Take the following steps to create and run a multimedia TV tuner capture application using the LEADTOOLS Media Foundation CaptureCtrl control.
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 TV Tuner Capture" in the Project Name field, and then choose OK. If desired, type a new location for your project or select a directory using the Browse button, and then choose OK.
In the "Solution Explorer" window, right-click on the "References" folder, and select "Add Reference..." from the context menu. In the "Add Reference" dialog box, select the ".NET" tab and select Leadtools.MediaFoundation and click OK.
Make sure Form1 is in design view. Go to the toolbox (View->Toolbox) and drag and drop a CaptureCtrl control on the form. NOTE: If you do not have CaptureCtrl in your toolbox, select Tools->Choose Toolbox Items from the menu. Click Browse and then select Leadtools.MediaFoundation.dll from "<LEADTOOLS_INSTALLDIR>\Bin\Dotnet4\Win32" and then click Open and then click OK. After adding it to the form, set the following properties on the capture control:
Property | Value |
---|---|
Name | _capturectrl |
Anchor | Top, Bottom, Left, Right |
Go to the toolbox (View->Toolbox) and drag and drop a ProgressBar control (to be used to display capture progress) on the form (below the capture control) and set the following properties:
Property | Value |
---|---|
Name | _progress |
Anchor | Bottom, Left, Right |
Go to the toolbox (View->Toolbox) and drag and drop 4 Button controls on the bottom of the form (for Capture, Channel Up and Channel Down) and set the following properties:
Property | Value |
---|---|
Name | _buttonCapture |
Text | Capture |
Anchor | Bottom, Right |
Name | _buttonChannelUp |
Text | Up |
Anchor | Bottom, Right |
Name | _buttonChannelDown |
Text | Down |
Anchor | Bottom, Right |
Go to the toolbox (View->Toolbox) and drag and drop a Label control, a Text control, another Label control and a ProgressBar control on the bottom left of the form (for a "Channel:" label, a channel text box, a "Signal:" label and a signal strength meter) and set the following properties:
Property | Value |
---|---|
Name | label1 |
Text | Channel: |
Anchor | Bottom, Left |
Name | _textChannel |
Anchor | Bottom, Left |
Locked | True |
ReadOnly | True |
TextAlign | Center |
Name | label2 |
Text | Signal: |
Anchor | Bottom, Left |
Name | _signal |
Anchor | Bottom, Left |
Switch Form1 to code view (right-click Form1 in the solution explorer then select View Code) and add the following lines at the beginning of the file:
using System.Runtime.InteropServices;
using Leadtools.MediaFoundation;
Imports System.Runtime.InteropServices
Imports Leadtools.MediaFoundation
Declare the following private variables:
private string _targetFile;
private int _captureTime;
Private _targetFile As String
Private _captureTime As Integer
Add an event handler to the Form1 Load event and code it as follows:
private void Form1_Load(object sender, EventArgs e)
{
if (_capturectrl.VideoDevices.Count == 0)
throw new Exception("No capture devices available");
if (_capturectrl.VideoDevices["Analog"] == null)
throw new Exception("No Analog TV capture devices available");
_capturectrl.VideoDevices["Analog"].Selected = true;
_capturectrl.UseVideoDeviceAudio = true;
_capturectrl..TargetFormats.Selection = TargetFormatType.MP4;
_targetFile = @"capture.mp4";
_captureTime = 30;
_capturectrl.PreviewSource = CapturePreview.Video;
_capturectrl.Preview = true;
DisplayChannelAndSignal();
}
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
If _capturectrl.VideoDevices.Count = 0 Then
Throw New Exception("No capture devices available")
End If
If _capturectrl.VideoDevices("Analog") Is Nothing Then
Throw New Exception("No Analog TV capture devices available")
End If
_capturectrl.VideoDevices("Analog").Selected = True
_capturectrl..TargetFormats.Selection = TargetFormatType.MP4
_targetFile = "capture.mp4"
_captureTime = 30
_capturectrl.PreviewSource = CapturePreview.Video
_capturectrl.Preview = True
DisplayChannelAndSignal()
End Sub
Add the following helper methods as follows:
private void DisplayChannelAndSignal()
{
if (_capturectrl.TVTuner != null)
{
int currChannel = _capturectrl.TVTuner.Channel;
_textChannel.Text = currChannel.ToString();
TunerSignalStrength signal = _capturectrl.TVTuner.SignalPresent;
switch (signal)
{
case TunerSignalStrength.NoSignal:
_signal.Value = 0;
break;
case TunerSignalStrength.HasNoSignalStrength:
_signal.Value = 10;
break;
case TunerSignalStrength.SignalPresent:
_signal.Value = 100;
break;
}
}
}
private void ChangeChannel(bool up)
{
int chanMin = _capturectrl.TVTuner.ChannelMin;
int chanMax = _capturectrl.TVTuner.ChannelMax;
int currChannel = _capturectrl.TVTuner.Channel;
int currVideoChannel = _capturectrl.TVTuner.VideoSubChannel;
if (up)
{
if (currChannel == chanMax)
currChannel = chanMin;
else
currChannel++;
}
else
{
if (currChannel == chanMin)
currChannel = chanMax;
else
currChannel--;
}
_capturectrl.TVTuner.SetChannel(currChannel, -1, -1);
DisplayChannelAndSignal();
}
Private Sub DisplayChannelAndSignal()
If Not _capturectrl.TVTuner Is Nothing Then
Dim currChannel As Integer = _capturectrl.TVTuner.Channel
_textChannel.Text = currChannel.ToString()
Dim signal As TunerSignalStrength = _capturectrl.TVTuner.SignalPresent
Select Case signal
Case TunerSignalStrength.NoSignal
_signal.Value = 0
Case TunerSignalStrength.HasNoSignalStrength
_signal.Value = 10
Case TunerSignalStrength.SignalPresent
_signal.Value = 100
End Select
End If
End Sub
Private Sub ChangeChannel(ByVal up As Boolean)
Dim chanMin As Integer = _capturectrl.TVTuner.ChannelMin
Dim chanMax As Integer = _capturectrl.TVTuner.ChannelMax
Dim currChannel As Integer = _capturectrl.TVTuner.Channel
Dim currVideoChannel As Integer = _capturectrl.TVTuner.VideoSubChannel
If up Then
If currChannel = chanMax Then
currChannel = chanMin
Else
currChannel += 1
End If
Else
If currChannel = chanMin Then
currChannel = chanMax
Else
currChannel -= 1
End If
End If
_capturectrl.TVTuner.SetChannel(currChannel, -1, -1)
DisplayChannelAndSignal()
End Sub
Add an event handler to the _capturectrl Progress event and code it as follows:
private void _capturectrl_Progress(object sender, ProgressEventArgs e)
{
_progress.Value = (int)((_progress.Maximum * e.time) / (_captureTime * 1000));
}
Private Sub _capturectrl_Progress(ByVal sender As System.Object, ByVal e As ProgressEventArgs) Handles _capturectrl.Progress
_progress.Value = CInt((_progress.Maximum * e.time) / (_captureTime * 1000))
End Sub
Add an event handler to the _capturectrl Complete event and code it as follows:
private void _capturectrl_Complete(object sender, EventArgs e)
{
MessageBox.Show("Capture Complete");
_buttonCapture.Enabled = true;
}
Private Sub _capturectrl_Complete(ByVal sender As System.Object, ByVal e As EventArgs) Handles _capturectrl.Complete
MessageBox.Show("Capture Complete")
_buttonCapture.Enabled = True
End Sub
Add an event handler to the _buttonChannelUp Click event and code it as follows:
private void _buttonChannelUp_Click(object sender, EventArgs e)
{
if (_capturectrl.TVTuner != null)
{
ChangeChannel(true);
}
}
Private Sub _buttonChannelUp_Click(ByVal sender As Object, ByVal e As EventArgs) Handles _buttonChannelUp.Click
If Not _capturectrl.TVTuner Is Nothing Then
ChangeChannel(True)
End If
End Sub
Add an event handler to the _buttonChannelDown Click event and code it as follows:
private void _buttonChannelDown_Click(object sender, EventArgs e)
{
if (_capturectrl.TVTuner != null)
{
ChangeChannel(false);
}
}
Private Sub _buttonChannelDown_Click(ByVal sender As Object, ByVal e As EventArgs) Handles _buttonChannelDown.Click
If Not _capturectrl.TVTuner Is Nothing Then
ChangeChannel(False)
End If
End Sub
Add an event handler to the _buttonCapture Click event and code it as follows:
private void _buttonCapture_Click(object sender, System.EventArgs e)
{
try
{
_capturectrl.Preview = true;
_capturectrl.TargetFile = _targetFile;
_capturectrl.UseTimeLimit = true;
_capturectrl.TimeLimit = _captureTime;
_capturectrl.StartCapture(CaptureMode.Video);
_buttonCapture.Enabled = false;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
Private Sub _buttonCapture_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles _buttonCapture.Click
Try
_capturectrl.Preview = True
_capturectrl.TargetFile = _targetFile
_capturectrl.UseTimeLimit = True
_capturectrl.TimeLimit = _captureTime
_capturectrl.StartCapture(CaptureMode.Video)
_buttonCapture.Enabled = False
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Build, and Run the program to test it.