Audio encoding apparatus and audio decoding apparatus for encoding in multiple stages a multi-pulse signal

摘要

Auxiliary multi-pulse setting circuit 130 set candidates of pulse positions so that the pulse positions to which no pulse is located are selected in auxiliary multi-pulse searching circuit 131 prior to the pulse positions at which pulses have already been encoded in multi-pulse searching circuit 110. Auxiliary multi-pulse searching circuit 131 generates an auxiliary multi-pulse signal according to the candidates of pulse positions set in auxiliary multi-pulse setting circuit 130 and encodes the auxiliary multi-pulse signal so that difference between the reproduced audio signal which is obtained by driving a linear predictive synthesis filter with the auxiliary multi-pulse signal and an input audio signal is minimized similarly to multi-pulse searching circuit 110.