ReadMessage Method

Imports Leadtools
Imports Leadtools.Multimedia
Imports LeadtoolsMultimediaExamples.Fixtures

Public _result As Boolean = False
Public _serverAndClient As CaptureAndPlayCtrlForm = New CaptureAndPlayCtrlForm()
Private _msgSent As Boolean = False
Private _captureCtrl As CaptureCtrl
Private _playCtrl As PlayCtrl
Private _pMux As LMNetMux
Private _pDemux As LMNetDmx

Private Const _networkUrl As String = "ltsf://127.0.0.1:27015" ' network stream url
Private Const _testMessage As String = "LEAD NETWORK"
Dim _recordedVideoFile As String = Path.Combine(LEAD_VARS.MediaDir, "mediafiles/output/LMNetDmx_ReadMessageExample.mp4")

Public Sub NetworkDemultiplexerExample()
    ' reference the capture control
    _captureCtrl = _serverAndClient.CaptureCtrl

    ' reference the play control
    _playCtrl = _serverAndClient.PlayCtrl

    Try
        ' try to find a video camera
        If _captureCtrl.VideoDevices("Logitech") Is Nothing Then
            Throw New Exception("No Logitech video device available")
        End If

        _captureCtrl.VideoDevices("Logitech").Selected = True

        ' select a video compressor
        _captureCtrl.VideoCompressors.Mpeg4.Selected = True

        ' set the target output file
        _captureCtrl.TargetFormat = TargetFormatType.NET
        _captureCtrl.TargetFile = _networkUrl

        If _captureCtrl.IsModeAvailable(CaptureMode.Video) Then
            ' just 10 seconds of capture time
            _captureCtrl.TimeLimit = 10
            _captureCtrl.UseTimeLimit = True

            _captureCtrl.FrameRate = 30
            _captureCtrl.UseFrameRate = True

            _captureCtrl.Preview = True

            ' subscribe to the started and progress events for this example
            ' we will connect a client after the capture starts
            ' and send a test message after 5 seconds.
            AddHandler _captureCtrl.Started, AddressOf CaptureCtrl_Started
            AddHandler _captureCtrl.Progress, AddressOf CaptureCtrl_Progress

            ' ready the capture graph in order to get the LNMetMux instance
            _captureCtrl.ReadyCapture(CaptureMode.Video)

            ' get the network multiplexer reference
            _pMux = TryCast(_captureCtrl.GetSubObject(CaptureObject.TargetFilter), LMNetMux)

            If Not _pMux Is Nothing Then
                ' set some mux settings
                _pMux.LiveSource = True
            End If

            ' start capture
            _captureCtrl.StartCapture(CaptureMode.Video)

            ' we'll loop on the state and pump messages for this example.
            ' but you should not need to if running from a Windows Forms application.
            Do While _captureCtrl.State = CaptureState.Running OrElse _playCtrl.State = PlayState.Running
                Application.DoEvents()
            Loop

            ' verify we have a recording file too
            _result = _result And File.Exists(_recordedVideoFile)

            ' release the mux and demux COM objects
            If Not _pMux Is Nothing Then
                Marshal.ReleaseComObject(_pMux)
            End If

            If Not _pDemux Is Nothing Then
                Marshal.ReleaseComObject(_pDemux)
            End If
        End If
    Catch e1 As Exception
        _result = False
    End Try
End Sub

Private Sub CaptureCtrl_Progress(ByVal sender As Object, ByVal e As ProgressEventArgs)
    ' for this test we will send a message after 
    ' 5 secs of capture time
    If e.time > 5000 AndAlso (Not _msgSent) Then
        _pMux.WriteMessage(_testMessage)
        Console.WriteLine("Server sent message")
        _msgSent = True
    End If
End Sub

Private Sub CaptureCtrl_Started(ByVal sender As Object, ByVal e As EventArgs)
    StartClient()
End Sub

Private Sub StartClient()
    Try
        Dim netSrc As LMNetSrc = New LMNetSrc()
        netSrc.CheckConnection(_networkUrl, 0, 5000)
        Marshal.ReleaseComObject(netSrc)
    Catch cex As COMException
        ' could not connect
        Return
    End Try

    _playCtrl.SourceFile = _networkUrl
    _pDemux = TryCast(_playCtrl.GetSubObject(PlayObject.Splitter), LMNetDmx)

    If Not _pDemux Is Nothing AndAlso _pDemux.AutoLiveTolerance < 5 Then
        ' reset the demux settings to defaults
        _pDemux.ResetToDefaults()

        ' set the live tolerance setting to 5 seconds
        ' this will cause the playback to be smoother on jittery
        ' network connections -- although, the playback may lag 
        ' behing the live stream when using a tolerance value > 0
        _pDemux.AutoLiveTolerance = 5

        ' set the output filename for recorded video
        _pDemux.OutputFileName = _recordedVideoFile
    End If

    _serverAndClient.TestTimer.Interval = 100
    AddHandler _serverAndClient.TestTimer.Tick, AddressOf PlayTimer_Tick
    _serverAndClient.TestTimer.Start()
End Sub

Private Sub PlayTimer_Tick(ByVal sender As Object, ByVal e As EventArgs)
    _serverAndClient.TestTimer.Enabled = False
    If Not _pDemux Is Nothing Then
        ' read any messages here
        Dim msg As String = _pDemux.ReadMessage()

        ' set the result to what we expect
        If msg = _testMessage Then
            _result = True
            Console.WriteLine("Client received message")
        End If

        ' get the bitrate
        Dim bitRate As Integer = _pDemux.BitRate
        Console.WriteLine("Client bitrate = {0}", bitRate)
    End If
    _serverAndClient.TestTimer.Enabled = True
End Sub

Public NotInheritable Class LEAD_VARS
Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 18\Media"
End Class