LibGDX compression classes extract into a standalone library (i.e. no OpenGL, LWJGL, etc. required)
The gradle build will checkout a specific version of libgdx, copy the compression source files into src/main/java, package renamed from com.badlogic.gdx.utils.compression to org.mini2Dx.gdx.compression and compile the standalone jar.
compile "org.mini2Dx:gdx-compression:1.9.13"
This project's only dependency is gdx-collections.
The entire com.badlogic.gdx.utils.compression package is included along with Base64Coder