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LBase::DecodeABIC

Summary

Decodes the ABIC data and updates the ppOutputData parameter with the uncompressed raw data.

Syntax

#include "ltwrappr.h"

static L_INT LBase::DecodeABIC(pInputData, nLength, ppOutputData, nAlign, nWidth, nHeight, bBiLevel)

Parameters

L_UCHAR * pInputData

Pointer to the input buffer that contains the ABIC compressed data.

L_INT nLength

Size of the compressed data.

L_UCHAR ** ppOutputData

Pointer to a pointer to an output buffer to be updated with the uncompressed raw data.

L_INT nAlign

Number of bytes used for aligning the uncompressed raw data pointed to by ppOutputData.

L_INT nWidth

Width of the compressed ABIC data image, in pixels.

L_INT nHeight

Height of the compressed data image, in pixels.

L_BOOL bBiLevel

Flag that indicates whether the input data is bi-level or grayscale. Possible values are:

Value	Meaning
TRUE	Input data pointed to by pInputData is 1-bit Bi-level.
FALSE	Input data pointed to by pInputData is 4-bit Grayscale.

Returns

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

Comments

This function decompresses 1-bit bi-level or 4-bit grayscale ABIC raw data.

The output buffer pointed to by ppOutputData is allocated automatically by the function. The user is responsible for freeing this ppOutputData buffer by calling GlobalFreePtr() function. The length of the output buffer can be calculated as follows:

bBiLevel value	nLength
TRUE	( ( (nWidth + 31) >> 3) & ~3)
FALSE	( ( (nWidth * 4 + 31) >> 3) & ~3)

Required DLLs and Libraries

LTFIL
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

#define DIB_WIDTH_BYTES(b) (((L_UINT) ((((L_UINT32) (b)) + 31) >> 3)) & ~3) 
#define ROUNDEDBYTESPERLINE(w, b) DIB_WIDTH_BYTES((L_UINT32) (w) * (L_UINT32) (b))  
 
L_INT LBase__DecodeABICExample( LBitmapBase&  Bitmap )  
{ 
   L_INT  nRet;  
   L_INT  nLength;  
   L_UCHAR  *pData;  
   L_INT  nOutLength;  
   L_UCHAR  *pOutData;  
   HANDLE  hFile;  
   RGBQUAD  MyGrayPal[ 16 ];  
   DWORD wgReadBytes = 0; 
    
   /* open file */  
   hFile = CreateFile(MAKE_IMAGE_PATH(TEXT("Image2Raw.ica")), GENERIC_ALL, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); 
   if( NULL != hFile )  
   { 
      /* calculate length of data and load it from the file */  
      SetFilePointer(hFile, 0, 0, FILE_END); 
      nLength = SetFilePointer(hFile, 0, 0, FILE_CURRENT); 
      SetFilePointer(hFile, 0, 0, FILE_BEGIN); 
       
      pData = (L_UCHAR *)GlobalAllocPtr( GMEM_FIXED, nLength );  
      if( NULL == pData )  
      { 
         CloseHandle(hFile ); 
         return -1; /* no memory */  
      } 
       
      while(wgReadBytes < (DWORD)nLength) 
      { 
         DWORD wReadBytes = 0; 
 
         if(! ReadFile (hFile, &pData[wgReadBytes], nLength-wgReadBytes, &wReadBytes, NULL))  
         { 
            GlobalFreePtr( pData );  
            CloseHandle(hFile );  
            return -1; /* failed while reading */  
         } 
         wgReadBytes+= wReadBytes; 
      } 
       
      CloseHandle(hFile );  
       
      /* decode the data */  
      pOutData = NULL;  
      nRet = LBase::DecodeABIC( pData, nLength, &pOutData, 4, 472 /* width */, 221 /* height */, FALSE );  
      GlobalFreePtr( pData );  
      if( SUCCESS == nRet )  
      { 
         if(Bitmap.IsAllocated()) 
            Bitmap.Free(); 
          
         nOutLength = 221 * ROUNDEDBYTESPERLINE( 472, 4 );  
          
         struct  
         { 
            BITMAPINFO  info;  
            RGBQUAD     colors[ 15 ];  
         } BitmapInfo;  
          
         memset(&BitmapInfo, 0, sizeof(BitmapInfo));  
         BitmapInfo.info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);  
         BitmapInfo.info.bmiHeader.biWidth = 472;  
         BitmapInfo.info.bmiHeader.biHeight = 221;  
         BitmapInfo.info.bmiHeader.biBitCount = 4;  
          
         nRet = Bitmap.ConvertFromDIB( &BitmapInfo.info, pOutData);  
          
         /* prepare gray scale 16-color palette */  
         for( L_INT k = 0 ; k < 16 ; k++ )  
         { 
            MyGrayPal[ k ].rgbBlue =(BYTE)( 0x11 * k);  
            MyGrayPal[ k ].rgbRed = (BYTE)(0x11 * k);  
            MyGrayPal[ k ].rgbGreen =(BYTE)(0x11 * k);  
            MyGrayPal[ k ].rgbReserved = 0;  
         } 
 
 
        nRet =  Bitmap.PutColors( 0, 16, MyGrayPal );  
 
         GlobalFreePtr( pOutData );  
         return nRet;  
      } 
   } 
   return -1;  
 
}