: This software offers an advanced repair option for severely corrupted files, including those with missing metadata or frame issues. Common Fixes for Choppy Playback
If "nippy" is a script using ffmpeg or mp4box that hasn't been updated since 2015, it might be failing on modern video files (like HEVC or AV1) or failing due to syntax changes in FFmpeg. nippy user since 2015 mp4 fix
This fixes 80% of issues without losing quality. : This software offers an advanced repair option