Linux Source Install Issues - /usr/include

Installing to Slackware 13.37:  setup.py fails to build and install because it expects avcodec.h, avformat.h and avio.h to be in the root of /usr/include rather than in subdirectories of /usr/include which is where those packages actually install to.  I symlinked these three files into the root of /usr/include and the install succeeded.