compiling only packages that have patented functionality

[Alberto Bursi]

I'm investigating about making an unofficial third party repository with 
OpenWrt (non-kmod) packages where patented functionality is enabled. For 
example ffmpeg from packages is missing some functionality in its 
"non-patented" form and most end users won't be able to just recompile 
from sources with that option enabled.

Is there a non-hacky way to build only packages that are affected by the 
"patented functionality" switch in the build system?

At the moment the only thing I can think about is a script that parses 
the package makefiles and compiles a list, and then builds only those 
packages with the SDK or buildroot.

-Alberto