How to fix out-of-sync subtitles
- Find how far off they are: play the video, note when a line should appear versus when it does, and take the difference in seconds.
- Paste the SRT, enter that difference, and shift. If subtitles appear 2 seconds late, shift by -2. If they appear early, shift by a positive number.
- Check the first and last lines after shifting, then save as a new .srt file.
Note: Times that would go below 00:00:00 are clamped to zero, so a large negative shift will not produce invalid timestamps.