All of the above.
You may opt to encode the overlay directly if you are compressing on-the-fly.
You may opt for Oceanvault to record the overlay configuration and data for every video file. “Oceanvault – Player” will be looking for these files every time you open a video file.
The overlay and data files are compatible with MS Excel so you can edit these files in post processing to correct mistakes, average out values, even add more overlay info such as elevation.
“Oceanvault – Player” can record the video with overlay when you are happy with the data.