Patent ID: 6411958
Filing Date: 2002-06-25
Classification: H03M,Y10S

Abstract:
In a computer implemented method of encoding symbols, a method of generating a structured listing of said symbols, the generating method comprising the steps of:(a) for an input stream of symbols, generating a first list having a plurality of entries, each entry identifying a symbol in the input stream and the frequency with which that symbol appears; (b) ordering the entries in the first list by frequency; (c) selecting the two symbols having the lowest frequency; (d) generating a new symbol to represent the two selected symbols, and allocating the new symbol a frequency based on the two selected symbols; (e) storing the new symbol as an entry in a second list along with an indication of the frequency allocated to the new symbol; (f) arranging for the entries for the two symbols selected at said step (c) to be unavailable for subsequent steps in the generation of the structured listing; and (g) repeating the steps (c) to (f) until only one available entry remains, in each iteration the two symbols selected at said step (c) being chosen from all available entries in the first and the second list.