I worked with ffmpeg for a few years about 6-7 years ago. If I learned anything from that time period, it's that whenever I started a sentence with "ffmpeg doesn't do ..." I was wrong. It may not do it out of the box, and the way to do it may not be documented anywhere, but I was always wrong.
This is probably the most complicated part about ffmpeg. It does EVERYTHING. However, much like the tar command, it takes a lot of googling and doc digging to find the right magic combination of flags and settings to make EVERYTHING happen.
That's not really a knock on it, ffmpeg has some pretty reasonable defaults all around. However, there's a billion codecs and use cases that make it's job challenging.
I'll agree, ffmpeg is super powerful, but here is a situation where I just couldn't get it working:
How do I take a sequence of 5000 pngs, apply a 5 frame crossfade between each one, and then output the resulting mp4 ?
I spent days on trying to figure it out, and in the end I had to generate the xfade frames with imagemagik, then I had to split the rendering into separate mp4s and stitch them together.
I just couldn't get it to slurp in a big list of files and do the filter all in one go. I can't exactly remember what went wrong when I tried to ask it to render the ~25000 frame from imagemagik.
I guess this fits your definition of "not do it out of the box".
