pixelfed/app/Http/Controllers/MediaController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use App\Media;

class MediaController extends Controller
{
	public function index(Request $request)
	{
		//return view('settings.drive.index');
	}

	public function composeUpdate(Request $request, $id)
	{
        abort(400, 'Endpoint deprecated');
	}	

	public function fallbackRedirect(Request $request, $pid, $mhash, $uhash, $f)
	{
		abort_if(!config_cache('pixelfed.cloud_storage'), 404);
		$path = 'public/m/_v2/' . $pid . '/' . $mhash . '/' . $uhash . '/' . $f;
		$media = Media::whereProfileId($pid)
			->whereMediaPath($path)
			->whereNotNull('cdn_url')
			->firstOrFail();

		return redirect()->away($media->cdn_url);
	}
}