在html中：

<vg-player (onPlayerReady)="onPlayerReady($event)">
  <video>...</video>
</vg-player>

在ts中，订阅加载元数据，例如：

api: VgApiService;
onPlayerReady(source: VgApiService) {
this.api = source;
this.api.getDefaultMedia().subscriptions.loadedMetadata.subscribe(this.play.bind(this))
}
play() {
this.api.play();
}