Coding Noob Needs Help/Guidance on Small Project

Hi,

There's a certain site which hosts media files and has a player that depends on a lot of third-party resources to play, while browsers have native support for those file types. Those 3rd-party resources are often blocked by ad blockers and I have no desire to white-list them. I would like to extract the direct link to the media file and make it playable on my custom web page.

The link to the media file is present in the page source of each page, always on the same line. It's not anchored in HTML but present in the JavaScript for the player, like so:

    $(document).ready(function(){
      $("#jquery_jplayer_1").jPlayer({
        ready: function () {
          $(this).jPlayer("setMedia", {
            [ext]: "https://[domain]/[filename.ext]"
          });
        },

In this example it's on line #5. [ext] = the file extension.

I want to build the following:

• A web page with a form with a single input field meant to receive links from that specific file host
• [Something] that extracts the file link from the source of the host's page
• Present the linked file as playable in an embedded native player

So far I've managed to create a form with an input box and a submit button, but it doesn't do anything yet. What is the best way to build the actual functionality? I know HTML/CSS. I have some rudimentary understanding of JavaScript/jQuery and Python3, so those would be my preferred tools.

For those worried about piracy: The files in question are not copyrighted and I'm not looking to make copies. I just want to make them playable. This is for personal use.

Thank you for reading this far. Any and all advice is welcome!