Use ltmmMemory for Memory Conversion Example for C++

// include the LEAD Multimedia TOOLKIT header 
#include "ltmm.h" 
 
#include "resource.h" 
#include <tchar.h> 
#include <stdio.h> 
#include <assert.h> 
 
HINSTANCE g_hInstance; // application instance handle 
IltmmConvert* g_pConvert; // convert object's interface pointer 
 
// user defined message id used for conversion events 
#define WM_CONVERTNOTIFY (WM_USER + 1000) 
 
// 
// ConvertDlgProc 
// starts the conversion process and provides status feedback 
// 
// controls:  
// IDC_CONVERTSTATUS - static control used for status messages 
// IDC_CONVERTPROGRESS - static control used for conversion progress 
// IDC_USERABORT - button control used to abort the conversion or exit the dialog 
 
BOOL CALLBACK ConvertDlgProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)  
{ 
   TCHAR sz[256];  
   HRESULT hr;  
   long state;  
 
   switch (msg)  
   { 
   case WM_INITDIALOG:  
      // assign the notification window 
      g_pConvert->SetNotifyWindow((long) hwnd, WM_CONVERTNOTIFY);  
       
      // set the abort button text 
      SetDlgItemText(hwnd, IDC_USERABORT, _T("Abort")); 
 
      // start the conversion 
      hr = g_pConvert->StartConvert(); 
 
      if(FAILED(hr))  
      { 
         _stprintf(sz, _T("conversion error 0x%.8X"), lParam);  
         SetDlgItemText(hwnd, IDC_CONVERTSTATUS, sz);  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTSTATUS));  
         SetDlgItemText(hwnd, IDC_USERABORT, _T("Exit")); 
         MessageBeep(0);  
      } 
      return TRUE;  
      break;  
 
   case WM_DESTROY:  
      // reset the notification window 
      g_pConvert->SetNotifyWindow((long) NULL, 0);  
#ifdef _DEBUG 
   { 
      long state, err, pc;  
      TCHAR sz[1024];  
       
      // get the current state 
      g_pConvert->get_State(&state);  
       
      // get the current state 
      g_pConvert->get_ConvertError(&err);  
 
      // get the amount converted 
      g_pConvert->get_PercentComplete(&pc);  
       
      _stprintf(sz, _T("state = %d, error = 0x%.8X, complete = %d%%"), state, err, pc);  
      MessageBox(NULL, sz, _T("debug"), MB_OK);  
   } 
#endif 
    
      break;  
   case WM_COMMAND:  
      switch (LOWORD(wParam))  
      { 
      case IDC_USERABORT:  
         // user abort... stop conversion 
         g_pConvert->get_State(&state);  
         if(state == ltmmConvert_State_Running)  
            g_pConvert->StopConvert(); 
         else 
         { 
            g_pConvert->get_ConvertError((long*) &hr);  
            EndDialog(hwnd, (long)hr);  
         } 
         return TRUE;  
         break;  
      } 
      break;  
 
   case WM_CONVERTNOTIFY:  
      switch(wParam)  
      { 
      case ltmmConvert_Notify_Started:  
         // indicate conversion has started 
         SetDlgItemText(hwnd, IDC_CONVERTSTATUS, TEXT("Starting conversion"));  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTSTATUS));  
         break;  
      case ltmmConvert_Notify_Complete:  
         // indicate an conversion complete 
         _stprintf(sz, _T("conversion complete")); 
         SetDlgItemText(hwnd, IDC_CONVERTSTATUS, sz);  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTSTATUS));  
         SetDlgItemText(hwnd, IDC_USERABORT, _T("Exit")); 
         break;  
      case ltmmConvert_Notify_ErrorAbort:  
         // indicate an error 
         _stprintf(sz, _T("conversion error 0x%.8X"), lParam);  
         SetDlgItemText(hwnd, IDC_CONVERTSTATUS, sz);  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTSTATUS));  
         SetDlgItemText(hwnd, IDC_USERABORT, _T("Exit")); 
         MessageBeep(0);  
         break;  
      case ltmmConvert_Notify_UserAbort:  
         // indicate user abort 
         _stprintf(sz, _T("conversion aborted\n")); 
         SetDlgItemText(hwnd, IDC_CONVERTSTATUS, sz);  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTSTATUS));  
         SetDlgItemText(hwnd, IDC_USERABORT, _T("Exit")); 
         MessageBeep(0);  
         break;  
      case ltmmConvert_Notify_Progress:  
         // indicate conversion progress 
         _stprintf(sz, _T("%3d%% complete"), lParam);  
         SetDlgItemText(hwnd, IDC_CONVERTPROGRESS, sz);  
         UpdateWindow(GetDlgItem(hwnd, IDC_CONVERTPROGRESS));  
         break;  
      } 
      return TRUE;  
      break;  
   } 
   return FALSE;  
} 
 
// 
// SetAVIRecompression 
// sets up LEAD video compression, MP3 audio compression, and AVI file output 
// 
// hwndParent = parent window for compressor property dialog boxes 
// 
HRESULT SetAVIRecompression(HWND hwndParent)  
{ 
   IltmmCompressors* pCompressors;  
   long index;  
   VARIANT_BOOL f;  
   BSTR bstr;  
    
   // select the LEAD video compressor 
   g_pConvert->get_VideoCompressors(&pCompressors);  
   bstr = SysAllocString(L"@device:sw:{33D9A760-90C8-11D0-BD43-00A0C911CE86}\\LEAD MCMP/MJPEG Codec (2.0)"); 
   pCompressors->Find(bstr, &index);  
   SysFreeString(bstr);  
    
   if(index < 0)  
   { 
      // compressor isn't registered 
      pCompressors->Release(); 
      return E_FAIL;  
   } 
   pCompressors->put_Selection(index);  
   pCompressors->Release(); 
 
   // select the MP3 audio video compressor 
   g_pConvert->get_AudioCompressors(&pCompressors);  
   bstr = SysAllocString(L"@device:cm:{33D9A761-90C8-11D0-BD43-00A0C911CE86}\\85MPEG Layer-3"); 
   pCompressors->Find(bstr, &index);  
   SysFreeString(bstr);  
    
   if(index < 0)  
   { 
      // compressor isn't registered 
      pCompressors->Release(); 
      return E_FAIL;  
   } 
 
   pCompressors->put_Selection(index);  
   pCompressors->Release(); 
    
   // set output format to AVI 
   g_pConvert->put_TargetFormat(ltmmConvert_TargetFormat_Avi);  
 
   // set video compressor properties 
   g_pConvert->HasDialog(ltmmConvert_Dlg_VideoCompressor, &f);  
   if(f)  
      g_pConvert->ShowDialog(ltmmConvert_Dlg_VideoCompressor, (long) hwndParent);  
 
   // set audio compressor properties 
   g_pConvert->HasDialog(ltmmConvert_Dlg_AudioCompressor, &f);  
   if(f)  
      g_pConvert->ShowDialog(ltmmConvert_Dlg_AudioCompressor, (long) hwndParent);  
    
   return S_OK;  
} 
 
// 
// RecompressMemory 
// recompresses from global memory to a file using the LEAD video and MP3 audio compressors 
// 
// 1. the source file is preloaded into memory object 
// 2. the source memory is recompressed to the target file 
// 
// pszSource = source file path 
// pszTarget = target file path 
// 
HRESULT RecompressMemory(LPCTSTR pszSource, LPCTSTR pszTarget)  
{ 
   HRESULT hr;  
   HANDLE hfile; 
   DWORD size, dwRead;  
   VARIANT var; 
   IltmmMemory *pMemSource = NULL, *pMemTarget = NULL; 
 
#ifndef _UNICODE 
   WCHAR wsz[MAX_PATH];  
#endif 
 
   // open the source file 
   hfile = CreateFile(pszSource, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, 0, NULL);  
   if(hfile == INVALID_HANDLE_VALUE)  
      return E_FAIL;  
 
   // allocate same-sized buffer 
   size = GetFileSize(hfile, NULL);  
    
   // create the source memory object 
   hr = CoCreateInstance(CLSID_ltmmMemory, NULL, CLSCTX_ALL, IID_IltmmMemory, (void**) &pMemSource); 
   if (FAILED(hr)) 
   { 
      AfxMessageBox(TEXT("Error allocating source memory object. Conversion aborted.")); 
      goto error; 
   } 
    
   hr = pMemSource->put_BufferSize(size); 
   if (FAILED(hr)) 
      goto error; 
 
   VariantInit(&var); 
   pMemSource->LockBuffer(&var); 
    
   // read the source file contents 
   ReadFile(hfile, var.parray->pvData, size, &dwRead, NULL); 
 
   pMemSource->Unlock(); 
   VariantClear(&var); 
   CloseHandle(hfile); 
   hfile = NULL; 
    
   // assign the source object 
   hr = g_pConvert->put_SourceStream(pMemSource); 
 
   if(FAILED(hr))  
      goto error; 
 
   // create the target memory stream 
   hr = CoCreateInstance(CLSID_ltmmMemory, NULL, CLSCTX_ALL, IID_IltmmMemory, (void**)&pMemTarget); 
   if (FAILED(hr)) 
   { 
      AfxMessageBox(TEXT("Error allocating target memory object. Conversion aborted.")); 
      goto error; 
   } 
 
   // set target stream 
   hr = g_pConvert->put_TargetStream(pMemTarget);  
   if (FAILED(hr))  
      goto error; 
 
   // setup AVI recompression 
   hr = SetAVIRecompression(NULL);  
   if (FAILED(hr))  
      goto error; 
 
   // do conversion 
   hr = (HRESULT)DialogBox(g_hInstance, (LPCTSTR)IDD_CONVERTDLG, NULL, ConvertDlgProc);  
   if (FAILED(hr)) 
      goto error; 
 
   // write the data to a file 
   hfile = CreateFile(pszTarget, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL); 
 
   long fl = 0;  
   unsigned long lBytesWritten;  
   IltmmMemory *pTarget = NULL;  
   VARIANT varData;  
   unsigned char *pBuffer = NULL;  
   SAFEARRAY sa;  
 
   hr = g_pConvert->get_TargetStream((IUnknown**)&pTarget);  
 
   if (FAILED(hr)) 
      goto error; 
 
   pTarget->get_BufferSize(&fl);  
   VariantInit(&varData);  
 
   // pass data 
   memset(&sa, 0, sizeof(sa));  
   sa.cbElements = sizeof(unsigned char);  
   sa.cDims = 1;  
   sa.fFeatures = (FADF_AUTO | FADF_FIXEDSIZE);  
   sa.pvData = new UCHAR[fl];  
   sa.rgsabound[0].cElements = fl;  
   V_VT(&varData) = (VT_ARRAY | VT_UI1);  
   V_ARRAY(&varData) = &sa;  
 
   // 
   // To lock the buffer for synchronization, use the following  
   // line instead of the line below :  
   // pTarget->LockBuffer(&varData);  
   // or 
   // pTarget->LockRegion(0, fl, &varData);  
   // You may also use the GetData() function 
   // To get the data without allocating a SAFEARRAY :  
   // pTarget->GetData(0, fl, &varData);  
   // 
 
   pTarget->CopyData(0, fl, &varData);  
   SafeArrayAccessData(V_ARRAY(&varData), (void**)&pBuffer);  
 
   // to manipulate the buffer bytes directly without a buffer pointer 
   // use the SetByte method, for example to change the first two 
   // bytes in the buffer :  
   // pTarget->SetByte(0, 0x10);  
   // pTarget->SetByte(1, 0x13);  
 
   WriteFile(hfile, pBuffer, fl, &lBytesWritten, NULL);  
 
   // if LockBuffer() or LockRegion() is used, Unloack() must be called :  
   // g_pTarget->Unlock(); 
 
   SafeArrayUnaccessData(V_ARRAY(&varData));  
   VariantClear(&varData);  
   CloseHandle(hfile);  
   hfile = NULL; 
 
   pTarget->Release(); 
 
error: 
   g_pConvert->ResetSource(); 
   g_pConvert->ResetTarget(); 
   if(pMemSource) 
      pMemSource->Release(); 
   if(pMemTarget) 
      pMemTarget->Release(); 
   if (hfile) 
      CloseHandle(hfile); 
   return hr;  
} 
 
int APIENTRY WinMain(HINSTANCE hInstance,  
                HINSTANCE hPrevInstance,  
                LPSTR      lpCmdLine,  
                int      nCmdShow)  
{ 
   HRESULT hr;  
    
   g_hInstance = hInstance;  
 
   // initialize COM library 
   hr = CoInitialize(NULL);  
   if(FAILED(hr))  
      goto error;  
 
   // create the convert object 
   hr = CoCreateInstance(CLSID_ltmmConvert, NULL, CLSCTX_INPROC_SERVER, IID_IltmmConvert, (void**) &g_pConvert);  
   if(FAILED(hr))  
      goto error;  
    
   hr = RecompressMemory(MAKE_MEDIA_PATH("source.avi"), MAKE_MEDIA_PATH("target.avi")); 
   if(FAILED(hr))  
      goto error;  
 
error:  
   // cleanup 
   if (g_pConvert)  
      g_pConvert->Release(); 
 
   CoUninitialize(); 
    
   return 0;  
}