Took 4 hours to figure out why subs kept desyncing on my rewatch

The audio track was fine, the video file was fine, but every 20 minutes the timing drifted until I realized my player was using a 25fps profile for a 23.976fps video. Has anyone else hit this with older fansubs or did I just waste an entire evening for nothing?

2 comments

2 Comments

jesse_fisher7d ago

God I hate when that happens lol. You didn't waste an evening, you just joined the club of people who've lost sleep over something a setting that takes two clicks could've fixed. I remember spending a whole night once trying to match audio to a show where the subs were early by like half a second, and it turned out my video player had a weird "auto adjust" option that was making things worse. Your 25fps vs 23.976 thing is way more clever though, at least you figured out the actual math problem. I just sat there grumbling and restarting the file like an idiot. Honestly, old fansubs are a whole other beast, they're lucky we still watch them at all.

ross.kevin7d ago

your 25fps vs 23.976 thing is way more clever" honestly that's the trap though, you think you solved it and then you realize older fansubs sometimes had variable frame rates baked in, not just a straight 25fps rip. I've had files where the sub timing drifts only during action scenes, which makes zero sense until you check the actual frame rate track and see it jumps between 23.9 and 24.5 randomly. That's when you stop blaming the player and start using mkvtoolnix to extract the timecodes and manually shift segments. One bad encode of Steins;Gate had me writing a script to adjust sync every 8 minutes, absolute nightmare. So yeah you wasted an evening but now you know the real enemy is lazy encoders who didn't flag the variable stuff.