In This Topic ▼

VCRHorizontalLocking Property

Summary

Gets or sets a value that indicates whether the decoder is expecting video from a tape source or a broadcast source.

Syntax

C++/CLI

public bool VCRHorizontalLocking { get; set; }

public: 
property bool VCRHorizontalLocking { 
   bool get(); 
   void set (    bool ); 
}

Property Value

true if the decoder expects video from a tape source; otherwise, false if the decoder expects video from a broadcast source.

Remarks

The timing accuracy of synchronization pulses are typically lower quality from a tape source than from a broadcast source. Setting the value to true tells the decoder to relax its standards. The lower standards provide a better chance of maintaining sync.

For more detailed information, refer to the Microsoft documentation for IAMAnalogVideoDecoder.get_VCRHorizontalLocking.

Example

using Leadtools; 
using Leadtools.Multimedia; 
using LeadtoolsMultimediaExamples.Fixtures; 
 
 
public bool _result = false; 
public CaptureCtrlForm _form = new CaptureCtrlForm(); 
 
public void AvailableTVFormatsExample() 
{ 
   try 
   { 
      // reference the forms capture control 
      CaptureCtrl capturectrl = _form.CaptureCtrl; 
 
      string outFile = Path.Combine(LEAD_VARS.MediaDir, "AnalogVideoDecoder_AvailableTVFormatsExample.avi"); 
      int lines = 0; 
      bool allResults = true; 
 
      // select the first device with the word "analog" in its name 
      // Replace "Analog" with the name of your tuner device 
      if (capturectrl.VideoDevices["Analog"] == null) 
         throw new Exception("No analog video capture device available"); 
 
      capturectrl.VideoDevices["Analog"].Selected = true; 
 
      AnalogVideoDecoder analogvideodecoder = capturectrl.AnalogVideoDecoder; 
      AnalogVideoStandard availableFormats = analogvideodecoder.AvailableTVFormats; 
      AnalogVideoStandard tvFormat = analogvideodecoder.TVFormat; 
 
      // check whether the format is NTSC and set it if not 
      if (tvFormat != AnalogVideoStandard.NTSC_M_J 
         && (availableFormats & AnalogVideoStandard.NTSC_M_J) == AnalogVideoStandard.NTSC_M_J) 
      { 
         // set the analog video decoder TV format 
         analogvideodecoder.TVFormat = AnalogVideoStandard.NTSC_M_J; 
 
         // check the changed format 
         allResults &= (analogvideodecoder.TVFormat == AnalogVideoStandard.NTSC_M_J); 
      } 
 
      // check whether Horizontal Locked is enabled 
      bool vLocked = capturectrl.AnalogVideoDecoder.HorizontalLocked; 
 
      // Some video device's Analog Decoder implementations do not 
      // support the following properties, so we wrap these property  
      // accesses with a special try block to catch possible exceptions 
      try 
      { 
         // check whether VCR Horizontal Sync locking is enabled and set it if not 
         bool vcrLocked = capturectrl.AnalogVideoDecoder.VCRHorizontalLocking; 
         if (!vcrLocked) 
         { 
            // set VCR horzontal sync locking 
            capturectrl.AnalogVideoDecoder.VCRHorizontalLocking = true; 
 
            // include this as one of our checks 
            allResults &= capturectrl.AnalogVideoDecoder.VCRHorizontalLocking; 
         } 
 
         // check whether output enabled is set and set it if not 
         bool outputEnabled = capturectrl.AnalogVideoDecoder.OutputEnable; 
         if (!outputEnabled) 
         { 
            // enable output 
            capturectrl.AnalogVideoDecoder.OutputEnable = true; 
 
            // include this as one of our checks 
            allResults &= capturectrl.AnalogVideoDecoder.OutputEnable; 
         } 
      } 
      catch (COMException cex) 
      { 
         // if the device does not support the properties above 
         // skip it and do not fail 
         if (cex.ErrorCode != (int)ErrorCode.E_PROP_ID_UNSUPPORTED 
            && cex.ErrorCode != (int)ErrorCode.E_PROP_SET_UNSUPPORTED) 
            throw cex; 
      } 
 
      int tries = 0; 
 
      // check scan line count a few times  
      // initial frames may differ from format spec, until frame data  
      // has propogated through the capture graph 
      while (lines != 525 && tries++ < 10) 
      { 
         // get the number of scan lines in the output format 
         lines = capturectrl.AnalogVideoDecoder.NumberOfLines; 
         System.Diagnostics.Debug.WriteLine("TV Format: " 
                                            + analogvideodecoder.TVFormat.ToString() 
                                            + ", Scan Lines: " 
                                            + lines.ToString()); 
      } 
 
      // include the line count check 
      allResults &= (lines == 525 && tries < 10); 
      System.Diagnostics.Debug.WriteLine("Tries: " + tries.ToString()); 
 
      // test results 
      _result = allResults; 
   } 
   catch (Exception) 
   { 
      _result = false; 
   } 
} 
 
static class LEAD_VARS 
{ 
   public const string MediaDir = @"C:\LEADTOOLS23\Media"; 
}

Requirements

Target Platforms

Reference

AnalogVideoDecoder Class

AnalogVideoDecoder Members

Download our FREE evaluation

Help Version 23.0.2024.2.29

Leadtools.Multimedia Assembly

Introduction

Getting Started

Namespaces

Leadtools.Multimedia Namespace

Leadtools.Multimedia.Common Namespace

Assemblies