Add dive information in video

[patrickelectric]

It's possible to use textoverlay to add log information with video while recording, similar to #32.
Ref.

[patrickelectric]

@jaxxzer what you think about that ?

[jaxxzer]

I've done this: https://github.com/bluerobotics/qgroundcontrol/tree/pr-video-text-overlay

It uses a ton of CPU to re-encode the video, so this implementation at least is not practical for most laptops.

[patrickelectric]

76e9baa CPU problem solved, I'll send a PR ASAP :)

[jaxxzer]

There was still some issue with this, the encoder is required to embed the text in the video, which required the high cpu use.

[Williangalvani]

Note: We decided subtitles (advanced substation alpha subtitles) are the best approach to overlay data on video without re-encoding and still allowing to turn the overlay on/off.
The discussion is now taking place here