Many modern video streams (like DASH or HLS) are served in small chunks. The native app uses the FFmpeg toolkit to merge these segments into a single file.
The Ant Video Downloader native app is a 32-bit Windows "messaging host" that provides extended features the browser extension cannot handle alone. Segment Merging: download native app for ant video downloader
Once the extension is installed, follow these steps: Many modern video streams (like DASH or HLS)