add singing vocoder and update f0 & excitation input feats

[DrWelles]

No description provided.

[DrWelles]

1. In parallel_wavegan/bin/preprocess.py, add two pitch-related features, f0 and excitation (sin-wave-based signals).
2. In parallel_wavegan/models/uhifigan.,py, a new singing vocoder with excitation and mel as input, and a UNet-based generator.
3. In parallel_wavegan/bin/normalize.py and parallel_wavegan/bin/decode.py, add MelF0ExcitationDataset to collect mel, f0 and excitation.
4. In parallel_wavegan/bin/train.py, use a more flexible data loader for model inputs.

[ftshijt]

@kan-bayashi Hi Tomoki, as I mentioned to you days back, this is the implementation for a singing-specific vocoder. Could you please take a look to see if it fits into the repo? Many thanks!

[kan-bayashi]

Sorry for late reply, and thank you for your great PR.
I am a little bit busy in this month, I will check and revise when I finished my tasks...

[kan-bayashi]

Now I almost finished my jobs in this fiscal year!
Sorry for too late reviewing.
I will check and refactor this PR in this weekend.

[kan-bayashi]

@DrWelles I refactored your PR (see #402)
If your branch seems master, so I'm wondering to push my changes to your repo.
Is it OK?

[DrWelles]

@DrWelles I refactored your PR (see #402) If your branch seems master, so I'm wondering to push my changes to your repo. Is it OK?

Sure

[kan-bayashi]

Thanks. I listed some points of my changes.

• I modified your codes to be compatible with all modes
• I removed duplicated codes (evaluate_*.py) and locate it in bin
• I added debug recipe of uhifigan for yesno
• I removed debug loggings
• I removed uhifigan_single.py since it seems not used. Is it OK?

[DrWelles]

Thanks. I listed some points of my changes.

• I modified your codes to be compatible with all modes
• I removed duplicated codes (evaluate_*.py) and locate it in bin
• I added debug recipe of uhifigan for yesno
• I removed debug loggings
• I removed uhifigan_single.py since it seems not used. Is it OK?

Great! And it's OK to remove uhifigan_single.py. :)

[kan-bayashi]

Thank you so much for your great feature & sorry for late merging!