Creating a LEADTOOLS Multimedia MPEG-2 Streaming Application

Perform the following steps to create and run a multimedia MPEG2 Streaming application using the LEADTOOLS Multimedia ConvertCtrl and PlayCtrl controls.

Start Visual Studio.
Choose File->New->Project... from the menu.
In the New Project dialog box, choose either "Visual C# Projects" or "VB Projects" in the Projects Type List, and choose "Windows Application " in the Templates List.
Type the project name as "Multimedia MPEG2 Streaming" in the Project Name field, and then click OK. If desired, type a new location for your project or select a directory using the Browse button, and then click OK.
In the "Solution Explorer" window, right-click the "References" folder, and select "Add Reference..." from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and select Leadtools.Multimedia and click OK. Also, right-click the "References" folder, and select "Add Reference..." from the context menu. In the "Add Reference" dialog box, select the "COM" tab and select:
- LEAD MPEG-2 Transport Multiplexer Library
- LEAD MPEG-2 Transport Demultiplexer Library
Note: The above COM objects must be registered; in case they were not; using regsvr32. For more information, refer to DirectShow Registry-free Activation.

Next click OK.

Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and drag a ConvertCtrl control and a PlayCtrl control on the form. NOTE: If you do not have ConvertCtrl or PlayCtrl controls in your toolbox, select Tools->Choose Toolbox Items from the menu. Click Browse and then select Leadtools.Multimedia.dll from "<LEADTOOLS_INSTALLDIR>\Bin\Dotnet4\Win32" and then click Open and then click OK. After adding these controls to the form, set the following properties:

Property	Value
Name	_convertctrl
Anchor	Top, Left
BackColor	Black
Name	_playctrl
Anchor	Top, Bottom, Left, Right
AutoStart	False

Go to the toolbox (View->Toolbox) and drag a Text control on the form (below the convert control) and set the following properties:

Property	Value
Name	_txtSrcFile
Anchor	Bottom, Left
Locked	True

Go to the toolbox (View->Toolbox) and drag a Button control to the right of the text control and set the following properties:

Property	Value
Name	_buttonBrowse
Text	...
Anchor	Bottom, Left

Go to the toolbox (View->Toolbox) and drag a TrackBar control on the form (below the play control) and set the following properties:

Property	Value
Name	_track
Anchor	Bottom, Left, Right
Maximum	10000

Go to the toolbox (View->Toolbox) and drag two Button controls to the bottom of the form (one below the convert control and one below the play control) and set the following properties:

Property	Value
Name	_buttonStartStop
Text	Start
Anchor	Bottom, Left
Name	_buttonPauseResume
Text	Pause
Anchor	Bottom, Right

Switch Form1 to code view (right-click Form1 in the Solution Explorer then choose View Code) and add the following lines to the beginning of the file:

vb 
Imports Leadtools.Multimedia 
Imports System.Runtime.InteropServices 
Imports LMMpg2MxTLib 
Imports LMMpgDmxTLib

using Leadtools.Multimedia; 
using System.Runtime.InteropServices; 
using LMMpg2MxTLib; 
using LMMpgDmxTLib;

Declare the following private variable:

vb 
Private Const SLIDER_MAX As Integer = 10000 
Private _streaming As Boolean = False 
Private _firstPTS As Double 
Private _lastPTS As Double

Private const int SLIDER_MAX = 10000; 
Private bool _streaming = false; 
Private double _firstPTS; 
Private double _lastPTS;

Add an event handler to the _convertctrl Started event and code it as follows:

vb 
Private Sub _convertCtrl_Started(ByVal sender As Object, ByVal e As EventArgs) Handles _convertCtrl.Started 
   _streaming = True 
   _buttonBrowse.Enabled = False 
   If _playctrl.State = PlayState.Stopped OrElse _playctrl.State = PlayState.NotReady Then 
      _playctrl.SourceFile = _convertCtrl.TargetFile 
      _playctrl.Run() 
   End If 
End Sub

void _convertCtrl_Started(object sender, EventArgs e) 
{ 
   _streaming = true; 
   _buttonBrowse.Enabled = false; 
   if (_playctrl.State == PlayState.Stopped ||   _playctrl.State == PlayState.NotReady) 
   { 
      _playctrl.SourceFile = _convertCtrl.TargetFile; 
      _playctrl.Run(); 
   } 
}

Add an event handler to the _convertctrl Complete event and code it as follows:

vb 
Private Sub _convertCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs) Handles _convertCtrl.Complete 
   If _streaming = True Then 
      _convertCtrl.StartConvert() 
   Else 
      _buttonStartStop.Text = "Start" 
      _buttonBrowse.Enabled = True 
   End If 
End Sub

void _convertCtrl_Complete(object sender, EventArgs e) 
{ 
   if (_streaming == true) 
      _convertCtrl.StartConvert(); 
   else 
   { 
      _buttonStartStop.Text = "Start"; 
      _buttonBrowse.Enabled = true; 
   } 
}

Add an event handler to the _playctrl TrackingPositionChanged event and code it as follows:

vb 
Private Sub _playctrl_TrackingPositionChanged(ByVal sender As Object, ByVal e As TrackingPositionChangedEventArgs) Handles _playctrl.TrackingPositionChanged 
   Dim demux As LMMpgDmxT = TryCast(_playctrl.GetSubObject(PlayObject.Splitter), LMMpgDmxT) 
   If Not demux Is Nothing Then 
      demux.RefreshPosition(0) 
                 
      _firstPTS = demux.FirstStreamPTS 
      _lastPTS = demux.LastStreamPTS 
                 
      _track.Value = PTSToSliderPosition(demux.CurrentStreamPTS) 
      Marshal.ReleaseComObject(demux) 
   End If 
End Sub

void _playctrl_TrackingPositionChanged(object sender, TrackingPositionChangedEventArgs e) 
{ 
   LMMpgDmxT demux = _playctrl.GetSubObject(PlayObject.Splitter) as LMMpgDmxT; 
   if (demux != null) 
   { 
      demux.RefreshPosition(0); 
                 
      _firstPTS = demux.FirstStreamPTS; 
      _lastPTS = demux.LastStreamPTS; 
                 
      _track.Value = PTSToSliderPosition(demux.CurrentStreamPTS); 
      Marshal.ReleaseComObject(demux); 
   } 
}

Add an event handler to the _track Scroll event and code it as follows:

vb 
Private Sub _track_Scroll(ByVal sender As Object, ByVal e As EventArgs) Handles _track.Scroll 
   Dim demux As LMMpgDmxT = TryCast(_playctrl.GetSubObject(PlayObject.Splitter), LMMpgDmxT) 
   If Not demux Is Nothing Then 
      demux.RefreshPosition(0) 
      demux.CurrentStreamPTS = SliderPositionToPTS(_track.Value) 
                 
      Marshal.ReleaseComObject(demux) 
   End If 
End Sub

private void _track_Scroll(object sender, EventArgs e) 
{ 
   LMMpgDmxT demux = _playctrl.GetSubObject(PlayObject.Splitter) as LMMpgDmxT; 
   if (demux != null) 
   { 
      demux.RefreshPosition(0); 
      demux.CurrentStreamPTS = SliderPositionToPTS(_track.Value); 
                 
      Marshal.ReleaseComObject(demux); 
   } 
}

Add the following helper methods for use by the _track control's scroll and _playctrl track positioning handlers:

vb 
Private Function PTSToSliderPosition(ByVal curPTS As Double) As Integer 
   Dim retVal As Integer = 0 
   If curPTS <= _firstPTS Then 
      retVal = 0 
   ElseIf curPTS >= _lastPTS Then 
      retVal = SLIDER_MAX 
   Else 
      retVal = CInt(((curPTS - _firstPTS) * SLIDER_MAX) / (_lastPTS - _firstPTS) + 0.5) 
   End If 
                 
   Return retVal 
End Function 
                 
Private Function SliderPositionToPTS(ByVal nPos As Integer) As Double 
   Return _firstPTS + CDbl(nPos) * (_lastPTS - _firstPTS) / CDbl(SLIDER_MAX) 
End Function

private int PTSToSliderPosition(double curPTS) 
{ 
   int retVal = 0; 
   if (curPTS <= _firstPTS) 
      retVal = 0; 
   else if (curPTS >= _lastPTS) 
      retVal = SLIDER_MAX; 
   else 
      retVal = (int)(((curPTS - _firstPTS) * SLIDER_MAX) / (_lastPTS - _firstPTS) + 0.5); 
                 
   return retVal; 
} 
                 
private double SliderPositionToPTS(int nPos) 
{ 
   return _firstPTS + (double)nPos * (_lastPTS - _firstPTS) / (double)SLIDER_MAX; 
}

Add an event handler to the _buttonBrowse Click event and code it as follows:

vb 
Private Sub _btnBrowse_Click(ByVal sender As Object, ByVal e As EventArgs) Handles _buttonBrowse.Click 
   Dim ofn As OpenFileDialog = New OpenFileDialog() 
   ofn.FileName = _txtSrcFile.Text 
   ofn.FilterIndex = 0 
                 
   If _txtSrcFile.Text <> String.Empty Then 
      ofn.InitialDirectory = Path.GetDirectoryName(_txtSrcFile.Text) 
   Else 
      ofn.InitialDirectory = Directory.GetCurrentDirectory() 
   End If 
                 
   ofn.Multiselect = False 
   ofn.Title = "Select Source Video" 
   ofn.CheckFileExists = True 
                 
   ofn.Filter = "MPEG2 Video Files (*.mpg)|*.mpg |   All files (*.*)|*.*" 
                 
   If ofn.ShowDialog() = DialogResult.OK Then 
      _txtSrcFile.Text = ofn.FileName 
   End If 
End Sub

private void _btnBrowse_Click(object sender, EventArgs e) 
{ 
   OpenFileDialog ofn = new OpenFileDialog(); 
   ofn.FileName = _txtSrcFile.Text; 
   ofn.FilterIndex = 0; 
                     
   if (_txtSrcFile.Text != string.Empty) 
      ofn.InitialDirectory = Path.GetDirectoryName(_txtSrcFile.Text); 
   else 
      ofn.InitialDirectory = Directory.GetCurrentDirectory(); 
                 
   ofn.Multiselect = false; 
   ofn.Title = "Select Source Video"; 
   ofn.CheckFileExists = true; 
                 
   ofn.Filter = "MPEG2 Video Files (*.mpg)|*.mpg |   All files (*.*)|*.*"; 
                 
   if (ofn.ShowDialog() == DialogResult.OK) 
   { 
      _txtSrcFile.Text = ofn.FileName; 
   } 
}

Add an event handler to the _buttonStartStop Click event and code it as follows:

vb 
Private Sub _btnStartStop_Click(ByVal sender As Object, ByVal e As EventArgs) Handles _buttonStartStop.Click 
   Dim srcFile As String = _txtSrcFile.Text 
                 
   If _streaming = False Then 
      If srcFile <> String.Empty AndAlso File.Exists(srcFile) Then 
         _convertCtrl.SourceFile = srcFile 
         _convertCtrl.AllowedStreams = StreamFormatType.AudioVideoCC 
         _convertCtrl.PreferredMPEG2Splitter = Leadtools.Multimedia.Constants.Filter_MPEG2_Transport_Demux 
         _convertCtrl.TargetFormat = TargetFormatType.MPEG2Transport 
         _convertCtrl.Preview = True 
         _convertCtrl.TargetFile = "udp://127.0.0.1:9005" 
                 
         Dim mux As LMMpg2MxT = TryCast(_convertCtrl.GetSubObject(ConvertObject.TargetFilter), LMMpg2MxT) 
         If Not mux Is Nothing Then 
            mux.OutputType = CInt(LMMpg2MxTLib.Mpg2MxT_OutputType.Mpg2MxT_OutputType_Broadcast) 
            mux.ResyncInterval = 10 
                 
            Marshal.ReleaseComObject(mux) 
         End If 
                 
         Try 
            _convertCtrl.StartConvert() 
            _buttonStartStop.Text = "Stop" 
            _buttonBrowse.Enabled = False 
         Catch e1 As Exception 
         End Try 
      End If 
   Else 
      If _streaming = True Then 
         _convertCtrl.StopConvert() 
         _buttonStartStop.Text = "Start" 
         _buttonBrowse.Enabled = True 
      End If 
   End If 
End Sub

private void _btnStartStop_Click(object sender, EventArgs e) 
{ 
   string srcFile = _txtSrcFile.Text; 
                 
   if (_streaming == false) 
   { 
      if (srcFile != string.Empty && File.Exists(srcFile)) 
      { 
         _convertCtrl.SourceFile = srcFile; 
         _convertCtrl.AllowedStreams = StreamFormatType.AudioVideoCC; 
         _convertCtrl.PreferredMPEG2Splitter = Constants.Filter_MPEG2_Transport_Demux; 
         _convertCtrl.TargetFormat = TargetFormatType.MPEG2Transport; 
         _convertCtrl.Preview = true; 
         _convertCtrl.TargetFile = @"udp://127.0.0.1:9005"; 
                 
         LMMpg2MxT mux = _convertCtrl.GetSubObject(ConvertObject.TargetFilter) as LMMpg2MxT; 
         if (mux != null) 
         { 
            mux.OutputType = (int)LMMpg2MxTLib.Mpg2MxT_OutputType.Mpg2MxT_OutputType_Broadcast; 
            mux.ResyncInterval = 10; 
                 
            Marshal.ReleaseComObject(mux); 
         } 
                 
         try 
         { 
            _convertCtrl.StartConvert(); 
            _buttonStartStop.Text = "Stop"; 
            _buttonBrowse.Enabled = false; 
         } 
         catch (Exception) { } 
      } 
   } 
   else 
   { 
      if (_streaming == true) 
      { 
         _convertCtrl.StopConvert(); 
         _buttonStartStop.Text = "Start"; 
         _buttonBrowse.Enabled = true; 
      } 
   } 
}

Add an event handler to the _buttonPauseResume Click event and code it as follows:

vb 
Private Sub _buttonPauseResume_Click(ByVal sender As Object, ByVal e As EventArgs) Handles _buttonPauseResume.Click 
   If _playctrl.State = PlayState.Running Then 
      _playctrl.Pause() 
      _buttonPauseResume.Text = "Resume" 
   ElseIf _playctrl.State = PlayState.Paused Then 
      _playctrl.Run() 
      _buttonPauseResume.Text = "Pause" 
   End If 
End Sub

private void _buttonPauseResume_Click(object sender, EventArgs e) 
{ 
   if (_playctrl.State == PlayState.Running) 
   { 
      _playctrl.Pause(); 
      _buttonPauseResume.Text = "Resume"; 
   } 
   else if (_playctrl.State == PlayState.Paused) 
   { 
      _playctrl.Run(); 
      _buttonPauseResume.Text = "Pause"; 
   } 
}

Build, and Run the program to test it. Click the [...] browse button to locate a video file for the convert / streaming output. Then click the Start button to begin streaming. Finally, click the Pause/Resume button to test pause and resume on the play control OR drag the track bar control to reposition the stream playback.