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Windows Media Video
Windows Media Video (WMV) is a series of video codecs and their corresponding video coding formats developed by Microsoft. It is part of the Windows Media framework. WMV consists of three distinct codecs: the original video compression technology, known as ''WMV'', originally designed for Internet streaming applications as a competitor to RealVideo, and ''WMV Screen'' and ''WMV Image'' compression technologies, which cater to specialized content. After standardization by the Society of Motion Picture and Television Engineers (SMPTE), WMV version 9 was adapted for physical-delivery formats such as and Blu-ray Disc and became known as . Microsoft also developed a digital container format called Advanced Systems Format to store video encoded by Windows Media Video. History In 2003, Microsoft drafted a video compression specification based on its WMV 9 format and submitted it to SMPTE for standardization. The standard was officially approved in March 2006 as SMPTE 421M, better kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Codec
A video codec is software or Computer hardware, hardware that data compression, compresses and Uncompressed video, decompresses digital video. In the context of video compression, ''codec'' is a portmanteau of ''encoder'' and ''decoder'', while a device that only compresses is typically called an ''Encoder (digital), encoder'', and one that only decompresses is a ''decoder''. The compressed data format usually conforms to a standard video coding format. The compression is typically lossy, meaning that the compressed video lacks some information present in the original video. A consequence of this is that decompressed video has lower quality than the original, uncompressed video because there is insufficient information to accurately reconstruct the original video. There are complex relationships between the video quality, the amount of data used to represent the video (determined by the bit rate), the complexity of the encoding and decoding algorithms, sensitivity to data losses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Encryption Standard
The Data Encryption Standard (DES ) is a symmetric-key algorithm for the encryption of digital data. Although its short key length of 56 bits makes it too insecure for modern applications, it has been highly influential in the advancement of cryptography. Developed in the early 1970s at IBM and based on an earlier design by Horst Feistel, the algorithm was submitted to the National Bureau of Standards (NBS) following the agency's invitation to propose a candidate for the protection of sensitive, unclassified electronic government data. In 1976, after consultation with the National Security Agency (NSA), the NBS selected a slightly modified version (strengthened against differential cryptanalysis, but weakened against brute-force attacks), which was published as an official Federal Information Processing Standard (FIPS) for the United States in 1977. The publication of an NSA-approved encryption standard led to its quick international adoption and widespread academic scrutiny. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Average Bit Rate
In ordinary language, an average is a single number or value that best represents a set of data. The type of average taken as most typically representative of a list of numbers is the arithmetic mean the sum of the numbers divided by how many numbers are in the list. For example, the mean or average of the numbers 2, 3, 4, 7, and 9 (summing to 25) is 5. Depending on the context, the most representative statistic to be taken as the average might be another measure of central tendency, such as the mid-range, median, mode or geometric mean. For example, the average personal income is often given as the median the number below which are 50% of personal incomes and above which are 50% of personal incomes because the mean would be higher by including personal incomes from a few billionaires. General properties If all numbers in a list are the same number, then their average is also equal to this number. This property is shared by each of the many types of average. Another universal p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Bit Rate
Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a higher bitrate (and therefore more storage space) to be allocated to the more complex segments of media files while less space is allocated to less complex segments. The average of these rates can be calculated to produce an average bitrate for the file. MP3, WMA and AAC audio files can optionally be encoded in VBR, while Opus and Vorbis are encoded in VBR by default. Variable bit rate encoding is also commonly used on MPEG-2 video, MPEG-4 Part 2 video ( Xvid, DivX, etc.), MPEG-4 Part 10/H.264 video, Theora, Dirac and other video compression formats. Additionally, variable rate encoding is inherent in lossless compression schemes such as FLAC and Apple Lossless. Advantages and disadvantages of VBR The advantages of VBR a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bit Stream
A bitstream (or bit stream), also known as binary sequence, is a sequence of bits. A bytestream is a sequence of bytes. Typically, each byte is an 8-bit quantity, and so the term octet stream is sometimes used interchangeably. An octet may be encoded as a sequence of 8 bits in multiple different ways (see bit numbering) so there is no unique and direct translation between bytestreams and bitstreams. Bitstreams and bytestreams are used extensively in telecommunications and computing. For example, synchronous bitstreams are carried by SONET, and Transmission Control Protocol transports an asynchronous bytestream. Relationship to bytestreams In practice, bitstreams are not used directly to encode bytestreams; a communication channel may use a signalling method that does not directly translate to bits (for instance, by transmitting signals of multiple frequencies) and typically also encodes other information such as framing and error correction together with its data. Exam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-4 Part 2
MPEG-4 Part 2, MPEG-4 Visual (formally International Organization for Standardization, ISO/International Electrotechnical Commission, IEC 14496-2) is a video encoding specification designed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC family of encoders. It uses block-wise motion compensation and a discrete cosine transform (DCT), similar to previous encoders such as MPEG-1#Part 2: Video, MPEG-1 Part 2 and H.262/MPEG-2 Part 2. Examples of popular implementations of the encoder specifications include DivX, Xvid and Nero Digital. MPEG-4 Part 2 is H.263 compatible in the sense that a basic H.263 bitstream is correctly decoded by an MPEG-4 Video decoder. (MPEG-4 Video decoder is natively capable of decoding a basic form of H.263.) In MPEG-4 Visual, there are two types of video object layers: the video object layer that provides full MPEG-4 functionality, and a reduced functionality video object layer, the video object layer with short headers (which prov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Video Standard
Audio Video Coding Standard (AVS) refers to the digital audio and digital video series compression standard formulated by the Audio and Video coding standard workgroup of China. Work began in 2002, and three generations of standards were published. The first generation AVS standard includes "Information Technology, Advanced Audio Video Coding, Part 2: Video" (AVS1) and "Information Technology, Advanced Audio Video Coding Part 16: Radio Television Video" (AVS+.) For the second generation, referred to as AVS2, the primary application target was ultra-high-definition television video, supporting the efficient compression of ultra-high-resolution ( 4K and above), high-dynamic-range videos, and was published as IEEE international standard IEEE 1857.4. An industry alliance was established to develop and promote AVS standards. A patent pool charges a small royalty for terminal products (like TVs,) excluding content providers and operators. The AVS3 codec was added to DVB's media deliv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MPEG-4 AVC
Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distribution of video content, used by 84–86% of video industry developers . It supports a maximum resolution of 8K UHD. The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower bit rates than previous standards (i.e., half or less the bit rate of MPEG-2, H.263, or MPEG-4 Part 2), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement. This was achieved with features such as a reduced-complexity integer discrete cosine transform (integer DCT), variable block-size segmentation, and multi-picture inter-picture prediction. An additional goal was to provide enough flexibility to allow the standard to be appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video Compression Format
A video coding format (or sometimes video compression format) is a content representation format of digital video content, such as in a data file or bitstream. It typically uses a standardized video compression algorithm, most commonly based on discrete cosine transform (DCT) coding and motion compensation. A computer software or hardware component that compresses or decompresses a specific video coding format is a video codec. Some video coding formats are documented by a detailed technical specification document known as a video coding specification. Some such specifications are written and approved by standardization organizations as technical standards, and are thus known as a video coding standard. There are ''de facto'' standards and formal standards. Video content encoded using a particular video coding format is normally bundled with an audio stream (encoded using an audio coding format) inside a multimedia container format such as AVI, MP4, FLV, RealMedia, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Video Resolutions 2
Common may refer to: As an Irish surname, it is anglicised from Irish Gaelic surname Ó Comáin. Places * Common, a townland in County Tyrone, Northern Ireland * Boston Common, a central public park in Boston, Massachusetts * Cambridge Common, common land area in Cambridge, Massachusetts * Clapham Common, originally common land, now a park in London, UK * Common Moss, a townland in County Tyrone, Northern Ireland * Lexington Common, a common land area in Lexington, Massachusetts * Salem Common Historic District, a common land area in Salem, Massachusetts People * Common (rapper) (born 1972), American hip hop artist, actor, and poet * Andrew Ainslie Common (1841–1903), English amateur astronomer * Andrew Common (1889–1953), British shipping director * John Common, American songwriter, musician and singer * Thomas Common (1850–1919), Scottish translator and literary critic Arts, entertainment, and media * ''Common'' (film), a 2014 BBC One film, written by Jimmy McGove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Video For Windows
Video for Windows was a suite of video-playing and editing software introduced by Microsoft in 1992. A runtime version for viewing videos only was made available as a free add-on to Windows 3.1, which then became an integral component of Windows 95. Video for Windows was mostly replaced by the July 1996 release of ActiveMovie, later known as DirectShow. Overview Video for Windows was first introduced in November 1992. It was developed as a reaction to Apple Computer's QuickTime technology, which added digital video to the Macintosh platform. Costing around $200, the product included video editing software, editing and transcoding, encoding programs for use with video input boards. A runtime version for viewing videos only was also made available as a free add-on to Windows 3.1 and Windows 3.11; it then became an integral component of Windows 95 and later. Like QuickTime, Video for Windows had three key aspects: Audio Video Interleave (AVI), a container file format designed to sto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Video Interleave
Audio Video Interleave (also Audio Video Interleaved and known by its initials and filename extension AVI, usually pronounced ) is a proprietary multimedia container format and Windows standard introduced by Microsoft in November 1992 as part of its Video for Windows software. AVI files can contain both audio and video data in an uncompressed 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. Codecs popularly used for AVI include DivX and Xvid, although many other codecs can also be contained in an AVI file. Many AVI files 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. In 2010 the US government's National Archives and Records Administration defined AVI as the official wrapper for preserving digital video. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
