Anyway, I installed ffmpeg onto my B+ Raspbian system (Side note of "some" interest: I think ffmpeg used to be installed by default in Raspbian; now you need to do it yourself). When I run it, I get a big glaring message to the effect that this program is "deprecated" and should not be used. This, of course, seems odd, since "ffmpeg" is a grand old program that lots of people use and it is hard to believe that it is now "deprecated".
Well, a bit of Googling reveals that there is an ego war behind it. Some people forked the code and decided to insert that message just to scare people. I found the following fragment of text:
Anyway, it seems to me that it would be better if the Pi went with the "real" ffmpeg instead of this fork. Apparently, the Debian people went with the fork, for reasons that are not at all clear.The "deprecated" message was designed to mislead users on purpose. The fake, so-called ffmpeg from the fork has been deprecated for avconv. Development of real ffmpeg from FFmpeg is very active. See:
Who can tell me the difference and relation between ffmpeg, libav, and avconv?
The FFmpeg/Libav situation