#include "ltwrappr.h"
L_INT LJp2FileFormat::ExtractFramesBufferMemory(pBuffer, uBufferSize, lpBuffer, puBufferSize, puFrames, uNumOfFrames)
L_UINT8 * pBuffer; |
/* pointer to a JPEG 2000 file in memory */ |
L_SIZE_T uBufferSize; |
/* size of the file in memory (in bytes)*/ |
L_UINT8 ** lpBuffer; |
/* pointer to a pointer */ |
L_SIZE_T * puBufferSize; |
/* pointer to a variable to be updated */ |
L_UINT32 * puFrames; |
/* frames indices */ |
L_UINT32 uNumOfFrames; |
/* number of frames to be extracted */ |
Extracts the frames that are specified by puFrames from the JPEG 2000 file in memory and save them into a new JPEG 2000 file in a memory buffer that is allocated by the function contains only the extracted frames headers and codestreams directly not through decompressing/compressing process.
Parameter |
Description |
pBuffer |
Pointer to the JPEG 2000 file in memory to extract frames from it. |
uBufferSize |
Size of the in memory (in bytes). |
lpBuffer |
Pointer to a pointer to be updated with an array of bytes that contains a JPEG 2000 file with extracted frames only. You must free this buffer by calling the Windows LocalFree() function. |
puBufferSize |
Address of a variable to be updated with the size of the memory buffer in bytes. |
puFrames |
Array of unsigned integers specifies the indices of the frames to be extracted from the input JPEG 2000 file. All indices shall be 0-based. If any frames index is out the frames number the function will return ERROR_INV_PARAMETER. |
uNumOfFrames |
Number of frames to be extracted. This field specifies the size of puFrames array. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
LJp2FileFormat::ExtractFramesBufferMemory extracts the specified frames from the JPEG 2000 file in memory and save them into a new JPEG 2000 file in a memory buffer that is allocated by the function contains only the extracted frames headers and codestreams directly not through decompressing/compressing process so it saves processor time and memory. This function is very suitable to server application where multiple clients request specific frames of a JPEG 2000 file so instead of decompressing then compressing the frames this function copies only the needed frames data to generate them and saves the data into a new JPEG 2000 file in a memory buffer.
Required DLLs and Libraries
LTJP2 For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application. |
Win32, x64.
See Also
Example
This example extracts a frame from JPX file.
L_INT LJp2FileFormat__ExtractFramesBufferMemoryExample(L_UINT8* pFileBuffer, L_SIZE_T uFileSize, L_UINT8** lpFrameBuffer, L_SIZE_T * puFrameSize) { L_INT nRet = 0; LJp2FileFormat Engine; L_JP2_FILEINFO Jp2FileInfo; L_UINT32 puFrames[1]; *lpFrameBuffer = NULL; *puFrameSize = 0; Jp2FileInfo.uStructSize = sizeof(L_JP2_FILEINFO); nRet = Engine.GetFileInfoMemory( pFileBuffer, uFileSize, &Jp2FileInfo); if(nRet != SUCCESS) return nRet; /*Extract the second frame*/ puFrames[0] = 0; nRet = Engine.ExtractFramesBufferMemory( pFileBuffer, uFileSize, lpFrameBuffer, puFrameSize, puFrames, 1); if(nRet != SUCCESS) return nRet; /*Free File Info structure*/ nRet = Engine.FreeFileInfo( &Jp2FileInfo); if(nRet != SUCCESS) return nRet; return SUCCESS; }