on the subject. ... G.723. ... G.726 is ITU-T speech codec operating at bit rates of 16-40 kbit/s. ... G.728 is a ITU-T standard for speech coding operating at 16 kbit/s. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... The introduction to this article provides insufficient context for those unfamiliar with the subject matter. ... G.729 is an audio data compression algorithm for voice that compresses voice audio in chunks of 10 milliseconds. ... Dolby Digital is the marketing name for a series of lossy audio compression technologies by Dolby Laboratories. ... Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is an audio codec developed by Apple Inc. ... Adaptive Transform Acoustic Coding (ATRAC) is a family of proprietary audio compression algorithms developed by Sony. ... Free Lossless Audio Codec (FLAC) is a popular file format for audio data compression. ... internet Low Bit Rate Codec (iLBC) is a royalty free narrowband speech codec, developed by Global IP Sound (GIPS). ... Monkeyâ€™s Audio is a file format for audio data compression. ... In telecommunication, a mu-law algorithm (Î¼-law) is a standard analog signal compression or companding algorithm, used in digital communications systems of the North American and Japanese digital hierarchies, to optimize (in other words, modify) the dynamic range of an audio analog signal prior to digitizing. ... Musepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160-180 kbit/s. ... Nellymoser is a single-channel (mono) format optimized for low-bitrate transmission of audio. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ... RealAudio is a proprietary audio format developed by RealNetworks. ... RTAudio is a Microsoft produced adaptive wide-band speech codec. ... SHN (Shorten) is a file format used to losslessly compress CD-quality audio files (44. ... Speex is a free software speech codec that may be used on VoIP applications and podcasts. ... Vorbis is an open source, lossy audio codec project headed by the Xiph. ... WavPack is a free, open source lossless audio compression format developed by David Bryant. ... Windows Media Audio (WMA) is an audio data compression technology developed by Microsoft. ... TAK (Toms lossless Audio Kompressor) is a lossless audio compressor which promises compression performance similar to Monkeys Audio â€œHighâ€ and decompression speed similar to FLAC. The codec also supports streaming (necessary headers for decompressing the audio are written to the stream every 2 seconds), error tolerance (single bit... Image compression is the application of Data compression on digital images. ... â€œISOâ€ redirects here. ... The International Electrotechnical Commission (IEC) is an international standards organization dealing with electrical, electronic and related technologies. ... The ITU Telecommunication Standardization Sector (ITU-T) coordinates standards for telecommunications on behalf of the International Telecommunication Union (ITU) and is based in Geneva, Switzerland. ... JPG redirects here. ... JPEG 2000 is a wavelet-based image compression standard. ... The Joint Photographic Experts Group, in addition to their well-known lossy image compression techniques, JPEG and JPEG 2000, also have three standards for lossless compression (of which JPEG-LS has a lossy mode): Lossless JPEG was developed as a late addition to JPEG in 1993, using a completely different... JBIG is a lossless image compression standard from the Joint Bi-level Image Experts Group, standardized as ISO/IEC standard 11544 and as ITU-T recommendation T.82. ... JBIG2 is an image compression standard for bi-level images, developed by the Joint Bi-level Image Experts Group. ... PNG (Portable Network Graphics), sometimes pronounced as ping, is a relatively new bitmap image format that is becoming popular on the World Wide Web and elsewhere. ... Wireless Application Protocol Bitmap Format (shortened to Wireless Bitmap and with file extension . ... .BMP or . ... GIF (Graphics Interchange Format) is a bitmap image format that is widely used on the World Wide Web, both for still images and for animations. ... ICER is a wavelet-based image compression file format used by the NASA Mars Rovers. ... ILBM is a subtype of the Interchange File Format used for storing picture data. ... PCX is an image file format that uses a simple form of run-length encoding (a type of lossless compression algorithm). ... PGF (Progressive Graphics File) is a wavelet-based bitmapped image format that employs lossless and lossy data compression. ... Truevisions (now Pinnacle Systems) TGA File Format, often referred to as TARGA File Format, is a raster graphics file format. ... â€œTIFFâ€ redirects here. ... JPEG XR (formerly HD Photo (formerly Windows Media Photo) ) is a still image compression algorithm and file format for continuous tone photographic images, developed by Microsoft as a part of the Windows Media family. ... A container format is a computer file format that can contain various types of data, compressed by means of standardized codecs. ... 3GP is a multimedia container format defined by the Third Generation Partnership Project (3GPP) for use on 3G mobile phones. ... // Audio-Video Interleaved, known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. ... Bink is a video file format (extension . ... DivX is a video codec created by DivX, Inc. ... DPX is also the name given to a mounting medium, see Di-n-butylPhthalate in Xylene. ... Flash Video (FLV) is a proprietary file format used to deliver video over the Internet using Adobe Flash Player (formerly known as Macromedia Flash Player) version 6, 7, 8, or 9. ... // The Matroska Multimedia Container is an open standard free multimedia container format that can hold an unlimited number of video, audio, picture or subtitle tracks inside a single file. ... For other parts of the MPEG-4 standard, see MPEG-4. ... Material eXchange Format (MXF) is a container format for professional digital video and audio media defined by a set of SMPTE standards. ... NUT is a patent-free, multimedia container format originally conceived by a few MPlayer and FFmpeg developers that were dissatisfied with the limitations of all currently available multimedia container formats such as AVI or Matroska. ... Ogg is an open standard for a free container format for digital multimedia, unrestricted by software patents and designed for efficient streaming and manipulation. ... Ogg Media (OGM), meaning Ogg Media File, is a container format (for video, audio and subtitle streams). ... QuickTime is a multimedia framework developed by Apple Inc. ... RealMedia is a multimedia container format created by RealNetworks. ... Smacker video is a video file format (with the file extension) developed by RAD Game Tools and oftenly used in computer games. ... A VOB file (DVD-Video Object or Versioned Object Base) is a container format contained in DVD-Video media. ... Audio Interchange File Format (AIFF) is an audio file format standard used for storing sound data for personal computers and other electronic audio devices. ... The Au file format is a simple audio file format that consists of a header of 6 32-bit words and then the data (high-order byte comes first). ... WAV (or WAVE), short for Waveform audio format, is a Microsoft and IBM audio file format standard for storing audio on PCs. ...

Contents

Codecs

References

External links