Clipstitch
Uility to make home movies from your digital camera files
... in easier-to-read form, and internally combines multiple ffmpeg commands to do certain tasks.. You can put Clipstitch commands into a text file and run as a script or type them in manually at a prompt.
You can:
Select portions of motion files with optional fades/slowmo/speedup, reverse play backwards.
Adjust clip order.
Concatenate to make your final "movie".
V5.5 introduced captions, and special effects features.
Docs: http://www.twentypede.com/leg4/clipstitch5.6.html