Thread: Phones and C++

I don't think there is any API for it. Of course you can tell your modem to dial, its kinda worthless otherwise
Windows used to have a phone dialer that would just dial, make a connection, and then sit there until you disconnected. You could then use the phone to talk.

I'm not sure how feasible it is to send analog sound from the modem itself. I suppose it's possible.

If you are using Windows you can use the Telephony API which includes the ability to manage phone lines, answer phones, hang up phone lines, read caller id, etc.

Originally Posted by jverkoey

Is there an API out there or even just a program that can answer the phone when it's plugged in to the 56k port on your computer?

Yes. There are several answering machine programs. The Windows API for this is called TAPI (Telephony API). Here is a good start page for TAPI applications. Be warned, it is somewhat complex.

As a starter, to receive notification of a call and answer it, you should look at these topics:

Code:

lineInitializeEx
  lineOpen
    Monitor for LINE_CALLSTATE event with LINECALLSTATE_OFFERING
    lineAnswer
      // Do something
      // Monitor for LINE_CALLSTATE with LINECALLSTATE_DISCONNECTED 
    lineDrop
    lineDeallocateCall
  lineClose
lineShutdown

Also is it possible to dial out using the 56k on your computer and send sound?

With a normal modem, you can send tones (such as digit tones). To send voice or other sound, I believe you need a voice modem. If I remember correctly, a voice modem would install itself as a sound device. Assumably, after establishing a call, you could use a sound API to play and record sound (you could also use the simpler MCI). You can dial out with lineMakeCall.

There is a nifty utility, included with the platform SDK, called Tapi Browser (TB20.exe) that allows you to call TAPI functions. So you can try all this out without writing a line of code. Use lineGetDevCaps to get info on your modem. If it supports voice, it should include "wave/*" under the dwDeviceClassesOffset field.

Awesome, yah I just found out all that TAPI stuff right after I posted and made the following program which calls my cell phone and just sits there....

The callback function doesn't seem to do anything though for some reason....so I'm a big lost.

Code:

#include <iostream>
#include <Tapi.h>
#include <conio.h>

#pragma comment(lib,"Tapi32.lib")

using namespace std;

VOID FAR PASCAL lineCallbackFunc(
  DWORD hDevice,
  DWORD dwMsg,
  DWORD dwCallbackInstance,
  DWORD dwParam1,
  DWORD dwParam2,
  DWORD dwParam3
);

int main()
{
	HLINEAPP hLineApp;
	DWORD numDevices=0;
	DWORD version=0x00020002;
	ULONG result=0;
	LINEINITIALIZEEXPARAMS lineInit;
	memset(&lineInit,0,sizeof(lineInit));
	lineInit.dwTotalSize=sizeof(lineInit);
	lineInit.dwNeededSize=sizeof(lineInit);
	lineInit.dwUsedSize=sizeof(lineInit);
	lineInit.dwOptions=LINEINITIALIZEEXOPTION_USEHIDDENWINDOW;

	if(!(result=lineInitializeEx(&hLineApp,GetModuleHandle(NULL),&lineCallbackFunc,"PhoneProgram",&numDevices,&version,&lineInit)))
	{
		cout << "Call center initialized Num Devices: " << numDevices << endl;

//		lineGenerateDigits(hCall

		HLINE hLine;
		LINECALLPARAMS lineCall;
		memset(&lineCall,0,sizeof(lineCall));
		lineCall.dwTotalSize=sizeof(lineCall);
		result=lineOpen(hLineApp,0,&hLine,version,0,0,LINECALLPRIVILEGE_OWNER,LINEMEDIAMODE_UNKNOWN,&lineCall);

		if(!result)
		{
			cout << "Success" << endl;
		
			HCALL hCall;
			memset(&lineCall,0,sizeof(lineCall));
			lineCall.dwTotalSize=sizeof(lineCall);

			if((result=lineMakeCall(hLine,&hCall,"619-8230",1,&lineCall))>0)
			{
				cout << "Success!" << endl;

				result=lineDial(hCall,"+1 (403) 619-8230",0);

				if(result>0)
				{
					cout << "Success! Calling!" << endl;
				}
				else
				{
					cout << "Error" << endl;
				}
			}
			else
				cout << result << endl;
			while(getch()!=27);

			lineShutdown(hLine);
		}
		else
		{
			cout << "Error\n" << result << endl;
		}
	}
	else
		cout << result << endl;
	return 0;
}

VOID FAR PASCAL lineCallbackFunc(
  DWORD hDevice,
  DWORD dwMsg,
  DWORD dwCallbackInstance,
  DWORD dwParam1,
  DWORD dwParam2,
  DWORD dwParam3
)
{
	cout << "Poll" << endl;
}

That poor little lonely hidden window wants to pump some IRON (some messages would be second best, car tyres would be a poor third choice)!