How to include library in a local directory in build?

[kitfox]

I'm trying to link to a third party library. I'd like to configure LIBS to refer to a local directory. When I use an absolute path (the first line below), I can link. However my other attempts to link in a local directory are failing.

What is the syntax to include a local directory in LIBS?

win32 {
LIBS += -LD:\bin\ffmpeg-20190403-b131a07-win32-dev\lib
#LIBS += -L./thirdParty/ffmpeg/win32/lib
#LIBS += -LthirdParty/ffmpeg/win32/lib
LIBS += -lavcodec -lavformat -lavutil -lswscale -lswresample
}

[mrjj]

Hi
Did you try with
LIBS += -L$$PWD/thirdParty/ffmpeg/win32/lib

That is assuming that thirdParty is a subfolder to the folder where the .pro file is.

[kitfox]

That worked!

[mrjj]

@kitfox
Super.
The reason the
#LIBS += -L./thirdParty/ffmpeg/win32/lib
#LIBS += -LthirdParty/ffmpeg/win32/lib

didn't work is that - at the time of invocation of the linker, the current directory is
likely the build folder so the linker would try to find the libs relative to that folder.

However, $$PWD is "where .pro file is" and hence the relative path can then work.