GUIDE / SUBTITLE SYNCHRONIZATION

PAL Framerate Drift: Why 23.976 FPS to 25 FPS Causes Progressive Desync

Understand why a subtitle track can begin aligned and drift further out of sync over time.

Why 23.976 FPS to 25 FPS creates progressive drift

A 23.976 FPS source and a 25 FPS release run at different rates. A subtitle line may match near the opening and then become increasingly early or late as the video continues. A single offset cannot repair an error that grows over time.

Apply linear framerate correction

Use the source-to-target relationship as a multiplier: 25 divided by 23.976 is approximately 1.042709. The PAL preset applies this linear scaling to every subtitle timestamp while keeping the original track untouched.

Verify the final scene

Check dialogue near the beginning, middle, and end of the video. If the alignment holds across all three points, download the corrected SRT and retain the original as a backup.