VLCWrapper - A Little C++-wrapper Around libvlc

• Download demo project [build with VLC 2.0.0] - 24.82 KB 

  For the demo, you need to download the actual VLC package and copy the plug-ins in the corresponding directory of the demo. You will also need to have libvlc.dll and libvlccore.dll in your path.

• Download source [VLC API 2.0.0 required!] - 248.88 KB

  This package includes projects for Visual Studio 6 and Visual Studio 2010. The source package also includes the VLC headers and the libs for linking. You can find the libs on the videolan site in special ZIP files intended for developers. They are bigger (~36MB) than the normal ZIPs on the download page.

Introduction

This article presents a little C++-wrapper for the libvlc-library, which is the core component of the VLC media player. I was looking for an easy way to integrate video playback in my C++ applications. Because I've been using VLC for media playback for many years now, I started playing around with the VLC API. The result is a little wrapper around the libvlc-library. It provides basic media playback functionality. Since v.2.0 the  libvlc-library is released under the LGPL, so you can use it in commercial applications. All sourcecode in this arcticle is licensed under the CPOL. Please excuse any bugs because this wrapper is more a quick hack than a feature complete wrapper. ;)

For testing purposes, I wrote a simple media player which uses the VLCWrapper. It's included in the example above.

Background

The most valuable source of information about the VLC API for me was the developer section on the VLC website and the documented C-headers of the VLC source. The project website is a good starting point if you plan to code something with VLC or extend the VLCWrapper.

The C++-Interface of VLCWrapper to LIBVLC

The interface declared in "VLCWrapper.h" is small and the member functions are quite self-explanatory. To get a good overlook, I stripped of the comments. Check out the sources for more information.  

class VLCWrapper
{
    std::auto_ptr<VLCWrapperImpl> pImpl_;
 
public:
    VLCWrapper();
    ~VLCWrapper();
    void SetOutputWindow(void* pHwnd);
    void SetEventHandler(VLCEventHandler event, void* pUserData);
    void OpenMedia(const char* pMediaPathName);
    void Play();
    void Pause();
    void Stop();
    int64_t GetLength();
    int64_t GetTime();
    void SetTime(int64_t newTime);
    void Mute(bool mute = true);
    bool GetMute();
    int  GetVolume();
    void SetVolume(int volume);
};  

Using the Code

Using the VLCWrapper is easy. The first step would be to add a new VLCWraper as a member of your window class and a CStatic for video output:

#include "VLCWrapper.h"

class CVlcDialogDlg : public CDialog
{
    VLCWrapper vlcPlayer_; /// Our VLCWrapper.
    .
    .
    //{{AFX_DATA(CVlcDialogDlg)
    CStatic vlcControl_;  /// This CStatic will be used as device context by libvlc.
    . . . 
    //}}AFX_DATA

Now we can initialize the VLCWrapper in OnInitDialog():

BOOL CVlcDialogDlg::OnInitDialog()
{
    CDialog::OnInitDialog();

    vlcPlayer_.SetOutputWindow((void*)vlcControl_.GetSafeHwnd()); // the CStatic will be 
							          // used for video output

    vlcPlayer_.SetEventHandler(&HandleVLCEvents, this);           // Set handler for vlc events

The handler function for VLC events:

static void HandleVLCEvents(const VLCEvent* pEvent, void* pUserData)
{
    CVlcDialogDlg* pDlg = reinterpret_cast<CVlcDialogDlg*>(pUserData); 
 
    switch(pEvent->type)
    {
    case libvlc_MediaPlayerTimeChanged:
       TRACE("VLC_EVT_TIME_CHANGED: new_time %d[ms]\n",
              pEvent->u.media_player_time_changed.new_time);
       if(pDlg)
           pDlg->UpdatePosition();
       break;
    } 
}

Now everything is in place, and you can start playing media files. E.g., the "Load" and "Play" members look like this:

void CVlcDialogDlg::OnBnClickedButtonLoad()
{
    CFileDialog dlgFile(TRUE);
    if(dlgFile.DoModal()==IDOK)
    {
        CString file=dlgFile.GetPathName();
        vlcPlayer_.OpenMedia((LPCTSTR)file);
        vlcPlayer_.Play();  // start media after loading....
    }
}

void CVlcDialogDlg::OnBnClickedButtonPlay()
{
    vlcPlayer_.Play();
}

History

• 03/12/2012 
• Updated the project to use the VLC API 2.0.0.
• Changed license to CPOL.  
• 09/20/2011 
• Added project files for Visual Studio 2010. 
• 09/11/2010
• Some bugfixes and optimizations, thanks to heretic13!
• Build the demo with VLC 1.1.4.
• Removed demo & source links to old VLCDialog versions which required VLC < 1.1.
• 05/29/2010
• Updated the project to use the VLC API 1.1
• The wrapper now uses an auto_ptr for its Pimpl. I missed deleting the Pimpl in the first versions
• Fixed a redraw error
• Thanks to Haim Engler for the hint on the memory leak and the redraw problem!
• 08/20/2009
• Pimped VlcDialog (Resizing, Icon-Buttons)
• Striped off dependency to "StdAfx.h" in class VLCWrapper and class VLCWrapperImpl
• Replaced a deprecated function call to libvlc; now SetOutputWindow(void*) takes a void pointer to a window handle
• 08/14/2009
• Some fixes in the example listings
• 08/11/2009
• Initial release