Data processing apparatus and methods

摘要

An adaptive filter 24 for filtering a signal comprising first streams interspersed with second streams (for example the A and B tracks of a signal retrieved from a tape storage device) comprises respective stores for storing initial filter coefficients for each type of stream. The corresponding coefficients are loaded for the beginning of each stream. The stored coefficients for each stream may be a standard set, or they may be from the adaption process of one or more previous streams of that type. The coefficients may be taken part way through the adaption process, in a minimum error portion of the stream.