I am developing an app in flutter which has requirements to load some videos in cache and then play it respectively.
below is my code what actually i am doing,

void downloadFile() async {
   
   

    var cacheFile = DefaultCacheManager();
    
        
        // get file  path from server
    
        var list = await giftOperations.getGiftName("1");
    
    
        // check if file is already cached or not
        for (var element in list) {
    
          var url = AppUrl.newBaseUrl + (element.animationFilePath ?? "");
    
          // if file is not cached then get the file from server and cache it
    
          var fileCachedAlready = await cacheFile.getFileFromCache(url);
    
          // if file is already cached then add it to the list
    
          if (fileCachedAlready != null && fileCachedAlready.file.existsSync()) {
            // do some code here
          } else {
            // download file from server through url and cache it
    
            await cacheFile.downloadFile(url);
    
            // add the file to the list
            
          }
}

then i get the file through the following code.

    var cachedFile =  await DefaultCacheManager().getFileFromCache(giftName.animationFilePath);
    ByteData data = await rootBundle.load(cachedFile!.file.path);
         List<int> bytes = data.buffer.asUint8List();
         var memory = Uint8List.fromList(bytes);

But here it throws the following error

FlutterError (Unable to load asset: "/data/user/0/com.example.mvvm/cache/libCachedImageData/3169cb20-5a38-11ef-b7b9-23c107b39441.mp4".
The asset does not exist or has empty data.)

What i am missing. Any help will be really appreciated.
And downloading data from server is very time consuming. Is there any way to run this parallel, fast and optimized.