spects.py 文件源码

def undo_melspect(spect, sample_rate=SAMPLE_RATE, fps=FPS, frame_len=FRAME_LEN, min_freq=MIN_FREQ, max_freq=MAX_FREQ, invert_melbank_method='transpose', phases='random', normalize=False):
    """
    Resynthesizes a mel spectrogram into a numpy array of samples.
    """
    # undo logarithmic scaling
    spect = undo_logarithmize(spect)
    # undo Mel filterbank
    spect = undo_melfilter(spect, sample_rate, frame_len, min_freq, max_freq, invert_melbank_method)
    # randomize or reuse phases
    if phases == 'random':
        spect = spect * np.exp(np.pi*2.j*np.random.random(spect.shape))
    elif phases is not None:
        spect = spect * np.exp(1.j * np.angle(phases))
    # undo STFT
    hop_size = sample_rate / fps
    samples = undo_stft(spect, hop_size, frame_len)
    # normalize if needed
    if normalize:
        samples -= samples.mean()
        samples /= np.abs(samples).max()
    return samples.astype(np.float32)