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Scalable Video Coding
Scalable Video Coding: (SVC) is the name for the Annex G extension of the H.264/MPEG-4 AVC video compression standard. SVC standardizes the encoding of a high-quality video bitstream that also contains one or more subset bitstreams (a form of layered coding). A subset video bitstream is derived by dropping packets from the larger video to reduce the bandwidth required for the subset bitstream. The subset bitstream can represent a lower spatial resolution (smaller screen), lower temporal resolution (lower frame rate), or lower quality video signal. H.264/MPEG-4 AVC was developed jointly by ITU-T and ISO/IEC JTC 1. These two groups created the Joint Video Team (JVT) to develop the H.264/MPEG-4 AVC standard. Overview The objective of the SVC standardization has been to enable the encoding of a high-quality video bitstream that contains one or more subset bitstreams that can themselves be decoded with a complexity and reconstruction quality similar to that achieved using the existi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Layered Coding
Layered coding is a type of data compression for digital video or digital audio where the result of compressing the source video data is not just one compressed data stream, as in other types of compression, but multiple streams, called ''layers'', allowing decompression even if some layers are missing. Overview With layered coding, multiple data streams or layers are created when compressing the original video stream. This is in contrast to other types of compression, where the result is typically a single data stream. During decompression, all layers can be combined to recreate the original video stream. Additionally, the stream can be decoded even if some layers are missing (though usually a layer hierarchy has to be respected, with a base layer that must available). If layers are missing, the resulting stream will have reduced visual quality, but will still be usable. Use cases Layered coding is helpful when the same video stream needs to be available in different qualitie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraunhofer Institute For Telecommunications
The Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, HHI, also known as Fraunhofer HHI or Fraunhofer Heinrich Hertz Institute, is an organization of the Fraunhofer Society based in Berlin. The institute engages in applied research and development in the fields of physics, electrical engineering and computer sciences. Competencies The Fraunhofer Heinrich Hertz Institute develops mobile and stationary broadband communication networks and multimedia systems. Focal points of independent and contract research conducted by Fraunhofer HHI are photonic components and systems, fiber optic sensor systems, and image signal processing and transmission. Future applications for broadband networks are developed as well. Research in this area focuses on 3D displays, UHD panorama video production, human-machine interaction through gesture control, optical satellite communication and data transmission technologies such as visible light communications. Scientists at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-4
MPEG-4 is a group of international standards for the compression of digital audio and visual data, multimedia systems, and file storage formats. It was originally introduced in late 1998 as a group of audio and video coding formats and related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) ( ISO/IEC JTC 1/SC29/WG11) under the formal standard ISO/IEC 14496 – ''Coding of audio-visual objects''. Uses of MPEG-4 include compression of audiovisual data for Internet video and CD distribution, voice (telephone, videophone) and broadcast television applications. The MPEG-4 standard was developed by a group led by Touradj Ebrahimi (later the JPEG president) and Fernando Pereira. Background MPEG-4 absorbs many of the features of MPEG-1 and MPEG-2 and other related standards, adding new features such as (extended) VRML support for 3D rendering, object-oriented composite files (including audio, video and VRML objects), support for externally specified Digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wayback Machine
The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, a nonprofit based in San Francisco, California. Created in 1996 and launched to the public in 2001, it allows the user to go "back in time" and see how websites looked in the past. Its founders, Brewster Kahle and Bruce Gilliat, developed the Wayback Machine to provide "universal access to all knowledge" by preserving archived copies of defunct web pages. Launched on May 10, 1996, the Wayback Machine had more than 38.2 million records at the end of 2009. , the Wayback Machine had saved more than 760 billion web pages. More than 350 million web pages are added daily. History The Wayback Machine began archiving cached web pages in 1996. One of the earliest known pages was saved on May 10, 1996, at 2:08p.m. Internet Archive founders Brewster Kahle and Bruce Gilliat launched the Wayback Machine in San Francisco, California, in October 2001, primarily to address the problem of web co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Efficiency Video Coding
High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding (AVC, H.264, or MPEG-4 Part 10). In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD, and unlike the primarily 8-bit AVC, HEVC's higher fidelity Main 10 profile has been incorporated into nearly all supporting hardware. While AVC uses the integer discrete cosine transform (DCT) with 4×4 and 8×8 block sizes, HEVC uses integer DCT and DST transforms with varied block sizes between 4×4 and 32×32. The High Efficiency Image Format (HEIF) is based on HEVC. , HEVC is used by 43% of video developers, and is the second most widely used video coding format after AVC. Concept In most ways, HEVC is an extensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LCEVC
Low Complexity Enhancement Video Coding (LCEVC) is a ISO/IEC video coding standard developed by the Moving Picture Experts Group (MPEG) under the project name MPEG-5 Part 2 LCEVC. Concept LCEVC specifies an enhancement layer which, when combined with a base video encoded with a separate codec, produces an enhanced video stream. The base layer is decodable by a hardware decoder, and the enhancement layer is suitable for software processing implementation with sustainable power consumption. The enhancement layer provides improved features to existing codecs, such as compression capability extension and lower encoding/decoding complexity, for live streaming or broadcasting applications. LCEVC leverages a base video codec (e.g., AVC, HEVC, VP9, AV1, EVC or VVC) and employs an efficient low-complexity enhancement that adds up to two layers of encoded residuals, along with normative signalled up-sampling methods, that correct artifacts produced by the base video codec and add deta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalability
Scalability is the property of a system to handle a growing amount of work by adding resources to the system. In an economic context, a scalable business model implies that a company can increase sales given increased resources. For example, a package delivery system is scalable because more packages can be delivered by adding more delivery vehicles. However, if all packages had to first pass through a single warehouse for sorting, the system would not be as scalable, because one warehouse can handle only a limited number of packages. In computing, scalability is a characteristic of computers, networks, algorithms, networking protocols, programs and applications. An example is a search engine, which must support increasing numbers of users, and the number of topics it indexes. Webscale is a computer architectural approach that brings the capabilities of large-scale cloud computing companies into enterprise data centers. In mathematics, scalability mostly refers to closure u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
JPEG 2000
JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding their original JPEG standard (created in 1992), which is based on a discrete cosine transform (DCT), with a newly designed, wavelet-based method. The standardized filename extension is .jp2 for ISO/IEC 15444-1 conforming files and .jpx for the extended part-2 specifications, published as ISO/IEC 15444-2. The registered MIME types are defined in RFC 3745. For ISO/IEC 15444-1 it is image/jp2. JPEG 2000 code streams are Region of interest, regions of interest that offer several mechanisms to support spatial random access or region of interest access at varying degrees of granularity. It is possible to store different parts of the same picture using different quality. JPEG 2000 is a compression standard based on a discrete wavelet transform (D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hierarchical Modulation
Hierarchical modulation, also called layered modulation, is one of the signal processing techniques for multiplexing and modulating multiple data streams into one single symbol stream, where base-layer symbols and enhancement-layer symbols are synchronously overplayed before transmission. Hierarchical modulation is particularly used to mitigate the cliff effect in digital television broadcast, particularly mobile TV, by providing a (lower quality) fallback signal in case of weak signals, allowing graceful degradation instead of complete signal loss. It has been widely proven and included in various standards, such as DVB-T, MediaFLO, UMB (Ultra Mobile Broadband, a new 3.5th generation mobile network standard developed by 3GPP2), and is under study for DVB-H. Hierarchical modulation is also taken as one of the practical implementations of superposition precoding, which can help achieve the maximum sum rate of broadcast channels. When hierarchical-modulated signals are transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bitrate Peeling
Bitrate peeling is a technique used in Ogg Vorbis audio encoded streams, wherein a stream can be encoded at one bit rate, bitrate but can be served at that or any lower bitrate. The purpose is to provide access to the clip for people with slower Internet connections, and yet still allow people with faster connections to enjoy the higher quality content. The server (computing), server automatically chooses which stream to deliver to the user, depending on user's connection speed. , Ogg Vorbis bitrate peeling existed only as a concept as there was not yet an encoder capable of producing peelable datastreamBounties - XiphWiki Difference from other technologies The difference between SureStream and bitrate peeling is that SureStream is limited to only a handful of pre-defined bitrates, with significant difference between them, and SureStream encoded files are big because they contain all of the bitrates used, while bitrate peeling uses much smaller steps to change the available bitra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Network Graphics
Portable Network Graphics (PNG, officially pronounced , colloquially pronounced ) is a raster-graphics file format that supports lossless data compression. PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF) — unofficially, the initials PNG stood for the recursive acronym "PNG's not GIF". PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency), and full-color non-palette-based RGB or RGBA images. The PNG working group designed the format for transferring images on the Internet, not for professional-quality print graphics; therefore non-RGB color spaces such as CMYK are not supported. A PNG file contains a single image in an extensible structure of ''chunks'', encoding the basic pixels and other information such as textual comments and integrity checks documented in RFC 2083. PNG files use the file extension PNG or png and hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adam7 Algorithm
Adam7 is an interlacing algorithm for raster images, best known as the interlacing scheme optionally used in PNG images. An Adam7 interlaced image is broken into seven subimages, which are defined by replicating this 8×8 pattern across the full image. The subimages are then stored in the image file in numerical order. Adam7 uses seven passes and operates in both dimensions, compared to only four passes in the vertical dimension used by GIF. This means that an approximation of the entire image can be perceived much more quickly in the early passes, particularly if interpolation algorithms such as bicubic interpolation are used. History Adam7 is named after Adam M. Costello, who suggested the method on February 2, 1995, and after the seven steps involved. It is a rearrangement of this five-pass scheme that had earlier been proposed by Lee Daniel Crocker: Alternative speculative proposals at the time included square spiral interlacing and using Peano curves, but these w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
