import { NativeModules } from 'react-native';  
// compress photo  
var compressOptions = {maxWidth: 1024, maxHeight: 1024, quality: 0.8};
var opt = {file: 'file path to the photo'};
NativeModules.AssetExport.exportPhoto(Object.assign(opt, compressOptions), (path, code) => {
    if(code > 0){
        console.log(path);// the path is the compressed photo path
    }
    else{
        this.onFailed && this.onFailed(path);
    }
});  
// compress video  
NativeModules.AssetExport.exportVideo(this.props.video, {width, height} ,uri => {
    if(uri.startsWith('file://'))
        uri = uri.substring(7);
    console.log(uri);// the uri is the compressed video path
});