Blog
Opening a short drama episode on a phone: from 8 seconds to 0.3 seconds
The video itself didn't change; the way the file was laid out was wrong.
The problem we measured
The Editor exports fragmented MP4, so the browser has to jump around reading it piece by piece, and it took 8–10 seconds before playback could start.
Method
The playback copy is repackaged: the index goes at the front, audio and video interleave every 0.5 seconds, and it's swapped in only after being checked frame by frame once written. The original file is untouched.
Result
On the live site, playback starts in 0.26–0.48 seconds. We later added 720p and 480p versions, picked by screen and network, and it steps down if it stalls.