Format strings with data from multiple files?

[horshack]

I use exiftool's format string functionality (-p) quite often. Is it possible to refer to multiple files with this option? My specific need is to calculate the delta creation time delta between the current file vs previous file across all files processed in a single invocation of exiftool (I'm using the SubSecDateTimeOriginal tag). For example, if exiftool processes 4 files in a single invocation, I want to calculate and print the delta time between file #1 vs file #0, file #2 vs file #1, file #3 vs file #2.

[StarGeek]

Realistically, not really on the command line, as exiftool only processes only one file at a time.

Technically, possibly.  There are a few examples in these forums where Phil basically puts a whole perl program into the command line, but it takes some knowledge of Perl and the exiftool library.  For example.  But at that point, you might as well write an actual script.