      // Get the slide video and its sources for each background
          const video = slide.querySelector('video');
          if (video) {
            setVideoBase64(video);
          } else {
            // Listen to the creation of the video element
            const observer = new MutationObserver((mutationsList) => {
              for (const mutation of mutationsList) {
                if (mutation.type === 'childList') {
                  for (const addedNode of mutation.addedNodes) {
              