| 摘要 |
In an audio signal processing circuit for carrying out a subband coding used for an audio signal coding, a subband filter (12A) receives 1152 audio samples (SI) of each one frame and divides the samples into 32 frequency bands to sequentially output a vector of first half subband signals (SFA) for a first half of the one frame and a vector of second half subband signals (SFB) for a second half of the one frame. A FFT circuit (111A) carries out an FFT processing for 512 audio samples of each of the first half and the second half of each one frame, to sequentially generate a first half power spectrum (PSA) and a second half power spectrum (PSB). A calculating circuit (113A) calculates a first half SMR vector (SMA) on the basis of the first half subband signals (SFA) and the first half power spectrum (PSA), and then, a second half SMR vector (SMB) on the basis of the second half subband signals (SFB) and the second half power spectrum (PSB). A comparing circuit (115) outputs a larger one of the first half SMR vector (SMA) and the second half SMR vector (SMB), as an SMR vector (SM) for the whole of a corresponding one frame.
|
