Video converters are one of the most plentiful software categories that I know of. (Almost tempted to say “a dime a dozen.”) A lot of them are simply interfaces riding on top of FFMpeg, which I believe is open source — whether so-attributed or not. Some of these are free. Others are branded and endlessly re-branded, by a lot of ostensible foreign companies that are actually operating under the same ownership. (You can tell when the interfaces turn out to be surprisingly similar.) But the better programs in this video apps category are pretty well known by now. Not yet another “WHO is that ?” name that pops up.