> That said, on the FFmpeg wiki we do have x265 building and linking instructions in our compilation guides for Ubuntu and other platforms. But people are less likely to update such builds, so if you've found x265 to regularly break ABI, better not include it.
There's no problem building and linking against x265; we already have such an option. I was referring to the fact that (at least once upon a time) x265 dylib version changed quite frequently, so if we ship FFmpeg with it by default, we need to revision-bump FFmpeg every time that happens, which means a recompilation for people who use FFmpeg but never touch x265 (~98%).