Wiki.js尚未支持在Markdown中直接解析 video 标签视频文件和YouTube等外部嵌入式视频，可通过在页面注入JS解析代码实现视频嵌入播放。以下代码注入可实现YouTube、Screencast视频嵌入Wiki.js,并可通过 video 标签解析mp4视频文件。

在Wiki.js管理后台进入 Admin Area -> Theme -> Code Injection，在 Head HTML Injection 下注入以下代码。

<script type="text/javascript" defer>
  const rxYoutube = /^.*^((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/|shorts\/)?)([\w\-]+)(\S+)?$/

  const rxScreencast = /^.*^((?:https?:)?\/\/)?(www\.)?(screencast\.com)(\/users)\/([a-z0-9_-]+)\/folders\/([a-z0-9%_-]+)\/media\/([a-z0-9_-]+)(?:\/)?$/im

  window.boot.register('vue', () => {
    window.onload = () => {
      document.querySelectorAll('.contents oembed, .contents a').forEach(elm => {
        const url = elm.hasAttribute('url') ? elm.getAttribute('url') : elm.getAttribute('href')
        let newElmHtml = null

        const ytMatch = url.match(rxYoutube)
        const scMatch = url.match(rxScreencast)

        if (ytMatch) {
          newElmHtml = `<iframe id="ytplayer" type="text/html" width="640" height="360" src="https://www.youtube-nocookie.com/embed/${ytMatch[5]}" frameborder="0" allow="accelerometer; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>`
        } else if (scMatch) {
          newElmHtml = `<iframe id="scplayer" type="text/html" width="640" height="360" src="${url}/embed" frameborder="0" allowfullscreen></iframe>`
        } else if (url.endsWith('.mp4')) {
          newElmHtml = `<video controls autostart="0" name="media" width="640" height="360"><source src="${url}" type="video/mp4"></video>`
          } else {
            return
          }
        }

        const newElm = document.createElement('div') 
        newElm.classList.add('responsive-embed')
        newElm.insertAdjacentHTML('beforeend', newElmHtml)
        elm.replaceWith(newElm)
      })
    }  
  })
</script>

在 CSS Override 下注入以下样式代码。

.responsive-embed {
  position: relative;
  padding-bottom: 56.2%;
  height: 0;
  margin: 10px 0;
  overflow: hidden;
}

.responsive-embed iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 5px;
}

在Markdown编辑器直接粘贴YouTube视频链接即可，比如：https://www.youtube.com/watch?v=KOc146R8sws

参考资料：https://github.com/requarks/wiki/discussions/4580