Università Ca' Foscari Venezia Department or Environmental Sciences, Informatics and Statistics MSc in Computer Science
Multimedia Systems
(2015-2016)
prof. Augusto Celentano
The glossary entries refer to Wikipedia articles. For each heading a synthesis of the first paragraph of the article is shown.
An A-law algorithm is a standard companding algorithm, used in European digital communications systems to optimize, i.e., modify, the dynamic range of an analog signal for digitizing. [ more ]
Adobe Flash (formerly Macromedia Flash) is a multimedia platform originally acquired by Macromedia and currently developed and distributed by Adobe Systems. Since its introduction in 1996, Flash has become a popular method for adding animation and interactivity to web pages. Flash is commonly used to create animation, advertisements, and various web page Flash components, to integrate video into web pages, and more recently, to develop rich Internet applications. [ more ]
Adobe Premiere Pro is a real-time, 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 made by Adobe Systems, though it can also be purchased separately. Even when purchased separately, it comes bundled with Adobe Encore and Adobe OnLocation. Premiere Pro supports many video editing cards and plug-ins for accelerated processing, additional file format support, and video/audio effects. Premiere Pro CS4 is the first version to be optimized for 64-bit operating systems, although it is not natively 64-bit.[1] [ more ]
Adobe Premiere → Adobe Premiere Pro
Adaptive DPCM (ADPCM) is a variant of DPCM (differential pulse-code modulation) that varies the size of the quantization step, to allow further reduction of the required bandwidth for a given signal-to-noise ratio. [ more ]
Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.[1] [ more ]
Advanced Audio Coding (AAC) is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.[1] [ more ]
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 format was co-developed by Apple Computer in 1988 based on Electronic Arts' Interchange File Format (IFF, widely used on Amiga systems) and is most commonly used on Apple Macintosh computer systems. [ more ]
Anycast is a network addressing and routing scheme whereby data is routed to the "nearest" or "best" destination as viewed by the routing topology. [ more ]
Audio compression is a form of data compression designed to reduce the transmission bandwidth requirement of digital audio streams and the storage size of audio files. Audio compression algorithms are implemented in computer software as audio codecs. Generic data compression algorithms perform poorly with audio data, seldom reducing data size much below 87% from the original, and are not designed for use in real time applications. Consequently, specifically optimized audio lossless and lossy algorithms have been created. Lossy algorithms provide greater compression rates and are used in mainstream consumer audio devices. [ more ]
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. Like the DVD video format, AVI files support multiple streaming audio and video, although these features are seldom used. Most AVI files also use the file format extensions developed by the Matrox OpenDML group in February 1996. These files are supported by Microsoft, and are unofficially called "AVI 2.0". [ more ]
Auditory masking occurs when the perception of one sound is affected by the presence of another sound (Gelfand 2004). The term masking is not confined to auditory perception as it can also be used in visual perception tasks. [ more ]
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Chroma subsampling is the practice of encoding images by implementing less resolution for chroma information than for luma information. It is used in many video encoding schemes - both analog and digital - and also in JPEG encoding. [ more ]
In the study of the perception of color, one of the first mathematically defined color spaces was the CIE 1931 XYZ color space, created by the International Commission on Illumination (CIE) in 1931.[1][2] [ more ]
A Lab color space is a color-opponent space with dimension L for lightness and a and b for the color-opponent dimensions, based on nonlinearly-compressed CIE XYZ color space coordinates. [ more ]
The CMYK color model, referred to as process color or four color, is a subtractive color model, used in color printing, also used to describe the printing process itself. CMYK refers to the four inks used in most color printing: cyan, magenta, yellow, and key black. Though it varies by print house, press operator, press manufacturer and press run, ink is typically applied in the order of the abbreviation. [ more ]
A codec is a device or computer program capable of encoding and/or decoding a digital data stream or signal. The word codec is a portmanteau (a blending of two or more words) of 'compressor-decompressor' or, more accurately, 'coder-decoder'. [ more ]
Color depth or bit depth, is a computer graphics term describing the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel (bpp), particularly when specified along with the number of bits used. Higher color depth gives a broader range of distinct colors. [ more ]
A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e.g. RGB and CMYK are color models). However, a color model with no associated mapping function to an absolute color space is a more or less arbitrary color system with no connection to any globally-understood system of color interpretation. [ more ]
A Compact Disc (also known as a CD) is an optical disc used to store digital data. It was originally developed to store sound recordings exclusively, but later it also allowed the preservation of other types of data. Audio CDs have been commercially available since October 1982. In 2009, they remain the standard physical storage medium for audio. [ more ]
A container or wrapper format is a file format, or often a stream format (the stream need not be stored as a file) whose specifications describe only the way data is stored (but not coded) within the file, and how much metadata could be, or is effectively stored. No specific codification of the data itself is implied or specified. A wrapper format is in fact, a meta-format, because it stores the data itself, and the information about how it is stored. A program which is able to correctly identify and open a file (read a stream) written in such a format might not be able to decode the actual data stored within, either because the metadata in the wrapper file is not sufficient or the software lacks the specific decoding algorithm required. Stated like that, a container format could, in theory, wrap any kind of data. Although there exist a few examples of such file formats (Microsoft Windows' DLL files are just an implicit one), most wrappers exist for particular data groups. This is due to the specific requirements of the desired information. The most relevant family of wrappers is, in fact, to be found among multimedia file formats, where the audio and/or video streams can effectively be coded with hundreds of different alternative algorithms, whereas they are stored in fewer file formats. In this case the algorithm (or algorithms, as in the case of mixed audio and video contents in a single video file format) used to actually store the data is called a codec (shorthand for coder/decoder). [ more ]
In computer science and information theory, data compression or source coding is the process of encoding information using fewer bits (or other information-bearing units) than an unencoded representation would use, through use of specific encoding schemes. [ more ]
Digital audio uses digital signals for sound reproduction. This includes analog-to-digital conversion, digital-to-analog conversion, storage, and transmission. In effect, the system commonly referred to as digital is in fact a discrete-time, discrete-level analog of a previous electrical analog. While modern systems can be quite subtle in their methods, the primary usefulness of a digital system is that, due to its discrete (in both time and amplitude) nature, signals can be corrected, once they are digital, without loss, and the digital signal can be reconstituted. The discreteness in both time and amplitude is key to this reconstitution, which is unavailable for a signal in which at least one of time or amplitude is continuous. While the hybrid systems (part discrete, part continuous) exist, they are no longer used for new modern systems. [ more ]
Digital video is a type of video recording system that works by using a digital rather than an analog video signal. The terms camera, video camera, and camcorder are used interchangeably in this article. [ more ]
DivX is a brand name of products created by DivX, Inc. (formerly DivXNetworks, Inc.), including the DivX Codec which has become popular due to its ability to compress lengthy video segments into small sizes while maintaining relatively high visual quality. [ more ]
The Dublin Core metadata element set is a standard for cross-domain information resource description. It defines conventions for describing things online in ways that make them easy to find. Dublin Core is widely used to describe digital materials such as video, sound, image, text, and composite media like web pages. Implementations of Dublin Core typically make use of XML and are Resource Description Framework based. Dublin Core is defined by ISO in ISO Standard 15836, and NISO Standard Z39.85-2007. [ more ]
DV is a digital video format created by Sony, JVC, Panasonic and other video camera producers, and launched in 1995. Its smaller tape form factor MiniDV has since become a standard for home and semi-professional video production; it is sometimes used for professional purposes as well, such as filmmaking and electronic news gathering (ENG). [ more ]
DVD, short for Digital Versatile Disc, is an optical disc storage media format, and was founded in 1995. Its main uses are video and data storage. DVDs are of the same dimensions as compact discs (CDs), but store more than six times as much data. [ more ]
In information theory, entropy is a measure of the uncertainty associated with a random variable. The term by itself in this context usually refers to the Shannon entropy, which quantifies, in the sense of an expected value, the information contained in a message, usually in units such as bits. Equivalently, the Shannon entropy is a measure of the average information content one is missing when one does not know the value of the random variable. The concept was introduced by Claude E. Shannon in his 1948 paper "A Mathematical Theory of Communication". [ more ]
Exchangeable image file format
Exchangeable image file format (Exif) is a specification for the image file format used by digital cameras. The specification uses the existing JPEG, TIFF Rev. 6.0, and RIFF WAV file formats, with the addition of specific metadata tags. It is not supported in JPEG 2000, PNG, or GIF. [ more ]
Exif → Exchangeable image file format
FairPlay is a digital rights management (DRM) technology created by Apple Inc., based on technology created by the company Veridisc. FairPlay is built into the QuickTime multimedia software and used by the iPhone, iPod, Apple TV, iTunes, and iTunes Store and the App Store. Any protected song or other form of media purchased from the iTunes Store with iTunes is encoded with FairPlay. FairPlay digitally encrypts AAC audio files and prevents users from playing these files on unauthorized computers. [ more ]
Final Cut Pro is a professional non-linear editing software application developed by Apple Inc. The current version of the application is only available for Mac OS X version 10.5.6 or later, and is a module of the Final Cut Studio product. The software logs and captures video onto a hard drive (internal or external), where it can be edited and processed. The current version of Final Cut Pro, version 7, runs only on Intel processors. It is compatible with many hardware interfaces. [ more ]
Free Lossless Audio Codec (FLAC) is a file format for lossless audio data compression. During compression, FLAC does not lose quality from the audio stream, as lossy compression formats such as MP3, AAC, and Vorbis do. Josh Coalson is the primary author of FLAC. [ more ]
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The Graphics Interchange Format (GIF) is a bitmap image format that was introduced by CompuServe in 1987 and has since come into widespread usage on the World Wide Web due to its wide support and portability. [ more ]
Google Video is a free video sharing website and also a video search engine from Google. Google Video allows select videos to be remotely embedded on other websites and provides the necessary HTML code alongside the media, similar to YouTube. This allows for websites to host large amounts of video remotely on Google Video without running into bandwidth or storage capacity issues. Some videos are also offered for sale through the Google Video Store. [ more ]
H.261 is a 1990 ITU-T video coding standard originally designed for transmission over ISDN lines on which data rates are multiples of 64 kbit/s. It is one member of the H.26x family of video coding standards in the domain of the ITU-T Video Coding Experts Group (VCEG). The coding algorithm was designed to be able to operate at video bit rates between 40 kbit/s and 2 Mbit/s. The standard supports two video frame sizes: CIF (352x288 luma with 176x144 chroma) and QCIF (176x144 with 88x72 chroma) using a 4:2:0 sampling scheme. It also has a backward-compatible trick for sending still picture graphics with 704x576 luma resolution and 352x288 chroma resolution (which was added in a later revision in 1993). [ more ]
H.263 is a video codec standard originally designed as a low-bitrate compressed format for videoconferencing. It was developed by the ITU-T Video Coding Experts Group (VCEG) in a project ending in 1995/1996 as one member of the H.26x family of video coding standards in the domain of the ITU-T. [ more ]
H.264/MPEG-4 AVC is a standard for video compression. The final drafting work on the first version of the standard was completed in May 2003. [ more ]
HSL and HSV are two related representations of points in an RGB color model that attempt to describe perceptual color relationships more accurately than RGB, while remaining computationally simple. HSL stands for hue, saturation and lightness, while HSV stands for hue, saturation and value. [ more ]
In computer science and information theory, Huffman coding is an entropy encoding algorithm used for lossless data compression. The term refers to the use of a variable-length code table for encoding a source symbol (such as a character in a file) where the variable-length code table has been derived in a particular way based on the estimated probability of occurrence for each possible value of the source symbol. It was developed by David A. Huffman while he was a Ph.D. student at MIT, and published in the 1952 paper "A Method for the Construction of Minimum-Redundancy Codes". [ more ]
ID3 is a metadata container most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, and other information about the file to be stored in the file itself. [ more ]
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication. [ more ]
In computing, JPEG (pronounced JAY-peg) (named after the Joint Photographic Experts Group who created the standard) is a commonly used method of compression for photographic images. The degree of compression can be adjusted, allowing a selectable tradeoff between storage size and image quality. JPEG typically achieves 10:1 compression with little perceptible loss in image quality. [ more ]
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 for better compression rates.[citation needed] [ more ]
A lossy compression method is one where compressing data and then decompressing it retrieves data that is different from the original, but is close enough to be useful in some way. Lossy compression is most commonly used to compress multimedia data (audio, video, still images), especially in applications such as streaming media and internet telephony. By contrast, lossless compression is required for text and data files, such as bank records, text articles, etc. In many cases it is advantageous to make a master lossless file which can then be used to produce compressed files for different purposes; for example a multi-megabyte file can be used at full size to produce a full-page advertisement in a glossy magazine, and a 10 kilobyte lossy copy made for a small image on a web page. [ more ]
The μ-law algorithm (often u-law, ulaw, mu-law, pronounced /mju/) is a companding algorithm, primarily used in the digital telecommunication systems of North America and Japan. Companding algorithms reduce the dynamic range of an audio signal. In analog systems, this can increase the signal-to-noise ratio (SNR) achieved during transmission, and in the digital domain, it can reduce the quantization error (hence increasing signal to quantization noise ratio). These SNR increases can be traded instead for reduced bandwidth for equivalent SNR. [ more ]
Adobe Director (formerly Macromedia Director) is a multimedia application authoring platform created by Macromedia—now part of Adobe Systems. It allows users to build applications built on a movie metaphor, with the user as the "director" of the movie. Originally designed for creating animation sequences, the addition of a powerful scripting language called Lingo made it a popular choice for creating CD-ROMs and standalone kiosks and web content using Adobe Shockwave. Adobe Director supports both 2D and 3D multimedia projects. [ more ]
MIDI (Musical Instrument Digital Interface) is an industry-standard protocol defined in 1982 that enables electronic musical instruments such as keyboard controllers, computers, and other electronic equipment to communicate, control, and synchronize with each other. MIDI allows computers, synthesizers, MIDI controllers, sound cards, samplers and drum machines to control one another, and to exchange system data. MIDI does not transmit an audio signal or media — it transmits "event messages" such as the pitch and intensity of musical notes to play, control signals for parameters such as volume, vibrato and panning, cues, and clock signals to set the tempo. As an electronic protocol, it is notable for its widespread adoption throughout the music industry. [ more ]
MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression. It is a common audio format for consumer audio storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on digital audio players. MP3 is an audio-specific format that was designed by the Moving Picture Experts Group as part of its MPEG-1 standard. The group was formed by several teams of engineers at Fraunhofer IIS in Erlangen, Germany, AT&T-Bell Labs (now a division of Alcatel-Lucent) in Murray Hill, NJ, USA, Thomson-Brandt, and CCETT as well as others. It was approved as an ISO/IEC standard in 1991. [ more ]
MPEG-1 is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to 1.5 Mbit/s (26:1 and 6:1 compression ratios respectively)[1] without excessive quality loss, making Video CDs, digital cable/satellite TV and digital audio broadcasting (DAB) possible.[2][3] [ more ]
MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information".[1] 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 bandwidth. [ more ]
The MPEG-21 standard, from the Moving Picture Experts Group, aims at defining an open framework for multimedia applications. MPEG-21 is ratified in the standards ISO/IEC 21000 - Multimedia framework (MPEG-21)[1][2][3][4][5][6]. [ more ]
MPEG-4 is a patented collection of methods defining compression of audio and visual (AV) digital data. It was introduced in late 1998 and designated a standard for a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) under the formal standard ISO/IEC 14496. Uses of MPEG-4 include compression of AV data for web (streaming media) and CD distribution, voice (telephone, videophone) and broadcast television applications. [ more ]
MPEG-7 is a multimedia content description standard. It was standardized in ISO/IEC 15938 (Multimedia content description interface).[1][2][3][4] This description will be associated with the content itself, to allow fast and efficient searching for material that is of interest to the user. MPEG-7 is formally called Multimedia Content Description Interface. Thus, it is not a standard which deals with the actual encoding of moving pictures and audio, like MPEG-1, MPEG-2 and MPEG-4. It uses XML to store metadata, and can be attached to timecode in order to tag particular events, or synchronise lyrics to a song, for example. [ more ]
The Moving Picture Experts Group (MPEG) was formed by the ISO to set standards for audio and video compression and transmission.[1] Its first meeting was in May 1988 in Ottawa, Canada. As of late 2005, MPEG has grown to include approximately 350 members per meeting from various industries, universities, and research institutions. MPEG's official designation is ISO/IEC JTC1/SC29 WG11 - Coding of moving pictures and audio.[2][3][4][5] [ more ]
Multicast addressing is a network technology for the delivery of information to a group of destinations simultaneously using the most efficient strategy to deliver the messages over each link of the network only once, creating copies only when the links to the multiple destinations split. [ more ]
A non-linear editing system (NLE) is a video editing (NLVE) or audio editing (NLAE) system which can perform random access on the source material. [ more ]
NTSC, named for the National Television System Committee is the analog television system used in most of the Americas, Japan, South Korea, Taiwan, Burma, and some Pacific island nations and territories (see map). NTSC is also the name of the U.S. standardization body that developed the broadcast standard.[1] The first NTSC standard was developed in 1941 and had no provision for color TV. [ more ]
Vorbis is a free software / open source project headed by the Xiph.Org Foundation (formerly Xiphophorus company). The project produces an audio format specification and software implementation (codec) for lossy audio compression. Vorbis is most commonly used in conjunction with the Ogg container format[7] and it is therefore often referred to as Ogg Vorbis. [ more ]
PAL, short for Phase Alternating Line, is an analogue television encoding system used in broadcast television systems in large parts of the world. Other common analogue television systems are SECAM and NTSC. This page primarily discusses the colour encoding system. See the articles on broadcast television systems and analogue television for additional discussion of frame rates, image resolution and audio modulation. For discussion of the 625-line / 25 frame per second television standard, see 576i. [ more ]
Pulse-code modulation (PCM) is a digital representation of an analog signal where the magnitude of the signal is sampled regularly at uniform intervals, then quantized to a series of symbols in a numeric (usually binary) code. PCM has been used in digital telephone systems and 1980s-era electronic musical keyboards. It is also the standard form for digital audio in computers and the compact disc "red book" format. It is also standard in digital video, for example, using ITU-R BT.601. Uncompressed PCM is not typically used for video in standard definition consumer applications such as DVD or DVR because the bit rate required is far too high. [ more ]
The Protected Media Path is a set of technologies creating a "Protected Environment", first included in Microsoft's Windows Vista operating system, that is used to enforce digital rights management (or DRM) protections on content. Its subsets are Protected Video Path (PVP) and Protected User Mode Audio (PUMA). [ more ]
Psychoacoustics is the study of subjective human perception of sounds. Alternatively it can be described as the study of the psychological correlates of the physical parameters of acoustics. [ more ]
QuickTime is a multimedia framework developed by Apple Inc., capable of handling various formats of digital video, media clips, sound, text, animation, music, and interactive panoramic images. It is available for Mac OS classic (System 7 onwards), Mac OS X and Microsoft Windows operating systems. The latest version is QuickTime X (10.0) and is only available on Mac OS X v10.6. [ more ]
The Real Time Streaming Protocol (RTSP) is a network control protocol for use in entertainment and communications systems to control streaming media servers. The protocol is used to establish and control media sessions between end points. Clients of media servers issue VCR-like commands, such as play and pause, to facilitate real-time control of playback of media files from the server. [ more ]
The Real-time Transport Protocol (RTP) defines a standardized packet format for delivering audio and video over the Internet. It was developed by the Audio-Video Transport Working Group of the IETF and first published in 1996 as RFC 1889, and superseded by RFC 3550 in 2003. [ more ]
RealVideo is a proprietary video format developed by RealNetworks. It was first released in 1997 and as of 2008[update] is at version 10.[1] RealVideo is supported on many platforms, including Windows, Mac, Linux, Solaris, and several mobile phones. [ more ]
An RGB color space is any additive color space based on the RGB color model. A particular RGB color space is defined by the three chromaticities of the red, green, and blue additive primaries, and can produce any chromaticity that is the triangle defined by those primary colors. The complete specification of an RGB color space also requires a white point chromaticity and a gamma correction curve. RGB is an acronym for Red, Green, Blue. [ more ]
The Resource Interchange File Format (RIFF) is a generic meta-format for storing data in tagged chunks. [ more ]
The Resource ReSerVation Protocol (RSVP), described in RFC 2205, is a Transport layer protocol designed to reserve resources across a network for an integrated services Internet. "RSVP does not transport application data but is rather an Internet control protocol, like ICMP, IGMP, or routing protocols" - RFC 2205. RSVP provides receiver-initiated setup of resource reservations for multicast or unicast data flows with scaling and robustness. [ more ]
RTP → Real-time Transport Protocol
RTSP → Real-time Streaming Protocol
SECAM, also written SÉCAM (Séquentiel couleur à mémoire[1], French for "Sequential Color with Memory"), is an analog color television system first used in France. A team led by Henri de France working at Compagnie Française de Télévision (later bought by Thomson) invented SECAM. It is, historically, the first European color television standard. [ more ]
Streaming media are multimedia that are constantly received by, and normally presented to, an end-user while being delivered by a streaming provider (the term "presented" is used in this article in a general sense that includes audio or video playback). The name refers to the delivery method of the medium rather than to the medium itself. The distinction is usually applied to media that are distributed over telecommunications networks, as most other delivery systems are either inherently streaming (e.g., television) or inherently non-streaming (e.g., books, video cassettes, audio CDs). The verb 'to stream' is also derived from this term, meaning to deliver media in this manner. Internet television is a commonly streamed media. [ more ]
The Internet Protocol Suite (commonly known as TCP/IP) is the set of communications protocols used for the Internet and other similar networks. It is named from two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were the first two networking protocols defined in this standard. Today's IP networking represents a synthesis of several developments that began to evolve in the 1960s and 1970s, namely the Internet and LANs (Local Area Networks), which emerged in the mid- to late-1980s, together with the advent of the World Wide Web in the early 1990s. [ more ]
The User Datagram Protocol (UDP) is one of the core members of the Internet Protocol Suite, the set of network protocols used for the Internet. With UDP, computer applications can send messages, in this case referred to as datagrams, to other hosts on an Internet Protocol (IP) network without requiring prior communications to set up special transmission channels or data paths. UDP is sometimes called the Universal Datagram Protocol. The protocol was designed by David P. Reed in 1980 and formally defined in RFC 768.[1] [ more ]
A video codec is a device or software that enables video compression and/or decompression for digital video. The compression usually employs lossy data compression. Historically, video was stored as an analog signal on magnetic tape. Around the time when the compact disc entered the market as a digital-format replacement for analog audio, it became feasible to also begin storing and using video in digital form, and a variety of such technologies began to emerge. [ more ]
Video compression refers to reducing the quantity of data used to represent digital video images, and is a combination of spatial image compression and temporal motion compensation. Video compression is an example of the concept of source coding in Information theory. This article deals with its applications: compressed video can effectively reduce the bandwidth required to transmit video via terrestrial broadcast, via cable TV, or via satellite TV services. [ more ]
Video for Windows (VfW, also referred to as Video Compression Manager (VCM)) was a multimedia framework developed by Microsoft that allowed Microsoft Windows to play digital video. [ more ]
Video on Demand (VOD) or Audio Video on Demand (AVOD) are systems which allow users to select and watch/listen to video or audio content on demand. [ more ]
Video is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion. [ more ]
A VOB file (Video Object) is a container format in DVD-Video media. VOB can contain video, audio, subtitle and menu contents multiplexed together into a stream form. VOB is based on the MPEG-2 program stream format, but with additional limitations and specifications in the private streams.[3] [4] The MPEG-2 program stream has provisions for non-standard data (as used in VOB files) in the form of so-called private streams. VOB files are a very strict subset of the MPEG-2 program stream standard. While all VOB files are MPEG-2 program streams, not all MPEG-2 program streams comply with the definition for a VOB file.[3] [ more ]
Vorbis is a free software / open source project headed by the Xiph.Org Foundation (formerly Xiphophorus company). The project produces an audio format specification and software implementation (codec) for lossy audio compression. Vorbis is most commonly used in conjunction with the Ogg container format[7] and it is therefore often referred to as Ogg Vorbis. [ more ]
WAV (or WAVE), short for Waveform audio format, also known as Audio for Windows, is a Microsoft and IBM audio file format standard for storing an audio bitstream on PCs. It is an application of the RIFF bitstream format method for storing data in "chunks", and thus is also close to the 8SVX and the AIFF format used on Amiga and Macintosh computers, respectively. It is the main format used on Windows systems for raw and typically uncompressed audio. The usual bitstream encoding is the Pulse Code Modulation (PCM) format. [ more ]
Windows Media DRM is a Digital Rights Management service for the Windows Media platform. It is designed to provide secure 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. [ more ]
Windows Media Video (WMV) is a compressed video file format for several proprietary codecs developed by Microsoft. The original codec, known as WMV, was originally designed for Internet streaming applications, as a competitor to RealVideo. The other codecs, such as WMV Screen and WMV Image, cater for specialized content. Through standardization from the Society of Motion Picture and Television Engineers (SMPTE),[1][2] WMV 9 has gained adoption for physical-delivery formats such as HD DVD and Blu-ray Disc.[3][4] [ more ]
Xvid (formerly "XviD") is a video codec library following the MPEG-4 standard, specifically MPEG-4 Part 2 Advanced Simple Profile (ASP). It uses ASP features such as b-frames, global and quarter pixel motion compensation, lumi masking, trellis quantization, and H.263, MPEG and custom quantization matrices. [ more ]
YCbCr or Y'CbCr is a family of color spaces used as a part of the Color image pipeline in video and digital photography systems. Y' is the luma component and Cb and Cr are the blue-difference and red-difference chroma components. The prime (') on the Y is to distinguish the luma from luminance, meaning that light intensity is non-linearly encoded using gamma. [ more ]
YIQ is the color space used by the NTSC color TV system, employed mainly in North and Central America, and Japan. In the U.S., currently federally mandated for analog over-the-air TV broadcasting as shown in this excerpt of the current FCC rules and regulations part 73 "TV transmission standard": [ more ]
YouTube is a video sharing website on which users can upload and share videos. Three former PayPal employees created YouTube in February 2005.[1] In November 2006, YouTube, LLC was bought by Google Inc. for $1.65 billion, and is now operated as a subsidiary of Google. The company is based in San Bruno, California, and uses Adobe Flash Video technology to display a wide variety of user-generated video content, including movie clips, TV clips, and music videos, as well as amateur content such as video blogging and short original videos. Most of the content on YouTube has been uploaded by individuals, although media corporations including CBS, the BBC, UMG and other organizations offer some of their material via the site, as part of the YouTube partnership program.[2] [ more ]
YUV is a color space typically used as part of a color image pipeline. It encodes a color image or video taking human perception into account, allowing reduced bandwidth for chrominance components, thereby typically enabling transmission errors or compression artifacts to be more efficiently masked by the human perception than using a "direct" RGB-representation. Other color spaces have similar properties, and the main reason to implement or investigate properties of Y'UV would be for interfacing with analog or digital television or photographic equipment that conforms to certain Y'UV standards. [ more ]
Last update September 5, 2016.