The lecture re-airs with cat

Tuesday's lecture was live: the instructor's display, captured by ffmpeg, streamed through a pipe to forty students: with ?n=41, because the forty-first receiver was curl -o lecture.webm, quietly saving an identical copy of what everyone watched.

Thursday, the students who missed it ask for the recording. Re-airing is one line: cat lecture.webm into a fresh pipe path, ?n set to however many show up, ?video on their end. Same stream, same embedded player, three days later.

There's no upload step, no video platform, no processing queue between "we recorded it" and "you can watch it." The recording was just another receiver, and the rerun is just another sender.