The original FFmpeg developers were mostly the people developing the project for fun and for personal reasons (i.e. being able to watch anime encoded in some weird format), the newer generation might’ve come for that reason but as often as not they were employed by some large company (or got employed by it soon after they started contributing) so their subsequent work was done mostly on behalf of their employer.
There are some people mentioned in the previous posts like Martin Storsjö so I’ll try to remember the others.
Derek Buitenhuis started his career by reverse-engineering VBLE codec in a very unorthodox way—asking its author to give him source code (IIRC he even introduced me to that guy later at VDD). Well, whatever works (I tried it once with TAK to no avail). Later he’s reverse-engineered a couple of lossless codecs in a more conventional way. Nowadays he works at Vimeo and has to deal with various abuses of MP4 format it seems.
Vittorio Giovara is an Italian from the same place as Luca Barbato. He reverse-engineered a couple of codecs but his main love is various details of video output. Nobody else likes colourspace primaries, interlacing modes and picture cropping just like him. Even his favourite Pokémon is called KROPPING! (sic). Also he has contributed to the Hedgewars game so his name is forever associated with hedgehogs. I heard that Vimeo employed him too.
Tomas Härdin is a guy from Northern Sweden who worked on MXF demuxer and wrote a Cinepak encoder. Something tells me that one of those things were done on behalf of his employer and another one was done just for fun.
Andreas Öman comes from the same region as Harry Hyquist, he eventually got hired by Spotify and moved to live near Luma. So no wonder he made improvements to H.264, AAC and DCA decoders. Also he mentored me during that Summer of Code when I tried to create AAC encoder but the outcome is not his fault.
Now if you say I’m scraping the bottom of the barrel you would be wrong, there are still more people to mention. I expect about four more posts with the last one being a general conclusion so stay tuned (or keep ignoring them, whatever).