First, you need to install ffmpeg. On Mac/Linux it could be as easy as using your packet manager. For example "brew install ffmpeg" or "apt install ffmpeg". On Windows, you need to download the binaries.
To find out the tbn of a video, just run
the tbn will be shown with the video stream information.
For reference, iPhone 15 uses tbn 600, Blackmagic Cam tbn 60000,
Davinci Resolve generally 15360, and YouTube 1000.
To extract the timepoints from a video, run
this will write all the timepoints into the file tmp.txt in the current working directory.
Those need to be copied into the textarea below.
Testdata from Blackmagic Cam, tbn 60000, target frame rate 60
Testdata from Blackmagic Cam, tbn 60000, target frame rate 30
Testdata from iPhone 15, tbn 600, target frame rate 60
Testdata from iPhone 15, tbn 600, target frame rate 25