class_docstr: Multi resolution STFT loss module.
class_docstr_tok: ["Multi","resolution","STFT","loss","module","."]
docstr: Calculate forward propagation.
  Args:
      x (Tensor): Predicted signal (B, T).
      y (Tensor): Groundtruth signal (B, T).
      input_lengths (Tensor): Length of groundtruth sample in samples (B).
  Returns:
      List[Tensor]: Multi resolution spectral convergence loss value.
      List[Tensor]: Multi resolution log STFT magnitude loss value.
docstr_tok: ["Calculate","forward","propagation",".","Args",":","x","(","Tensor",")",":","Predicted","signal","(","B",",","T",")",".","y","(","Tensor",")",":","Groundtruth","signal","(","B",",","T",")",".","input_lengths","(","Tensor",")",":","Length","of","groundtruth","sample","in","samples","(","B",")",".","Returns",":","List","[","Tensor","]",":","Multi","resolution","spectral","convergence","loss","value",".","List","[","Tensor","]",":","Multi","resolution","log","STFT","magnitude","loss","value","."]
code: def forward(self, *, x, y, input_lengths=None):
      """Calculate forward propagation.
      Args:
          x (Tensor): Predicted signal (B, T).
          y (Tensor): Groundtruth signal (B, T).
          input_lengths (Tensor): Length of groundtruth sample in samples (B).
      Returns:
          List[Tensor]: Multi resolution spectral convergence loss value.
          List[Tensor]: Multi resolution log STFT magnitude loss value.
      """
      sc_loss = [0.0] * len(self.stft_losses)
      mag_loss = [0.0] * len(self.stft_losses)
      for i, f in enumerate(self.stft_losses):
          sc_l, mag_l = f(x=x, y=y, input_lengths=input_lengths)
          sc_loss[i] = sc_l
          mag_loss[i] = mag_l
  
      return sc_loss, mag_loss
  
imports: import torch
  import torch.nn.functional
  from nemo.core.classes import Loss, typecheck
  from nemo.core.neural_types.elements import AudioSignal, LengthsType, LossType, SpectrogramType
  from nemo.core.neural_types.neural_type import NeuralType
label_desc: Use image node_id 4 for calling the MultiResolutionSTFTLoss obj's underlying member method code with example usage: obj.forward() and returns: sc_loss,  mag_loss