Patent ID: 7082163

Claim:
A picture coding method including the steps of: inputting moving picture data having an arbitrary frame rate that is not known in advance; determining the input frame rate of the inputted moving picture data; providing a target value for a buffer storage amount; determining a buffer remaining amount of the coded picture data stored in a buffer and not yet outputted by the apparatus; calculating a correction amount based on a difference of said target value and said buffer remaining amount; and calculating a target code amount for use in said coding step by adding said correction amount to said reference target code amount, wherein said target code amount is based on said input frame rate; providing a reference coding frame rate based upon said input frame rate; calculating a reference target code amount using said reference coding frame rate, wherein said target code amount is determined based upon the reference target code amount; and updating said reference coding frame rate, wherein said reference coding frame rate is determined based upon an average value of said measured frame rates within a time interval, and wherein, when the reference coding frame rate before being updated is larger than the reference coding frame rate after being updated, a value between said reference coding frame rate before being updated and said reference coding frame rate after being updated is used as an updated reference coding frame rate.