extracting ipkg, .deb files

List the contents of archive
ar -t sdlquake_1.0.9-r0.1_armv7a.ipk

Extract the contents
ar -x sdlquake_1.0.9-r0.1_armv7a.ipk

command to extract the deb packages:
dpkg-deb -x {deb-package name} {target directory}