The audio coding equipment, audio coded manner and the computer reading possible record media which records audio coded algorithm

摘要

To improve the tone quality by reducing the difference between the pitch period of an adaptive code vector and that of a sound source code vector without increasing the operation volume required for search of a sound source code book. SOLUTION: A digital sound input signal is divided into frames by a frame division part 12, and they are divided into sub-frames by a sub-frame division part 14, and a formant parameter extraction part 16 analyzes frames to extract and encode formant parameters, and a pitch period extraction part 18 uses formant parameters of sub-frames and frames to extract and encode the pitch period of sub-frames and a noise source extraction part 20 extracts and encodes noise source components of sub-frames; and when a pulse will be made rise in a non-integer sample position and pulses are made rise in plural integer sample positions between which the non-integer sample position is interposed.