Patent ID: 7006570

Claim:
A video signal coding method comprising the steps of: determining a coding difficulty level d of an input video signal for each unit of time; measuring visual characteristics of the input video signal; determining a reference value for allocating coding bits on the basis of temporally b (d) for the amount of coding bits b allocated for each unit of time and related in advance to the coding difficulty level d of said input video signal for each unit of time; determining an actual amount of allocated coding bits b x on the basis of the reference value; and generating coded data by coding the input video signal for each unit of time on the basis of said actual amount of allocated coding bits b x, wherein part of the sum B_av of the amounts of allocated bits b_av per unit time for a certain period of time T_vbr, or B_av=b_av×T_vbr, is stored as virtual buffer V_vbr in advance and the actual reference value of the amount of allocated coding bits b_real is obtained by b _real=( B — av−V — vbr )/ T — vbr so that an amount of allocated bits not smaller than b_real is given as long as V_vbr>0 but an amount smaller than b_real is given otherwise in said step of determining the actual amount of allocated coding bits on the basis of said reference value.