<video
  id="videoALL" 
  src="video/01.mp4" 
  poster="images/1.jpg" /*视频封面*/
  preload="auto" 
  webkit-playsinline="true" /*这个属性是ios 10中设置可以
                     让视频在小窗内播放，也就是不是全屏播放*/  
  playsinline="true"  /*IOS微信浏览器支持小窗内播放*/ 
  x-webkit-airplay="allow" 
  x5-video-player-type="h5"  /*启用H5播放器,是wechat安卓版特性*/
  x5-video-player-fullscreen="true" /*全屏设置，
                     设置为 true 是防止横屏*/>
  x5-video-orientation="portraint" /*播放器支付的方向，
                     landscape横屏，portraint竖屏，默认值为竖屏*/
  style="object-fit:fill">
</video>

<div id="videobox">
   <video 
    id="videoALL" 
    src="mp4.mp4" 
    poster="1.jpg" 
    preload="auto" 
    webkit-playsinline="true" 
    playsinline="true" 
    x-webkit-airplay="allow" 
    x5-video-player-type="h5" 
    x5-video-player-fullscreen="true" 
    x5-video-orientation="portraint"
    style="object-fit:fill">
    </video> 
   <div id="btn" onclick="playcontr()"></div>
</div>
<div id="videoend"><div id="againbtn" onclick="playcontr()"></div></div>

*{
            padding: 0;
            margin: 0;
        }
    #videobox{position: absolute;width: 100%;height: 100%;background-color: green;background-image: url(1.jpg);background-size: 100% 100%;background-position: top;overflow: hidden;}
    #videoALL{
  height: auto;
  position: absolute;
  width: 100%;
  top: 0;
  left: 0;
  object-fit: fill;
  display: block;
  background-size: cover;
  overflow: hidden;}
    #btn,#againbtn{width: 81px;height: 75px;position: absolute;top: 50%;left:50%;margin-top: -37.5px;margin-left: -40.5px;background-image: url(btn.png);background-size: 100% 100%;}
    #videoend{position: absolute;background-color: pink;display: none;background-image: url(2.jpg);background-size: cover;background-position: top;}

<script>
var videoALL = document.getElementById('videoALL'),
    videobox = document.getElementById('videobox'),
    btn = document.getElementById('btn'),
    videoend =  document.getElementById('videoend');
var clientWidth = document.documentElement.clientWidth;
var clientHeight = document.documentElement.clientHeight;
videoALL.style.width = clientWidth + 'px';
videoALL.style.height = 'auto';
document.addEventListener('touchmove', function(e){e.preventDefault()}, false);
function stylediv(divId){
    divId.style.width = clientWidth + 'px';
    divId.style.height = clientHeight +200+ 'px'; 
}
stylediv(videobox);
stylediv(videoend);
var u = navigator.userAgent; 
var isAndroid = u.indexOf('Android') > -1 || u.indexOf('Adr') > -1; //android终端 
var isiOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/); //ios终端 
function playcontr(){
    if (isAndroid) {
       videoALL.style.width = window.screen.width + 'px';
       videoALL.style.height = window.screen.height + 'px'; 
    }
    videobox.style.display = "block";
    videoALL.play();
    btn.style.display = "none";
    videoend.style.display = "none";
};
videoALL.addEventListener('pause',function(){  
    videoALL.style.width = clientWidth + 'px';
    btn.style.display = "block";
})  
videoALL.addEventListener("ended",function(){
    videoALL.pause();
    videobox.style.display = "none";
    videoend.style.display = "block";
});
</script>