Broadcasting Union. An organization comprising European broadcasters which co-ordinates the production and technical interests of European broadcasting. It has within its structure a number of committees which make recommendations to ITU-R. Website: www.ebu.ch

ECC Error Check and Correct

This system appends check data to a data packet in a communications channel or to a data block on a disk, which allows the receiving or reading system both to detect small errors in the data stream (caused by line noise or disk defects) and, provided they are not too long, to correct them. See also: Checksum, CRC

EDL Edit Decision List

A list of the decisions that describe a series of edits. EDLs can be produced during an off-line session and passed to the on-line suite to control the conforming of the final edit. In order to work across a range of equipment there are some widely adopted standards such as CMX 3400 and 3600. News journalists working with integrated news production systems can effectively create EDLs at their desktops. EDLs have been frozen in time and not kept pace with the continued development of post production. They do not carry information on DVEs, color correction, layering, keying etc., or carry other data about ownership, rights, etc. The development of AAF has filled these gaps. See also: AAF, Conform, OMFI

Effects (digital film) Digital effects processes have replaced the traditional film optical effects, and provide a lot more toward the completion of the project. Initially this was a separate digital operation aside from the mainstream photochemical work, but now, with DI becoming popular, it works alongside the digital workflow. Digital ‘optical’ film effects can retain their full image quality irrespective of the number of effects layers used, provided that the images remain uncompressed. The results can generally be seen immediately making the process interactive and able to quickly refine the result. All this can be seen in context with the rest of the movie, making for better continuity and less need of final grades.

Electronic program guides (EPG) DTV allows broadcasters to transmit electronic program guides. For many, this service is considered essential to keep viewers up to date with, and enable them to navigate between, the increased number of channels DTV brings. The program guide database allows a receiver to build an on-screen grid of program information and contains control information to ease navigation.

Embedded audio

Audio that is carried within an SDI or HD-SDI data stream – so simplifying cabling and routing. The standard (ANSI/SMPTE 272M-1994) allows embedding up to four groups each of four mono audio channels. See also: 1000/1001

Encryption The process of coding data so that a specific code or key is required to restore the original data. In conditional access broadcasts this is used to make transmissions secure from unauthorized reception and is often found on satellite or cable systems. Today, the growth of digital services to homes is in danger of being held back because of the content owners’ concern about piracy – digital copies being perfect clones of their valuable assets. Encryption and content security are vital to the growth of digital media markets.

ENG

Electronic News gathering. Term applied to a small portable outfit, with a broadcast quality TV camera, VTR and/or microwave link, usually used for news. The term was originated to distinguish between newsgathering on film and video tape (electronic). ENG refers to compatible studio or portable editing equipment. See also: ING

Entry point

A point in a coded bit stream from which a complete picture can be decoded without first having to store data from earlier pictures. In the MPEG-2 frame sequence this can only be at an I-frame – the only frames encoded with no reference to others.

EPK

Electronic Press Kit is a film deliverable usually consisting of film excerpts, trailers and interviews produced to help publicize a film.

Error detection, concealment and correction No means of digital recording is perfect. Both magnetic tape and disks suffer from a few marginal areas where recording and replay is difficult or even impossible. However the errors can be detected and some remedial action taken by concealment or correction. The former attempts to hide the problem by making it less noticeable whereas the latter actually corrects the error so that perfect data is output. When the recorded data is an image, an error can simply be concealed by using data from previous or following TV lines, fields or frames. The result is not guaranteed to be identical to the original but the process is relatively simple and, as important, quick. If the stored information is from a database, a computer program or from special image processing, then 100% accuracy of data is essential. This can be ensured by recording data in a manner where any errors can be detected and the correct data calculated from other information recorded for this purpose. This is error correction. A difference between computer systems and TV is that the latter is continuous and cannot wait for a late correction. Either the correct result must be ready in time or some other action taken – the show must go on – placing a very tight time constraint on any TV-rate error correction. In contrast, a computer can usually afford to wait a few milliseconds. Digital VTRs monitor the error rate and provide warnings of excessive errors, which although not immediately visible, may build up during multiple tape passes. Although error rates from disks are generally many times lower than those expected from digital videotape, they can still occur. To protect against this there is data redundancy and the replay of all data is checked. If an error is detected there is sufficient additional information stored to calculate and substitute the correct data. The total failure of a disk drive can be covered and the missing data re-generated and recorded onto a new replacement – making the system highly accurate and very secure. See also: ECC, Dylan, EXOR, RAID

Essence

The material that television programs are made of. In other words, the video, audio and any other material such as graphics and captions that are added to make up the final result. See also: AAF

Ethernet Ethernet is a form of Local Area Network (LAN) widely used for interconnecting computers and standardized in IEEE 802.3, allowing a wide variety of manufacturers to produce compatible interfaces and extend

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GLOSSARY OF TERMS