CODER AND ADAPTIVE DECODER

摘要

PURPOSE:To select a predictive system suitable for a video signal in a short time unit by deciding which predictive system is selected based on a data resulting from coding a predictive error data and outputting a relevant coding data by each stored prediction system as the coded data. CONSTITUTION:An adaptive changeover switch 10 encodes a predictive error data being an input data, stores the coded data by one field, calculates a parameter deciding which data of an input data is to be selected, selects an optimum predictive system according to the parameter and outputs a coded data (c) corresponding to the predictive system. An adaptive decoder 11 decodes the coded data (c) into a predictive error data and uses a data by three preceding field data to be stored to decode the field data. Then the field data 1 of one preceding field corresponding to the coded data (c) and a frame data (m) of one preceding frame time composed of the data of two-preceding field of the field data 1 are outputted.