Real Time Speech Enhancement in the Waveform Domain (Interspeech 2020)

We provide a [PyTorch][pytorch] implementation of the paper: [Real Time Speech Enhancement in the Waveform Domain][arxiv]. In which, we present a causal speech enhancement model working on the raw waveform that runs in real-time on a laptop CPU. The proposed model is based on an encoder-decoder architecture with skip-connections. It is optimized on both time and frequency domains, using multiple loss functions. Empirical evidence shows that it is capable of removing various kinds of background noise including stationary and non-stationary noises, as well as room reverb. Additionally, we suggest a set of data augmentation techniques applied directly on the raw waveform which further improve model performance and its generalization abilities.

Audio samples can be found here: [Samples][web]

The proposed model is based on the Demucs architecture, originally proposed for music source-separation: ([Paper][demucs-ppr], [Code][demucs-code]).

Colab

If you want to play with the pretrained model inside colab for instance, start from this Colab Example for Denoiser.

Installation

First, install Python 3.7 (recommended with Anaconda).

Through pip (you just want to use pre-trained model out of the box)

Just run

pip install denoiser

Development (if you want to train or hack around)

Clone this repository and install the dependencies. We recommend using a fresh virtualenv or Conda environment.

git clone https://github.com/facebookresearch/denoiser
cd denoiser
pip install -r requirements.txt  # If you don't have cuda
pip install -r requirements_cuda.txt  # If you have cuda

Live Speech Enhancement

If you want to use denoiser live (for a Skype call for instance), you will need a specific loopback audio interface.

Mac OS X

On Mac OS X, this is provided by [Soundflower][soundflower]. First install Soundflower, and then you can just run

python -m denoiser.live

In your favorite video conference call application, just select "Soundflower (2ch)" as input to enjoy your denoised speech.

Watch our live demo presentation in the following link: [Demo][demo].

Linux (tested on Ubuntu 20.04)

You can use the pacmd command and the pavucontrol tool:

• run the following commands:

pacmd load-module module-null-sink sink_name=denoiser
pacmd update-sink-proplist denoiser device.description=denoiser

This will add a Monitor of Null Output to the list of microphones to use. Select it as input in your software.

• Launch the pavucontrol tool. In the Playback tab, after launching python -m denoiser.live --out INDEX_OR_NAME_OF_LOOPBACK_IFACE and the software you want to denoise for (here an in-browser call), you should see both applications. For denoiser interface as Playback destination which will output the processed audio stream on the sink we previously created.

Other platforms

At the moment, we do not provide official support for other OSes. However, if you have a a soundcard that supports loopback (for instance Steinberg products), you can try to make it work. You can list the available audio interfaces with python -m sounddevice. Then once you have spotted your loopback interface, just run

python -m denoiser.live --out INDEX_OR_NAME_OF_LOOPBACK_IFACE

By default, denoiser will use the default audio input. You can change that with the --in flag.

Note that on Windows you will need to replace python by python.exe.

Troubleshooting bad quality in separation

denoiser can introduce distortions for very high level of noises. Audio can become crunchy if your computer is not fast enough to process audio in real time. In that case, you will see an error message in your terminal warning you that denoiser is not processing audio fast enough. You can try exiting all non required applications.

denoiser was tested on a Mac Book Pro with an 2GHz quadcore Intel i5 with DDR4 memory. You might experience issues with DDR3 memory. In that case you can trade overall latency for speed by processing multiple frames at once. To do so, run

python -m denoiser.live -f 2

You can increase to -f 3 or more if needed, but each increase will add 16ms of extra latency.

Denoising received speech

You can also denoise received speech, but you won't be able to both denoise your own speech and the received speech (unless you have a really beefy computer and enough loopback audio interfaces). This can be achieved by selecting the loopback interface as the audio output of your VC software and then running

python -m denoiser.live --in "Soundflower (2ch)" --out "NAME OF OUT IFACE"

Training and evaluation

Quick Start with Toy Example

1. Run sh make_debug.sh to generate json files for the toy dataset.
2. Run python train.py

Configuration

We use [Hydra][hydra] to control all the training configurations. If you are not familiar with Hydra we recommend visiting the Hydra [website][hydra-web]. Generally, Hydra is an open-source framework that simplifies the development of research applications by providing the ability to create a hierarchical configuration dynamically.

The config file with all relevant arguments for training our model can be found under the conf folder. Notice, under the conf folder, the dset folder contains the configuration files for the different datasets. You should see a file named debug.yaml with the relevant configuration for the debug sample set.

You can pass options through the command line, for instance ./train.py demucs.hidden=32. Please refer to conf/config.yaml for a reference of the possible options. You can also directly edit the config.yaml file, although this is not recommended due to the way experiments are automatically named, as explained hereafter.

Checkpointing

Each experiment will get a unique name based on the command line options you passed. Restarting the same command will reuse the existing folder and automatically start from a previous checkpoint if possible. In order to ignore previous checkpoints, you must pass the restart=1 option. Note that options like device, num_workers, etc. have no influence on the experiment name.

Setting up a new dataset

If you want to train using a new dataset, you can:

1. Create a separate config file for it.
2. Place the new config files under the dset folder. Check conf/dset/debug.yaml for more details on configuring your dataset.
3. Point to it either in the general config file or via the command line, e.g. ./train.py dset=name_of_dset.

You also need to generate the relevant .jsonfiles in the egs/folder. For that purpose you can use the python -m denoiser.audio command that will scan the given folders and output the required metadata as json. For instance, if your noisy files are located in $noisy and the clean files in $clean, you can do

out=egs/mydataset/tr
mkdir -p $out
python -m denoiser.audio $noisy > $out/noisy.json
python -m denoiser.audio $clean > $out/clean.json

Usage

1. Data Structure

The data loader reads both clean and noisy json files named: clean.json and noisy.json. These files should contain all the paths to the wav files to be used to optimize and test the model along with their size (in frames). You can use python -m denoiser.audio FOLDER_WITH_WAV1 [FOLDER_WITH_WAV2 ...] > OUTPUT.json to generate those files. You should generate the above files for both training and test sets (and validation set if provided). Once this is done, you should create a yaml (similarly to conf/dset/debug.yaml) with the dataset folders' updated paths. Please check conf/dset/debug.yaml for more details.

2. Training

Training is simply done by launching the train.py script:

./train.py

This scripts read all the configurations from the conf/config.yaml file.

Distributed Training

To launch distributed training you should turn on the distributed training flag. This can be done as follows:

./train.py ddp=1

Logs

Logs are stored by default in the outputs folder. Look for the matching experiment name. In the experiment folder you will find the best.th serialized model, the training checkpoint checkpoint.th, and well as the log with the metrics trainer.log. All metrics are also extracted to the history.json file for easier parsing. Enhancements samples are stored in the samples folder (if noisy_dir or noisy_json is set in the dataset).

Fine tuning

You can fine-tune one of the 3 pre-trained models dns48, dns64 and master64. To do so:

./train.py continue_pretrained=dns48
./train.py continue_pretrained=dns64 demucs.hidden=64
./train.py continue_pretrained=master64 demucs.hidden=64

3. Evaluating

Evaluating the models can be done by:

python -m denoiser.evaluate --model_path=<path to the model> --data_dir=<path to folder containing noisy.json and clean.json>

Note that the path given to --model_path should be obtained from one of the best.th file, not checkpoint.th. It is also possible to use pre-trained model, using either --dns48, --dns64or --master64. For more details regarding possible arguments, please see:

usage: denoiser.evaluate [-h] [-m MODEL_PATH | --dns48 | --dns64 | --master64]
                         [--device DEVICE] [--dry DRY]
                         [--num_workers NUM_WORKERS] [--streaming]
                         [--data_dir DATA_DIR] [--matching MATCHING]
                         [--no_pesq] [-v]

Speech enhancement using Demucs - Evaluate model performance

optional arguments:
  -h, --help            show this help message and exit
  -m MODEL_PATH, --model_path MODEL_PATH
                        Path to local trained model.
  --dns48               Use pre-trained real time H=48 model trained on DNS.
  --dns64               Use pre-trained real time H=64 model trained on DNS.
  --master64            Use pre-trained real time H=64 model trained on DNS
                        and Valentini.
  --device DEVICE
  --dry DRY             dry/wet knob coefficient. 0 is only input signal, 1
                        only denoised.
  --num_workers NUM_WORKERS
  --streaming           true streaming evaluation for Demucs
  --data_dir DATA_DIR   directory including noisy.json and clean.json files
  --matching MATCHING   set this to dns for the dns dataset.
  --no_pesq             Don't compute PESQ.
  -v, --verbose         More loggging

4. Denoising

Generating the enhanced files can be done by:

python -m denoiser.enhance --model_path=<path to the model> --noisy_dir=<path to the dir with the noisy files> --out_dir=<path to store enhanced files>

Notice, you can either provide noisy_dir or noisy_json for the test data. Note that the path given to --model_path should be obtained from one of the best.th file, not checkpoint.th. It is also possible to use pre-trained model, using either --dns48, --dns64or --master64. For more details regarding possible arguments, please see:

usage: denoiser.enhance [-h] [-m MODEL_PATH | --dns48 | --dns64 | --master64]
                        [--device DEVICE] [--dry DRY]
                        [--num_workers NUM_WORKERS] [--streaming]
                        [--out_dir OUT_DIR] [--batch_size BATCH_SIZE] [-v]