video视频播放在APP有一层灰，在小程序则正常显示

<template>  
    <view>  
        <video :style="{'width':`${widht}px`,'height':`${height}px`}"  
            src="https://dingxin-prod-1300739938.cos.ap-guangzhou.myqcloud.com/static/video/2021-12/goods/202112031638515633054.mp4" />  
    </view>  
</template>  

<script>  
    export default {  
        data() {  
            return {  
                widht: 0,  
                height: 0,  
            }  
        },  
        onLoad() {  
            uni.getSystemInfo({  
                success: data => {  
                    this.widht = data.windowWidth  
                    this.height = data.windowHeight  
                },  
            })  
        },  
    }  
</script>

这是为什么呢？