Function spectrogram_func_librosa

dali/test/python/operator_2/test_spectrogram.py:95–122

(nfft, win_len, win_step, window, center, input_data)

def spectrogram_func_librosa(nfft, win_len, win_step, window, center, input_data):
    # Squeeze to 1d
    if len(input_data.shape) > 1:
        input_data = np.squeeze(input_data)

    if window is None:
        window = hann_win

    out = (
        np.abs(
            stft(
                y=input_data,
                n_fft=nfft or win_len,
                center=center,
                win_length=win_len,
                hop_length=win_step,
                window=window,
                pad_mode="reflect",
            )
        )
        ** 2
    )

    # Alternative way to calculate the spectrogram:
    # out, _ = librosa.core.spectrum._spectrogram(
    #     y=input_data, n_fft=nfft, hop_length=win_step, window=hann_win, power=2)

    return out


class SpectrogramPythonPipeline(Pipeline):