StartVideoPreview Method

Summary

Starts the video preview inside the window handle specified through the

owner parameter.

Syntax

C++/CLI

Python

public void StartVideoPreview( 
   IntPtr owner, 
   bool stretchToFitParent 
)

public: 
void StartVideoPreview(  
   IntPtr owner, 
   bool stretchToFitParent 
)

def StartVideoPreview(self,owner,stretchToFitParent):

Parameters

owner
Window handle where to display the streaming video preview.

stretchToFitParent
Specifies whether the video display is stretched to fit the parent window. Possible values are:

Value	Meaning
true	Stretch the video preview to fit the parent window.
false	Video is displayed in a supported resolution smaller than the parent window.

Remarks

This function will start the video stream preview in the window or the control specified through the owner parameter.

This function will internally set the image directory of the captured still images to the device's default path unless you changed the destination images directory property yourself as mentioned in the WiaSession.AcquireImageFromVideo documentation.

Example

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.Wia; 
 
 
       
public void IsVideoPreviewAvailableExample(IntPtr parent) 
{ 
   if (!WiaSession.IsAvailable(WiaVersion.Version1)) 
   { 
      Console.WriteLine("WIA version 1.0 not installed."); 
      return; 
   } 
 
   WiaSession wiaSession = new WiaSession(); 
   wiaSession.Startup(WiaVersion.Version1); 
 
   DialogResult res = wiaSession.SelectDeviceDlg(parent, WiaDeviceType.StreamingVideo, WiaSelectSourceFlags.NoDefault); 
   if (res != DialogResult.OK) 
   { 
      Console.WriteLine("Error selecting WIA device."); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   // start the video preview 
   wiaSession.StartVideoPreview(parent, false); 
 
   // determine whether a video preview is available 
   bool available = wiaSession.IsVideoPreviewAvailable(); 
   if (!available) 
   { 
      Console.WriteLine("No streaming video available."); 
      wiaSession.EndVideoPreview(); 
      wiaSession.Shutdown(); 
      return; 
   } 
 
   // Resize the video preview area to fit the parent window. 
   // I am calling this resize function here only for demonstration purposes, but you 
   // should call it in your window resize event. 
   wiaSession.ResizeVideoPreview(true); 
 
   // acquire an image from the video source. 
   string takenPictureFileName = wiaSession.AcquireImageFromVideo(); 
 
   string strMsg = String.Format("Acquired image was saved to the following path:\n{0}", takenPictureFileName); 
   Console.WriteLine(strMsg); 
 
   wiaSession.EndVideoPreview(); 
   wiaSession.Shutdown(); 
}