LEADTOOLS Image File Support (Leadtools.Codecs assembly)
LEAD Technologies, Inc

ReadExtensions(String,Int32) Method

Example 





Leadtools.Codecs Namespace > RasterCodecs Class > ReadExtensions Method : ReadExtensions(String,Int32) Method
The input file name.
1-based index of the page within the file that contains the extension.
Loads extensions from the specified Exif file. .NET support
Syntax
public CodecsExtensionList ReadExtensions( 
   string fileName,
   int pageNumber
)
'Declaration
 
Public Overloads Function ReadExtensions( _
   ByVal fileName As String, _
   ByVal pageNumber As Integer _
) As CodecsExtensionList
'Usage
 
Dim instance As RasterCodecs
Dim fileName As String
Dim pageNumber As Integer
Dim value As CodecsExtensionList
 
value = instance.ReadExtensions(fileName, pageNumber)
public CodecsExtensionList ReadExtensions( 
   string fileName,
   int pageNumber
)
 function Leadtools.Codecs.RasterCodecs.ReadExtensions(String,Int32)( 
   fileName ,
   pageNumber 
)

public:
CodecsExtensionList^ ReadExtensions( 
   String^ fileName,
   int pageNumber
)

Parameters

fileName
The input file name.
pageNumber
1-based index of the page within the file that contains the extension.

Return Value

An CodecsExtensionList object that contains the extensions found in this file.
Remarks

Please note that not all Exif files have extensions.

Currently, this method works only with Exif files. Exif files can contain extra data stored as "FlashPix extensions". This method can be used to access this extra data. LEADTOOLS refers to this extra data as "extensions".

You must dispose the CodecsExtensionList returned from this method when you are done using it.

Example
  
Private Sub ExtensionsExample(ByVal exifFileName As String)
      Dim codecs As RasterCodecs = New RasterCodecs()
      Dim stampFileName As String = Path.Combine(LEAD_VARS.ImagesDir, "Extension.bmp")
      Dim audioFileNameTemplate As String = Path.Combine(LEAD_VARS.ImagesDir, "Extension{0}.wav")

      ' Read the extensions from the file
      Console.WriteLine("Reading the extensions from the exif file")
      Dim extensionList As CodecsExtensionList = codecs.ReadExtensions(exifFileName, 1)
      If Not extensionList Is Nothing Then
         If (extensionList.Flags And CodecsExtensionListFlags.Stamp) = CodecsExtensionListFlags.Stamp Then
            Console.WriteLine("Stamp extension: Found, saving to {0}", stampFileName)
            Dim stampImage As RasterImage = extensionList.CreateStamp()
            codecs.Save(stampImage, stampFileName, RasterImageFormat.Bmp, 24)
            stampImage.Dispose()
         Else
            Console.WriteLine("Stamp extension: Not found")
         End If

         If (extensionList.Flags And CodecsExtensionListFlags.Audio) = CodecsExtensionListFlags.Audio Then
            Console.WriteLine("Audio extension: Found, saving ...")
            Dim audioData As RasterNativeBuffer
            Dim streamIndex As Integer = 0

            Do
               audioData = extensionList.GetAudioData(streamIndex)
               If audioData.Data <> IntPtr.Zero Then
                  Dim audioFileName As String = String.Format(audioFileNameTemplate, streamIndex)
                  Console.WriteLine("To {0}", audioFileName)
                  Using fs As FileStream = File.Create(audioFileName)
                     Dim data As Byte() = New Byte(CInt(audioData.Length) - 1) {}
                     Marshal.Copy(audioData.Data, data, 0, CInt(audioData.Length))
                     fs.Write(data, 0, CInt(audioData.Length))
                  End Using

                  streamIndex += 1
               End If
            Loop While audioData.Data <> IntPtr.Zero

            Console.WriteLine("{0} total audio streams found", streamIndex)
         Else
            Console.WriteLine("Audio extension: Not found")
         End If

         Dim extensions As CodecsExtension() = extensionList.GetExtensions()
         Console.WriteLine("Total number of extensions found in the file: {0}", extensions.Length)

         Dim i As Integer = 0
         Do While i < extensions.Length
            Dim extension As CodecsExtension = extensions(i)
            Console.WriteLine(" {0}. Name: {1}, Clsid: {2}, UCDefault: {3}, DatLength: {4}", i, extension.Name, extension.Clsid, extension.UCDefault, extension.DataLength)
            i += 1
         Loop

         extensionList.Dispose()
      Else
         Console.WriteLine("No extensions were found in the file")
      End If

      codecs.Dispose()
   End Sub

Public NotInheritable Class LEAD_VARS
   Public Const ImagesDir As String = "C:\Users\Public\Documents\LEADTOOLS Images"
End Class
void ExtensionsExample(string exifFileName)
     {
         RasterCodecs codecs = new RasterCodecs();
         string stampFileName = Path.Combine(LEAD_VARS.ImagesDir, "Extension.bmp");
         string audioFileNameTemplate = Path.Combine(LEAD_VARS.ImagesDir, "Extension{0}.wav");

         // Read the extensions from the file
         Console.WriteLine("Reading the extensions from the exif file");
         CodecsExtensionList extensionList = codecs.ReadExtensions(exifFileName, 1);
         if (extensionList != null)
         {
             if ((extensionList.Flags & CodecsExtensionListFlags.Stamp) == CodecsExtensionListFlags.Stamp)
             {
                 Console.WriteLine("Stamp extension: Found, saving to {0}", stampFileName);
                 RasterImage stampImage = extensionList.CreateStamp();
                 codecs.Save(stampImage, stampFileName, RasterImageFormat.Bmp, 24);
                 stampImage.Dispose();
             }
             else
                 Console.WriteLine("Stamp extension: Not found");

             if ((extensionList.Flags & CodecsExtensionListFlags.Audio) == CodecsExtensionListFlags.Audio)
             {
                 Console.WriteLine("Audio extension: Found, saving ...");
                 RasterNativeBuffer audioData;
                 int streamIndex = 0;

                 do
                 {
                     audioData = extensionList.GetAudioData(streamIndex);
                     if (audioData.Data != IntPtr.Zero)
                     {
                         string audioFileName = string.Format(audioFileNameTemplate, streamIndex);
                         Console.WriteLine("To {0}", audioFileName);
                         using (FileStream fs = File.Create(audioFileName))
                         {
                             byte[] data = new byte[audioData.Length];
                             Marshal.Copy(audioData.Data, data, 0, (int)audioData.Length);
                             fs.Write(data, 0, (int)audioData.Length);
                         }

                         streamIndex++;
                     }
                 }
                 while (audioData.Data != IntPtr.Zero);

                 Console.WriteLine("{0} total audio streams found", streamIndex);
             }
             else
                 Console.WriteLine("Audio extension: Not found");

             CodecsExtension[] extensions = extensionList.GetExtensions();
             Console.WriteLine("Total number of extensions found in the file: {0}", extensions.Length);

             for (int i = 0; i < extensions.Length; i++)
             {
                 CodecsExtension extension = extensions[i];
                 Console.WriteLine(" {0}. Name: {1}, Clsid: {2}, UCDefault: {3}, DatLength: {4}",
                    i, extension.Name, extension.Clsid, extension.UCDefault, extension.DataLength);
             }

             extensionList.Dispose();
         }
         else
             Console.WriteLine("No extensions were found in the file");

         codecs.Dispose();
     }

static class LEAD_VARS
{
   public const string ImagesDir = @"C:\Users\Public\Documents\LEADTOOLS Images";
}
RasterCodecsExamples.prototype.ExtensionsExample = function () {
   Tools.SetLicense();
   with (Leadtools) {
      with (Leadtools.Codecs) {
         var exifFileName = "Assets\\Extension-audioandstamp.jpg";
         var codecs = new RasterCodecs();

         var stampFileName = "Extension.bmp";

         var stampImage;
         // Read the extensions from the file
         console.info("Reading the extensions from the exif file");
         return Tools.AppInstallFolder().getFileAsync(exifFileName).then(function (loadFile) {
            return codecs.readExtensionsAsync(LeadStreamFactory.create(loadFile), 1)
         })
            .then(function (extensionList) {

               if (extensionList != null) {
                  if ((extensionList.flags & CodecsExtensionListFlags.stamp) == CodecsExtensionListFlags.stamp) {
                     console.info("Stamp extension: Found, saving to ", stampFileName);
                     stampImage = extensionList.createStamp();
                     var async = Tools.AppLocalFolder().createFileAsync(stampFileName);
                     return WinJS.Promise.join(async).then(function (saveFile) {
                        return codecs.saveAsync(stampImage, LeadStreamFactory.create(saveFile), RasterImageFormat.bmp, 24)
                     })
                     .then(function () {
                        stampImage.close();
                     });
                  }
                  else
                     console.info("Stamp extension: Not found");

                  if ((extensionList.flags & CodecsExtensionListFlags.audio) == CodecsExtensionListFlags.audio) {
                     console.info("Audio extension: Found, saving ...");
                     var audioData;
                     var streamIndex = 0;

                     do {
                        var stream;
                        audioData = extensionList.getAudioData(streamIndex);
                        if (audioData != null && audioData.length > 0) {
                           var audioFileName = "Extension" + streamIndex + ".wav";
                           console.info("To ", audioFileName);

                           var async = Tools.AppLocalFolder().createFileAsync(audioFileName);

                           return WinJS.Promise.join(async).then(function (saveFile) {
                              return saveFile.openSequentialReadAsync()
                           })
                           .then(function (stream) {
                              var data = new Array(audioData.length);
                              audioData.getData(0, data, 0, data.length);
                              return stream.writeAsync(data)
                           })
                           .done(function () {
                              stream.close();
                           });
                           streamIndex++;
                        }
                     }
                     while (audioData != null && audioData.length > 0);

                     console.info(streamIndex, " total audio streams found");
                  }
                  else
                     console.info("Audio extension: Not found");

                  var extensions = extensionList.getExtensions();
                  console.info("Total number of extensions found in the file: ", extensions.length);

                  for (var i = 0; i < extensions.length; i++) {
                     var extension = extensions[i];
                     console.info(i, " . Name: " + extension.name + " , Clsid: " + extension.clsid + ", UCDefault: " + extension.ucDefault + ", DatLength: ", extension.data.length);
                  }

                  extensionList.close();
               }
               else
                  console.info("No extensions were found in the file");

               codecs.close();
            });
      }
   }
}
async Task ExtensionsExample(string exifFileName)
{
   RasterCodecs codecs = new RasterCodecs();
   string stampFileName = "Extension.bmp";
   string audioFileNameTemplate = "Extension{0}.wav";

   // Read the extensions from the file
   Debug.WriteLine("Reading the extensions from the exif file");
   StorageFile loadFile = await Tools.AppInstallFolder.GetFileAsync(exifFileName);
   CodecsExtensionList extensionList = await codecs.ReadExtensionsAsync(LeadStreamFactory.Create(loadFile), 1);
   if (extensionList != null)
   {
      if ((extensionList.Flags & CodecsExtensionListFlags.Stamp) == CodecsExtensionListFlags.Stamp)
      {
         Debug.WriteLine("Stamp extension: Found, saving to {0}", stampFileName);
         RasterImage stampImage = extensionList.CreateStamp();
         StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(stampFileName);
         await codecs.SaveAsync(stampImage, LeadStreamFactory.Create(saveFile), RasterImageFormat.Bmp, 24);
         stampImage.Dispose();
      }
      else
         Debug.WriteLine("Stamp extension: Not found");

      if ((extensionList.Flags & CodecsExtensionListFlags.Audio) == CodecsExtensionListFlags.Audio)
      {
         Debug.WriteLine("Audio extension: Found, saving ...");
         RasterNativeBuffer audioData;
         int streamIndex = 0;

         do
         {
            audioData = extensionList.GetAudioData(streamIndex);
            if (audioData != null && audioData.Length > 0)
            {
               string audioFileName = string.Format(audioFileNameTemplate, streamIndex);
               Debug.WriteLine("To {0}", audioFileName);

               StorageFile saveFile = await Tools.AppLocalFolder.CreateFileAsync(audioFileName);
               using (var stream = await saveFile.OpenStreamForWriteAsync())
               {
                  byte[] data = new byte[audioData.Length];
                  audioData.GetData(0, data, 0, data.Length);
                  stream.Write(data, 0, data.Length);
               }

               streamIndex++;
            }
         }
         while (audioData != null && audioData.Length > 0);

         Debug.WriteLine("{0} total audio streams found", streamIndex);
      }
      else
         Debug.WriteLine("Audio extension: Not found");

      CodecsExtension[] extensions = extensionList.GetExtensions();
      Debug.WriteLine("Total number of extensions found in the file: {0}", extensions.Length);

      for (int i = 0; i < extensions.Length; i++)
      {
         CodecsExtension extension = extensions[i];
         Debug.WriteLine(" {0}. Name: {1}, Clsid: {2}, UCDefault: {3}, DatLength: {4}",
            i, extension.Name, extension.Clsid, extension.UCDefault, extension.Data.Length);
      }

      extensionList.Dispose();
   }
   else
      Debug.WriteLine("No extensions were found in the file");

   codecs.Dispose();
}
Requirements

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

See Also

Reference

RasterCodecs Class
RasterCodecs Members
Overload List
Exif File Extensions

 

 

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