Automatic video clip subtitle generation?

[Lutz Vieweg]

Hi all,

I've got a somewhat weird feature idea, and first want to find out
whether somebody else would find this useful:

Many divers like to record videos while diving - I certainly do.
While editing recordings from my last vacation (if you are interested
in the result and you don't mind transferring 3.6GB, you can download
it here:
> http://archive.org/download/Curacao_Under_the_Wind_and_Under_Water/Curacao_Under_the_Wind_and_Under_Water_2012.mp4  ) I noticed how tedious it was to keep track of what scene was recorded
where - just because there were so many (about 1000) clips. That caused
me to give up the idea of creating a subtitle track that would have -
optional for the viewer - informed about the dive site where the
shots where taken.

Later on I found that since the camera itself records the time and date
in a (PGS-) subtitle track (inside its AVCHD *.MTS files), it should
theoretically be possible to automatically generate such an informal
subtitle track, by extracting the dive site information from the
subsurface data, indexed by the date and time found in the *.MTS files.

The coarse idea would be to first extract the PGS subtitles from the
.MTS files (using e.g. mplayer), then to OCR them (using tesseract or
alike), then to lookup the time stamps in the subsurface .xml file,
extracting the dive spot location from there, then to create a
subtitle track from that and re-mux the *.MTS files into e.g. MKV
containers along with the additional subtitle track. I still have to
figure out if that is possible in a way that would survive the rest
of my editing workflow (using avidemux and kdenlive).

But before I endeavor to try this, I'd be interested in some feed back:
- Is such a feature that you would find useful?
- Does your underwater camera also record date/time as PGS subtitles?
- Do you have any experience with passing subtitles through a video
   post production workflow?

Regards,

Lutz Vieweg