LGPL FFmpeg and NVENC in a closed source commercial application?

We are using the NVENC as part of FFmpeg in a closed source commercial project. We are compiling FFmpeg using LGPL 2.1 and releasing the FFmpeg source code in compliance with that license. Is the NVENC code that is compiled into the FFmpeg binaries compatible with LGPL 2.1? Do we need to release the NVENC source code? If not, how do you suggest going about using FFmpeg and NVENC in a closed source commercial application?

I am not a laywer, etc, but we wrote the ffmpeg code that interfaces with nvenc so that turning it on did not stop your ffmpeg build from being lgpl compliant (it does not requrie the non-free flag).

The basic theory here is that nvenc itself is covered by the system library exception (the libraries come with the driver) and the header files that are bundled with ffmpeg are MIT licensed, and so are lgpl compatible.

So as long as you are following lgpl 2.1 in your use of ffmpeg, turning on nvenc support does not change anything.