Recompressing an AVI File Selection for C

The following code demonstrates how to recompress an AVI file selection:

#define MAKE_MEDIA_PATH(pFileName) (TEXT("C:\\LEADTOOLS 18\\Media\\")TEXT(pFileName))


// define helper macros for using interfaces under C
#ifndef COBJMACROS
   #define COBJMACROS
#endif

// include the LEAD Multimedia TOOLKIT header
#include "ltmm.h"

#include "resource.h"
#include <tchar.h>
#include <stdio.h>
#include <assert.h>

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]; 
   BSTR bstr1 = NULL; 
   BSTR bstr2 = NULL; 
   HRESULT hr; 
   long state; 
   long type; 
   long streams; 
   IltmmVCRControl* pVCR; 


   switch (msg) 
   {
   case WM_INITDIALOG: 
      // assign the notification window
      IltmmConvert_SetNotifyWindow (g_pConvert, (long) hwnd, WM_CONVERTNOTIFY); 

      // set the abort button text
      SetDlgItemText(hwnd, IDC_USERABORT, _T("Abort"));

      // uncomment the following line to view the the graph in DirectShow GraphEdit
      // IltmmConvert_EditGraph(g_pConvert); 

      IltmmConvert_get_UnrenderedStreams(g_pConvert, &streams); 
      if(streams != 0) 
         MessageBox(hwnd, _T("Not all the streams could be rendered."), _T("Convert"), MB_ICONEXCLAMATION | MB_OK); 

      IltmmConvert_get_TargetVCRControl(g_pConvert, &pVCR); 
      hr = IltmmVCRControl_Record(pVCR); 
      IUnknown_Release(pVCR); 

      if(SUCCEEDED(hr)) 
         Sleep(2000); 

      // start the conversion
      hr = IltmmConvert_StartConvert (g_pConvert); 
      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); 

         // stop, if VCR
         IltmmConvert_get_TargetVCRControl(g_pConvert, &pVCR); 
         IltmmVCRControl_Stop (pVCR); 
         IUnknown_Release(pVCR); 
      }
      return TRUE; 
      break; 
   case WM_DESTROY: 
      // reset the notification window

      IltmmConvert_SetNotifyWindow (g_pConvert, (long) NULL, 0); 
#ifdef _DEBUG
      {
         long state, err, pc; 
         double start, end, dur; 
         TCHAR sz[1024]; 

         // get the current state
         IltmmConvert_get_State (g_pConvert, &state); 

         // get the current state
         IltmmConvert_get_ConvertError(g_pConvert, &err); 

         // get the amount converted
         IltmmConvert_get_PercentComplete(g_pConvert, &pc); 

         // get the start
         IltmmConvert_get_SelectionStart (g_pConvert, &start); 

         // get the end
         IltmmConvert_get_SelectionEnd(g_pConvert, &end); 

         // get the duration
         IltmmConvert_get_Duration(g_pConvert, &dur); 

         _stprintf(sz, _T("state = %d, error = 0x%.8X, complete = %d 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
   IltmmConvert_get_VideoCompressors(g_pConvert, &pCompressors); 
   bstr = SysAllocString(L"@device:sw:{33D9A760-90C8-11D0-BD43-00A0C911CE86}\\LEAD MCMP/MJPEG Codec (2.0)");
   IltmmCompressors_Find(pCompressors, bstr, &index); 
   SysFreeString(bstr); 
   if(index < 0) 
   {
      // compressor isn't registered
      IUnknown_Release(pCompressors); 
      return E_FAIL; 
   }
   IltmmCompressors_put_Selection(pCompressors, index); 
   IUnknown_Release(pCompressors); 


   // select the MP3 audio video compressor
   IltmmConvert_get_AudioCompressors(g_pConvert, &pCompressors); 
   bstr = SysAllocString(L"@device:cm:{33D9A761-90C8-11D0-BD43-00A0C911CE86}\\85MPEG Layer-3");
   IltmmCompressors_Find(pCompressors, bstr, &index); 
   SysFreeString(bstr); 
   if(index < 0) 
   {
      // compressor isn't registered
      IUnknown_Release(pCompressors); 
      return E_FAIL; 
   }
   IltmmCompressors_put_Selection(pCompressors, index); 
   IUnknown_Release(pCompressors); 

   // set output format to AVI
   IltmmConvert_put_TargetFormat(g_pConvert, ltmmConvert_TargetFormat_Avi); 
#ifdef _DEBUG
   {
      long v; 
      IltmmConvert_get_TargetFormat(g_pConvert, &v); 
      assert(v == ltmmConvert_TargetFormat_Avi); 
   }
#endif

   // set video compressor properties
   IltmmConvert_HasDialog(g_pConvert, ltmmConvert_Dlg_VideoCompressor, &f); 
   if(f) 
      IltmmConvert_ShowDialog(g_pConvert, ltmmConvert_Dlg_VideoCompressor, (long) hwndParent); 

   // set audio compressor properties
   IltmmConvert_HasDialog(g_pConvert, ltmmConvert_Dlg_AudioCompressor, &f); 
   if(f) 
      IltmmConvert_ShowDialog(g_pConvert, ltmmConvert_Dlg_AudioCompressor, (long) hwndParent); 

   return S_OK; 
}
//
// RecompressFileSelection
// recompresses a file selection using the LEAD video and MP3 audio compressors
//
// pszSource = source file path
// pszTarget = target file path
// dStart = selection start (fraction of duration) 
// dEnd = selection end (fraction of duration) 
//
HRESULT RecompressFileSelection(LPCTSTR pszSource, LPCTSTR pszTarget, double dStart, double dEnd, HINSTANCE hInstance) 
{
   HRESULT hr; 
   BSTR bstr; 
#ifndef _UNICODE
   WCHAR wsz[MAX_PATH]; 
#endif
   double duration;   


   // set source file
#ifdef _UNICODE
   bstr = SysAllocString(pszSource); 
#else
   swprintf(wsz, L"%hs", pszSource); 
   bstr = SysAllocString(wsz); 
#endif
   hr = IltmmConvert_put_SourceFile(g_pConvert, bstr); 
   SysFreeString(bstr); 
   if(FAILED(hr)) 
      return hr; 

   // set target file
#ifdef _UNICODE
   bstr = SysAllocString(pszTarget); 
#else
   swprintf(wsz, L"%hs", pszTarget); 
   bstr = SysAllocString(wsz); 
#endif
   hr = IltmmConvert_put_TargetFile(g_pConvert, bstr); 
   SysFreeString(bstr); 
   if(FAILED(hr)) 
      return hr; 

   // setup selection
   hr = IltmmConvert_get_Duration(g_pConvert, &duration); 
   if(FAILED(hr)) 
      return hr; 

   hr = IltmmConvert_put_SelectionStart(g_pConvert, duration * dStart); 
   if(FAILED(hr)) 
      return hr; 

   hr = IltmmConvert_put_SelectionEnd(g_pConvert, duration * dEnd); 
   if(FAILED(hr)) 
      return hr; 

   // setup AVI recompression
   hr = SetAVIRecompression(NULL); 
   if(FAILED(hr)) 
      return hr; 

   // do conversion
   hr = (HRESULT) DialogBox(hInstance, (LPCTSTR)IDD_CONVERTDLG, NULL, ConvertDlgProc); 


   return hr; 
}

void RecompressingAVIFileSelection_Example ( HINSTANCE hInstance /*application instance handle*/ )
{
   HRESULT hr ;

   // 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 = RecompressFileSelection(MAKE_MEDIA_PATH("source.avi"), MAKE_MEDIA_PATH("target.avi"), 0.30, 0.60, hInstance); 
   if(FAILED(hr)) 
      goto error; 

error: 
   // cleanup

   if(g_pConvert) 
      IUnknown_Release(g_pConvert); 

   CoUninitialize();
}