System comprising a preliminary processing device controlled in

Abstract

In an encoding system comprising a buffer circuit for successively storing variable length codes and for producing the stored codes at a predetermined rate as transmission codes, a controller produces a control signal which stepwise specifies a variable amount of the stored codes. Responsive to the control signal, a preliminary processing circuit preliminarily processes the digital video signals into preliminarily processed signals which are dependent on the amounts and which are predictively encoded in accordance with an encoding rule by a non-recursive predictive encoder into predictive error signals with information of the preliminarily processed signals preserved. For use in the buffer circuit, a variable length encoder controlled by the control signal further encodes the predictive error signals into the variable length codes of code lengths related to the amounts. The processing circuit may comprise at least one of a quantizer, a thinning circuit, and a band compression circuit. A decoding system decodes the transmission codes in accordance with a decoding rule reversible to the encoding rule to produce reproductions of the preliminarily processed signals. A combination of the encoding and the decoding systems is connected in cascade to at least one of an additional combination of the encoding and the decoding systems to repeatedly edit and/or dub video signals in a digital form. The encoding system may additionally comprise an additional predictive encoder operable, when the amount is large to compensate for that visibly perceptible degradation of picture qualities which would otherwise result from a reduction in the numbers of bits representative of the predictive error signals produced by the non-recursive predictive encoder.