def forward(self, x_mag, y_mag):
        """Calculate forward propagation.

        Args:
            x_mag (Tensor): Magnitude spectrogram of predicted signal (B, #frames, #freq_bins).
            y_mag (Tensor): Magnitude spectrogram of groundtruth signal (B, #frames, #freq_bins).

        Returns:
            Tensor: Log STFT magnitude loss value.

        """
        delta_win_length=5
        
        loss_1 = F.l1_loss(torch.log(y_mag), torch.log(x_mag))

        x_mag=torch.log(x_mag).transpose(-1,-2)
        y_mag=torch.log(y_mag).transpose(-1,-2)
        
        x_del = torchaudio.functional.compute_deltas(x_mag ,win_length=delta_win_length)
        y_del = torchaudio.functional.compute_deltas(y_mag ,win_length=delta_win_length)
        loss_2 = F.l1_loss(y_del, x_del)
        
        x_acc = torchaudio.functional.compute_deltas(x_del ,win_length=delta_win_length)
        y_acc = torchaudio.functional.compute_deltas(y_del ,win_length=delta_win_length)
        loss_3 = F.l1_loss(y_acc, x_acc)


        return loss_1 + loss_2 + loss_3
Calculate forward propagation.

        Args:
            x_mag (Tensor): Magnitude spectrogram of predicted signal (B, #frames, #freq_bins).
            y_mag (Tensor): Magnitude spectrogram of groundtruth signal (B, #frames, #freq_bins).

        Returns:
            Tensor: Log STFT magnitude loss value.

        
train/target_speaker_extraction/losses/stft_loss.py