So I want MEncoder to encode all png files as an avi file from the earliest date modified to the last date modified, and I'd like each frame to be spaced out by 3 seconds.
The mf:// syntax says you can pass a listfile, so you can pass a list of files, sorted by date, that way.
To sort your files, if the names are simple enough and they're all in one directory,
If you need to handle more complicated stuff (e.g., subdirectories), you could use find and perl together. I'm ignoring the possibility of newlines in the filenames, as I doubt
That's not particularly efficient (it calls