freetuxtv fails to cross build from source, because the upstream
configure.ac hard codes the build architecture pkg-config in several
places. Using the standard autoconf macros such as PKG_CHECK_MODULES is
the intended way to use pkg-config and once doing so, freetuxtv cross
builds successfully. I'm attaching a patch for your convenience. Please
consider forwarding it upstream, because it also helps with other Linux
distributions such as Yocto or PtxDist.

Helmut