Multigeneration Performance of a Digital Composite VTR
A composite DVTR designed to operate in an existing composite environment must provide distortion-free signals after many generations. In this article, the effect of each distortion is investigated, and methods are developed to minimize the cumulative effects of all analog distortions. The sampling process of the analog-to-digital (A/D) converter introduces quantizing noise that may become noticeable after many generations. The accuracy of the sampling phase for the A/D clock is also considered, as measurement error could accumulate and impair the quality of the picture. The RF channel, including the head-to-tape interface, is the source of noise that introduces errors in the digital data. Use of a powerful error-correction system can correct nearly all such errors. Operating environment is also considered. Satisfactory multi-generation performance of a composite DVTR can be achieved by keeping analog circuitry within the recorder to a minimum. With care, the remaining causes of distortion can be controlled to provide acceptable quality in a composite environment after many analog generations.
- Print ISSN
- 0036-1682
- Published
- 1989-10
- Content type
- Original Research
- DOI
- 10.5594/J02637