Patent ID: 7593463

Claim:
A video signal coding method, comprising: determining a motion vector of an input video signal; measuring visual characteristics of the input video signal; determining a coding difficulty level d of the input video signal for each unit of time from the motion vector of the input video signal; determining an average amount of allocated bits per unit time; determining a reference value for allocating coding bits on the basis of a function b (d) for an amount of coding bits b allocated for each unit of time from (i) the coding difficulty level d of said input video signal for each unit of time, from (ii) the measured visual characteristics of said input video signal and from (iii) the average amount of allocated bits per unit time; determining an actual amount of allocated coding bits b_x on the basis of the reference value by controlling the actual amount of allocated bits so that the sum of the generated bits obtained when coding the input video signal for a certain period of time T_vbr does not exceed the amount of bits available for recording a signal having the length of the period of time T_vbr on a recording medium; 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 the coding difficulty level d is determined using an equation d=ME _error ×W — ME+MV×W — MV+Z×W — AC+b — gen×W — GEN+q _scale ×W — Q, wherein the W_ME value is a weight to a motion prediction error; the W_MV value is a weight to the motion vector; the W_AC value is a weight to a deviation of a brightness value; the W_GEN value is a weight to an amount of generated bits; the W_Q value is a weight to a Q scale; the Z value is an index indicating a deviation of brightness activity; the ME_error value is a prediction error of a time unit; the MV value is a motion vector; the b_gen value is an amount of generated information; and the q_scale value is the Q scale.