I'm trying to access a gif file from an already loaded source to read it's meta data
(by using the console in devTools)

The html is as such:

<video>
 <source src="https://somesite.com/somegif.gif?format=mp4">
</video>

and I already have a function which reads and prints the meta data but it takes File data type as an argument:

function gifMetadata(file){
  let fileReader = new FileReader();
  fileReader.readAsArrayBuffer(file);
  ...
}

so how do I get file from source without having to fetch() the data again?