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WriteScriptStream Method

Summary

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

Syntax

C++/CLI

public void WriteScriptStream( 
   string ScriptType, 
   string ScriptCommand, 
   double ScriptTime 
)

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

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["USB"] == null) 
         throw new Exception("No USB audio device available"); 
 
      _capturectrl.VideoDevices["USB"].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:\LEADTOOLS23\Media"; 
}

Requirements

Target Platforms

Reference

WMScript Class

WMScript Members

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Help Version 23.0.2024.2.29

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies