WriteScriptStream Method

Summary

Adds a stream-based script to be executed at a particular time during playback.

Syntax
C#
VB
C++
public void WriteScriptStream( 
   string ScriptType, 
   string ScriptCommand, 
   double ScriptTime 
) 
Public Sub WriteScriptStream( _ 
   ByVal ScriptType As String, _ 
   ByVal ScriptCommand As String, _ 
   ByVal ScriptTime As Double _ 
)  
public: 
void WriteScriptStream(  
   String^ ScriptType, 
   String^ ScriptCommand, 
   double ScriptTime 
)  

Parameters

ScriptType
The name of the script command.

ScriptCommand
The script command.

ScriptTime
Time (in seconds) when the script command should execute.

Remarks

Header scripts are added when you know how many scripts you have and their location beforehand. Also, since they are stored in the header, they will need to be all downloaded before playback begins. Stream scripts are added when you don't know how many you will have or when there are too many and you don't want to slow down the start of the playback. For example, if you have a live capture and there are certain notifications that you will receive during the capture, you would use stream scripts.

Stream scripts can be processed using the MediaEventHandler event handler for PlayCtrl. Stream script commands generate EC_OLE_EVENT event codes. See Processing Windows Media Script Commands for an example of how Stream Scripts are processed.

See the Microsoft documentation, Using Script Commands Supported by Windows Media Player, for a complete list of script commands supported by Windows Media Player.

Example
C#
VB
using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
public DateTime _startTime; 
CaptureCtrl _capturectrl; 
WMScript _mux; 
 
public void WriteScriptStreamExample() 
{ 
   _capturectrl = _form.CaptureCtrl; 
 
   // reference the capture control 
   string outFile = Path.Combine(LEAD_VARS.MediaDir, "WriteScriptStream_Dest.wmv"); 
 
   try 
   { 
      _capturectrl.TargetFormat = TargetFormatType.WMVMux; 
      _capturectrl.TargetFile = outFile; 
 
      // set an audio device, use the name of your device here 
      if (_capturectrl.VideoDevices["Logitech"] == null) 
         throw new Exception("No USB audio device available"); 
 
      _capturectrl.VideoDevices["Logitech"].Selected = true; 
 
      if (_capturectrl.IsModeAvailable(CaptureMode.Video)) 
      { 
         _capturectrl.FrameDelay = .033;  // 30 frames per second 
         _capturectrl.TimeLimit = 10;     // just 10 seconds of capture time 
         _capturectrl.UseTimeLimit = true; 
 
         // call ReadyCapture, so the target object is added 
         _capturectrl.ReadyCapture(CaptureMode.Video | CaptureMode.InhibitRun); 
 
         // get the scripter object 
         _mux = _capturectrl.WMScripter; 
         if (_mux == null) 
            return; 
 
         // enable the script stream 
         _mux.EnableScriptStream = true; 
 
         // subscribe to the complete event 
         _capturectrl.Complete += new EventHandler(CaptureCtrl_Complete); 
 
         // subscribe to the error abort event 
         _capturectrl.ErrorAbort += new ErrorAbortEventHandler(CaptureCtrl_ErrorAbort); 
 
         // set the start time 
         _startTime = DateTime.Now; 
 
         // set a timer so we can write the Script commands every second 
         _form.TestTimer.Interval = 1000; 
         _form.TestTimer.Tick += new EventHandler(TestTimer_Tick); 
         _form.TestTimer.Start(); 
 
         // start the capture process 
         _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) 
            Application.DoEvents(); 
      } 
   } 
   catch (Exception) 
   { 
      return; 
   } 
 
   // 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) 
      Application.DoEvents(); 
 
   _result = true; 
} 
 
public void TestTimer_Tick(object sender, EventArgs e) 
{ 
   // stop the capture 
   try 
   { 
      double elapsedTime = (DateTime.Now - _startTime).TotalMilliseconds / 1000; 
      String sz = String.Format("Sample caption script at {0} seconds", elapsedTime); 
      _mux.WriteScriptStream("caption", sz, elapsedTime); 
   } 
   catch (Exception) 
   { 
      _result = false; 
      _capturectrl.StopCapture(); 
   } 
} 
 
public void CaptureCtrl_Complete(object sender, EventArgs e) 
{ 
   // set result 
   _result = true; 
   // the capture has finished, do not write scripts anymore 
   // Note that since the capture has finished automatically, I do not need to call _mux.CloseScriptStream() 
   _form.TestTimer.Stop(); 
} 
 
public void CaptureCtrl_ErrorAbort(object sender, ErrorAbortEventArgs e) 
{ 
   // set result 
   _result = false; 
   // the capture has finished, do not write scripts anymore 
   // Note that since the capture has finished automatically, I do not need to call _mux.CloseScriptStream() 
   _form.TestTimer.Stop(); 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media"; 
} 
Imports Leadtools 
Imports Leadtools.Multimedia 
Imports LeadtoolsMultimediaExamples.Fixtures 
 
Public _result As Boolean = False 
Public _form As New CaptureCtrlForm() 
Public _startTime As DateTime 
Private _capturectrl As CaptureCtrl 
Private _mux As WMScript 
 
Public Sub WriteScriptStreamExample() 
   _capturectrl = _form.CaptureCtrl 
 
   ' reference the capture control 
   Dim outFile As String = Path.Combine(LEAD_VARS.MediaDir, "WriteScriptStream_Dest.wmv") 
 
   Try 
      _capturectrl.TargetFormat = TargetFormatType.WMVMux 
      _capturectrl.TargetFile = outFile 
 
      ' set an audio device, use the name of your device here 
      If _capturectrl.VideoDevices("Logitech") Is Nothing Then 
         Throw New Exception("No USB audio device available") 
      End If 
 
      _capturectrl.VideoDevices("Logitech").Selected = True 
 
      If _capturectrl.IsModeAvailable(CaptureMode.Video) Then 
 
         _capturectrl.FrameDelay = 0.033 ' 30 frames per second 
 
         _capturectrl.TimeLimit = 10 ' just 10 seconds of capture time 
         _capturectrl.UseTimeLimit = True 
 
         ' call ReadyCapture, so the target object is added 
         _capturectrl.ReadyCapture(CaptureMode.Video Or CaptureMode.InhibitRun) 
 
         ' get the scripter object 
         _mux = _capturectrl.WMScripter 
         If _mux Is Nothing Then 
            Return 
         End If 
 
         ' enable the script stream 
         _mux.EnableScriptStream = True 
 
         ' subscribe to the complete event 
         AddHandler _capturectrl.Complete, AddressOf CaptureCtrl_Complete 
 
         ' subscribe to the error abort event 
         AddHandler _capturectrl.ErrorAbort, AddressOf CaptureCtrl_ErrorAbort 
 
         ' set the start time 
         _startTime = DateTime.Now 
 
         ' set a timer so we can write the Script commands every second 
         _form.TestTimer.Interval = 1000 
         AddHandler _form.TestTimer.Tick, AddressOf TestTimer_Tick 
         _form.TestTimer.Start() 
 
         ' start the capture process 
         _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 
            Application.DoEvents() 
         End While 
      End If 
   Catch generatedExceptionName As Exception 
      Return 
   End Try 
 
   ' 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 
      Application.DoEvents() 
   End While 
 
   _result = True 
End Sub 
 
Public Sub TestTimer_Tick(ByVal sender As Object, ByVal e As EventArgs) 
   ' stop the capture 
   Try 
      Dim elapsedTime As Double = (DateTime.Now - _startTime).TotalMilliseconds / 1000 
      Dim sz As [String] = [String].Format("Sample caption script at {0} seconds", elapsedTime) 
      _mux.WriteScriptStream("caption", sz, elapsedTime) 
   Catch generatedExceptionName As Exception 
      _result = False 
      _capturectrl.StopCapture() 
   End Try 
End Sub 
 
Public Sub CaptureCtrl_Complete(ByVal sender As Object, ByVal e As EventArgs) 
   ' set result 
   _result = True 
   ' the capture has finished, don't write scripts anymore 
   ' Note that since the capture has finished automatically, I don't need to call _mux.CloseScriptStream() 
   _form.TestTimer.[Stop]() 
End Sub 
 
Public Sub CaptureCtrl_ErrorAbort(ByVal sender As Object, ByVal e As ErrorAbortEventArgs) 
   ' set result 
   _result = False 
   ' the capture has finished, don't write scripts anymore 
   ' Note that since the capture has finished automatically, I don't need to call _mux.CloseScriptStream() 
   _form.TestTimer.[Stop]() 
End Sub 
 
Public NotInheritable Class LEAD_VARS 
   Public Const MediaDir As String = "C:\Program Files (x86)\LEAD Technologies\LEADTOOLS 20\Media" 
End Class 
Requirements

Target Platforms

See Also

Reference

WMScript Class

WMScript Members

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