def _extract_mel_features(
        self,
        one_waveform: np.ndarray,
    ) -> np.ndarray:
        """
        Extracts log-mel filterbank features for one waveform array (unbatched).
        """
        log_mel_spec = spectrogram(
            one_waveform,
            window=self.window,
            frame_length=self.sample_size,
            hop_length=self.sample_stride,
            fft_length=self.n_fft,
            mel_filters=self.mel_filters,
            mel_floor=self.mel_floor,
            log_mel="log10",
        )
        return log_mel_spec.T

        Extracts log-mel filterbank features for one waveform array (unbatched).
        
dpkd/transformers/src/transformers/models/speecht5/feature_extraction_speecht5.py