Problem with SDK pointers - c++ to Delphi translating - c++

Question

I'm struggling with HikVision SDK, trying to get it work in Delphi. There's some samples in C++, but I've stuck with pointers issues while translating to Delphi. Till that moment code seems to work, as I get correct plate number.
Is this correct equivalent: BYTE *pBuffer -> PByte ?
How to extract picture from pBuffer?
C++ code:
typedef struct tagNET_ITS_PICTURE_INFO
{
DWORD dwDataLen; //Media data length
BYTE byType;
BYTE byAbsTime[32];
NET_VCA_RECT struPlateRect;
BYTE *pBuffer; //Data pointer
DWORD dwUTCTime;
//...
}NET_ITS_PICTURE_INFO, *LPNET_ITS_PICTURE_INFO;
typedef struct tagNET_ITS_PLATE_RESULT
{
//...
NET_DVR_PLATE_INFO struPlateInfo;
NET_ITS_PICTURE_INFO struPicInfo[6];
}NET_ITS_PLATE_RESULT, *LPNET_ITS_PLATE_RESULT;
void CALLBACK MSesGCallback(LONG lCommand, NET_DVR_ALARMER *pAlarmer, char *pAlarmInfo, DWORD dwBufLen, void* pUser)
{
char filename[100];
FILE *fSnapPic = NULL;
switch (lCommand) {
case COMM_ITS_PLATE_RESULT: {
NET_ITS_PLATE_RESULT struITSPlateResult = { 0 };
memcpy(&struITSPlateResult, pAlarmInfo, sizeof(struITSPlateResult));
printf("Plate: %s\n", struITSPlateResult.struPlateInfo.sLicense);
if (struITSPlateResult.struPicInfo[0].dwDataLen != 0)
{
sprintf(filename, "./pic/%d.jpg", 0);
fSnapPic = fopen(filename, "wb");
fwrite(struITSPlateResult.struPicInfo[0].pBuffer, struITSPlateResult.struPicInfo[0].dwDataLen, 1, fSnapPic);
fclose(fSnapPic);
}
}
}
return;
}
Delphi code:
LPNET_ITS_PICTURE_INFO = ^NET_ITS_PICTURE_INFO;
NET_ITS_PICTURE_INFO = record
dwDataLen: DWORD;
byType: BYTE;
byAbsTime: array [0..31] of BYTE;
struPlateRect: NET_VCA_RECT;
pBuffer: PByte; // ????????
dwUTCTime: DWORD;
//(...)
end;
LPNET_ITS_PLATE_RESULT = ^NET_ITS_PLATE_RESULT;
NET_ITS_PLATE_RESULT = record
//(...)
struPlateInfo: NET_DVR_PLATE_INFO;
struPicInfo: Array [0..5] of NET_ITS_PICTURE_INFO;
end;
procedure MessageCallBack(lCommand:longint; pAlarmer:LPNET_DVR_ALARMER; pAlarmInfo:PAnsiChar; dwBufLen:LongInt; pUser:pointer); stdcall;
var
struAlarmInfo: LPNET_DVR_ALARMINFO_V30;
struPlateResult: LPNET_ITS_PLATE_RESULT;
begin
case lCommand of
COMM_ITS_PLATE_RESULT:
begin
New(struPlateResult);
FillChar(struPlateResult^, SizeOf(NET_ITS_PLATE_RESULT), 0);
Move(pAlarmInfo^, struPlateResult^, Sizeof(NET_ITS_PLATE_RESULT));
Form1.memoOut.Lines.Add('sLicense: ' + struPlateResult.struPlateInfo.sLicense);
if (struPlateResult.struPicInfo[0].dwDataLen >0) then
??? how to get the picture from struPlateResult.struPicInfo[0].pBuffer ?
end;
end;
end;
Regards

Answer 1

Yes, PByte or PByteArray is correct translation.
If buffer contains valid file contents, you can save it into file:
FS := TFileStream.Create('test.jpg', fmCreate);
try
FS.Write(struITSPlateResult.struPicInfo[0].pBuffer^,
struITSPlateResult.struPicInfo[0].dwDataLen);
finally
FS.Free;
end;