Realizing that I had not copied trip videos before I had reformatted and reused the memory card made me first bang my head against the desk, then trying to recover what's still left on the card.
I tried two different programs, putting the results in two different folders. The second program seemed to recover more files than the first one did, but at closer inspection many of those files were just tiny fragments of one video.
So I try to make a "union" of all those fragments. Unfortunately the recovery process destroyed the creation dates of the files (Most files were AVCHD (BDMV, m2ts), a few were MP4).
After having previewed all the fragments, I'd like to rename the files using a common pattern like
YYYY-MM-DD_HHMMSS@HHMMSS (year, month, day, hour, minute, second plus duration) or
YYYY-MM-DD_HHMMSS-HHMMSS using creation date and time as well as ending time (starting time plus duration).
Sorting those files by name I should easily find duplicates and overlaps.
Despite of that renaming using exiftool, I wonder whether someone has mastered a similar challenge before. Other software I have available is EDIUS 8 and the free version of Davici Resolve. I don't know (or how) whether they could assist aligning all those fragments in to one sequence, but that is very much what I want eventually.