QUANTIZATION CONTROL CIRCUIT

摘要

PURPOSE:To prevent deterioration in picture quality by deciding an optimum scaling factor from DCT coefficient data not only from a 1st generation source but also in the case of dubbing in which information of the scaling factor cannot be received. CONSTITUTION:A DCT coefficient data DCTCOEF are fed to a 1st block 20 of a quantization control section 3. The 1st block 20 employs the binary tree retrieval method to obtain a scaling factor Fn by which a bit rate is set to be an object rate or below. A 2nd block 30 detects an object in which an error is minimized among plural objects based on the scaling factor Fn. Information as to preceding scaling factors is generated as a correction value based on the detection and the correction value is added to the scaling factor Fn, resulting in generating a scaling factor SF. Quantization for equal length processing is implemented by using the scaling factor SF.