Cannot detect for live camera?

[ngochai27595]

Hi author,
I'm trying to detect hand of two cameras in my conference like below image. But the result always return null. Could you help me? Thanks
Here is my code:
const largeVideo = ((document.getElementById('largeVideo'): any): HTMLVideoElement);
const localVideo = ((document.getElementById('localVideo_container'): any): HTMLVideoElement);
// Load the model.
const defaultParams = {
flipHorizontal: false,
modelType: "ssd640fpnlite",
modelSize: "medium",
};
handTrack.load(defaultParams).then(model => {
console.log("model loaded");
setTimeout(() => { clearInterval(checkHighFive); }, 6000);
checkHighFive = setInterval(()=>{
let localHand = false;
model.detect(localVideo).then(predictions => {
console.log('Predictions localVideo: ', predictions);
if(predictions.lenght > 0 && predictions[0].label == "open"){
localHand = true;
}
});
model.detect(remoteVideo).then(predictions => {
console.log('Predictions remoteVideo: ', predictions);
if(predictions.lenght > 0 && predictions[0].label == "open" && localHand){
this.props.dispatch(highFive(true));
setTimeout(() => { this.props.dispatch(highFive(false)); }, 4000);
this.props.conference.sendCommandOnce('HIGH_FIVE', { value:_participant.id });
clearInterval(checkHighFive);
}
});
}, 500);
})