Modulation apparatus/method, demodulation apparatus/method and program presenting medium

A modulation method to be adopted in a modulation apparatus for converting data with a basic data length of m bits into variable length code (d, k ;

• m, n ;
• r) with a basic code length of n bits where d is a minimum run and k is a run length limit, said. modulation method characterized by including a conversion step of converting input data into code in accordance with a conversion table wherein said conversion table enforces a conversion rule, according to which the remainder of division of a ‘1’ count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of a ‘1’ count of an element in the string of code words resulting from conversion of said data string by 2 and conversion codes of said conversion table comprise:
• basic codes for d=1, k=7, m=2 and n=3;
• first substitution codes for limiting the number of consecutive appearances of said minimum run d;
• and
• second substitution codes for keeping said run length limit k.

A program presenting medium for presenting a program implementing processing including a conversion step of converting input data into code in accordance with a conversion table data in a modulation apparatus for converting data with a basic data length of m bits into variable length code (d, k ;

• m, n ;
• r) with a basic code length of n bits where d is a minimum run and k is a run length limit, said program presenting medium characterized in that said conversion table enforces a conversion rule, according to which the remainder of division of a ‘1’ count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of a ‘1’ count of an element in the string of code words resulting from conversion of said data string by 2 and conversion codes of said conversion table comprise:
• basic codes for d=1, k=7, m=2 and n=3;
• first substitution codes for limiting the number of consecutive appearances of said minimum run d;
• and
• second substitution codes for keeping said run length limit k.

A demodulation apparatus for converting variable length code (d, k ;

• m, n ;
• r) with a basic code length of n bits into data with a basic data length of m bits where d is a minimum run and k is a run length limit, said demodulation apparatus characterized by having conversion means for converting input code into data in accordance with a conversion table wherein said conversion table enforces a conversion rule, according to which the remainder of division of a ‘1’ count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of a ‘1’ count of an element in the string of code words resulting from conversion of said data string by 2 and conversion codes of said conversion table comprise:
• basic codes for d=1, k=7, m=2 and n=3;
• first substitution codes for limiting the number of consecutive appearances of said minimum run d;
• and
• second substitution codes for keeping said run length limit k.

A demodulation method to be adopted in a demodulation apparatus for converting variable length code (d, k m, n ;

• r) with a basic code length of n bits into data with a basic data length of m bits where d is a minimum run (and k is a run length limit?), said modulation method characterized by having a conversion step of converting input code into data in accordance with a conversion table wherein said conversion table enforces a conversion rule, according to which the remainder of division of a ‘1’ count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of a ‘1’ count of an element in the string of code words resulting from conversion of said data string by 2 and conversion codes of said conversion table comprise:
• basic codes for d=1, k=7, m=2 and n=3;
• first substitution codes for limiting the number of consecutive appearances of said minimum run d;
• and
• second substitution codes for keeping said run length limit k.

A program presenting medium for presenting a program including a conversion step of converting input code into data in accordance with a conversion table in a demodulation apparatus for converting variable length code (d, k ;

• m, n ;
• r) with a basic code length of n bits into data with a basic data length of m bits where d is a minimum run and k is a run length limit, said program presenting medium characterized in that said conversion table enforces a conversion rule, according to which the remainder of division of a ‘1 ’ count of an element in a data string by 2 having a value of 0 or 1 shall always be equal to the remainder of division of a ‘1’, count of an element in the string of code words resulting from conversion of said data string by 2 and conversion codes of said conversion table comprise:
• basic codes for d=1, k=7, m=2 and n=3;
• first substitution codes for limiting the number of consecutive appearances of said minimum run d;
• and
• second substitution codes for keeping said run length limit k.