::Rename all multimedia files in directory '.' to names like '2020-03-27 10-44-55.jpg'
::based on EXIF DateTimeOriginal
::(plus a copy number with a leading '_' if a file with the same name already exists)
::After some tests change TestName to FileName. 
::exiftool.exe -k -P -d "%Y-%m-%d %H-%M-%S%%+c.%%e" "-TestName<DateTimeOriginal" .
exiftool.exe -k -P -d "%%Y-%%m-%%d %%H-%%M-%%S%%%%+c.%%%%e" "-TestName<DateTimeOriginal" .