Sending a two dimensional array to a C plus plus DLL

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Dear All,
I'm new to ctypes and was wondering if anyone can help me with the
following:

I have a DLL function as follows:
-----------------------------
int __declspec(dllexport) **test1(int ** image_data);
int ** test1(int ** image_data) {
int i;
i=image_data[0][0];
//image_data[0][1] = 7;
return image_data;
}

------------------------------
and some python code that sends a two dimensional array to it:

------------------------------
from ctypes import *

mydll=cdll.LoadLibrary("c:/.../win32project3.dll")

mydll.test1.argtypes = [POINTER(POINTER(c_int * 3)*5)]
mydll.test1.restype = POINTER(POINTER(c_int * 3)*5)

inner_type=c_int*3
array_type=inner_type*5
image_data=array_type(inner_type(1,1,1),inner_type(2,2,2),inner_type(3,3,3),inner_type(4,4,4),inner_type(5,5,5))
pointer_to_array=POINTER(POINTER(c_int*3)*5)
pi=cast(image_data,pointer_to_array)
pi2=mydll.test1(pi)
array=(pi2[0][0][0])
------------------------------

The program returns an error on the penultimate line of Python and the
i=image_data[0][0]
line of the DLL:

WindowsError: exception: access violation reading 0x000000001

Likewise writing to the array (uncomment the following line) results in the
an access violation writing.. error.
Any ideas?
Many thanks in advance,

-- 
Andy N

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<div dir=3D"ltr">Dear All,<div>I&#39;m new to ctypes and was wondering if a=
nyone can help me with the following:</div><div><br></div><div>I have a DLL=
 function as follows:</div><div>-----------------------------</div><div><di=
v><span style=3D"white-space:pre">	</span>int<span style=3D"white-space:pre=
">	</span>__declspec(dllexport)<span style=3D"white-space:pre">	</span>**te=
st1(int ** image_data);</div><div><span style=3D"white-space:pre">	</span>i=
nt<span style=3D"white-space:pre">	</span>** test1(int ** image_data) {</di=
v><div><span style=3D"white-space:pre">		</span>int i;</div><div><span styl=
e=3D"white-space:pre">		</span>i=3Dimage_data[0][0];</div><div><span style=
=3D"white-space:pre">		</span>//image_data[0][1] =3D 7;</div><div><span sty=
le=3D"white-space:pre">		</span></div><div><span style=3D"white-space:pre">=
		</span>return image_data;</div><div><span style=3D"white-space:pre">	</sp=
an>}</div><div><br></div><div>------------------------------</div><div>and =
some python code that sends a two dimensional array to it:</div><div><br></=
div><div>------------------------------</div><div><div>from ctypes import *=
</div><div><br></div><div>mydll=3Dcdll.LoadLibrary(&quot;c:/.../win32projec=
t3.dll&quot;)</div><div><br></div><div>mydll.test1.argtypes =3D [POINTER(PO=
INTER(c_int * 3)*5)]</div><div>mydll.test1.restype =3D POINTER(POINTER(c_in=
t * 3)*5)</div><div><br></div><div>inner_type=3Dc_int*3</div><div>array_typ=
e=3Dinner_type*5</div><div>image_data=3Darray_type(inner_type(1,1,1),inner_=
type(2,2,2),inner_type(3,3,3),inner_type(4,4,4),inner_type(5,5,5))</div><di=
v>pointer_to_array=3DPOINTER(POINTER(c_int*3)*5)</div><div>pi=3Dcast(image_=
data,pointer_to_array)<br></div><div>pi2=3Dmydll.test1(pi)</div><div>array=
=3D(pi2[0][0][0])</div></div><div>------------------------------</div><div>=
<br></div><div>The program returns an error on the penultimate line of Pyth=
on and the=C2=A0</div><div>i=3Dimage_data[0][0]=C2=A0</div><div>line of the=
 DLL:</div><div><br></div><div>WindowsError: exception: access violation re=
ading 0x000000001</div><div><br></div><div>Likewise writing to the array (u=
ncomment the following line) results in the an access violation writing.. e=
rror.</div><div>Any ideas?</div><div>Many thanks in advance,</div><div><br>=
</div>-- <br><div class=3D"gmail_signature"><div dir=3D"ltr">Andy N<br></di=
v></div>
</div></div>

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