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Audio To Video Synchronization
Audio-to-video synchronization (AV synchronization, also known as lip sync, or by the lack of it: lip-sync error, lip flap) refers to the relative timing of audio (sound) and video (image) parts during creation, post-production (mixing), transmission, reception and play-back processing. AV synchronization is relevant in television, videoconferencing, or film. In industry terminology, the lip-sync error is expressed as the amount of time the audio departs from perfect synchronization with the video where a positive time number indicates the audio leads the video and a negative number indicates the audio lags the video. This terminology and standardization of the numeric lip-sync error is utilized in the professional broadcast industry as evidenced by the various professional papers, standards such as ITU-R BT.1359-1, and other references below. Digital or analog audio video streams or video files usually contain some sort of synchronization mechanism, either in the form of int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lip Sync
Lip sync or lip synch (pronounced , like the word ''sink'', despite the Hard and soft C, spelling of the participial forms ''synced'' and ''syncing''), short for lip synchronization, is a technical term for matching a Speech, speaking or singing person's lip movements with sung or spoken vocals. Audio for lip syncing is generated through the sound reinforcement system in a live performance or via television, computer, cinema Loudspeaker, speakers, or other forms of Audio signal, audio output. The term can refer to any of a number of different techniques and processes, in the context of live performances and audiovisual recordings. In Filmmaking, film production, lip syncing is often part of the post-production phase. Dubbing foreign-language films and making Animation, animated characters appear to speak both require elaborate lip syncing. Many video games make extensive use of lip-synced sound files to create an immersive environment in which on-screen characters appear to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcasting
Broadcasting is the data distribution, distribution of sound, audio audiovisual content to dispersed audiences via a electronic medium (communication), mass communications medium, typically one using the electromagnetic spectrum (radio waves), in a :wikt:one-to-many, one-to-many model. Broadcasting began with AM radio, which came into popular use around 1920 with the spread of vacuum tube radio transmitters and radio receiver, receivers. Before this, most implementations of electronic communication (early radio, telephone, and telegraph) were wikt:one-to-one, one-to-one, with the message intended for a single recipient. The term ''broadcasting'' evolved from its use as the agricultural method of sowing seeds in a field by casting them broadly about. It was later adopted for describing the widespread distribution of information by printed materials or by telegraph. Examples applying it to "one-to-many" radio transmissions of an individual station to multiple listeners appeared as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Displays
A plasma display panel is a type of flat-panel display that uses small cells containing Plasma (physics), plasma: Ionization, ionized gas that responds to electric fields. Plasma televisions were the first large (over diagonal) flat-panel displays to be released to the public. Until about 2007, plasma displays were commonly used in large televisions. By 2013, they had lost nearly all market share due to competition from low-cost liquid-crystal displays (LCDs). Manufacturing of plasma displays for the United States retail market ended in 2014, and manufacturing for the Chinese market ended in 2016. Plasma displays are obsolete, having been superseded in most if not all aspects by OLED displays. Competing display technologies include cathode-ray tube (CRT), organic light-emitting diode (OLED), CRT projectors, AMLCD, digital light processing (DLP), SED-tv, LED display, field emission display (FED), and quantum dot display (QLED). History Early development Kálmán Tihanyi, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixelated
Pixelization (in British English pixelisation) or mosaic processing is any technique used in editing images or video, whereby an image is blurred by displaying part or all of it at a markedly lower resolution. It is primarily used for censorship. The effect is a standard graphics filter, available in all but the most basic bitmap graphics editors. In media Pixelization has also been used for artistic effect, notably in the art print ''The Wave of the Future'', a reinterpretation of Katsushika Hokusai's ''The Great Wave off Kanagawa''. In this updated print, the image of the large ocean wave shifts from the traditional style of the Japanese woodcut print to a pixelized image and finally to a wireframe model computer graphics image. ''Westworld'' (1973) was the first feature film to use digital image processing to pixelize photography to simulate an android's point of view. The 2010 third-person cover shooter Kane & Lynch 2: Dog Days also used pixelization for artistic purpose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Television
Digital television (DTV) is the transmission of television signals using Digital signal, 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 (4:3) of analog TV. It makes more economical use of scarce radio spectrum space; it can transmit up to seven channels in the same Bandwidth (signal processing), bandwidth as a single analog channel, and provides many new features that analog television cannot. A digital television transition, transition from analog to digital broadcasting began around 2000. Different digital television broadcasting st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Projectionist
A projectionist is a person who operates a movie projector, particularly as an employee of a movie theater. Projectionists are also known as "operators". Historical background N.B. The dates given in the subject headings are approximate. Early cinema (1895–1915) The need for professional projectionists arose from the commercial showing of movie films to the general public in buildings specifically designed for the purpose or using variety theatres as part of the "bill", which began towards the end of the first decade of the twentieth century. Before the emergence of purpose-built movie theaters, film projectors in venues such as Funfair, fairgrounds, music halls and Nickelodeon (movie theatre), Nickelodeons were usually operated by a showman or presenter, in the same way as a magic lantern, lanternist. The light source for most projectors in the early period was limelight, which did not require an electricity supply. Between approximately 1905 and 1915, two factors combined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Movie Projector
A movie projector (or film projector) is an optics, opto-mechanics, mechanical device for displaying Film, motion picture film by projecting it onto a movie screen, screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras. Modern movie projectors are specially built video projectors (see also digital cinema). Many projectors are specific to a particular film gauge and not all movie projectors are film projectors since the use of film is required. Predecessors The main precursor to the movie projector was the magic lantern. In its most common setup it had a concave mirror behind a light source to help direct as much light as possible through a painted glass picture slide and a lens, out of the lantern onto a screen. Simple mechanics to have the painted images moving were probably implemented since Christiaan Huygens introduced the apparatus around 1659. Initially, candles and oil lamps were used, but oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RTP Control Protocol
The RTP Control Protocol (RTCP) is a binary-encoded out-of-band signaling protocol that functions alongside the Real-time Transport Protocol (RTP). RTCP provides statistics and control information for an RTP session. It partners with RTP in the delivery and packaging of multimedia data but does not transport any media data itself. The primary function of RTCP is to provide feedback on the quality of service (QoS) in media distribution by periodically sending statistics information such as transmitted octet and packet counts, packet loss, packet delay variation, and round-trip delay time to participants in a streaming multimedia session. An application may use this information to control quality of service parameters, perhaps by limiting flow, or using a different codec. Protocol functions Typically RTP will be sent on an even-numbered UDP port, with RTCP messages being sent over the next higher odd-numbered port. RTCP itself does not provide any flow encryption or authen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RTCP
The RTP Control Protocol (RTCP) is a binary-encoded out-of-band signaling protocol that functions alongside the Real-time Transport Protocol (RTP). RTCP provides statistics and control information for an RTP session. It partners with RTP in the delivery and packaging of multimedia data but does not transport any media data itself. The primary function of RTCP is to provide feedback on the quality of service (QoS) in media distribution by periodically sending statistics information such as transmitted octet and packet counts, packet loss, packet delay variation, and round-trip delay time to participants in a streaming multimedia session. An application may use this information to control quality of service parameters, perhaps by limiting flow, or using a different codec. Protocol functions Typically RTP will be sent on an even-numbered UDP port, with RTCP messages being sent over the next higher odd-numbered port. RTCP itself does not provide any flow encryption or auth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Real-time Transport Protocol
The Real-time Transport Protocol (RTP) is a network protocol for delivering audio and video over IP networks. RTP is used in communication and entertainment systems that involve streaming media, such as telephony, video teleconference applications including WebRTC, television services and web-based push-to-talk features. RTP typically runs over User Datagram Protocol (UDP). RTP is used in conjunction with the RTP Control Protocol (RTCP). While RTP carries the media streams (e.g., audio and video), RTCP is used to monitor transmission statistics and quality of service (QoS) and aids synchronization of multiple streams. RTP is one of the technical foundations of voice over IP and in this context is often used in conjunction with a signaling protocol such as the Session Initiation Protocol (SIP) which establishes connections across the network. RTP was developed by the Audio-Video Transport Working Group of the Internet Engineering Task Force (IETF) and first published i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Format Conversion
Data conversion is the conversion of computer data from one format to another. Throughout a computer environment, data is encoded in a variety of ways. For example, computer hardware is built on the basis of certain standards, which requires that data contains, for example, parity bit checks. Similarly, the operating system is predicated on certain standards for data and file handling. Furthermore, each computer program handles data in a different manner. Whenever any one of these variables is changed, data must be converted in some way before it can be used by a different computer, operating system or program. Even different versions of these elements usually involve different data structures. For example, the changing of bits from one format to another, usually for the purpose of application interoperability or of the capability of using new features, is merely a data conversion. Data conversions may be as simple as the conversion of a text file from one character encoding sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
