TensorFlow 1 version View source on GitHub

Computes the Short-time Fourier Transform of signals.

    signals, frame_length, frame_step, fft_length=None,
    window_fn=tf.signal.hann_window, pad_end=False, name=None

Implemented with TPU/GPU-compatible ops and supports gradients.


  • signals: A [..., samples] float32/float64 Tensor of real-valued signals.
  • frame_length: An integer scalar Tensor. The window length in samples.
  • frame_step: An integer scalar Tensor. The number of samples to step.
  • fft_length: An integer scalar Tensor. The size of the FFT to apply. If not provided, uses the smallest power of 2 enclosing frame_length.
  • window_fn: A callable that takes a window length and a dtype keyword argument and returns a [window_length] Tensor of samples in the provided datatype. If set to None, no windowing is used.
  • pad_end: Whether to pad the end of signals with zeros when the provided frame length and step produces a frame that lies partially past its end.
  • name: An optional name for the operation.


A [..., frames, fft_unique_bins] Tensor of complex64/complex128 STFT values where fft_unique_bins is fft_length // 2 + 1 (the unique components of the FFT).


  • ValueError: If signals is not at least rank 1, frame_length is not scalar, or frame_step is not scalar.