Digital signal coding method and apparatus, digital signal decoding apparatus, digital signal arithmetic coding method and digital signal arithmetic decoding method
In a bit stream syntax containing compressed video slice data for compressed video data of a slice structure, a slice header for compressed video slice data has attached thereto a slice start code, a register reset flag indicating whether a register value, which designates a status of a codeword occurring in an arithmetic coding process, should be reset in the next transmission unit, an initial register value which indicates a register value to be used to start arithmetic coding/decoding to build/decompose the next transmission unit, only when the register reset flag indicates that the register should not be reset.
1. A digital signal coding apparatus for making a compression coding of a digital signal, comprising:
a coding unit for arithmetic coding said digital signal by determining a context model to be used for each type of coding data among a plurality of context models;
wherein said coding unit, when said digital signal is divided for each predetermined unit to be coded, multiplexes into a bit stream information representing an initial state of probability of occurrence of the context of model corresponding to the type of said coding data and information of initializing a register value which shows an arithmetic coding process with a bit stream as part of the coded data of said predetermined unit.
2. A digital signal coding method for making a compression coding of a digital signal, comprising:
arithmetic coding said digital signal by determining a context model to be used for each type of coding data among a plurality of context models;
dividing said digital signal for each predetermined unit to be coded, and
multiplexing into a bit stream information representing an initial state of probability of occurrence of the context of model corresponding to the type of said coding data and information of initializing a register value which shows an arithmetic coding process with a bit stream as part of the coded data of said predetermined unit.