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From: kees de Kapper on 21 Jun 2010 11:27
Hi all,

I've got the following problem.

Running the following matlab code,
the first calllib results in nRet = 0, which means OK
the second calllib let Matlab crash instantaniously.

This has something to do with the declaration of the phAcqDesc pointer, which should behave like a windows HANDLE.

But what do I do wrong?

====== Matlab code, library call to the c++ code ===============\/

loadlibrary('xisl','Acq.h');

phAcqDesc = libpointer('voidPtr'); % HACQDESC *phAcqDesc
dwChannelType = uint32(1); % DWORD dwChannelType
nChannelNr = int32(0); % int nChannelNr,
bEnableIRQ = int32(0); % BOOL bEnableIRQ
Rows = uint32(256); % UINT Rows
Columns = uint32(256); % UINT Columns,
dwSortFlags = uint32(2); % UINT dwSortFlags
bSelfInit = int32(1); % BOOL bSelfInit
bAlwaysOpen = int32(1); % BOOL bAlwaysOpen

nRet = calllib('xisl','Acquisition_Init', phAcqDesc, ...
dwChannelType, nChannelNr, ...
bEnableIRQ, ...
Rows, Columns, ...
dwSortFlags, ...
bSelfInit, bAlwaysOpen);


nRet = calllib('xisl','Acquisition_SetCameraMode', phAcqDesc, uint32(0));

====== Original C++ code in DLL library ======================\/

typedef HANDLE HACQDESC;
typedef UINT ACQDESCPOS;

_DLL_DECL UINT WINAPI Acquisition_Init(HACQDESC *phAcqDesc,
DWORD dwChannelType, int nChannelNr,
BOOL bEnableIRQ,
UINT Rows, UINT Columns,
UINT dwSortFlags,
BOOL bSelfInit, BOOL bAlwaysOpen);

_DLL_DECL UINT WINAPI Acquisition_SetCameraMode(HACQDESC hAcqDesc, UINT dwMode);
From: Philip Borghesani on 21 Jun 2010 12:57
A c calling example would have been helpful. Try this:

phAcqDesc = libpointer('voidPtr',uint32(0)); % HACQDESC *phAcqDesc

It is possible that the function needs memory to put the handle into. In 64 bit MATLAB a uint64 will be needed.

Phil

"kees de Kapper" <kees_de_kapper(a)hotmail.com> wrote in message news:hvo0d8$23a$1(a)fred.mathworks.com...
> Hi all,
>
> I've got the following problem.
>
> Running the following matlab code, the first calllib results in nRet = 0, which means OK
> the second calllib let Matlab crash instantaniously.
>
> This has something to do with the declaration of the phAcqDesc pointer, which should behave like a windows HANDLE.
>
> But what do I do wrong?
> ====== Matlab code, library call to the c++ code ===============\/
>
> loadlibrary('xisl','Acq.h');
>
> phAcqDesc = libpointer('voidPtr'); % HACQDESC *phAcqDesc
> dwChannelType = uint32(1); % DWORD dwChannelType
> nChannelNr = int32(0); % int nChannelNr,
> bEnableIRQ = int32(0); % BOOL bEnableIRQ Rows = uint32(256); % UINT Rows
> Columns = uint32(256); % UINT Columns, dwSortFlags = uint32(2); % UINT dwSortFlags
> bSelfInit = int32(1); % BOOL bSelfInit
> bAlwaysOpen = int32(1); % BOOL bAlwaysOpen
>
> nRet = calllib('xisl','Acquisition_Init', phAcqDesc, ...
> dwChannelType, nChannelNr, ...
> bEnableIRQ, ...
> Rows, Columns, ...
> dwSortFlags, ...
> bSelfInit, bAlwaysOpen);
>
>
> nRet = calllib('xisl','Acquisition_SetCameraMode', phAcqDesc, uint32(0));
>
> ====== Original C++ code in DLL library ======================\/
>
> typedef HANDLE HACQDESC;
> typedef UINT ACQDESCPOS;
>
> _DLL_DECL UINT WINAPI Acquisition_Init(HACQDESC *phAcqDesc,
> DWORD dwChannelType, int nChannelNr,
> BOOL bEnableIRQ, UINT Rows, UINT Columns, UINT dwSortFlags,
> BOOL bSelfInit, BOOL bAlwaysOpen);
>
> _DLL_DECL UINT WINAPI Acquisition_SetCameraMode(HACQDESC hAcqDesc, UINT dwMode);
>


From: kees de Kapper on 22 Jun 2010 05:46
Thank you for replying. It is an 32bit DLL as well as an 32 bit Matlab version.
This is the call in windows:

==============================================\/
HACQDESC hAcqDesc=NULL;
DWORD dwChannelType, dwRows, dwColumns, dwSortFlags;
int nChannelNr;
BOOL bEnableIRQ, bSelfInit, bAlwaysOpen;

Acquisition_Init(&hAcqDesc,
dwChannelType, nChannelNr,
bEnableIRQ,
Rows, Columns,
dwSortFlags,
bSelfInit, bAlwaysOpen);

Acquisition_SetCameraMode(hAcqDesc,0);
==============================================/\

Could you give me a clue, how to call these functions properly in Matlab including the pointers.

thanx,
Kees



"Philip Borghesani" <philip_borghesani(a)mathworks.spam> wrote in message <hvo5ll$d03$1(a)fred.mathworks.com>...
> A c calling example would have been helpful. Try this:
>
> phAcqDesc = libpointer('voidPtr',uint32(0)); % HACQDESC *phAcqDesc
>
> It is possible that the function needs memory to put the handle into. In 64 bit MATLAB a uint64 will be needed.
>
> Phil
>
From: kees de Kapper on 22 Jun 2010 06:42
I think I got the first part of the clue.

Indeed the addition of uint32(0) helped a lot. I tried it before but another issue caused the problem and I did not notice it. Namely, I forgot to put the return-variables in the left-hand-side of the call function. It should have been:

[nRet,phAcqDesc] =calllib('xisl','Acquisition_Init',phAcqDesc, dwChannelType, nChannelNr, bEnableIRQ, Rows, Columns, dwSortFlags, bSelfInit, bAlwaysOpen);

However, there is still a problem. Now, I can get a pointer back. But this iis a pointer to a datatype called HANDLE (a know windows datatype). This datatype is not know in Matlab. The error message I got using get(phAcqDesc, 'value') is therefore 'The datatype and size of the value must be defined before the value can be retrieved.'.

I need this 'value', since the other functions needs the handle and not the pointer:
C++ code: Acquisition_SetCameraMode(hAcqDesc,0);
(c++header declaration:_DLL_DECL UINT WINAPI Acquisition_SetCameraMode(HACQDESC hAcqDesc, UINT dwMode);)

What is the solution for this problem? How can I call this function properly?

thanx!
From: kees de Kapper on 22 Jun 2010 08:45
I've made some progress but stuck now. To clarify my question, I re-post the c++ code and my Matlab implementation. The Matlab program crashes during the last function call (Acquisition_SetCameraMode).
What could be the cause, and what would be a solution?

many thanks in advance,
Kees

====================================================
====== Original C++ code: Header.h ===========================\/

typedef HANDLE HACQDESC;
typedef UINT ACQDESCPOS;

_DLL_DECL UINT WINAPI Acquisition_Init(HACQDESC *phAcqDesc,
DWORD dwChannelType, int nChannelNr,
BOOL bEnableIRQ,
UINT Rows, UINT Columns,
UINT dwSortFlags,
BOOL bSelfInit, BOOL bAlwaysOpen);
_DLL_DECL UINT WINAPI Acquisition_SetCameraMode(HACQDESC hAcqDesc, UINT dwMode);

====== Original C++ code: main.c ============================\/

HACQDESC hAcqDesc=NULL;
DWORD dwChannelType, dwRows, dwColumns, dwSortFlags;
int nChannelNr;
BOOL bEnableIRQ, bSelfInit, bAlwaysOpen;

Acquisition_Init(&hAcqDesc,
dwChannelType, nChannelNr,
bEnableIRQ,
Rows, Columns,
dwSortFlags,
bSelfInit, bAlwaysOpen);

Acquisition_SetCameraMode(hAcqDesc,0);
====================================================
====================================================

====================================================
====== Matlab code, library call to the c++ code ===================\/

loadlibrary('xisl','Acq.h');

% phAcqDesc is a pointer to a handle (hAcqDesc)
phAcqDesc = libpointer('voidPtr', uint32(0)); % HACQDESC *phAcqDesc
dwChannelType = uint32(1); % DWORD dwChannelType
nChannelNr = int32(0); % int nChannelNr,
bEnableIRQ = int32(0); % BOOL bEnableIRQ
Rows = uint32(256); % UINT Rows
Columns = uint32(256); % UINT Columns,
dwSortFlags = uint32(2); % UINT dwSortFlags
bSelfInit = int32(1); % BOOL bSelfInit
bAlwaysOpen = int32(1); % BOOL bAlwaysOpen


[nRet, phAcqDesc] = calllib('xisl','Acquisition_Init', phAcqDesc, ...
dwChannelType, nChannelNr, ...
bEnableIRQ, ...
Rows, Columns, ...
dwSortFlags, ...
bSelfInit, bAlwaysOpen);

% Then (re)set the data type since it appeared to be unknown
setdatatype(phAcqDesc, 'voidPtr', 1, 1);

% get the value (the handle 'hAcqDesc') from the pointer
hAcqDesc = get(phAcqDesc, 'Value');

[nRet, hAcqDesc] = calllib('xisl','Acquisition_SetCameraMode', hAcqDesc, uint32(0));

====================================================
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