ONNX format

[AigizK]

You could use this PR: p0p4k/vits2_pytorch#43

[w11wo]

I've attempted to apply the same exporting script to MB-iSTFT-VITS2, but I'm running into some trouble during the export. I think it's related to complex numbers being only partially supported by torch.onnx, or something along those lines.

Here's the error log in case anyone's interested:

Traceback (most recent call last):
  File "/content/MB-iSTFT-VITS2/export_onnx.py", line 110, in <module>
    main()
  File "/content/MB-iSTFT-VITS2/export_onnx.py", line 91, in main
    torch.onnx.export(
  File "/usr/local/lib/python3.10/dist-packages/torch/onnx/utils.py", line 506, in export
    _export(
  File "/usr/local/lib/python3.10/dist-packages/torch/onnx/utils.py", line 1548, in _export
    graph, params_dict, torch_out = _model_to_graph(
  File "/usr/local/lib/python3.10/dist-packages/torch/onnx/utils.py", line 1117, in _model_to_graph
    graph = _optimize_graph(
  File "/usr/local/lib/python3.10/dist-packages/torch/onnx/utils.py", line 658, in _optimize_graph
    _C._jit_pass_erase_number_types(graph)
RuntimeError: Unknown number type: complex

To reproduce, I've prepared a Colab notebook here. It uses the models from here.

[FENRlR]

pytorch/pytorch#81075
It looks like we need more time for this.

[nshmyrev]

It is actually easy to export, see the patch here:

alphacep@29c91d4