Patent ID: 7016287

Claim:
A method of modulating a source data to be written onto an optical recording medium under the conditions of a given code rate and limited run length, comprising the steps of: (a) modulating the source data based on a first mapping table and modulating the same source data based on a second mapping table, the first mapping table containing coded data corresponding to the source data, the second mapping table containing at least one coded data, capable of suppressing low frequency components, which at least one source data among all source data contained in the first mapping table is mapped to, wherein the first mapping table includes a 2/3 sub-table containing 3-bit coded data for 2-bit source data, a 4/6 sub-table containing 6-bit coded data for 4-bit source data, a 6/9 sub-table containing 9-bit coded data for 6-bit source data, and a 8/12 sub-table containing 12-bit coded data for 8-bit source data; and (b) selecting one of the modulated data based on at least one condition among the conditions of: the value of a previous source data, the time when low-frequency suppression has been conducted, the value of subsequent modulated data, and whether or not RLL constraints are violated.