returns the normalized STFT results, i.e., multiplied by
     (\text{frame_length})^{-0.5}.

If "return_complex" is "True" (default if input is complex), the
     return is a "input.dim() + 1" dimensional complex tensor. If
     "False", the output is a "input.dim() + 2" dimensional real
     tensor where the last dimension represents the real and imaginary
     components.

Returns either a complex tensor of size ( \times N \times T) if
   "return_complex" is true, or a real tensor of size ( \times N
   \times T \times 2). Where * is the optional batch size of "input",
   N is the number of frequencies where STFT is applied and T is the
   total number of frames used.
Warning:
 This function changed signature at version 0.4.1. Calling with
 the previous signature may cause error or return incorrect
 result.

Parameters:
      * input (Tensor) -- the input tensor
  * **n_fft** (*int*) -- size of Fourier transform
