NICAM
In order to strengthen parity protection for the sound samples, the parity bit is calculated on only the top six bits of each NICAM sample. Early BBC NICAM research showed that uncorrected errors in the least significant four bits were preferable to the reduced overall protection offered by parity-protecting all ten bits.
[
VHS recording of NICAM audio
As far as NICAM-capable video cassette recorders are concerned, the common practice is to record the NICAM-derived stereo stream on the VHS Hi-Fi tracks while the mono compatibility signal is recorded on the linear track.
[
See also
[
References
- ^ Croll, M.G., Osborne, D.W. and Spicer, C.R. (1974), Digital sound signals: the present BBC distribution system and a proposal for bit-rate reduction by digital companding. IEE Conference publication No. 119, pp. 90–96
- ^ Bartlett, C.J.C. and Greszczuk, J. (1964), Companding in a p.c.m. system. Symposium on Transmission Aspects of Communication Networks, London, IEE 1964, pp. 183–186.
- ^ Osborne, D.W. (1972) Digital sound signals: further investigation of instantaneous and other rapid companding systems. BBC Research Dept. Report 1972/31.
- ^ Jones, A.H. (1978), Digital coding of audio signals for point-to-point transmission. IEE Conference Publication No. 166, pp. 25–28
- ^ Gilchrist, N.H.C. (1978), Digital sound signals: tests to compare the performance of five companding systems for high-quality sound signals. BBC Research Department Report 1978/26.
- ^ ETSI ETS EN 300 163, (previously: EBU T 3266)
- ^ Broadcasting System Details. University of Surrey – Department of Electronic Engineering. Retrieved on 2007-08-30.
- ^ Analogue TV technologies
- ^ World-Wide T.V. Standards
- ^ Steve Hosgood. "All You Ever Wanted to Know About NICAM but were Afraid to Ask". Retrieved on 2007-08-30.
[
Further reading
- Osborne, D.W. and Croll, M.G. (1973), Digital sound signals: Bit-rate reduction using an experimental digital compandor. BBC Research Department Report 1973/41.
- Croll, M.G., Osborne, D.W. and Reid, D.F. (1973), Digital sound signals: Multiplexing six high-quality sound channels for transmission at a bit-rate of 2.048 Mbit/s. BBC Research Department Report 1973/42.
- Reid, D.F. and Croll, M.G. (1974), Digital sound signals: The effect of transmission errors in a near-instantaneous digitally companded system. BBC Research Department Report 1974/24.
- Reid, D.F. and Gilchrist, N.H.C. (1977), Experimental 704 kbit/s multiplex equipment for two 15 kHz sound channels. BBC Research Department Report 1977/38.
- Kalloway, M.J. (1978), An experimental 4-phase d.p.s.k. stereo sound system: the effect of multipath propagation. BBC Research Department Report 1978/15.
[
External links
Related websites or technical explainations
- A technical description of NICAM
- The BBC's information page on NICAM
- Overview of Television Broadcasting Systems
- HOW NICAM WORKS, IBA TECHNICAL BULLETEN: http://youtube.com/watch?v=WHMme3XlJDI
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||
For more information review our copyright contact and privacy policy.