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Error Detection And Handling
In television technology, Error Detection and Handling (EDH) protocol is an optional but commonly used addition to the Standard Definition- Serial Digital Interface (SDI) standard. This protocol allows an SD-SDI receiver to verify that each field of video is received correctly. The SD-SDI transmitter calculates two CRC values for each video field—one corresponding to the active picture, and corresponding to the entire field (excluding the switching lines)--and places them in an EDH ancillary data packet. The EDH packet is inserted at a specific location in each field of video. The SD-SDI receiver also generates the same two CRC values for each field and compares them against the CRC values in the received EDH packet to determine if each field of video is received without errors. The EDH packet also contains bits to signal that a prior link in a broadcast or transmission chain contained an error; equipment which receives a video signal with an incorrect CRC, and retransmits the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Television
Television, sometimes shortened to TV, is a telecommunication medium for transmitting moving images and sound. The term can refer to a television set, or the medium of television transmission. Television is a mass medium for advertising, entertainment, news, and sports. Television became available in crude experimental forms in the late 1920s, but only after several years of further development was the new technology marketed to consumers. After World War II, an improved form of black-and-white television broadcasting became popular in the United Kingdom and the United States, and television sets became commonplace in homes, businesses, and institutions. During the 1950s, television was the primary medium for influencing public opinion.Diggs-Brown, Barbara (2011''Strategic Public Relations: Audience Focused Practice''p. 48 In the mid-1960s, color broadcasting was introduced in the U.S. and most other developed countries. The availability of various types of archival st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Redundancy Check
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on the remainder of a polynomial division of their contents. On retrieval, the calculation is repeated and, in the event the check values do not match, corrective action can be taken against data corruption. CRCs can be used for error correction (see bitfilters). CRCs are so called because the ''check'' (data verification) value is a ''redundancy'' (it expands the message without adding information) and the algorithm is based on ''cyclic'' codes. CRCs are popular because they are simple to implement in binary hardware, easy to analyze mathematically, and particularly good at detecting common errors caused by noise in transmission channels. Because the check value has a fixed length, the function that generates it is occasionally used as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancillary Data
Ancillary data is data that has been added to given data and uses the same form of transport. Common examples are cover art images for media files or streams, or digital data added to radio or television broadcasts. Television Ancillary data (commonly abbreviated as ANC data), in the context of television systems, refers to a means which by non-video information (such as audio, other forms of essence, and metadata) may be ''embedded'' within the serial digital interface. Ancillary data is standardized by SMPTE as ''SMPTE 291M: Ancillary Data Packet and Space Formatting''. Ancillary data can be located in non-picture portions of horizontal scan lines. This is known as horizontal ancillary data (HANC). Ancillary data can also be located in non-picture regions of the frame, This is known as vertical ancillary data (VANC). Technical details Location Ancillary data packets may be located anywhere within a serial digital data stream, with the following exceptions: * They should no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-definition Television
High-definition television (HD or HDTV) describes a television system which provides a substantially higher image resolution than the previous generation of technologies. The term has been used since 1936; in more recent times, it refers to the generation following standard-definition television (SDTV), often abbreviated to HDTV or HD-TV. It is the current de facto standard video format used in most broadcasts: terrestrial broadcast television, cable television, satellite television and Blu-ray Discs. Formats HDTV may be transmitted in various formats: * 720p (1280 horizontal pixels × 720 lines): 921,600 pixels * 1080i (1920×1080) interlaced scan: 1,036,800 pixels (~1.04 MP). * 1080p (1920×1080) progressive scan: 2,073,600 pixels (~2.07 MP). ** Some countries also use a non-standard CEA resolution, such as 1440×1080i: 777,600 pixels (~0.78 MP) per field or 1,555,200 pixels (~1.56 MP) per frame When transmitted at two megapixels per frame, HDTV provides about five times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SMPTE
The Society of Motion Picture and Television Engineers (SMPTE) (, rarely ), founded in 1916 as the Society of Motion Picture Engineers or SMPE, is a global professional association of engineers, technologists, and executives working in the media and entertainment industry. As an internationally recognized standards organization, SMPTE has published more than 800 technical standards and related documents for broadcast, filmmaking, digital cinema, audio recording, information technology (IT), and medical imaging. SMPTE also publishes the ''SMPTE Motion Imaging Journal'', provides networking opportunities for its members, produces academic conferences and exhibitions, and performs other industry-related functions. SMPTE membership is open to any individual or organization with an interest in the subject matter. In the US, SMPTE is a 501(c)(3) organization, 501(c)3 non-profit charitable organization. History The Motion Picture and Television Engineers was founded in 1913 by Cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Error Detection And Correction
In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communication channels. Many communication channels are subject to channel noise, and thus errors may be introduced during transmission from the source to a receiver. Error detection techniques allow detecting such errors, while error correction enables reconstruction of the original data in many cases. Definitions ''Error detection'' is the detection of errors caused by noise or other impairments during transmission from the transmitter to the receiver. ''Error correction'' is the detection of errors and reconstruction of the original, error-free data. History In classical antiquity, copyists of the Hebrew Bible were paid for their work according to the number of stichs (lines of verse). As the prose books of the Bible were hardly ever ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using digital encoding, in contrast to the earlier analog television technology which used analog signals. At the time of its development it was considered an innovative advancement and represented the first significant evolution in television technology since color television in the 1950s. Modern digital television is transmitted in high-definition television (HDTV) with greater resolution than analog TV. It typically uses a widescreen aspect ratio (commonly 16:9) in contrast to the narrower format of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same bandwidth as a single analog channel, and provides many new features that analog television cannot. A transition from analog to digital broadcasting began around 2000. Different digital television broadcasting standards have been adopted in different parts of the world; below are the more widel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
