Justin, you listed istft here, but I can't find istft in ONNX's list of operators. Is the idea to implement istft in terms of the available onnx operators?

Edit: This PR also lists ISTFT in its description, but there's no mention of ISTFT in the code changes. Now I'm confused. Does ONNX opset 17 support ISTFT or not?

Hi @iver56, I can confirm that ISTFT is not in opset 17. However onnx is open to including it as a new op (please feel free to open an issue in the onnx/onnx repo if not already existed). We plan to support exporting istft from pytorch in spite of the missing ISTFI op.

If I may add, even though ISTFT is not available, both forward and inverse operations for DFT are supported by ONNX. Reference This should help users implement ISTFT on their own.
Would it be possible to include support for FFT as well ?

@stonelazy i think so. Do you have a list of related torch functions you think could be fitting?

@stonelazy i think so. Do you have a list of related torch functions you think could be fitting?

I hope am not wrong, below are the torch's equivalent in ONNX.
Torch's FFT's equivalent is ONNX's DFT
Torch's IFFT is same ONNX's DFT but with inverse option selected.
Torch's Melscale equivalent is ONNX's Melweight.