A track can be served as pieces: the server writes a VOD playlist whose entries are its own piece URLs (segments, init maps, AES-128 keys; byte ranges folded in; yt-dlp's DASH fragments become the same list). A piece buffer per track fills like the byte buffer. Picks a single file, then a split byte pair, then pieces. DRM, live, master playlists are refused. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>