A guy on a forum said my subtitles were timed to the wrong frame rate, and he was right
I had been ripping my old kung fu tapes to digital for months and always just guessed the subtitle timing by eye, which meant they drifted about 3 seconds off by the end of the movie. Someone on a trading board pointed out that my PAL tapes run at 25 frames per second but I was syncing to NTSC at 23.976, so of course it slid. I got a free tool called Subtitle Edit and now I fix the frame rate first thing before I touch a single line. My last rip of a battered copy of Master of the Flying Guillotine finally lines up perfect, and it feels good. Anyone else got a go to trick for matching subs to a weird tape speed?
You ever notice how PAL tapes always run a touch fast too, so the audio is pitched up and the movie ends quicker than the theater cut? That speedup plus the frame rate mismatch is a double whammy nobody warns you about. I had a copy of Police Story where the subs were fine but everyone sounded like chipmunks, because 25 to 23.976 is about a 4 percent squeeze. Subtitle Edit's frame rate change tool fixes the subs in one click, then you just nudge the start time and you're done. Master of the Flying Guillotine is a great pick for testing this too, since the dubbing and subs never match up anyway.