There is a dependency to libavresample.so but it is not declared in cmake so its not copied during the make install.

$ ldd libavtranscoder.so
linux-vdso.so.1 => (0x00007ffdbc99a000)
libavformat.so.54 (0x00007feaa9fa1000)
libavcodec.so.54 (0x00007feaa924a000)
libavutil.so.52 (0x00007feaa9025000)
libswscale.so.2 (0x00007feaa8dde000)
libavresample.so.1 => /usr/lib/x86_64-linux-gnu/libavresample.so.1 (0x00007feaa8b8b000)