opus/dnn/torch/fargan

Framewise Auto-Regressive GAN (FARGAN)

Implementation of FARGAN, a low-complexity neural vocoder. Pre-trained models are provided as C code in the dnn/ directory with the corresponding model in dnn/models/ directory (name starts with fargan_). If you don't want to train a new FARGAN model, you can skip straight to the Inference section.

Data preparation

For data preparation you need to build Opus as detailed in the top-level README. You will need to use the --enable-deep-plc configure option. The build will produce an executable named "dump_data". To prepare the training data, run:

./dump_data -train in_speech.pcm out_features.f32 out_speech.pcm

Where the in_speech.pcm speech file is a raw 16-bit PCM file sampled at 16 kHz. The speech data used for training the model can be found at: https://media.xiph.org/lpcnet/speech/tts_speech_negative_16k.sw

Training

To perform pre-training, run the following command:

python ./train_fargan.py out_features.f32 out_speech.pcm output_dir --epochs 400 --batch-size 4096 --lr 0.002 --cuda-visible-devices 0

Once pre-training is complete, run adversarial training using:

python adv_train_fargan.py out_features.f32 out_speech.pcm output_dir --lr 0.000002 --reg-weight 5 --batch-size 160 --cuda-visible-devices 0 --initial-checkpoint output_dir/checkpoints/fargan_400.pth

The final model will be in output_dir/checkpoints/fargan_adv_50.pth.

The model can optionally be converted to C using:

python dump_fargan_weights.py output_dir/checkpoints/fargan_adv_50.pth fargan_c_dir

which will create a fargan_data.c and a fargan_data.h file in the fargan_c_dir directory. Copy these files to the opus/dnn/ directory (replacing the existing ones) and recompile Opus.

Inference

To run the inference, start by generating the features from the audio using:

./fargan_demo -features test_speech.pcm test_features.f32

Synthesis can be achieved either using the PyTorch code or the C code. To synthesize from PyTorch, run:

python test_fargan.py output_dir/checkpoints/fargan_adv_50.pth test_features.f32 output_speech.pcm

To synthesize from the C code, run:

./fargan_demo -fargan-synthesis test_features.f32 output_speech.pcm