ffmpeg took a different approach (sort of like a single program/system with many command line options). Some say its easier to use (at least easier than gst-launch)

I find the ffmpeg options dizzying whereas the single syntax for gst-launch and parse_bin_from_description is pretty neat. But then I guess you've still got a selection of randomly named properties to discover and correctly set.

occasionally they have events exchanged that can't be implemented with gst-launch, you have to do it in C. Go figure.