I think I found small bug in configure.ac https://git.cinelerra-gg.org/git/?p=goodguy/cinelerra.git;a=blob;f=cinelerra... 301 PKG_3RD([libtheora],[auto], 302 [libtheora-1.1.1], 303 [ lib/.libs/libtheora.a \ 304 lib/.libs/libtheoradec.a \ 305 lib/.libs/libtheoraenc.a ], 306 [ . ]) if last line indicate where includes located in module's tree .. then for libtheora this location is thirdparty/libtheora-1.1.1/include/ so, *I think* last line should bre replaced with [ include ]) I fixed it locally in global_config , so it reads: static_blds += libtheora ver_libtheora := $(THIRDPARTY)/libtheora-1.1.1 inc_libtheora := \ -I$(ver_libtheora)/include \ but this file generated by configure, right? I think this can fix my error about building CinGG without libtheora installed (error was in ffmpeg, but if buildsystem consistently use those parameters ..)