METHOD AND DEVICE FOR ALLOCATING DYNAMIC BIT FOR AUDIO CODING

摘要

PROBLEM TO BE SOLVED: To easily and inexpensively allocate a dynamic bit by replacing the absolute threshold of a unit with the minimum absolute threshold among plural units, adjusting the absolute threshold of a unit having a 1st time interval, calculating the peak energy of each unit and calculating a signal-to-masking ratio based on it and the absolute threshold. SOLUTION: The peak energy of the whole units is calculated by using the index of a scale factor and processing that adjusts absolute threshold is performed when an MDCT module 105 of a short block is used. Also, masking effect value of a high pass side slope and masking effect value of a low pass side slope are subjected to calculation processing by using the peak energy of the units and a signal-to-masking ratio SMR of the whole units is calculated. Bandwidth undergoes calculation processing and a sample bit number that is allocated to each unit is calculated based on the SMR value of the unit and SMR offset value.