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silero-vad/README.md
Dimitrii Voronin 4818f351e2 Update README.md
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[![Mailing list : test](http://img.shields.io/badge/Email-gray.svg?style=for-the-badge&logo=gmail)](mailto:hello@silero.ai) [![Mailing list : test](http://img.shields.io/badge/Telegram-blue.svg?style=for-the-badge&logo=telegram)](https://t.me/joinchat/Bv9tjhpdXTI22OUgpOIIDg) [![License: CC BY-NC 4.0](https://img.shields.io/badge/License-MIT-lightgrey.svg?style=for-the-badge)](https://github.com/snakers4/silero-vad/blob/master/LICENSE)
[![Open on Torch Hub](https://img.shields.io/badge/Torch-Hub-red?logo=pytorch&style=for-the-badge)](https://pytorch.org/hub/snakers4_silero-vad/) (coming soon)
[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/snakers4/silero-vad/blob/master/silero-vad.ipynb)
![header](https://user-images.githubusercontent.com/12515440/89997349-b3523080-dc94-11ea-9906-ca2e8bc50535.png)
- [Silero VAD](#silero-vad)
- [Getting Started](#getting-started)
- [PyTorch](#pytorch)
- [ONNX](#onnx)
- [Metrics](#metrics)
- [Performance Metrics](#performance-metrics)
- [VAD Quality Metrics](#vad-quality-metrics)
- [FAQ](#faq)
- [How VAD Works](#how-vad-works)
- [VAD Quality Metrics Methodology](#vad-quality-metrics-methodology)
- [How Number Detector Works](#how-number-detector-works)
- [How Language Classifier Works](#how-language-classifier-works)
- [Contact](#contact)
- [Get in Touch](#get-in-touch)
- [Commercial Inquiries](#commercial-inquiries)
# Silero VAD
![image](https://user-images.githubusercontent.com/36505480/102872739-ce099280-4448-11eb-967b-724440165eb5.png)
**Silero VAD: pre-trained enterprise-grade Voice Activity Detector (VAD), Number Detector and Language Classifier.**
Enterprise-grade Speech Products made refreshingly simple (see our [STT](https://github.com/snakers4/silero-models) models).
Currently, there are hardly any high quality / modern / free / public voice activity detectors except for WebRTC Voice Activity Detector ([link](https://github.com/wiseman/py-webrtcvad)). WebRTC though starts to show its age and it suffers from many false positives.
Also in some cases it is crucial to be able to anonymize large-scale spoken corpora (i.e. remove personal data). Typically personal data is considered to be private / sensitive if it contains (i) a name (ii) some private ID. Name recognition is a highly subjective matter and it depends on locale and business case, but Voice Activity and Number Detection are quite general tasks.
**Key features:**
- Modern, portable;
- Low memory footprint;
- Superior metrics to WebRTC;
- Trained on huge spoken corpora and noise / sound libraries;
- Slower than WebRTC, but fast enough for IOT / edge / mobile applications;
- Unlike WebRTC (which mostly tells silence from voice), our VAD can tell voice from noise / music / silence;
**Typical use cases:**
- Spoken corpora anonymization;
- Can be used together with WebRTC;
- Voice activity detection for IOT / edge / mobile use cases;
- Data cleaning and preparation, number and voice detection in general;
- PyTorch and ONNX can be used with a wide variety of deployment options and backends in mind;
## Getting Started
The models are small enough to be included directly into this repository. Newer models will supersede older models directly.
Currently we provide the following functionality:
| PyTorch | ONNX | VAD | Number Detector | Language Clf | Languages | Colab |
|-------------------|--------------------|---------------------|-----------------|--------------|------------------------|-------|
| :heavy_check_mark:| :heavy_check_mark: | :heavy_check_mark: | | | `ru`, `en`, `de`, `es` | [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/snakers4/silero-vad/blob/master/silero-vad.ipynb) |
**Version history:**
| Version | Date | Comment |
|---------|-------------|---------------------------------------------------|
| `v1` | 2020-12-15 | Initial release |
| `v2` | coming soon | Add Number Detector or Language Classifier heads, lift 250 ms chunk VAD limitation |
### PyTorch
[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/snakers4/silero-vad/blob/master/silero-vad.ipynb)
[![Open on Torch Hub](https://img.shields.io/badge/Torch-Hub-red?logo=pytorch&style=for-the-badge)](https://pytorch.org/hub/snakers4_silero-vad/) (coming soon)
```python
import torch
torch.set_num_threads(1)
from pprint import pprint
model, utils = torch.hub.load(repo_or_dir='snakers4/silero-vad',
model='silero_vad',
force_reload=True)
(get_speech_ts,
_, read_audio,
_, _, _) = utils
files_dir = torch.hub.get_dir() + '/snakers4_silero-vad_master/files'
wav = read_audio(f'{files_dir}/en.wav')
# full audio
# get speech timestamps from full audio file
speech_timestamps = get_speech_ts(wav, model,
num_steps=4)
pprint(speech_timestamps)
```
### ONNX
[![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/snakers4/silero-vad/blob/master/silero-vad.ipynb)
You can run our model everywhere, where you can import the ONNX model or run ONNX runtime.
```python
import onnxruntime
from pprint import pprint
_, utils = torch.hub.load(repo_or_dir='snakers4/silero-vad',
model='silero_vad',
force_reload=True)
(get_speech_ts,
_, read_audio,
_, _, _) = utils
files_dir = torch.hub.get_dir() + '/snakers4_silero-vad_master/files'
def init_onnx_model(model_path: str):
return onnxruntime.InferenceSession(model_path)
def validate_onnx(model, inputs):
with torch.no_grad():
ort_inputs = {'input': inputs.cpu().numpy()}
outs = model.run(None, ort_inputs)
outs = [torch.Tensor(x) for x in outs]
return outs
model = init_onnx_model(f'{files_dir}/model.onnx')
wav = read_audio(f'{files_dir}/en.wav')
# get speech timestamps from full audio file
speech_timestamps = get_speech_ts(wav, model, num_steps=4, run_function=validate_onnx)
pprint(speech_timestamps)
```
## Metrics
### Performance Metrics
All speed test were run on AMD Ryzen Threadripper 3960X using only 1 thread:
```
torch.set_num_threads(1) # pytorch
ort_session.intra_op_num_threads = 1 # onnx
ort_session.inter_op_num_threads = 1 # onnx
```
#### Streaming Latency
Streaming latency depends on 2 variables:
- **num_steps** - number of windows to split each audio chunk into. Our post-processing class keeps previous chunk in memory (250 ms), so new chunk (also 250 ms) is appended to it. The resulting big chunk (500 ms) is split into **num_steps** overlapping windows, each 250 ms long.
- **number of audio streams**
So **batch size** for streaming is **num_steps * number of audio streams**. Time between receiving new audio chunks and getting results is shown in picture:
| Batch size | Pytorch model time, ms | Onnx model time, ms |
| :-------------: |:-------------:| :-----:|
| **2** | 9 | 2 |
| **4** | 11 | 4 |
| **8** | 14 | 7 |
| **16** | 19 | 12 |
| **40** | 36 | 29 |
| **80** | 64 | 55 |
| **120** | 96 | 85 |
| **200** | 157 | 137 |
We are working on lifting this 250 ms constraint.
#### Full Audio Throughput
**RTS** (seconds of audio processed per second, real time speed, or 1 / RTF) for full audio processing depends on **num_steps** (see previous paragraph) and **batch size** (bigger is better).
| Batch size | num_steps | Pytorch model RTS | Onnx model RTS |
| :-------------: |:-------: | :-------------:| :-----:|
| **40** | **4** | 68 | 86 |
| **40** | **8** | 34 | 43 |
| **80** | **4** | 78 | 91 |
| **80** | **8** | 39 | 45 |
| **120** | **4** | 78 | 88 |
| **120** | **8** | 39 | 44 |
| **200** | **4** | 80 | 91 |
| **200** | **8** | 40 | 46 |
### VAD Quality Metrics
We use random 250 ms audio chunks for validation. Speech to non-speech ratio among chunks is about ~50/50 (i.e. balanced). Speech chunks are sampled from real audios in four different languages (English, Russian, Spanish, German), then random background noise is added to some of them (~40%).
Since our VAD (only VAD, other networks are more flexible) was trained on chunks of the same length, model's output is just one float from 0 to 1 - **speech probability**. We use speech probabilities as thresholds for precision-recall curve. This can be extended to 100 - 150 ms (coming soon). Less than 100 - 150 ms cannot be distinguished as speech with confidence.
[Webrtc](https://github.com/wiseman/py-webrtcvad) splits audio into frames, each frame has corresponding number (0 **or** 1). We use 30ms frames for webrtc, so each 250 ms chunk is split into 8 frames, their **mean** value is used as a treshold for plot.
![image](https://user-images.githubusercontent.com/36505480/102872739-ce099280-4448-11eb-967b-724440165eb5.png)
## FAQ
### How VAD Works
- Audio is split into 250 ms chunks;
- VAD keeps record of a previous chunk (or zeros at the beginning of the stream);
- Then this 500 ms audio (250 ms + 250 ms) is split into N (typically 4 or 8) windows and the model is applied to this window batch. Each window is 250 ms long (naturally, windows overlap);
- Then probability is averaged across these windows;
- Though typically pauses in speech are 300 ms+ or longer (pauses less than 200-300ms are typically not meaninful), it is hard to confidently classify speech vs noise / music on very short chunks (i.e. 30 - 50ms);
- We are working on lifting this limitation, so that you can use 100 - 125ms windows;
### VAD Quality Metrics Methodology
Please see [Quality Metrics](#quality-metrics)
### How Number Detector Works
TBD, but there is no explicit limiation on the way audio is split into chunks.
### How Language Classifier Works
TBD, but there is no explicit limiation on the way audio is split into chunks.
## Contact
### Get in Touch
Try our models, create an [issue](https://github.com/snakers4/silero-vad/issues/new), start a [discussion](https://github.com/snakers4/silero-vad/discussions/new), join our telegram [chat](https://t.me/joinchat/Bv9tjhpdXTI22OUgpOIIDg), [email](mailto:hello@silero.ai) us.
### Commercial Inquiries
Please see our [wiki](https://github.com/snakers4/silero-models/wiki) and [tiers](https://github.com/snakers4/silero-models/wiki/Licensing-and-Tiers) for relevant information and [email](mailto:hello@silero.ai) us directly.