I was faced with similar problem in configuring LibAV
./configure --target-os=mingw32 --arch=x86 --enable-shared --enable-static \
--enable-dxva2 --disable-encoders --enable-hwaccel=dxva2 --extra-cflags=-O3 \
hw-accelerator of dxva2 was disabled since dxva2api.h was absent.
I suggest to specify where is located dxva2api.h and add its ...
I found this article while building Dropbox (https://linux.dropbox.com/packages/nautilus-dropbox-2.10.0.tar.bz2) on a remote CentOS 7 machine.
While I have installed pygtk using yum install pygtk2 pygtk2-devel, the the ./configure command still exits with the statement:
checking for pygtk... no
configure: error: couldn't find pygtk
Opening the a python ...