yt-dlp is an open-source command-line tool maintained by the open-source community as an evolution of the original youtube-dl project. It works by simulating a browser session to retrieve video manifest files (which list available quality streams) from video hosting platforms, then downloading and merging the best video and audio streams using FFmpeg.
yt-dlp is continuously updated to maintain compatibility as platforms update their APIs and player interfaces. TransmuteBox always runs the latest yt-dlp release.