Infer with existing f0

[Pentalimbed]

Is your feature request related to a problem? Please describe.

I need to batch infer a large number audio files with multiple speakers. This is isn't usually a problem since my machine can handle it fast enough, but using harvest it gets extraordinarily slow after a while. See #677. Since we can already extract sepearte f0 before training, we might as well enable options to do that before inference.

Describe alternatives you've considered

Solving the slowdown problem with harvest as described in #677

Additional context

No response

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

Are you willing to resolve this issue by submitting a Pull Request?

• [ ] Yes, I have the time, and I know how to start.
• [ ] Yes, I have the time, but I don't know how to start. I would need guidance.
• [X] No, I don't have the time, although I believe I could do it if I had the time...
• [ ] No, I don't have the time and I wouldn't even know how to start.