The standard algorithm plugins require a customized version of pHash. The customized version is based on pHash version 0.9 and can be downloaded from here. The upstream version of pHash does not work with Rihamark at the moment. The required changes are currently integrated into the upstream version of pHash.
At the moment Rihamark always lists the pHash plugins as available no matter if this dependency is met or not. If you don't install pHash, but ask Rihamark to benchmark one of its algorithms it simply hangs at the moment. This will be solved in a more user-friendly way in the future.
pHash is written
in C/C++. Required are the JNI shared library (libpHash-jni.so)
and the pHash shared library itself (libpHash.so). So if you want
to use the standard algorithm plugins you have to take care
yourself that the Java virtual machine finds the JNI shared library and that
your operating system finds the pHash shared library.
If you are using a Unix based operating system the easiest
solution is to put a symlink to both libraries into /usr/lib.
If you don't want to put any symlinks into /usr/lib you can also
start Rihamark using the following commands:
$ export LD_LIBRARY_PATH=<...>/pHash/bindings/java/.libs/
$ java -Djava.library.path=<...>/pHash/bindings/java/.libs/ -jar rmk-gui.jar
$ ./configure --enable-java
rmk-gui.jar.
Then run the command java -jar rmk-gui.jar. Please also
consider the required and the optional depedencies!