PreloadCodecs Method

Visual Basic
C#
WinRT C#
WinRT JavaScript
C++

public void PreloadCodecs( 
   int fixedCodecs,
   int cachedCodecs,
   string codecs
)

'Declaration
 
Public Sub PreloadCodecs( _
   ByVal fixedCodecs As Integer, _
   ByVal cachedCodecs As Integer, _
   ByVal codecs As String _
)

'Usage
 
Dim instance As RasterCodecs
Dim fixedCodecs As Integer
Dim cachedCodecs As Integer
Dim codecs As String
 
instance.PreloadCodecs(fixedCodecs, cachedCodecs, codecs)

public void PreloadCodecs( 
   int fixedCodecs,
   int cachedCodecs,
   string codecs
)

 function Leadtools.Codecs.RasterCodecs.PreloadCodecs( 
   fixedCodecs ,
   cachedCodecs ,
   codecs 
)

public:
void PreloadCodecs( 
   int fixedCodecs,
   int cachedCodecs,
   String^ codecs
)

Parameters

fixedCodecs: Number of codecs that should stay loaded in memory at all times.
cachedCodecs: Number of codecs that should be loaded, but can be unloaded later to make room for other codecs.
codecs: A System.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:

Leadtools.Codecs.Bmp.dll
Leadtools.Codecs.Tif.dll
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.

Visual Basic
C#
WinRT C#
WinRT JavaScript
Silverlight C#
Silverlight VB

Public Sub PreloadCodecsExample()
      Dim codecs As RasterCodecs = New RasterCodecs()

      Dim srcFileName1 As String = Path.Combine(LEAD_VARS.ImagesDir, "Image1.j2k")
      Dim srcFileName2 As String = 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")
      codecs.IgnoreCodecs("cmp")

      ' try to get info on a j2k image
      Dim info As CodecsImageInfo = codecs.GetInformation(srcFileName1, False)
      Console.WriteLine("j2k - Width: {0}, Height {1}", info.Width, info.Height)

      ' try to get info on a cmp image
      Try
         info = codecs.GetInformation(srcFileName2, False)
      Catch
         Console.WriteLine("GetInformation for cmp failed - sample success!")
      End Try

      ' Clean up
      codecs.Dispose()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class

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");
         codecs.IgnoreCodecs("cmp");

         // 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
         try
         {
             info = codecs.GetInformation(srcFileName2, false);
         }
         catch
         {
             Console.WriteLine("GetInformation for cmp failed - sample success!");
         }

         // Clean up
         codecs.Dispose();
     }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

RasterCodecs Class
RasterCodecs Members
Loading File Codecs
Fast File Info