Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms
Imports AForge.Video
Imports AForge.Video.DirectShow

Public Class Form1
    Dim VideoCaptureSource As VideoCaptureDevice
    'Dim VideoCaptureSource2 As VideoCaptureDevice
    Dim VideoDevices As New FilterInfoCollection(FilterCategory.VideoInputDevice)
    'Dim VideoDevices2 As New FilterInfoCollection(FilterCategory.VideoInputDevice)

    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Try
            Timer1.Interval = 80
            Timer1.Enabled = False

            If VideoSourcePlayer1.IsRunning = True Then
                VideoSourcePlayer1.GetCurrentVideoFrame()
            End If

            If VideoSourcePlayer2.IsRunning = True Then
                VideoSourcePlayer2.GetCurrentVideoFrame()
            End If
        Catch ex As Exception

        End Try
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Try
            ' enumerate video devices
            If VideoDevices.Count = 0 Then
                ComboBox1.Items.Add("No Video Devices")
            End If

            Dim i As Integer = 1, n As Integer = VideoDevices.Count
            While i <= n
                Dim cameraName As String = i + " : " + VideoDevices(i - 1).Name
                ComboBox1.Items.Add(cameraName)
                ComboBox2.Items.Add(cameraName)
                System.Math.Max(System.Threading.Interlocked.Increment(i), i - 1)
            End While

            ' check cameras count
            If VideoDevices.Count = 1 Then
                ComboBox2.Items.Clear()
                ComboBox2.Items.Add("Only one camera found")
                ComboBox2.SelectedIndex = 0
                ComboBox2.Enabled = False
            Else
                ComboBox2.SelectedIndex = 1
            End If

            ComboBox1.SelectedIndex = 0
        Catch
            Button2.Enabled = False
            ComboBox1.Items.Add("No cameras found")
            ComboBox2.Items.Add("No cameras found")
            ComboBox1.SelectedIndex = 0
            ComboBox2.SelectedIndex = 0
            ComboBox1.Enabled = True
            ComboBox2.Enabled = True
        End Try
    End Sub

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        StopCameras()
    End Sub

    Sub StartCameras()
        ' create first video source
        Dim videoSource1 As New VideoCaptureDevice(VideoDevices(ComboBox1.SelectedIndex).MonikerString)
        VideoSourcePlayer1.VideoSource = videoSource1
        VideoSourcePlayer1.Start()

        ' create second video source
        If ComboBox2.Enabled = True Then
            System.Threading.Thread.Sleep(500)

            Dim videoSource2 As New VideoCaptureDevice(VideoDevices(ComboBox2.SelectedIndex).MonikerString)
            VideoSourcePlayer2.VideoSource = videoSource2
            VideoSourcePlayer2.Start()
        End If
        ' start timer
        Timer1.Start()
    End Sub

    Sub StopCameras()
        VideoSourcePlayer1.SignalToStop()
        VideoSourcePlayer2.SignalToStop()
        VideoSourcePlayer1.WaitForStop()
        VideoSourcePlayer2.WaitForStop()
        VideoDevices = Nothing
        VideoCaptureSource = Nothing
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        StartCameras()
        Button1.Enabled = False
        Button2.Enabled = True
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        StopCameras()
        Button1.Enabled = True
        Button2.Enabled = False
    End Sub
End Class