vue videojs使用canvas截取视频画面

前言
刚开始做的时候太多坑，导致一直报错：
Uncaught (in promise) TypeError: Failed to execute ‘drawImage’ on ‘CanvasRenderingContext2D’: The provided value is not of type ‘(CSSImageValue or HTMLCanvasElement or HTMLImageElement or HTMLVideoElement or ImageBitmap or OffscreenCanvas or SVGImageElement or VideoFrame)’.

直接上代码！！！

1、html

<el-button class="capture-item" type="primary" @click="captureScreenshot">截图el-button>

<video id="viewer" class="video-js vjs-default-skin" crossorigin="anonymous" controls>
      <source :src="playVideo.url" type='video/mp4'>
video>

2、js

/** 初始化视频播放器 */
    const initViewer = async () => {
      await nextTick() // 等待 DOM 更新

      // 初始化 video.js
      player.value = videojs('viewer', {
        controls: true,
        autoplay: true,
        fluid: true,
      });
    }
    
// 截图功能
    const captureScreenshot = () => {
      if (!player.value) return;

      const videoElement = player.value.el().querySelector('video');
      if (!videoElement) return;

      // 创建 Canvas
      const canvas = document.createElement('canvas');
      const ctx = canvas.getContext('2d');
      if (!ctx) return;

      // 设置 Canvas 尺寸（可排除控制条）
      const controlHeight = 30; // 控制条高度
      canvas.width = videoElement.videoWidth;
      canvas.height = videoElement.videoHeight - controlHeight;

      // 绘制当前帧
      ctx.drawImage(
        videoElement,
        0, 0,
        videoElement.videoWidth, videoElement.videoHeight - controlHeight, // 源尺寸
        0, 0,
        canvas.width, canvas.height // 目标尺寸
      );

      // 转换为 DataURL
      const dataUrl = canvas.toDataURL('image/png');

      downloadImage(dataUrl);
    };

    // 下载图片
    const downloadImage = (dataUrl: string) => {
      const link = document.createElement('a');
      link.download = `视频截图_${new Date()}.png`;
      link.href = dataUrl;
      link.click();
    };

我这里是截取完画面下载到浏览器！

3、图例

点击《截图》，直接下载