script.js

const video = document.getElementById('video');
const constraints = {
    audio: false,
    video: {
        width: 720, height: 560
    }
}

Promise.all([
    faceapi.nets.tinyFaceDetector.loadFromUri('./models'),
    faceapi.nets.faceLandmark68Net.loadFromUri('./models'),
    faceapi.nets.faceRecognitionNet.loadFromUri('./models'),
    faceapi.nets.faceExpressionNet.loadFromUri('./models'),
    // faceapi.nets.ageGenderNet.loadFromUri('./models'),
]).then(startVideo)

async function startVideo() {
    try {
        const stream = await navigator.mediaDevices.getUserMedia(constraints);
        video.srcObject = stream;
    }
    catch (e) {
        console.log(e);
    }
}

video.addEventListener('play', () => {
    const canvas = faceapi.createCanvasFromMedia(video);
    document.body.append(canvas);
    const displaySize = { width: 720, height: 560 };
    faceapi.matchDimensions(canvas, displaySize);
    setInterval(async () => {
        const detections = await faceapi.detectAllFaces(video, new faceapi.TinyFaceDetectorOptions()).withFaceLandmarks().withFaceExpressions()
        const resizedDetections = faceapi.resizeResults(detections, displaySize)
        canvas.getContext('2d').clearRect(0, 0, canvas.width, canvas.height)
        faceapi.draw.drawDetections(canvas, resizedDetections)
        faceapi.draw.drawFaceLandmarks(canvas, resizedDetections)
        faceapi.draw.drawFaceExpressions(canvas, resizedDetections)
    }, 100);
  })