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L_ReadFileMetaDataItems

Summary

Gets all the metadata tags stored in a file.

Syntax

#include "l_bitmap.h"

L_LTFIL_API L_INT L_ReadFileMetaDataItems(pszFile, pMetaData, pLoadOptions)

Parameters

L_TCHAR * pszFile

Character string that contains the input file name.

pL_FILEMETADATAITEMS pMetaData

Pointer to a L_FILEMETADATAITEMS structure that will be filled with the metadata items from the source image file. When this data is no longer needed pass it to the L_FreeFileMetaDataItems function to free the allocated memory.

pLOADFILEOPTION pLoadOptions

Pointer to optional extended load options. Pass NULL to use the default load options.

Returns

Value	Meaning
SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

You must free the data allocated with this function using the L_FreeFileMetaDataItems function.

The file referenced by pszFile must be a file format that supports XMP. For example PNG, PDF, JPEG, TIFF, SVG, DOC, DOCX, XLS, XLSX, PPT and PPTX.

To determine if a file format supports metadata tags, use L_FileMetaDataItemsSupported.

The metadata tags returned by this function are different than data associated with TIF tags. The TIF tags associate metadata with an integer identifier (the tag number). The metadata returned by this function is identified by a string identifier (the key).

Also, the metadata in TIF tags can take various forms (numbers, strings, rationals, arrays of numbers). The metadata value returned by this function can take only one form: a string. Of course, a number can also be returned by this function, but the number is returned as a string. And it is up to you to convert the string value back to a number.

Required DLLs and Libraries

LTFIL
LFXMP
For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64, Linux.

Example

This example demonstrates the functions related to MetaData items. Checks MetaData support, reads MetaData items, prints MetaDataItems data, and then frees allocated MetaData items.

L_INT PrintFileMetaData(L_TCHAR* pFileName) 
{ 
   L_INT nRet; 
   L_BOOL bIsMetaDataSupported; 
   FILEINFO FileInfo = { 0 }; 
 
   //Get file information 
   nRet = L_FileInfo(pFileName, &FileInfo, sizeof(FILEINFO), 0, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   //Check if MetaData supported for the specified file format. 
   bIsMetaDataSupported = L_FileMetaDataItemsSupported(FileInfo.Format); 
   if(bIsMetaDataSupported) 
   { 
      L_FILEMETADATAITEMS MetaDataItems = { 0 }; 
      MetaDataItems.uStructSize = sizeof(L_FILEMETADATAITEMS); 
 
      //Read MetaData Items 
      nRet = L_ReadFileMetaDataItems(pFileName, &MetaDataItems, NULL); 
      if(nRet != SUCCESS) 
         return nRet; 
 
      wprintf(L"Items count %u\n", MetaDataItems.uCount); 
      for(L_UINT i = 0; i < MetaDataItems.uCount; i++) 
      { 
         //Print Key & Value for each item in MetaDataItems 
         const L_FILEMETADATAITEM* item = &MetaDataItems.pItems[i]; 
 
         //key Ex: L_FILEMETADATAKEY_TITLE 
         wprintf(L"%s: %s\n", item->Key, item->Value); 
      } 
 
      //Free MetaData Items 
      L_FreeFileMetaDataItems(&MetaDataItems); 
   } 
 
   return SUCCESS; 
}