js实现GIF动图分解成多帧图片上传

在项目中遇到需要支持上传gif图片，并把其分解的帧图片一次展示给用户。话不多说直接上代码

分解gif图片需要使用libgif-js这个库！

1. 引入Git库

import SuperGif from './libgif.js'

2. 分解Gif为png图片

const GifDecomposer = {
 structureGifObject (gifFiles, cb) { // gifFiles 获取的文件对象 e.target.files[0]
   const gifImg = document.createElement('img');
   gifImg.setAttribute('rel:animated_src', URL.createObjectURL(gifFiles));
   gifImg.setAttribute('rel:auto_play', '0');
   // Modified pictures must be added to the body
   document.body.appendChild(gifImg);
   // Construction example
   var rub = new SuperGif({ gif: gifImg });
   rub.load(() => {
     var img_list = [];
     for (let i=1; i <= rub.get_length(); i++) {
       // Traversing through each frame of a GIF instance
       rub.move_to(i);
       // Converting each frame of canvas into a file object
       let cur_file = this.convertCanvasToImage(rub.get_canvas(), gifFiles.name.replace('.gif', '') + `-${i}`)
       img_list.push({
         file_name: cur_file.name,
         url: URL.createObjectURL(cur_file),
         file: cur_file,
       })
     }
     cb(img_list)
   });
 },
 dataURLtoFile (dataurl, filename) {
   const arr = dataurl.split(',');
   const mime = arr[0].match(/:(.*?);/)[1];
   const bstr = atob(arr[1]);
   var n = bstr.length;
   const u8arr = new Uint8Array(n);
   while (n--) {
     u8arr[n] = bstr.charCodeAt(n);
   }
   return new File([u8arr], filename, {type:mime});
 },
 convertCanvasToImage (canvas, filename) {
   return this.dataURLtoFile(canvas.toDataURL('image/png'), filename);
 }
}

3. 上传每一张图片

/**
* costume upload GIF decomposer
*/
const filesImg = function (list, storage, costumeFormat, assetType, handleCostume) {
 let proDataList = list.map((item, index) => {
     return new Promise(function(resolve, reject) {
       let reader = new FileReader();
       reader.readAsArrayBuffer(item.file);
       reader.onload = () => {
         let data = {result: reader.result, type: item.file.type, name: item.file.name}
         resolve(data);
       };
       reader.onerror = (error) => {reject(error)};
     })
   })
 Promise.all(proDataList).then(res => {
   res.forEach(item => {
   // 上传
   })
 }).catch(data => {console.log(data)})
}

来源：https://blog.csdn.net/weixin_42856280/article/details/89372802