Picture Quality Criteria, Error Statistics and Error Correction for the D-1 Format DVTR

The generally accepted picture quality requirement of the D-1 format (4:2:2) DVTR was that it should provide a quality of 4.5 on the CCIR 5 point scale, after 20 generations. It was also understood that there should be margin to allow for tape degeneration in the field, and also for “difficult” pictures. If and when the quality degraded below this level it should be gradual and graceful. From several preliminary experiments and demonstrations it was clear that there was a gap between the raw error rate that could be achieved from a DVTR, at an acceptable tape consumption, and that which was required to meet the picture quality expected. Some form of error management would be required. This would take the form of error correction to handle the regularly expected errors and error concealment to handle burst errors which overloaded the error correction system. The latter would also provide graceful degradation when conditions fell outside of the normally specified range, such as damaged tape or a clogged head.

Published

1986-02

Content type

Original Research

DOI

10.5594/M00770

ISBN

978-1-61482-915-7