Python C Extension passing arguments by reference

Question

I am trying to write a python C wrapper for a function (libFunc) whose prototype is

libFunc(char**, int*, char*, int)

How do I use PyArg_ParseTuple for setting up the arguments for function call. Here is what I currently have

#include <Python.h>

    PyObject* libFunc_py(PyObject* self, PyObject* args)
    {
        char* input;
        char** output;
        int inputlen;
        int* outputlen;

        PyArg_ParseTuple(args, "sisi" , output, outputlen, &input, &inputlen);


        int ret = libFunc(output, outlen, input, inputlen);


        return Py_BuildValue("i", ret);
    }

I am able to do the same with ctypes using byref.