[RESOLVED] Processing Time For PVOID Into Byte Array Conversion

[2kaud]

queue<PVOID> mypvoidQ;

Er... No. queue needs a type of data that is to be stored. PVOID is not a suitable type as this is just a pointer to void.

I've knocked up some code to demonstrate the idea between a producer thread and a consumer thread for you. Its just win32 not MFC but you should get the idea about using a queue and sync between the threads. I don't have a camera to test so I don't know the timings for loss of data - but if this sort of program design still looses data from the camera then you really are in trouble as all the producer is doing is adding blocks of data to the queue.

Hope this helps

#include <iostream>
#include <queue>
#include <conio.h>
using namespace std;

#include <windows.h>
#include <process.h>

#define BUFSIZE	2048

//Structure with methods for camera data blocks
struct scam {
	char* pdata;

	scam()
	{
		pdata = (char*)new char[BUFSIZE];
		memset(pdata, 0, BUFSIZE);
	}

	scam (const char* dat)
	{
		size_t ll = strlen(dat);

		if (ll > BUFSIZE - 1) {
			ll = BUFSIZE - 1;
		}

		pdata = (char*)new char[BUFSIZE];
		memset(pdata, 0, BUFSIZE);
		memcpy(pdata, dat, ll);
		pdata[ll + 1] = 0;
	}

	scam(const char *dat, int no)
	{
		pdata = (char*)new char[BUFSIZE];
		memcpy(pdata, dat, min(no, BUFSIZE));
	}

	~scam()
	{
		delete [] pdata;
	}

	scam(const scam& scm)
	{
		pdata = (char*)new char[BUFSIZE];
		memcpy(pdata, scm.pdata, BUFSIZE);
	}

	scam& operator=(const scam& scm)
	{
		if (this != &scm) {
			delete [] pdata;
			pdata = (char*)new char[BUFSIZE];
			memcpy(pdata, scm.pdata, BUFSIZE);
		}
		return *this;
	}

	void SetData(const char *dat, int no)
	{
		memset(pdata, 0, BUFSIZE);
		memcpy(pdata, dat, min(no, BUFSIZE));
	}

};

CRITICAL_SECTION	ccrit;

HANDLE	sync;

queue<scam> camdata;

//CONSUMER
unsigned __stdcall consume(void* pArguments)
{
scam	dataOut;

	while (true) {
		dataOut = "";
		WaitForSingleObject(sync, INFINITE);
		EnterCriticalSection(&ccrit);
		dataOut = camdata.front();
		camdata.pop();
		if (!camdata.empty()) {
			SetEvent(sync);
		}
		LeaveCriticalSection(&ccrit);

		//PROCESS CAMERA DATA BLOCK HERE
		cout << dataOut.pdata << endl;
	}
	return 0;
}


int main()
{
unsigned	thid;

	sync = CreateEvent(NULL, FALSE, FALSE, "camev");

	InitializeCriticalSection(&ccrit);

	_beginthreadex(NULL, 0, &consume, NULL, 0, &thid);

	//PRODUCER
scam	dataIn1;

	//test loop - would be 'while there is data from camera'
	for (int i = 1; i < 50; i++) {
		EnterCriticalSection(&ccrit);

		//ADD DATA BLOCK HERE FROM CAMERA
		dataIn1.SetData("dfdgrehgfdhghghgdhgdhghngfegfrzz", 32);
		camdata.push(dataIn1);

		SetEvent(sync);
		LeaveCriticalSection(&ccrit);
	}

	_getch();
	DeleteCriticalSection(&ccrit);
	return (0);
}