16. The learning device according to claim 14 further comprising: predictive tap extraction means for extracting from said decoded filter data prediction taps used along with said tap coefficients for predicting said filter data; said learning means effecting learning so that the prediction errors of prediction values of said filter data obtained on carrying out predictive calculations using said prediction taps and tap coefficients will be statistically smallest.
17. The learning device according to claim 16 further comprising: class tap extraction means for extracting a class tap from said decoded filter data, said class tap being used for sorting said filter data to one of a plurality of classes, by way of classification, and classification means for finding the class for said filter data based on said class tap; said learning means performing learning so that the prediction errors of prediction values of said filter data obtained on carrying out predictive calculations using said prediction taps and said tap coefficients associated with the class of said filter data will be statistically smallest.