PURPOSE: To suppress the generation of a run length at the time of modulating and encoding picture data encoded at its information volume and to suppress error propagation to a limited encoding word range.

CONSTITUTION: Picture data Di are orthogonally transformed by an orthogonal transformation circuit 1 and then supplied to an information volume encoding circuit 2. The circuit 2 encodes a variable length variable rate by a B2 code. An error correction encoding circuit 3 adds an error correcting code to output data from the circuit 2 and then the code-added data are supplied to a recording modulation encoding circuit 4. The circuit 4 encodes a variable length fixed rate by new 1 and 7 codes. The circuit 4 allows one or plural bit pairs of a code word obtained by encoding information volume to coincide with a data word and allocates a code word with a shorter run length in the descending order of data word generation probability. Since the generation of long run length can be prevented and a low frequency spectrum can be suppressed, the influence of DC interruption or the like can be reduced and error propagation can be suppressed to a limited code word range.