Patent ID: 6928112

Claim:
A signal coding method comprising the steps of: determining a coding difficulty for each unit time of an input signal; obtaining a reference value of allocation data amount interrelated with said coding difficulty of said input signal for said each unit time based on a standardized relationship between coding difficulty and allocation data amount, wherein said standardized relationship is based on a reference motion picture image sequence previously coded by way of variable bit rate coding with a predetermined average bit rate; modifying said reference value of said allocation data amount into an actual allocation data amount; and generating coded data by coding said input signal for said each unit time according to said actual allocation data amount, wherein said step of modifying said reference value of said allocation data amount into an actual allocation data amount is characterized in that a total B av of allocation bit amount up to a current time is compared to a total B gen of actually generated coding bit amount up to the current time while coding the input signal for each unit time with a constant allocation bit amount b av, and if a value (B av−B gen) is positive, it is allowed to assign an allocation bit amount equal to or above b av which is defined as follows: b av=T GOP×BV/T SEQ wherein BV is a bit amount available in a signal recording medium for a moving picture recording; T SEQ is a time length of a moving picture sequence which can be recorded on a signal recording medium; and T GOP is a unit time length.