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PreloadCodecs Method

Specifies the file format codecs to be loaded.
public void PreloadCodecs( 
   int fixedCodecs, 
   int cachedCodecs, 
   string codecs 
Public Sub PreloadCodecs( _ 
   ByVal fixedCodecs As Integer, _ 
   ByVal cachedCodecs As Integer, _ 
   ByVal codecs As String _ 
public void preloadCodecs(int fixedCodecs, int cachedCodecs, String codecs) 
void PreloadCodecs(  
   int fixedCodecs, 
   int cachedCodecs, 
   String^ codecs 


Number of codecs that should stay loaded in memory at all times.

Number of codecs that should be loaded, but can be unloaded later to make room for other codecs.

A String containing the codecs which should be loaded.


If codecs is empty, all file codecs LEADTOOLS can find will be loaded and LEADTOOLS will determine the order in which the files will be used. codecs is in the form xyz, yuv ... where Xyz are the 3 letters describing the file codec as in Leadtools.Codecs.Xyz.dll. For instance, if codecs is BMP,TIF,CMP then the following codecs will be loaded in the following order:

  1. Leadtools.Codecs.Bmp.dll
  2. Leadtools.Codecs.Tif.dll
  3. Leadtools.Codecs.Cmp.dll

The first fixedCodecs will stay in memory at all times, then the next cachedCodecs will be loaded. However, if other codecs will be needed, the cached codecs might be unloaded to make room for the new DLLs.

It is recommended that the most commonly used DLLs be loaded as fixed to minimize the time required to load/unload file codecs. Also, some DLLs may require additional DLLs (like the Leadtools.Pdf.dll or Leadtools.Codecs.Tif.dll) so the exact number of DLLs loaded is not necessarily equal fixedCodecs + cachedCodecs.

Before calling this method, you can get the default preload codecs list using PreloadCodecsList.


This example preloads the j2k filter and ignores the cmp filter.

using Leadtools; 
using Leadtools.Codecs; 
using Leadtools.ImageProcessing; 
using Leadtools.ImageProcessing.Color; 
using Leadtools.Svg; 
public void PreloadCodecsExample() 
	RasterCodecs codecs = new RasterCodecs(); 
	string srcFileName1 = Path.Combine(LEAD_VARS.ImagesDir, "Image1.j2k"); 
	string srcFileName2 = Path.Combine(LEAD_VARS.ImagesDir, "Image1.cmp"); 
	// display the original values before changing them 
	Console.WriteLine("PreloadCodecList - {0}", codecs.PreloadCodecsList); 
	Console.WriteLine("FixedPreloadCodecs - {0}", codecs.FixedPreloadCodecs); 
	Console.WriteLine("CachedPreloadCodecs - {0}", codecs.CachedPreloadCodecs); 
	Console.WriteLine("IgnoreCodecList - {0}", codecs.IgnoreCodecsList); 
	// preload only the j2k filter and ignore the cmp filter 
	codecs.PreloadCodecs(1, 1, "j2k"); 
	// try to get info on a j2k image 
	CodecsImageInfo info = codecs.GetInformation(srcFileName1, false); 
	Console.WriteLine("j2k - Width: {0}, Height {1}", info.Width, info.Height); 
	// try to get info on a cmp image 
		info = codecs.GetInformation(srcFileName2, false); 
		Console.WriteLine("GetInformation for cmp failed - sample success!"); 
	// Clean up 
static class LEAD_VARS 
   public const string ImagesDir = @"C:\LEADTOOLS21\Resources\Images"; 

Target Platforms

Help Version 21.0.2021.7.2
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Leadtools.Codecs Assembly
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2021 LEAD Technologies, Inc. All Rights Reserved.