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Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
System developed by Comstat Corp. for satellite links.
Industry:Entertainment
General Instrument’s latest distribution system and is the standard for 4DTV product. DC2 uses standard MPEG-2 video encoding, but just about everything else in this “standard” is unique to DC2. For example, DVB/MPEG-2 uses Musicam for audio whereas DC2 uses Dolby AC-3. Despite using the same video standard, DVB/MPEG-2 and DC2 signals are totally incompatible and no receiver can currently receive both.
Industry:Entertainment
DVD is the outcome of a battle between two formerly rivalling camps of optical data discs, each supporting the MMCD (Multimedia CD) and the SD (Super Density) formats. The MMDC and SD proposals featured different error correction, modulation, disc structure, etc., but targeted identical markets. Wisely, the two camps merged and agreed on a third format, that was a mix of the other two. The DVD, initially, addressed only movie player applications, but the nature of the medium has attracted other applications, too. In light of the increasing number of possible applications of the new disc format, it was therefore renamed to Digital Versatile Disc. The DVD consortium intends to position the DVD as a high-capacity, multimedia storage medium. A total of nine working groups in the consortium elaborate on various technology specific topics, such as video, ROM applications, audio-only systems, and copyprotection.
The movie player application remains the DVD’s reason for being, but there’s a chance that the DVD may also take over a huge share of the CD-ROM market. The promoters of the format agreed in December 1995 on a core set of specifications. The system operates at an average data rate of 4.69 Mbit/s and features 4.7 GB data capacity, which allows MPEG-2 coding of movies, or which may be used for a high-resolution music disc. For the PAL and NTSC specifications of the DVD, different audio coding has been chosen to obey market patterns. For the NTSC version, the Dolby AC-3 coding will be mandatory, with MPEG audio as an option, whereas the opposite is true for PAL and SECAM markets.
Industry:Entertainment
Patented circuitry within the Vista switcher, which allows the insertion of a digital effects device within the architecture of the switcher.
This allows multi-channels of digital effects to be used on a single M/E, which would otherwise require 3 M/Es.
Industry:Entertainment
A video signal represented by computer-readable binary numbers that describe colours and brightness levels.
Industry:Entertainment
The key channel processor, providing a separate channel specifically for black and white key signals that processes and manipulates an external key signal in the same way as source video in 3D space.
Industry:Entertainment
A) A system developed in Europe for digital television transmission, originally for standard definition only, though high-definition modes have now been added to the specification.
DVB defines a complete system for terrestrial, satellite, and cable transmission.
Like the ATSC system, DVB uses MPEG-2 compression for video, but it uses MPEG audio compression and COFDM modulation for terrestrial transmission. b) At the end of 1991, the European Launching Group (ELG) was formed to spearhead the development of digital TV in Europe. During 1993, a Memorandum of Understanding was drafted and signed by the ELG participants, which now included manufacturers, regulatory bodies and other interest groups. At the same time, the ELG became Digital Video Broadcasting (DVB). The TV system provided by the DVB is based on MPEG-2 audio and video coding, and DVB has added various elements not included in the MPEG specification, such as modulation, scrambling, and information systems. The specifications from DVB are offered to either ETSI or CENELEC for standardization, and to the ITU.
Industry:Entertainment
Sign or symbol used to convey a specific quantity of information either by itself or with other numbers of its set: 2, 3, 4, and 5 are digits.
The base or radix must be specified and each digit’s value assigned.
Industry:Entertainment
A) Tape width is 1/4", metal particle formula.
The source and reconstructed video sample rate is similar to that of CCIR-601, but with additional chrominance subsampling (4:1:1 in the case of 30 Hz and 4:2:0 in the case of 25 Hz mode). For 30 frames/sec, the active source rate is 720 pixels/lines x 480 lines/frame x 30 frames/sec x 1.5 samples/pixel average x 8 samples/pixel = ~124 Mbit/sec. A JPEG-like still image compression algorithm (with macroblock adaptive quantization) applied with a 5:1 reduction ratio (target bit rate of 25 Mbit/sec) averaged over a period of roughly 100 microseconds (100 microseconds is pretty small compared to MPEG’s typical 1/4 second time average!) b) A digital tape recording format using approximately 5:1 compression to produce near-Betacam quality on a very small cassette. Originated as a consumer product, but being used professionally as exemplified by Panasonic’s variation, DVC-Pro.
Industry:Entertainment
A) Having discrete states. Most digital logic is binary, with two states (on or off). b) A discontinuous electrical signal that carries information in binary fashion. Data is represented by a specific sequence of off-on electrical pulses. A method of representing data using binary numbers. An analogue signal is converted to digital by the use of an analog-to-digital (A/D) converter chip by taking samples of the signal at a fixed time interval (sampling frequency). Assigning a binary number to these samples, this digital stream is then recorded onto magnetic tape. Upon playback, a digital-to-analog (D/A) converter chip reads the binary data and reconstructs the original analogue signal. This process virtually eliminates generation loss as every digital-to-digital copy is theoretically an exact duplicate of the original allowing multi-generational dubs to be made without degradation.
In actuality of course, digital systems are not perfect and specialised hardware/software is used to correct all but the most severe data loss.
Digital signals are virtually immune to noise, distortion, crosstalk, and other quality problems. In addition, digitally based equipment often offers advantages in cost, features, performance, and reliability when compared to analogue equipment.
Industry:Entertainment
