L_Jp2ReadBoxMemory (original) (raw)

Summary

Reads a box of type eBoxType at uBoxIndex from a JPEG 2000 file in memory.

Syntax

#include "l_bitmap.h"

L_LTJP2_API L_INT EXT_FUNCTION L_Jp2ReadBoxMemory(hJp2, pBuffer, uBufferSize, eBoxType, plBox, uBoxIndex)

Parameters

L_HJP2 hJp2

JPEG 2000 engine handle that was created by the L_Jp2Create function.

L_UINT8 * pBuffer

Pointer to a JPEG 2000 file in memory.

L_SIZE_T uBufferSize

Size of JPEG 2000 file in bytes.

eJP2BOXTYPE eBoxType

Box type. It specifies the type of the box to be read from the file.

L_VOID ** plBox

Pointer to a pointer to be updated with the box data structure.

L_UINT32 uBoxIndex

Zero based box index. It specifies the box the user wants to read.

Returns

Comments

L_Jp2ReadBoxMemory reads a box of type eBoxType at uBoxIndex from a JPEG 2000 file in memory.

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.

Required DLLs and Libraries

• LTJP2
• LTIMGEFX
• LFJ2K
• 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.

See Also

Functions

• L_Jp2FreeBoxes
• L_Jp2ReadBox
• L_Jp2AppendBoxes
• L_Jp2AppendBoxesMemory

Topics

• Programming with JPEG 2000 Features
• Programming with JPX Features
• Raster Image Functions: Working with JPEG 2000
• Raster Image Functions: Working with JPX

Example

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

L_INT Jp2ReadBoxMemoryExample(L_UINT8* pFileBuffer, L_SIZE_T uFileSize, L_UINT8** pMPEG7Data, L_SIZE_T* puSize) { L_HJP2 hEngine; L_INT nRet; pL_JP2_MPEG7_BOX pMPEG7Box; L_JP2_FILEINFO Jp2FileInfo; // Create JPEG 2000 engine handle hEngine = L_Jp2Create(); Jp2FileInfo.uStructSize = sizeof(L_JP2_FILEINFO); nRet = L_Jp2GetFileInfoMemory(hEngine, pFileBuffer, uFileSize, &Jp2FileInfo); if (nRet != SUCCESS) return nRet; if (Jp2FileInfo.MPEG7.uNumOfBoxes == 0) return 0; nRet = L_Jp2ReadBoxMemory(hEngine, pFileBuffer, uFileSize, 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 = L_Jp2FreeBoxes(hEngine, L_JPXB_MPEG7, pMPEG7Box, 1); if (nRet != SUCCESS) return nRet; // Free File Info structure nRet = L_Jp2FreeFileInfo(hEngine, &Jp2FileInfo); if (nRet != SUCCESS) return nRet; // Destroy engine handle nRet = L_Jp2Destroy(hEngine); if (nRet != SUCCESS) return nRet; return SUCCESS; }