In This Topic ▼

LJp2FileFormat::ReadBox

#include "ltwrappr.h"

L_INT LJp2FileFormat::ReadBox(pszFile, eBoxType, plBox, uBoxIndex)

L_TCHAR * pszFile;	JPEG 2000 file name
eJP2BOXTYPE eBoxType;	box type
L_VOID * * plBox;	pointer to a pointer
L_UINT32 uBoxIndex;	box index

Reads a box of type eBoxType at uBoxIndex from the specified JPEG 2000 file.

Parameter	Description
pszFile	Character string that contains the name of the JPEG 2000 file.
eBoxType	Box type. It specifies the type of the box to be read from the file.
plBox	Pointer to a pointer to be updated with the box data structure.
uBoxIndex	0-based box index. It specifies the box to read.

Returns

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

Comments

LJp2FileFormat::ReadBox reads a box of type eBoxType at uBoxIndex from the specified JPEG 2000 file.

If the uBoxIndex is greater than the number of boxes, the function returns: ERROR_INV_PARAMETER.

L_JP2B_RESOLUTION and L_JPXB_RESOLUTION boxes cant be read using this function. All of the engines boxes will be reset and updated with the new loaded boxes only.

You must free the allocated box by calling the LJp2FileFormat::FreeBoxes function.

Required DLLs and Libraries

LTJP2
LFJ2K
LTIMGEFX

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.

Example

This example reads an MPEG7 box stored in a JPEG 2000 file.

L_INT LJp2FileFormat__ReadBoxExample(L_UINT8 ** pMPEG7Data, L_SIZE_T* puSize) 
{ 
   LJp2FileFormat Engine; 
   L_INT  nRet = 0; 
   pL_JP2_MPEG7_BOX pMPEG7Box; 
   L_JP2_FILEINFO Jp2FileInfo; 
 
   Jp2FileInfo.uStructSize = sizeof(L_JP2_FILEINFO); 
   nRet = Engine.GetFileInfo(MAKE_IMAGE_PATH(TEXT("image1.jpx")),&Jp2FileInfo); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   if(Jp2FileInfo.MPEG7.uNumOfBoxes == 0) 
      return 0; 
 
   nRet = Engine.ReadBox(MAKE_IMAGE_PATH(TEXT("image1.jpx")),L_JPXB_MPEG7, (L_VOID**)&pMPEG7Box,0); 
   if(nRet != SUCCESS) 
      return nRet; 
    
   *pMPEG7Data = (L_UINT8*)malloc(pMPEG7Box->uDataSize); 
   memcpy(*pMPEG7Data, pMPEG7Box->pData,pMPEG7Box->uDataSize); 
   *puSize = pMPEG7Box->uDataSize; 
    
   /*Free the read box*/ 
   nRet = Engine.FreeBoxes( L_JPXB_MPEG7, pMPEG7Box, 1); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   /*Free File Info structure*/ 
   nRet = Engine.FreeFileInfo( &Jp2FileInfo); 
   if(nRet != SUCCESS) 
      return nRet; 
 
   return SUCCESS; 
}

Download our FREE evaluation

Help Version 20.0.2020.4.5

LEADTOOLS Raster Imaging C++ Class Library Help

Introduction

Version History

Getting Started

LEADTOOLS Raster Imaging Features

Redistributables/Files To Be Included With Your Application

Quick Reference

Tutorials

Classes and Member Functions

Summary of Features

Functions:	LJp2FileFormat::FreeBoxes, LJp2FileFormat::ReadBoxMemory, LJp2FileFormat::AppendBoxes, LJp2FileFormat::AppendBoxesMemory
Topics:	Implementing JPEG 2000 Features
	Raster Image Functions: Working with JPEG 2000
	Programming with JPX Features
	JPX File Comments
	Raster Image Functions: Working with JPX