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AutoLiveTolerence Property
See Also 
LMNetDmx Namespace > ILMNetDmx Interface : AutoLiveTolerence Property



Gets or sets the tolerance setting which determines whether the network demux should favor live playback (AutoLiveTolerance = 0) or smooth playback (AutoLiveTolerance > 0).

Syntax

Visual Basic (Declaration) 
<DispIdAttribute(5)>
Property AutoLiveTolerence As Double
Visual Basic (Usage)Copy Code
Dim instance As ILMNetDmx
Dim value As Double
 
instance.AutoLiveTolerence = value
 
value = instance.AutoLiveTolerence
C# 
[DispIdAttribute(5)]
double AutoLiveTolerence {get; set;}
C++/CLI 
[DispIdAttribute(5)]
property double AutoLiveTolerence {
   double get();
   void set (    double value);
}

Property Value

A double value indicating the tolerance value in seconds.

Example

Visual BasicCopy Code
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"
Private Const _recordedVideoFile As String = "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
C#Copy Code
public bool _result = false;
      public CaptureAndPlayCtrlForm _serverAndClient = new CaptureAndPlayCtrlForm();
      bool _msgSent = false;
      CaptureCtrl _captureCtrl;
      PlayCtrl _playCtrl;
      LMNetMux _pMux;
      LMNetDmx _pDemux;

      const string _networkUrl = @"ltsf://127.0.0.1:27015"; // network stream url
      const string _testMessage = "LEAD NETWORK";
      const string _recordedVideoFile = Path.Combine(LEAD_VARS.MediaDir ,"LMNetDmx_ReadMessageExample.mp4");

      public void 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"] == null)
               throw new Exception("No Logitech video device available");

            _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))
            {
               // 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.
               _captureCtrl.Started += new EventHandler(CaptureCtrl_Started);
               _captureCtrl.Progress += new ProgressEventHandler(CaptureCtrl_Progress);

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

               // get the network multiplexer reference
               _pMux = _captureCtrl.GetSubObject(CaptureObject.TargetFilter) as LMNetMux;

               if (_pMux != null)
               {
                  // set some mux settings
                  _pMux.LiveSource = true;
               }

               // 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.
               while (_captureCtrl.State == CaptureState.Running
                     || _playCtrl.State == PlayState.Running)
               {
                  Application.DoEvents();
               }

               // verify we have a recording file too
               _result &= File.Exists(_recordedVideoFile);

               // release the mux and demux COM objects
               if (_pMux != null)
                  Marshal.ReleaseComObject(_pMux);

               if (_pDemux != null)
                  Marshal.ReleaseComObject(_pDemux);
            }
         }
         catch (Exception)
         {
            _result = false;
         }
      }

      void CaptureCtrl_Progress(object sender, ProgressEventArgs e)
      {
         // for this test we will send a message after 
         // 5 secs of capture time
         if (e.time > 5000 && !_msgSent)
         {
            _pMux.WriteMessage(_testMessage);
            Console.WriteLine("Server sent message");
            _msgSent = true;
         }
      }

      void CaptureCtrl_Started(object sender, EventArgs e)
      {
         StartClient();
      }

      private void StartClient()
      {
         try
         {
            LMNetSrc netSrc = new LMNetSrc();
            netSrc.CheckConnection(_networkUrl, 0, 5000);
            Marshal.ReleaseComObject(netSrc);
         }
         catch (COMException cex)
         {
            // could not connect
            return;
         }

         _playCtrl.SourceFile = _networkUrl;
         _pDemux = _playCtrl.GetSubObject(PlayObject.Splitter) as LMNetDmx;

         if (_pDemux != null && _pDemux.AutoLiveTolerance < 5)
         {
            // 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;
         }

         _serverAndClient.TestTimer.Interval = 100;
         _serverAndClient.TestTimer.Tick += new EventHandler(PlayTimer_Tick);
         _serverAndClient.TestTimer.Start();
      }

      void PlayTimer_Tick(object sender, EventArgs e)
      {
         _serverAndClient.TestTimer.Enabled = false;
         if (_pDemux != null)
         {
            // read any messages here
            string msg = _pDemux.ReadMessage();

            // set the result to what we expect
            if (msg == _testMessage)
            {
               _result = true;
               Console.WriteLine("Client received message");
            }

            // get the bitrate
            int bitRate = _pDemux.BitRate;
            Console.WriteLine("Client bitrate = {0}", bitRate);
         }
         _serverAndClient.TestTimer.Enabled = true;
      }

static class LEAD_VARS
{
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 17\Media";
}

Remarks

The AutoLiveTolerance is measured in seconds. Currently, all values > 0 for AutoLiveTolerance, instruct the network demux to prefer smooth video over live video. Future versions of demultiplexer will use this value to fine-tune the video playback latency.

The default is 0, which will force the network demux to favor live video. This can cause jerky playback on jittery networks with high latencies. VPNs and wireless networks are examples of jittery networks.

These jittery networks have occasional bottlenecks, which cause some packets to arrive with significant delays (could be several seconds). For these networks, the default behavior of choosing live video will cause the playback to freeze and then speed up when the interruptions occur, causing multiple packets to arrive at the same time. If this effect becomes undesirable, you can set the AutoLiveTolerance to a value greater than 0 (for example, set it to 3) to allow the demux to smooth the playback.

NOTE: You should keep in mind, however, that once you favor smooth playback, the playback stream will start to drift behind the live stream. As a result, there might be a delay of several seconds between what you see and what is captured at the other end.

Requirements

Target Platforms: Microsoft .NET Framework 2.0, Windows 2000, Windows XP, Windows Server 2003 family, Windows Server 2008 family, Windows Vista, Windows 7

See Also