qmf_realtime.py 文件源码

def DCT4(samples):
   #use a DCT3 to implement a DCT4:
   samplesup=np.zeros(2*N)
   #upsample signal:
   samplesup[1::2]=samples
   y=spfft.dct(samplesup,type=3,norm='ortho')*np.sqrt(2)#/2
   return y[0:N]