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Linear Timecode
Linear (or Longitudinal) Timecode (LTC) is an encoding of SMPTE timecode data in an audio signal, as defined in SMPTE 12M specification. The audio signal is commonly recorded on a VTR track or other storage media. The bits are encoded using the biphase mark code (also known as ''FM''): a 0 bit has a single transition at the start of the bit period. A 1 bit has two transitions, at the beginning and middle of the period. This encoding is self-clocking. Each frame is terminated by a ' sync word' which has a special predefined sync relationship with any video or film content. A special bit in the linear timecode frame, the ''biphase mark correction'' bit, ensures that there are an even number of AC transitions in each timecode frame. The sound of linear timecode is a jarring and distinctive noise and has been used as a sound-effects shorthand to imply ''telemetry'' or ''computers''. Generation and Distribution In broadcast video situations, the LTC generator should be tied int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encoding
In communications and information processing, code is a system of rules to convert information—such as a letter, word, sound, image, or gesture—into another form, sometimes shortened or secret, for communication through a communication channel or storage in a storage medium. An early example is an invention of language, which enabled a person, through speech, to communicate what they thought, saw, heard, or felt to others. But speech limits the range of communication to the distance a voice can carry and limits the audience to those present when the speech is uttered. The invention of writing, which converted spoken language into visual symbols, extended the range of communication across space and time. The process of encoding converts information from a source into symbols for communication or storage. Decoding is the reverse process, converting code symbols back into a form that the recipient understands, such as English or/and Spanish. One reason for coding is to e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Indian Standards
The Bureau of Indian Standards (BIS) is the National Standards Body of India under Department of Consumer affairs, Ministry of Consumer Affairs, Food & Public Distribution, Government of India. It is established by the Bureau of Indian Standards Act, 2016 which came into effect on 12 October 2017. The Minister in charge of the Ministry or Department having administrative control of the BIS is the ex-officio President of the BIS. BIS has 500 plus scientific officers working as Certification Officers, Member secretaries of technical committees and lab OIC's. The organisation was formerly the Indian Standards Institution (ISI), set up under the Resolution of the Department of Industries and Supplies No. 1 Std.(4)/45, dated 3 September 1946. The ISI was registered under the Societies Registration Act, 1860. A new Bureau of Indian standards (BIS) Act 2016 which was notified on 22 March 2016, has been brought into force with effect from 12 October 2017. The Act establishes the Burea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the latter half of the 19th century after commercialization of the electric telegraph, the telephone, and electrical power generation, distribution, and use. Electrical engineering is now divided into a wide range of different fields, including computer engineering, systems engineering, power engineering, telecommunications, radio-frequency engineering, signal processing, instrumentation, photovoltaic cells, electronics, and optics and photonics. Many of these disciplines overlap with other engineering branches, spanning a huge number of specializations including hardware engineering, power electronics, electromagnetics and waves, microwave engineering, nanotechnology, electrochemistry, renewable energies, mechatronics/control, and ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broadcast Engineering
Broadcast engineering is the field of electrical engineering, and now to some extent computer engineering and information technology, which deals with radio and television broadcasting. Audio engineering and RF engineering are also essential parts of broadcast engineering, being their own subsets of electrical engineering. Broadcast engineering involves both the studio and transmitter aspects (the entire airchain), as well as remote broadcasts. Every station has a broadcast engineer, though one may now serve an entire station group in a city. In small media markets the engineer may work on a contract basis for one or more stations as needed. Duties Modern duties of a broadcast engineer include maintaining broadcast automation systems for the studio and automatic transmission systems for the transmitter plant. There are also important duties regarding radio towers, which must be maintained with proper lighting and painting. Occasionally a station's engineer must deal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biphase Mark Code
Differential Manchester encoding (DM) is a line code in digital frequency modulation in which data and clock signals are combined to form a single two-level self-synchronizing data stream. In various specific applications, this method is also called by various other names, including biphase mark code (CC), F2F (frequency/double frequency), Aiken biphase, and conditioned diphase.US DoD: ''Design handbook for fiber optic communications systems, Military handbook.'' Dept. of Defense, 1985, p. 65. Definition Differential Manchester encoding is a differential encoding technology, using the presence or absence of transitions to indicate logical value. An improvement to Manchester coding which is a special case of binary phase-shift keying, it is not necessary to know the initial polarity of the transmitted message signal, because the information is not represented by the absolute voltage levels but by their transitions. Differential Manchester encoding has the following advantag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manchester Code
In telecommunication and data storage, Manchester code (also known as phase encoding, or PE) is a line code in which the encoding of each data bit is either low then high, or high then low, for equal time. It is a self-clocking signal with no DC component. Consequently, electrical connections using a Manchester code are easily galvanically isolated. Manchester code derives its name from its development at the University of Manchester, where the coding was used for storing data on the magnetic drums of the Manchester Mark 1 computer. Manchester code was widely used for magnetic recording on 1600 bpi computer tapes before the introduction of 6250 bpi tapes which used the more efficient group-coded recording. Manchester code was used in early Ethernet physical layer standards and is still used in consumer IR protocols, RFID and near-field communication. Features Manchester coding is a special case of binary phase-shift keying (BPSK), where the data controls the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rewritable Consumer Timecode
The Rewriteable Consumer Timecode (RCTC, RC Timecode, or RC Time Code) is a nearly frame accurate timecode method developed by Sony for 8mm and Hi8 analog tape formats.Sony CCD-V801 Manual Page 9 covers RC Timecode and Data Code formats. The RC timecode is written by the video camera directly to analog tape tracks and records the hour, minute, second and frame for each frame of video recorded to tape. Officially, RCTC is accurate to within ±2 to 5 frames. The RC timecode information is written in a separate area of the track so as to not disturb the audio or video information recorded on the tape. The RC timecode was used in conjunction with the datacode to record date, time and frame information directly to the 8mm tape tracks. On several video camera models, |
AES-EBU Embedded Timecode
AES3 is a standard for the exchange of digital audio signals between professional audio devices. An AES3 signal can carry two channels of pulse-code-modulated digital audio over several transmission media including balanced lines, unbalanced lines, and optical fiber. AES3 was jointly developed by the Audio Engineering Society (AES) and the European Broadcasting Union (EBU) and so is also known as AES/EBU. The standard was first published in 1985 and was revised in 1992 and 2003. AES3 has been incorporated into the International Electrotechnical Commission's standard IEC 60958, and is available in a consumer-grade variant known as S/PDIF. History and development The development of standards for digital audio interconnect for both professional and domestic audio equipment, began in the late 1970s in a joint effort between the Audio Engineering Society and the European Broadcasting Union, and culminated in the publishing of AES3 in 1985. The AES3 standard has been revised in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CTL Timecode
Control track longitudinal timecode, or CTL timecode, developed by JVC in the early 1990s, is a unique technique for embedding, or ''striping'', reference SMPTE timecode onto a videotape. Similar to the way VITC timecode is embedded in the vertical interval area of a video signal, CTL timecode embeds SMPTE timecode in the '' control track'' area of helical scan video recordings. The advantage of both VITC and CTL timecode is that an audio track does not have to be sacrificed for linear timecode. Though a very effective technology, and still probably in limited use today, CTL timecode never really caught on. JVC is apparently the only manufacturer that included CTL timecode capability in their video products, and this was limited to select professional S-VHS equipment. When it was introduced, there was much negativity about CTL timecode, because people misunderstood how it worked. Many incorrectly assumed that CTL timecode was nothing more than a ''control track pulse'' signal. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIDI Timecode
MIDI time code (MTC) embeds the same timing information as standard SMPTE timecode as a series of small 'quarter-frame' MIDI messages. There is no provision for the user bits in the standard MIDI time code messages, and SysEx messages are used to carry this information instead. The quarter-frame messages are transmitted in a sequence of eight messages, thus a complete timecode value is specified every two frames. If the MIDI data stream is running close to capacity, the MTC data may arrive a little behind schedule which has the effect of introducing a small amount of jitter. In order to avoid this it is ideal to use a completely separate MIDI port for MTC data. Larger full-frame messages, which encapsulate a frame worth of timecode in a single message, are used to locate to a time while timecode is not running. Unlike standard SMPTE timecode, MIDI timecode's quarter-frame and full-frame messages carry a two-bit flag value that identifies the rate of the timecode, specifying it a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burnt-in Timecode
Burnt-in timecode (often abbreviated to BITC by analogy to VITC) is a human-readable on-screen version of the timecode information for a piece of material superimposed on a video image. BITC is sometimes used in conjunction with "real" machine-readable timecode, but more often used in copies of original material on to a non-broadcast format such as VHS, so that the VHS copies can be traced back to their master tape and the original time codes easily located. Many professional VTRs can "burn" (overlay) the tape timecode onto one of their outputs. This output (which usually also displays the setup menu or on-screen display) is known as the ''super out'' or ''monitor out''. The ''character'' switch or menu item turns this behaviour on or off. The ''character'' function is also used to display the timecode on the preview monitors in linear editing suites. Videotapes that are recorded with timecode numbers overlaid on the video are referred to as ''window dubs'', named after the "w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertical Interval Timecode
Vertical Interval Timecode (VITC, pronounced "vitsee") is a form of SMPTE timecode encoded on one scan line in a video signal. These lines are typically inserted into the vertical blanking interval of the video signal. With one exception, VITC contains the same payload as SMPTE linear timecode (LTC), embedded in a new frame structure with extra synchronization bits and an error-detection checksum. The exception is that VITC is encoded twice per interlaced video frame, once in each field, and one additional bit (the "field flag") is used to distinguish the two fields. A video frame may contain more than one VITC code if necessary, recorded on different lines. This is often used in production, where different entities may want to encode different sets of time-code metadata on the same tape. As a practical matter, VITC can be more 'frame-accurate' than LTC, particularly at very slow tape speeds on analog formats. LTC readers can lose track of code at slow jog speeds whereas VITC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
