Patent ID: 6150966
Filing Date: 2000-11-21
Classification: H03M

Abstract:
Coding system (1) for adaptive, context-dependent data-compression coding a first digital signal (2) into a second digital signal (3), the coding system comprising:a first arrangement (5), a context extractor and probability estimator, being provided withan input (7) for receiving the first digital signal comprising a number of symbols,an output (8) for generating a fourth digital signal comprising at least one probability signal, an estimated probability signal,a first coding apparatus (4), an entropy encoder, being provided witha first input (6) for receiving the first digital signal comprising said number of symbols,a second input (8) for receiving the fourth digital signal originating from the first arrangement, andan output (9) for generating the second digital signal,the coding section being provided withmemory means (20) comprising at least a first memory field (21) and a second memory field (22) for storing in the first memory field at leastfirst information (B1) relating to at least two probability signals, andsecond information (a.sub.1,b.sub.1) relating to at least a first number of symbols having a first value and a second number of symbols having a second value, and for storing in the second memory field at leastthird information (B2) relating to at least two probability signals, andfourth information (a.sub.2,b.sub.2) relating to at least a third number of symbols having a first value and a fourth number of symbols having a second value, andprocessor means coupled to the memory means (20) for adapting the information in response to a further received symbol,characterized in that the coding section is provided withcombining means for combining at least two probability signals into a first combination signal, the first information (B1) being a function of this first combination signal, and for combining at least two probability signals into a second combination signal, the third information (B2) being a function of this second combination signal, and for combining at least two probability signals into a third combination signal, andconverting means for converting the third combination signal into at least one probability signal.