How can populate local pkgconfig paths to other packages?

[hce <webmail.hce@gmail.com>]

Hi,

I like to build FFMPEG and QT4 to my local directory and to compile
VLC based on those local packages. But my PKG_CONFIG_PATH is pointing
to /usr/lib/pkgconfig. How can I pass those local pkgconfig paths to
other packages? One solution I can think of is to copy all local
installed packages /home/local/ffmpeg/install/lib/pkgconfig/*.pc to
/usr/lib/pkgconfig. Please advise and correct me if it will cause the
problems.

Thank you.

Kind Regards,

Jim