util.py 文件源码

def stft_mc(x,N=1024,hop=None,window='hann'):
    # N=1024
    if hop is None:
        hop=N/2
    S=x.shape
    if len(S)==1:
        nch=1
        nsampl=len(x)
        x=np.reshape(x,(1,nsampl)) 
    else:
        nch=S[0]
        nsampl=S[1]
    xdtype=x.dtype
    nfram=int(scipy.ceil(float(nsampl)/float(hop)))
    npad=int(nfram)*hop-nsampl
    pad=np.zeros((nch,npad)).astype(xdtype)
    x=np.concatenate((x,pad),axis=1)
    #pad the edges to avoid window taper effects
    pad=np.zeros((nch,N)).astype(xdtype)
    x=np.concatenate((pad,x,pad),axis=1)
    for ich in range(0,nch):
        x0=x[ich,:]
        if not x0.flags.c_contiguous:
            x0=x0.copy(order='C')
        X0=librosa.core.stft(x0,n_fft=N,hop_length=hop,window=window,center=False,dtype=np.complex64)
        if ich==0:
            X=np.zeros((N/2+1,X0.shape[1],nch)).astype(np.complex64)
            X[:,:,0]=X0
        else:
            X[:,:,ich]=X0
    return X