This is an implementation of **vanilla transformer encoder**/**conformer** as acoustic model for singing voice conversion.

There are four stages in total:

1. Data preparation
2. Features extraction
3. Training
4. Inference/conversion

> **NOTE:** You need to run every command of this recipe in the `Amphion` root path:
> ```bash
> cd Amphion
> ```

## 1. Data Preparation

### Dataset Download

By default, we utilize the five datasets for training: M4Singer, Opencpop, OpenSinger, SVCC, and VCTK. How to download them is detailed [here](../../datasets/README.md).

### Configuration

Specify the dataset paths in  `exp_config.json`. Note that you can change the `dataset` list to use your preferred datasets.

```json
    "dataset": [
        "m4singer",
        "opencpop",
        "opensinger",
        "svcc",
        "vctk"
    ],
    "dataset_path": {
        // TODO: Fill in your dataset path
        "m4singer": "[M4Singer dataset path]",
        "opencpop": "[Opencpop dataset path]",
        "opensinger": "[OpenSinger dataset path]",
        "svcc": "[SVCC dataset path]",
        "vctk": "[VCTK dataset path]"
    },
```

## 2. Features Extraction

### Content-based Pretrained Models Download

By default, we utilize the Whisper and ContentVec to extract content features. How to download them is detailed [here](../../../pretrained/README.md).

### Configuration

Specify the dataset path and the output path for saving the processed data and the training model in `exp_config.json`:

```json
    // TODO: Fill in the output log path. The default value is "Amphion/ckpts/svc"
    "log_dir": "ckpts/svc",
    "preprocess": {
        // TODO: Fill in the output data path. The default value is "Amphion/data"
        "processed_dir": "data",
        ...
    },
```

### Run

Run the `run.sh` as the preproces stage (set  `--stage 1`).

```bash
sh egs/svc/TransformerSVC/run.sh --stage 1
```

> **NOTE:** The `CUDA_VISIBLE_DEVICES` is set as `"0"` in default. You can change it when running `run.sh` by specifying such as `--gpu "1"`.

## 3. Training

### Configuration
Specify the detailed configuration for transformer block in `exp_config.json`. For key `type`, `conformer` and `transformer` are supported:
```json
"model": {
        ...
        "transformer":{
            // 'conformer' or 'transformer'
            "type": "conformer",
            "input_dim": 384,
            "output_dim": 100,
            "n_heads": 2,
            "n_layers": 6,
            "filter_channels":512,
            "dropout":0.1,
        }
    }
```
We provide the default hyparameters in the `exp_config.json`. They can work on single NVIDIA-24g GPU. You can adjust them based on you GPU machines.

```json
"train": {
        "batch_size": 32,
        ...
        "adamw": {
            "lr": 2.0e-4
        },
        ...
    }
```

### Run

Run the `run.sh` as the training stage (set  `--stage 2`). Specify a experimental name to run the following command. The tensorboard logs and checkpoints will be saved in `Amphion/ckpts/svc/[YourExptName]`.

```bash
sh egs/svc/TransformerSVC/run.sh --stage 2 --name [YourExptName]
```

> **NOTE:** The `CUDA_VISIBLE_DEVICES` is set as `"0"` in default. You can change it when running `run.sh` by specifying such as `--gpu "0,1,2,3"`.

## 4. Inference/Conversion

### Pretrained Vocoder Download

We fine-tune the official BigVGAN pretrained model with over 120 hours singing voice data. The benifits of fine-tuning has been investigated in our paper (see this [demo page](https://www.zhangxueyao.com/data/MultipleContentsSVC/vocoder.html)). The final pretrained singing voice vocoder is released [here](../../../pretrained/README.md#amphion-singing-bigvgan) (called `Amphion Singing BigVGAN`).

### Run

For inference/conversion, you need to specify the following configurations when running `run.sh`:

| Parameters                                          | Description                                                                                                                                | Example                                                                                                                                                                            |
| --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `--infer_expt_dir`                                  | The experimental directory which contains `checkpoint`                                                                                     | `Amphion/ckpts/svc/[YourExptName]`                                                                                                                                                 |
| `--infer_output_dir`                                | The output directory to save inferred audios.                                                                                              | `Amphion/ckpts/svc/[YourExptName]/result`                                                                                                                                          |
| `--infer_source_file` or `--infer_source_audio_dir` | The inference source (can be a json file or a dir).                                                                                        | The `infer_source_file` could be `Amphion/data/[YourDataset]/test.json`, and the `infer_source_audio_dir` is a folder which includes several audio files (*.wav, *.mp3 or *.flac). |
| `--infer_target_speaker`                            | The target speaker you want to convert into. You can refer to `Amphion/ckpts/svc/[YourExptName]/singers.json` to choose a trained speaker. | For opencpop dataset, the speaker name would be `opencpop_female1`.                                                                                                                |
| `--infer_key_shift`                                 | How many semitones you want to transpose.                                                                                                  | `"autoshfit"` (by default), `3`, `-3`, etc.                                                                                                                                        |

For example, if you want to make `opencpop_female1` sing the songs in the `[Your Audios Folder]`, just run:

```bash
cd Amphion
sh egs/svc/TransformerSVC/run.sh --stage 3 --gpu "0" \
	--infer_expt_dir Amphion/ckpts/svc/[YourExptName] \
	--infer_output_dir Amphion/ckpts/svc/[YourExptName]/result \
	--infer_source_audio_dir [Your Audios Folder] \
	--infer_target_speaker "opencpop_female1" \
	--infer_key_shift "autoshift"
```

## Citations

```bibtex
@inproceedings{transformer,
  author       = {Ashish Vaswani and
                  Noam Shazeer and
                  Niki Parmar and
                  Jakob Uszkoreit and
                  Llion Jones and
                  Aidan N. Gomez and
                  Lukasz Kaiser and
                  Illia Polosukhin},
  title        = {Attention is All you Need},
  booktitle    = {{NIPS}},
  pages        = {5998--6008},
  year         = {2017}
}
```