This tool uses the technique of compiling to bytecode prior to encoding so that source code is eliminated, and runtime overheads are reduced.
There are two ways to recover the source.
1. Reversing the whole tool. The safest and hardest way to get the opcodes of the file. First remove the custom base64 encoding (image1) if any. Read the header data and any license/external/dynamic key. Extract all classes, functions, and code opcodes. Reconstruct the source code!
2. Patch the loader. Patch the ioncube loader to be able to capture the opcodes with a custom php executable. Finally, reconstruct the source code from opcodes!
License / External / Dynamic keys make decoding harder and time consuming but no safer.