L_StartDecompressBuffer - Raster Imaging C API Help

L_StartDecompressBuffer

#include "l_bitmap.h"

L_LTFIL_API L_INT L_StartDecompressBuffer(phDecompress, pStartDecompressData)

L_HGLOBAL *phDecompress;

pointer to the decompression handle

pSTARTDECOMPRESSDATA pStartDecompressData;

pointer to a structure

Initializes the buffered decompression engine. The decompression is then carried out using the L_DecompressBuffer function. It is ended by the L_StopDecompressBuffer function.

Parameter

Description

phDecompress

Pointer to the handle that identifies the decompression process.

pStartDecompressData

Pointer to a structure that contains information about the decompression process.

Returns

SUCCESS

The function was successful.

< 1

An error occurred. Refer to Return Codes.

Comments

You must declare a handle of type HGLOBAL before calling this function. Pass the address of this handle to this function and the function will initialize the handle.

If this function is called for an unsupported format, it will return ERROR_INV_PARAMETER.

Currently, raw JPEG must contain all the Huffman tables encoded. That is, it must be a readable JPEG file.

Required DLLs and Libraries

LTFIL
File format DLLs

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.

See Also

Functions:

L_DecompressBuffer, L_StopDecompressBuffer, L_StartCompressBuffer, L_CompressBuffer, L_EndCompressBuffer

Topics:

Compressing and Decompressing Buffers

 

Raster Image Functions: Low-Level Decompression

Example

#include <fcntl.h> 
#include <io.h> 
#include <Tchar.h> 
 
#define TAG_STRIPOFFSETS         0x111 
#define TAG_STRIPBYTECOUNTS      0x117 
#define TAG_ROWSPERSTRIP         0x116 
#define MAX_STRIPS               1000 
 
// Returns maximum index 
L_INT ReadTag(L_TCHAR *pszFileName, L_UINT16 uTag,   L_INT StripArray[]) 
{ 
   L_UINT16 uType; 
   L_UINT32 uCount; 
 
   L_ReadFileTag(pszFileName, uTag, &uType, &uCount, StripArray, NULL); 
   return uCount; 
} 
 
// Example 1 
// This sample loads raw data from packbits.tif 
// packbits.tif is a 24-bit tif packbits compressed file  
// packbits.tif has 46 strips of packbits data 
// The strip information is obtained by reading the TIF tags TAG_STRIPOFFSETS and TAG_STRIPBYTECOUNTS 
// The strips are directly read and fed to the L_Compress APIs 
L_INT StartDecompressBufferFirstExample(L_VOID) 
{ 
   L_INT nRet; 
   L_TCHAR *szFileName = MAKE_IMAGE_PATH(TEXT("packbits.tif")); 
   L_HANDLE fd; 
   L_UCHAR *pBuf = NULL; 
   BITMAPHANDLE Bitmap; 
   FILEINFO TempFileInfo; 
   L_INT  nRowsPerStrip=0; 
   STARTDECOMPRESSDATA StartDecompressData; 
   DECOMPRESSDATA      DecompressData; 
   L_INT  nIndex = 0; 
   HGLOBAL hDecompress; 
   L_INT StripOffsets[MAX_STRIPS]; 
   L_INT StripSizes[MAX_STRIPS]; 
   L_INT nMaxIndex; 
   DWORD wReadBytes; 
    
   memset(&TempFileInfo, 0, sizeof(FILEINFO)); 
   TempFileInfo.uStructSize = sizeof(TempFileInfo); 
   nRet = L_FileInfo (szFileName, &TempFileInfo, sizeof(FILEINFO), 0, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
    
    
   //****************************** 
   //*** L_StartDecompressBuffer 
   //****************************** 
   memset(&StartDecompressData, 0, sizeof(STARTDECOMPRESSDATA) ); 
   memset(&DecompressData, 0, sizeof(DECOMPRESSDATA) ); 
    
   StartDecompressData.uStructSize = sizeof(STARTDECOMPRESSDATA); 
   StartDecompressData.pBitmap = &Bitmap; 
   StartDecompressData.uBitmapStructSize = sizeof(BITMAPHANDLE); 
   StartDecompressData.uStripsOrTiles = DECOMPRESS_STRIPS; 
   StartDecompressData.uFormat = FILE_RAW_PACKBITS; 
   StartDecompressData.nWidth = TempFileInfo.Width;             
   StartDecompressData.nHeight = TempFileInfo.Height;           
   StartDecompressData.nBitsPerPixel = TempFileInfo.BitsPerPixel;     
   StartDecompressData.nViewPerspective = TempFileInfo.ViewPerspective;  
   StartDecompressData.nRawOrder = TempFileInfo.Order;            
   StartDecompressData.nLoadOrder = ORDER_BGRORGRAY; 
   StartDecompressData.nXResolution = TempFileInfo.XResolution; 
   StartDecompressData.nYResolution = TempFileInfo.YResolution; 
   StartDecompressData.pfnReadCallback = NULL;  
   StartDecompressData.uFlags = 0;           
   StartDecompressData.pUserData = NULL;        
       
   StartDecompressData.nPhotoInt = 2;              // TIFF tag  0-6  WhiteIsZero(0) BlackIsZero(1) RGB(2) 
    
   nRet = L_StartDecompressBuffer(&hDecompress, &StartDecompressData); 
   if(nRet != SUCCESS) 
      return nRet; 
    
   //****************************** 
   //*** L_DecompressBuffer 
   //****************************** 
    
   nMaxIndex = ReadTag(szFileName, TAG_STRIPOFFSETS,    StripOffsets); 
   ReadTag(szFileName, TAG_STRIPBYTECOUNTS, StripSizes); 
   ReadTag(szFileName, TAG_ROWSPERSTRIP, &nRowsPerStrip); 
    
   fd = CreateFile(szFileName, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); 
   DecompressData.nRow = 0;//Note--this field is ignored for strips 
   for (nIndex = 0; nIndex < nMaxIndex; nIndex++) 
   { 
      //seek to the first strip 
      SetFilePointer(fd,StripOffsets[nIndex] , 0, FILE_BEGIN); 
      pBuf = (L_UCHAR *)malloc(StripSizes[nIndex]); 
      ReadFile (fd, pBuf, StripSizes[nIndex], &wReadBytes, NULL); 
             
      DecompressData.uStructSize = sizeof(DECOMPRESSDATA); 
      DecompressData.pBuffer = pBuf;                        //pointer to raw data 
      DecompressData.nWidth = TempFileInfo.Width;           //Width of uncompressed strip/tile 
      DecompressData.nHeight = nRowsPerStrip;               //Height of uncompressed strip/tile 
      if (nIndex == (nMaxIndex - 1 )) 
      { 
         //fewer rows per strip 
         DecompressData.nHeight = TempFileInfo.Height - (nMaxIndex - 1) * nRowsPerStrip; 
      } 
       
      DecompressData.uOffset = 0;                           //Offset of strip relative to buffer 
      DecompressData.nBufferSize = StripSizes[nIndex];//Size of strip after compression 
      DecompressData.nCol = 0;                              //Col offset of tile 
      DecompressData.uFlags = DECOMPRESS_CHUNK_COMPLETE; 
      DecompressData.nReserved1 = 0;                        //Reserved for future use 
       
      nRet = L_DecompressBuffer ( hDecompress, &DecompressData); 
      if(nRet != SUCCESS) 
         return nRet; 
       
      free(pBuf); 
   } 
    
   CloseHandle(fd); 
    
   //****************************** 
   //*** L_StopDecompressBuffer 
   //****************************** 
   L_StopDecompressBuffer (hDecompress); 
 
   // Bitmap contains the uncompressed bitmap 
   nRet = L_SaveBitmap (MAKE_IMAGE_PATH(TEXT("Uncompressed.bmp")), &Bitmap, FILE_BMP, 24, 0, NULL); 
   L_FreeBitmap(&Bitmap); 
   return nRet; 
} 
 
 
// Example 2 
// This sample is similar to LoadRawPackbitsStrips(), except the data 
// is fed to L_Decompress APIs as tiles instead of strips and the image 
// created is 4x the size of the original image, consisting of four of the original images 
// This sample loads raw data from packbits.tif 
// packbits.tif is a 24-bit tif packbits compressed file  
// packbits.tif has 46 strips of packbits data 
// The strip information is obtained by reading the TIF tags TAG_STRIPOFFSETS and TAG_STRIPBYTECOUNTS 
// The strips are directly read and fed to the L_Compress APIs 
L_INT StartDecompressBufferSecondExample() 
{ 
   L_INT nRet; 
   L_TCHAR *szFileName = MAKE_IMAGE_PATH(TEXT("packbits.tif")); 
   L_HANDLE fd; 
   L_UCHAR *pBuf = NULL; 
   BITMAPHANDLE Bitmap; 
   FILEINFO TempFileInfo; 
   L_INT  nRowsPerStrip=0; 
   STARTDECOMPRESSDATA StartDecompressData; 
   DECOMPRESSDATA      DecompressData; 
   L_INT  nIndex = 0; 
   HGLOBAL hDecompress; 
   L_INT nCurrentRow = 0; 
   L_INT StripOffsets[MAX_STRIPS]; 
   L_INT StripSizes[MAX_STRIPS]; 
   L_INT nMaxIndex; 
   DWORD wReadBytes; 
    
   memset(&TempFileInfo, 0, sizeof(FILEINFO)); 
   TempFileInfo.uStructSize = sizeof(TempFileInfo); 
   nRet = L_FileInfo (szFileName, &TempFileInfo, sizeof(FILEINFO), 0, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
    
   //****************************** 
   //*** nRet = L_StartDecompressBuffer 
   //****************************** 
   memset(&StartDecompressData, 0, sizeof(STARTDECOMPRESSDATA) ); 
   memset(&DecompressData, 0, sizeof(DECOMPRESSDATA) ); 
    
   StartDecompressData.uStructSize = sizeof(STARTDECOMPRESSDATA);           // For versioning 
   StartDecompressData.pBitmap = &Bitmap; 
   StartDecompressData.uBitmapStructSize = sizeof(BITMAPHANDLE); 
   StartDecompressData.uStripsOrTiles = DECOMPRESS_TILES; 
   StartDecompressData.uFormat = FILE_RAW_PACKBITS; 
   StartDecompressData.nWidth = TempFileInfo.Width * 2;           // 
   StartDecompressData.nHeight = TempFileInfo.Height * 2;          // 
   StartDecompressData.nBitsPerPixel = TempFileInfo.BitsPerPixel;    // 
   StartDecompressData.nViewPerspective = TempFileInfo.ViewPerspective; // 
   StartDecompressData.nRawOrder = TempFileInfo.Order;           // ORDER_RGB, ORDER_BGR 
   StartDecompressData.nLoadOrder = ORDER_BGRORGRAY;           // ORDER_RGB, ORDER_BGR 
   StartDecompressData.nXResolution = TempFileInfo.XResolution; 
   StartDecompressData.nYResolution = TempFileInfo.YResolution; 
   StartDecompressData.pfnReadCallback = NULL;  // optional callback function 
   StartDecompressData.uFlags = 0;          // DECOMPRESS_LSB, DECOMPRESS_PAD4, DECOMPRESS_WHITEONBLACK, DECOMPRESS_PALETTE 
   StartDecompressData.pUserData = NULL;       // 
    
   StartDecompressData.nPhotoInt = 2;              // TIFF tag  0-6  WhiteIsZero(0) BlackIsZero(1) RGB(2) 
   //StartDecompressData.nPlanarConfig;   // TIFF tag  1 = Chunky,  2 = Planar format 
    
   nRet = L_StartDecompressBuffer(&hDecompress, &StartDecompressData); 
   if(nRet != SUCCESS) 
      return nRet; 
    
   //****************************** 
   //*** L_DecompressBuffer 
   //****************************** 
    
   nMaxIndex = ReadTag(szFileName, TAG_STRIPOFFSETS,    StripOffsets); 
   ReadTag(szFileName, TAG_STRIPBYTECOUNTS, StripSizes); 
   ReadTag(szFileName, TAG_ROWSPERSTRIP, &nRowsPerStrip); 
    
   fd= CreateFile(szFileName, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); 
 
   nCurrentRow = 0; 
   for (nIndex = 0; nIndex < nMaxIndex; nIndex++) 
   { 
      //seek to the first strip 
      SetFilePointer(fd, StripOffsets[nIndex], 0, FILE_BEGIN); 
      pBuf = (L_UCHAR *)malloc(StripSizes[nIndex]); 
      ReadFile(fd, pBuf, StripSizes[nIndex], &wReadBytes, NULL); 
       
      DecompressData.uStructSize = sizeof(DECOMPRESSDATA); 
      DecompressData.pBuffer = pBuf;                        //pointer to raw data 
      DecompressData.nWidth = TempFileInfo.Width;           //Width of uncompressed strip/tile 
      DecompressData.nHeight = nRowsPerStrip;               //Height of uncompressed strip/tile 
      if (nIndex == (nMaxIndex - 1 )) 
      { 
         //fewer rows per strip 
         DecompressData.nHeight = TempFileInfo.Height - (nMaxIndex - 1) * nRowsPerStrip; 
      } 
       
      DecompressData.uOffset = 0;                           //Offset of strip relative to buffer 
      DecompressData.nBufferSize = StripSizes[nIndex];      //Size of strip after compression 
      DecompressData.nRow = nCurrentRow;                    //Row offset of tile 
      DecompressData.nCol = 0;                              //Col offset of tile 
      DecompressData.uFlags = DECOMPRESS_CHUNK_COMPLETE; 
      DecompressData.nReserved1 = 0;                        //Reserved for future use 
       
      //Strips in upper left corner 
      nRet = L_DecompressBuffer ( hDecompress, &DecompressData); 
      if(nRet != SUCCESS) 
         return nRet; 
       
      //Strips in upper right corner 
      DecompressData.nRow = nCurrentRow; 
      DecompressData.nCol = TempFileInfo.Width; 
      L_DecompressBuffer( hDecompress, &DecompressData); 
       
      //Strips in lower left corner 
      DecompressData.nRow = TempFileInfo.Height + nCurrentRow; 
      DecompressData.nCol = 0; 
      L_DecompressBuffer( hDecompress, &DecompressData); 
       
      //Strips in lower right corner 
      DecompressData.nRow = TempFileInfo.Height + nCurrentRow; 
      DecompressData.nCol = TempFileInfo.Width; 
      nRet = L_DecompressBuffer( hDecompress, &DecompressData); 
      if(nRet != SUCCESS) 
         return nRet; 
       
      free(pBuf); 
 
      nCurrentRow += DecompressData.nHeight; 
   } 
    
   CloseHandle(fd); 
    
   //****************************** 
   //*** L_StopDecompressBuffer 
   //****************************** 
   L_StopDecompressBuffer(hDecompress); 
 
   // Bitmap contains the uncompressed bitmap 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Uncompressed.bmp")), &Bitmap, FILE_BMP, 24, 0, NULL); 
   L_FreeBitmap(&Bitmap); 
   return nRet; 
} 
 
// Example 3 
// This sample loads raw data from OCR1.tif 
// This file is a tif ccitt group4 compressed with a single strip  
// The strip information is obtained by reading the TIF tags TAG_STRIPOFFSETS and TAG_STRIPBYTECOUNTS 
// The strip is directly read and fed to the L_Decompress APIs 
L_INT StartDecompressBufferThirdExample() 
{ 
   L_INT nRet; 
   L_TCHAR *szFileName = MAKE_IMAGE_PATH(TEXT("OCR1.tif")); 
 
   L_HANDLE fd; 
   L_UCHAR *pBuf = NULL; 
   BITMAPHANDLE Bitmap; 
   FILEINFO TempFileInfo; 
   L_INT  nRowsPerStrip=0; 
   STARTDECOMPRESSDATA StartDecompressData; 
   DECOMPRESSDATA      DecompressData; 
   L_INT  nIndex = 0; 
   HGLOBAL hDecompress; 
   L_INT StripOffsets[MAX_STRIPS]; 
   L_INT StripSizes[MAX_STRIPS]; 
   L_INT nMaxIndex; 
    DWORD wReadBytes; 
    
   memset(&TempFileInfo, 0, sizeof(FILEINFO)); 
   TempFileInfo.uStructSize = sizeof(TempFileInfo); 
   nRet = L_FileInfo(szFileName, &TempFileInfo, sizeof(FILEINFO), 0, NULL); 
   if(nRet != SUCCESS) 
      return nRet; 
    
    
   //****************************** 
   //*** L_StartDecompressBuffer 
   //****************************** 
   memset(&StartDecompressData, 0, sizeof(STARTDECOMPRESSDATA) ); 
   memset(&DecompressData, 0, sizeof(DECOMPRESSDATA) ); 
    
   StartDecompressData.uStructSize = sizeof(STARTDECOMPRESSDATA);  
   StartDecompressData.pBitmap = &Bitmap; 
   StartDecompressData.uBitmapStructSize = sizeof(BITMAPHANDLE); 
   StartDecompressData.uStripsOrTiles = DECOMPRESS_TILES; 
   StartDecompressData.uFormat = FILE_FAX_G3_1D; 
   StartDecompressData.nWidth = TempFileInfo.Width;   
   StartDecompressData.nHeight = TempFileInfo.Height;  
   StartDecompressData.nBitsPerPixel = TempFileInfo.BitsPerPixel;  
   StartDecompressData.nViewPerspective = TempFileInfo.ViewPerspective;  
   StartDecompressData.nRawOrder = TempFileInfo.Order;           // ORDER_RGB, ORDER_BGR 
   StartDecompressData.nLoadOrder = ORDER_BGRORGRAY; 
   StartDecompressData.nXResolution = TempFileInfo.XResolution; 
   StartDecompressData.nYResolution = TempFileInfo.YResolution; 
   StartDecompressData.pfnReadCallback = NULL;   
 
   StartDecompressData.uFlags = 0; 
   StartDecompressData.pUserData = NULL;        // 
   StartDecompressData.nPhotoInt = 0;     // TIFF tag  0-6  TIFF tag  0=WhiteIsZero,  1=BlackIsZero 
    
   nRet = L_StartDecompressBuffer(&hDecompress, &StartDecompressData); 
   if(nRet != SUCCESS) 
      return nRet; 
    
   //****************************** 
   //*** L_DecompressBuffer 
   //****************************** 
    
   nMaxIndex = ReadTag(szFileName, TAG_STRIPOFFSETS,    StripOffsets); 
   nMaxIndex = ReadTag(szFileName, TAG_STRIPBYTECOUNTS, StripSizes); 
   ReadTag(szFileName, TAG_ROWSPERSTRIP, &nRowsPerStrip); 
    
   fd= CreateFile(szFileName, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); 
    
   DecompressData.nRow = 0;                                 //This field is ignored with strips 
   for (nIndex = 0; nIndex < nMaxIndex; nIndex++) 
   { 
      //seek to the first strip 
      SetFilePointer(fd, StripOffsets[nIndex], 0, FILE_BEGIN); 
      pBuf = (L_UCHAR *)malloc(StripSizes[nIndex]); 
      ReadFile(fd, pBuf, StripSizes[nIndex], &wReadBytes, NULL); 
       
      DecompressData.uStructSize = sizeof(DECOMPRESSDATA); 
      DecompressData.pBuffer = pBuf;                        //pointer to raw data 
      DecompressData.nWidth = TempFileInfo.Width;           //Width of uncompressed strip/tile 
      DecompressData.nHeight = nRowsPerStrip;               //Height of uncompressed strip/tile 
      if (nIndex == (nMaxIndex - 1 )) 
      { 
         //fewer rows per strip 
         DecompressData.nHeight = TempFileInfo.Height - (nMaxIndex - 1) * nRowsPerStrip; 
      } 
       
      DecompressData.uOffset = 0;                           //Offset of strip relative to buffer 
      DecompressData.nBufferSize = StripSizes[nIndex];//Size of strip after compression 
      DecompressData.nCol = 0;                              //Col offset of tile 
      DecompressData.uFlags = DECOMPRESS_CHUNK_COMPLETE; 
      DecompressData.nReserved1 = 0;                        //Reserved for future use 
       
      nRet = L_DecompressBuffer( hDecompress, &DecompressData); 
      if(nRet != SUCCESS) 
         return nRet; 
       
      free(pBuf); 
   } 
    
   CloseHandle(fd); 
    
   //****************************** 
   //*** L_StopDecompressBuffer 
   //****************************** 
   L_StopDecompressBuffer(hDecompress); 
 
   // Bitmap contains the uncompressed bitmap 
   nRet = L_SaveBitmap(MAKE_IMAGE_PATH(TEXT("Uncompressed.bmp")), &Bitmap, FILE_BMP, 24, 0, NULL); 
   L_FreeBitmap(&Bitmap); 
   return nRet;  
} 
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