Modulation system

A method of recording auxiliary information, comprising the steps of:

• generating a final 15-bit output code word in response to every 8-bit input code word by referring to a set of encoding tables,
• wherein the encoding tables contain output code words assigned to input code words, and contain state information accompanying each output code word, wherein the state information designates an encoding table among the encoding tables which is used next to generate an output code word immediately following the output code word accompanied with the state information in a manner such that a resultant succession of the output code words follows predetermined run length limiting rules, and wherein NRZI conversion results of output code words in first specified one of the encoding tables which are assigned to prescribed input code words are opposite in polarity to NRZI conversion results of output code words in second specified one of the encoding tables which are assigned to the prescribed input code words;
• generating a first candidate current output code word in response to a current input code word equal to one of the prescribed input code words by referring to the first specified one of the encoding tables;
• generating a second candidate current output code word in response to the current input code word equal to said one of the prescribed input code words by referring to the second specified one of the encoding tables;
• calculating a first DSV from the first candidate current output code word and previous final output code words;
• calculating a second DSV from the second candidate current output code word and previous final output code words;
• determining which of an absolute value of the first DSV and an absolute value of the second DSV is smaller;
• selecting one from the first and second candidate current output code words which corresponds to the smaller DSV absolute value as a final current output code word;
• and
• superimposing auxiliary information on a sequence of final output code words;
• wherein the auxiliary information contains at least one of 1) an information piece about an encryption key, 2) an information piece being a base of an encryption key, 3) a designating information piece for identifying an encryption key, 4) a designating information piece for identifying a base of an encryption key, 5) an information piece about a region or regions corresponding to one or more countries, one or more zones, or one or more spaces, 6) an information piece about identification of an individual, 7) an information piece about identification of a group of persons, 8) an information piece about a rating, 9) an information piece about identification of an apparatus maker or a device maker, 10) an information piece about identification of a contents provider, 11) an information piece about time, 12) an information piece about contents authors, 13) an information piece about identification of a reproducing apparatus or a reproducing device, 14) an information piece about identification of a connection apparatus or a connection device, 15) an information piece about identification of a medium on which contents information is recorded, 16) an information piece about identification of contents information, 17) an information piece about accounting, 18) an information piece about playback control, 19) an information piece about an address to be accessed, 20) an information piece about recording control, 21) an information piece about a URL address related to contents information, 22) an information piece representing characters, 23) an information piece representing an auxiliary picture, 24) an information piece about audio, 25) an information piece about a copyright, and 26) an information piece about legitimacy of a recording medium storing data.

An apparatus for recording auxiliary information, comprising:

• means for generating a final 15-bit output code word in response to every 8-bit input code word by referring to a set of encoding tables, wherein the encoding tables contain output code words assigned to input code words, and contain state information accompanying each output code word, wherein the state information designates an encoding table among the encoding tables which is used next to generate an output code word immediately following the output code word accompanied with the state information in a manner such that a resultant succession of the output code words follows predetermined run length limiting rules, and wherein NRZI conversion results of output code words in first specified one of the encoding tables which are assigned to prescribed input code words are opposite in polarity to NRZI conversion results of output code words in second specified one of the encoding tables which are assigned to the prescribed input code words;
• means for generating a first candidate current output code word in response to a current input code word equal to one of the prescribed input code words by referring to the first specified one of the encoding tables;
• means for generating a second candidate current output code word in response to the current input code word equal to said one of the prescribed input code words by referring to the second specified one of the encoding tables;
• means for calculating a first DSV from the first candidate current output code word and previous final output code words;
• means for calculating a second DSV from the second candidate current output code word and previous final output code words;
• means for determining which of an absolute value of the first DSV and an absolute value of the second DSV is smaller;
• means for selecting one from the first and second candidate current output code words which corresponds to the smaller DSV absolute value as a final current output code word;
• and
• means for superimposing auxiliary information on a sequence of final output code words;
• wherein the auxiliary information contains at least one of 1) an information piece about an encryption key, 2) an information piece being a base of an encryption key, 3) a designating information piece for identifying an encryption key, 4) a designating information piece for identifying a base of an encryption key, 5) an information piece about a region or regions corresponding to one or more countries, one or more zones, or one or more spaces, 6) an information piece about identification of an individual, 7) an information piece about identification of a group of persons, 8) an information piece about a rating, 9) an information piece about identification of an apparatus maker or a device maker, 10) an information piece about identification of a contents provider, ii) an information piece about time, 12) an information piece about contents authors, 13) an information piece about identification of a reproducing apparatus or a reproducing device, 14) an information piece about identification of a connection apparatus or a connection device, 15) an information piece about identification of a medium on which contents information is recorded, 16) an information piece about identification of contents information, 17) an information piece about accounting, 18) an information piece about playback control, 19) an information piece about an address to be accessed, 20) an information piece about recording control, 21) an information piece about a URL address related to contents information, 22) an information piece representing characters, 23) an information piece representing an auxiliary picture, 24) an information piece about audio, 25) an information piece about a copyright, and 26) an information piece about legitimacy of a recording medium storing data.

A modulation apparatus comprising:

• means for generating a final 15-bit output code word in response to every 8-bit input code word by referring to a set of encoding tables, wherein the encoding tables contain output code words assigned to input code words, and contain state information accompanying each output code word, wherein the state information designates an encoding table among the encoding tables which is used next to generate an output code word immediately following the output code word accompanied with the state information;
• means for generating a first candidate current output code word in response to a current input code word equal to one of prescribed input code words by referring to one of first and second specified encoding tables among the encoding tables which is designated by state information accompanying an immediately-preceding final output code word;
• means for generating a second candidate current output code word in response to the current input code word equal to said one of the prescribed input code words by referring to the other of the first and second specified encoding tables under conditions where a succession of the second candidate current output code word and the immediately-preceding final output code word follows a run length limiting rule;
• means for calculating a first DSV from the first candidate current output code word and previous final output code words;
• means for calculating a second DSV from the second candidate current output code word and previous final output code words;
• means for determining which of an absolute value of the first DSV and an absolute value of the second DSV is smaller;
• means for selecting one from the first and second candidate current output code words which corresponds to the smaller DSV absolute value as a final current output code word;
• and
• means for changing the run length limiting rule to change a maximum run length in a sequence of final output code words in response to auxiliary information to superimpose the auxiliary information on the sequence of the final output code words.

A modulation method comprising the steps of:

• generating a final 15-bit output code word in response to every S-bit input code word by referring to a set of encoding tables, wherein the encoding tables contain output code words assigned to input code words, and contain state information accompanying each output code word, wherein the state information designates an encoding table among the encoding tables which is used next to generate an output code word immediately following the output code word accompanied with the state information;
• generating a first candidate current output code word in response to a current input code word equal to one of prescribed input code words by referring to one of first and second specified encoding tables among the encoding tables which is designated by state information accompanying an immediately-preceding final output code word;
• generating a second candidate current output code word in response to the current input code word equal to said one of the prescribed input code words by referring to the other of the first and second specified encoding tables under conditions where a succession of the second candidate current output code word and the immediately-preceding final output code word follows a run length limiting rule;
• calculating a first DSV from the first candidate current output code word and previous final output code words:
• calculating a second DSV from the second candidate current output code word and previous final output code words;
• determining which of an absolute value of the first DSV and an absolute value of the second DSV is smaller;
• selecting one from the first and second candidate current output code words which corresponds to the smaller DSV absolute value as a final current output code word;
• and
• changing the run length limiting rule to change a maximum run length in a sequence of final output code words in response to auxiliary information to superimpose the auxiliary information on the sequence of the final output code words.