Per user direction ('pakai dank sebagai referensi karena itu yg berhasil'):
drop the custom setInterval/tail-drop emission clock entirely. The demuxer
now writes each access unit straight to vPipe with a monotonic PTS and lets
BaseMediaStream (ported 1:1 from @dank074) handle pacing via sleep-PTS + A/V
sync, exactly like the upstream library. The custom clocks were the source of
the blank tile (IDR delivery race) and the lag (head-drop watching 10s-old
frames).
Adds proper backpressure: pause ffmpeg stdout when vPipe.write() returns
false, resume on drain — mirrors dank's 'resume &&= vPipe.write(packet)' so the
encoder self-throttles to the WebRTC sender's real pace instead of bursting.