Encoding method of recording media

An encoding method for a recording media for simplifying the calculation loading of possible paths by using predetermined state and path conditions during a look-ahead calculation of a encoding procedure and increasing an overall encoding speed, the method comprising the steps of:

• executing initialization settings and performing a look-ahead calculation from a node n, which further includes the steps of:
• executing initialization settings of a path length L and a path selection criterion P required for selecting optimal code word for encoding;
• and
• executing initialization settings of a state condition S, a reserved quantity R, and a selection condition C required for computing possible paths;
• when the length of look-ahead is smaller than said path length L, the current step further comprising the steps of:
• computing a digital sum value (DSV) of candidate code word in each of m possible paths at the node n:
• C1[n], . . . , Cm[n];
• determining the states of said m possible paths according to the state condition S;
• reserving R possible paths among m possible paths according to the selection condition C when its number exceeds the reserved quantity R;
• and
• executing the next look-ahead calculation;
• and
• when the length of look-ahead is equal to the path length L, the current step further contains the steps of:
• using the code word of an optimal path selected according to the path selection criterion P to perform encoding;
• and
• executing the look-ahead calculation of the next node when the encoding is not completed.