Patent ID: 7626520

Claim:
An encoding method performed by an encoding apparatus for carrying out variable-length conversion encoding involving a look-ahead operation of at least either one information word or one code word upon encoding, said encoding method comprising: converting an information word to a temporary code word in accordance with a basic code conversion table which has information words associated with temporary code words therein, wherein each information word is converted to a temporary code word such that the maximum transition run of one bits at the beginning and at the end of said temporary code word is limited to two and that the maximum run length of zero bits at the beginning and at the end of said temporary code word is limited to between four and ten; and converting the temporary code word to a code word in accordance with a violation code conversion table constituted by code conversion rules which are prohibited by said basic code conversion table and which are used solely to convert either the temporary code word in effect at present or the temporary code word acquired earlier by said look-ahead operation.