dcsimg

Direct Show Application for Previewing and Playing Movies

WEBINAR:
On-Demand

Desktop-as-a-Service Designed for Any Cloud ? Nutanix Frame


.



Environment: VC6 SP4, Win98/2000

It's a simple Direct Show Application, used for previeing video files from disk. It also captures the real time data from a video capture device and allows you to preview it.

Technical Side:

I've used pure MFC classes and created a dialog based application and everything regarding GUI is the same as any particular MFC app is created. I've used the Direct Show 8 APIs that are mainly written in the form of COM Interfaces. You can download the Direct Show 8 SDK from Microsoft's site or from the Direct Show site itself.

Some of the interfaces used in the Applliation include:

  1. IGraphBuilder: Opens and renders the video file
  2. IMediaControl : Is used to control the playback commands to the file
  3. IMediaEventEx : Controls the events on media files.It implements the callback functions to implement various events like play, pause, stop etc.
  4. IMediaSeeking : Provides set of functions to seek into the video file backwards or forwards.
  5. IBasicAudio : Controls the only audio renderer
  6. IBasicVideo : Controls the video only files that do not have any playback sound.
  7. IVideoWindow : Provides functions to view the video data in a view window.

Initilialize and play the movie file using the following code fragment. This code can be downloaded as part of the demo project.

BOOL CMovieDlg::OpenMediaFile()
{
  LPCWSTR wstrMediaFile;

  CFileDialog dlgFile(TRUE, 
                      NULL,
                      NULL,
                      OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
                      "Movie Files (*.avi;*.mpg;*.mpeg) | 
                      *.avi;*.mpg;*.mpeg | 
                      Audio Files (*.wav;*mp3;*.mpa;*.mpu;*.au) |
                      *.wav;*.mp3;*.mpa;*.mpu;*.au | 
                      Midi Files (*.mid;*.midi;*.rmi) |
                      *.mid;*.midi;*.rmi| | ", this);

  if(dlgFile.DoModal() == IDOK)
  {
     m_strMediaFile  = dlgFile.GetPathName();
  }
  else
     return FALSE;

  USES_CONVERSION;
  wstrMediaFile = A2W(m_strMediaFile);

  CoCreateInstance( CLSID_FilterGraph,
                    NULL,
                    CLSCTX_INPROC,
                    IID_IGraphBuilder,
                    (void **)&m_pGraph);
  HRESULT hr = m_pGraph->RenderFile(wstrMediaFile, NULL);
  if(FAILED(hr))
  {
     char szMsg[200];
     AMGetErrorText(hr, szMsg, sizeof(szMsg));
     AfxMessageBox(szMsg);
  }

  // Specify the owner window.
  IVideoWindow* pVidWin = NULL;
  m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&pVidWin);
  pVidWin->put_Owner((OAHWND)m_hWnd);
  pVidWin->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS);

  CRect rc;
  GetDlgItem(IDC_STATIC_FRAME)->GetWindowRect(rc);
  ScreenToClient(rc);
  pVidWin->SetWindowPosition(rc.left, rc.top, rc.Width(), rc.Height());

  // Set the owner window to receive event notices.
  m_pGraph->QueryInterface(IID_IMediaEventEx,
                           (void **)&m_pEvent);
  m_pEvent->SetNotifyWindow((OAHWND)m_hWnd, WM_GRAPHNOTIFY, 0);

  // Set the Media Seeking
  m_pGraph->QueryInterface(IID_IMediaSeeking,
                           (void **)&m_pMediaSeeking);
  m_pGraph->QueryInterface(IID_IBasicAudio,
                           (void **)&m_pBasicAudio);
  m_pGraph->QueryInterface(IID_IBasicVideo,
                           (void **)&m_pBasicVideo);

  if ((!pVidWin) || (!m_pBasicVideo))
  {
     m_bAudioOnly = TRUE;
     TRACE0("No video interface.  Assuming audio/MIDI "
            "file or unsupported video codec.\r\n");
  }

  long lVisible;
  hr = pVidWin->get_Visible(&lVisible);

  m_bAudioOnly = FALSE;
  if(FAILED(hr))
  {
     // If this is an audio-only clip, get_Visible() won't work.
     //
     // Also, if this video is encoded with an unsupported codec,
     // we won't see any video, although the audio will work 
     // if it is of a supported format.
   
     if(hr == E_NOINTERFACE)
     {
       m_bAudioOnly = TRUE;
       m_pBasicAudio->put_Volume(m_lVolume);
     }
     else
       TRACE1(TEXT("Failed(%08lx) in pVW->get_Visible()!\r\n"),
              hr);
  }

  LONGLONG lDuration;

  hr = m_pMediaSeeking->GetDuration(&lDuration);
  if(SUCCEEDED(hr))
  {
     m_sldrVideo.SetRange(0,(int)1000);
     m_sldrVideo.SetLineSize((int)100);
     m_sldrVideo.SetTicFreq((int)10);
  }

  return TRUE;
}

BOOL CMovieDlg::Play()
{
  // Run the graph
  IVideoWindow *pVidWin = NULL;

  if(m_pGraph)
  {
     m_pGraph->QueryInterface(IID_IVideoWindow,
                              (void **)&pVidWin);
     pVidWin->put_Visible(OATRUE);

     m_pGraph->QueryInterface(IID_IMediaControl,
                              (void **)&m_pMediaControl);
     m_pMediaControl->Run();


     SetTimer(101, 100, NULL);

     return TRUE;
  }

  return FALSE;
}

Downloads

Download demo project - 9.79 Kb
Download source - 826 Kb


This article was originally published on November 6th, 2001

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date