It's a joke. Doesn't work.

So far, it seems to be a brilliant extension, but I will have to figure out all its possibilities.
For example, I think I installed the ffmpeg correctly, but when I try to merge, my Firewall asks for permission to connect to 127.0.0.1 etc.
I'm guessing that this is not a problem, but I will have to figure that out before I allow it.
It would be nice if that was explained somewhere.
PS: I gave the permission to my firewall, because the adress 127.0.0.1 directs to my own computer ("localhost") and in the "settings" of the extension I Installed the "native client" and the "Ffmpeg". The merging didn't work at first, but then I specified the path where the "Ffmpeg" is located, and the path where I wanted the merged file to be created, and it worked!
BRILLIANT!!!
PPS: The problem with this extension is that the developer did a poor job of explaining how it works and how to set it up correctly. For example a very basic thing was never explained: when one downloads a "video only" resolution, an audio file will be downloaded too, and if the extension is set up correctly, the two will be merged.
Fascinating how some people don't understand the need for good communication...
Take a look at this video which explains just that:
https://www.youtube.com/watch?v=xGqn2RRbcjw
And I still don't know what "Post processing (if FFmpeg is installed)" is about?

nice tool but the built in download manager of FF is slow , can it link the download to IDM?

My experience is the same as a reviewer below; the files aren't automatically merged, even if I point it to ffmpeg. But this is actually a plus! The DASH_A and DASH_V files are saved separately in my default download directory. So, if I want just audio or video, no need to do anything. And, the ffmpeg command to merge them is straightforward, and because it is a copy, fast and no loss of quality because of demuxing and muxing. e.g. ffmpeg -i file_DASH_A.mp4 -i file_DASH_V.mp4 -c:a copy -c:v copy file.mp4
Perfect!

Want to download 1080p and higher resolution videos? This is the only plugin does this with transparency.

Works like a charm!

unfortunately broken again. fix would be appreciated. thx

faltan opciones/links, menu innecesario; sorry

it worked like a charm for me. Thanks