Glossary

Audio CD recorders (and also PCs with CD writers) now use two types of blank CD to record sound. CD-Recordable was developed first and is a 'write once' system. That means you cannot erase so if you make a mistake while recording, that's it! When blank CD-Rs first appeared on the market in the late 1980s, they cost around ?16 for a 60-minute disc and the recorders were ?3000 plus! Today, a blank CD-R which offers over 70 minutes of record time can be had for around ?1 and recorders are a fraction of the original price. While most modern CD players can handle homemade recordings on CD-R, some older models may not be able to cope with such discs.

Unlike CD-Rs, CD-RWs are Re-Writable so they can be erased and recorded over again. Great for making the perfect music CD. But take care - not all CD players can playback recordings made on CD-RWs as the format's disc structure differs slightly from conventional audio CDs.

A typical receiver's amplifier may not be sufficient to handle extremely high peaks, particularly those needed for the kinds of explosive effects present in movie soundtracks. The Class H+ amplifier has been developed to provide extra 'headroom' and therefore prevents distortion at high volume. It is also very efficient, therefore creating less heat.

There are two types of cables and sockets used to connect digital audio equipment. Optical cables use thin fibre optic leads. Coaxial (or electrical) cables are thicker and the sockets look the same as conventional RCA connectors. Arguably, coaxial digital cables offer better performance but optical ones can be easier to use and hide.

A circuit or software module used to compress and/or decompress data. When an analog video signal is converted to a digital signal, the resulting digital data is a massive 20MB per second. The codec is used to compress this data for recording (for example, to a memory card), and then to decompress it to its original form for playback

Commercials can be quickly edited out of a recording for seamless and continuous playback of a programme.

The video signal is separated into its component form i.e. red, green and blue (RGB). For television, the signal is modified and referred to as YUV. It offers the highest quality of picture reproduction, especially from a DVD source. Component video input connections are usually three RCA phono-type plugs colour coded red, green and blue. Often labeled Y, Pb, Pr

A process that uses an algorithm to reduce data volume while preserving the original data content. Compression is used to reduce the time required to send and receive data over a network, and to enable the recording of more data onto a memory card or other storage medium.

Charged Couple Device- the key image-processing component. A semiconductor chip which coordinates photosensors (pixels) to turn a picture into electronic signals. Most cameras have a 1 chip but the best is a 3CCD unit with a chip for each color element (red, green and blue). The higher the number of pixels the more information can be resolved resulting in a better picture.

The Crystal Engine is a special image processing circuit for 3CCD camera systems. Processing the signal from each of the three CCDs independently, it gives both moving and still pictures exceptional quality.