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11.10.2008 at 12:16PM PST, ID: 23892245
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7.8

How can I recover the jpeg files and create multiple jpeg files using c?

Asked by codedreamer in Programming Languages, Game Programming, Multimedia Programming

The signatures 0xff 0xd8 0xff 0xe0 or
0xff 0xd8 0xff 0xe1 should be in the first 4 bytes of every jpeg file.  The input file is card.raw.  I  tried to attach it, but it's too large.Start Free Trial 
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/****************************************************************************
 * bmp.h
 *
  * BMP-related data types based on Microsoft's own.
 ***************************************************************************/
 
 
/* 
 * Common Data Types 
 *
 * The data types in this section are essentially aliases for C/C++ 
 * primitive data types.
 *
 * Adapted from http://msdn.microsoft.com/en-us/library/cc230309.aspx.
 */
 
typedef unsigned char   BYTE;
typedef unsigned long   DWORD;
typedef long            LONG;
typedef unsigned short  WORD;
 
 
/*
 * BITMAPFILEHEADER
 *
 * The BITMAPFILEHEADER structure contains information about the type, size,
 * and layout of a file that contains a DIB [device-independent bitmap].
 *
 * Adapted from http://msdn2.microsoft.com/en-us/library/ms532321.aspx.
 */
 
typedef struct 
{ 
    WORD   bfType; 
    DWORD  bfSize; 
    WORD   bfReserved1; 
    WORD   bfReserved2; 
    DWORD  bfOffBits; 
} __attribute__((__packed__)) 
BITMAPFILEHEADER; 
 
 
/*
 * BITMAPINFOHEADER
 *
 * The BITMAPINFOHEADER structure contains information about the 
 * dimensions and color format of a DIB [device-independent bitmap].
 *
 * Adapted from http://msdn2.microsoft.com/en-us/library/ms532290.aspx.
 */
       
typedef struct
{
    DWORD  biSize; 
    LONG   biWidth; 
    LONG   biHeight; 
    WORD   biPlanes; 
    WORD   biBitCount; 
    DWORD  biCompression; 
    DWORD  biSizeImage; 
    LONG   biXPelsPerMeter; 
    LONG   biYPelsPerMeter; 
    DWORD  biClrUsed; 
    DWORD  biClrImportant; 
} __attribute__((__packed__))
BITMAPINFOHEADER; 
 
 
/* 
 * RGBTRIPLE
 *
 * This structure describes a color consisting of relative intensities of
 * red, green, and blue.
 *
 * Adapted from http://msdn.microsoft.com/en-us/library/aa922590.aspx.
 */
 
typedef struct
{
    BYTE  rgbtBlue;
    BYTE  rgbtGreen;
    BYTE  rgbtRed;
} __attribute__((__packed__))
RGBTRIPLE;
 
 
 
/****************************************************************************
 * 
 *
 
 
 ***************************************************************************/
       
#include <stdio.h>
#include <stdlib.h>
 
#include "bmp.h"
 
 
int
main(int argc, char *argv[])
{
    // ensure proper usage
    if (argc != 1)
    {
        printf("Usage: recover\n");
        return 1;
    }
 
    // open input file 
    FILE *inptr = fopen("/home/cs50/pub/share/pset5/card.raw", "r");
    if (inptr == NULL)
    {
        printf("Could not open file.\n");
        return 2;
    }
    FILE *outptr = fopen("test.jpg","w");
 
    // read infile's BITMAPFILEHEADER
    BITMAPFILEHEADER bf;
    fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);
 
    // read infile's BITMAPINFOHEADER
    BITMAPINFOHEADER bi;
    fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
 
//    char *buffer = malloc(bf* sizeof(BYTE));
    //if (buffer == NULL)
    //      return 4;
   // buffer=fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);
    
    printf("bf.bfType=%x\n",bf.bfType);
    printf("bf.bfOffBits=%ld\n",bf.bfOffBits);
    printf("bi.biSize=%ld\n",bi.biSize);
    printf("bi.biBitCount=%x\n",bi.biBitCount);
    printf("bi.biCompression=%ld\n",bi.biCompression);
    // ensure infile is (likely) a 24-bit uncompressed BMP 4.0
//    if (bf.bfType != 0x58eb || bf.bfOffBits != 134348852 
 //   || bi.biSize != 131104)
 //   {
  //      fprintf(stderr, "Unsupported file format.\n");
  //      return 4;
  //  }
    
    unsigned char * buffer[1048576]={' '};
    unsigned char found;
    
    found='n';
    fread(&buffer, sizeof(BYTE), 1048576, inptr);
    for (int i=0; i< 512; i++)
    {
       printf("buffer[]=%x\n",buffer[i]);
    
      //  if (buffer[0] == 0xff && buffer[1] == 0xd8  && buffer[2] == 0xff && 
      //  buffer[3] == 0xe0)
        if ((buffer[i] ==  0xff)
           &&
           (buffer[i+1] == 0xd8)
           &&
           (buffer[i+2] == 0xff)
           &&
           (buffer[i+3] == 0xe0))
        {
            printf("found\n");
            found='y';
            exit;
        }
        
        if ((buffer[i] == 0xff && buffer[i+1] == 0xd8  && buffer[i+2] == 0xff &&
        buffer[i+3] == 0xe1))
        {
            printf("found,too\n");
            found='y';
            exit;
        }
        
    }
    printf("found=%c\n",found);
    // write outfile's BITMAPFILEHEADER
//    fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);
 
    // write outfile's BITMAPINFOHEADER
  //  fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);
 
    // determine padding for scanlines
 //   int padding =  (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;
    // define red 
    //char red = 0x00f;
    
    // iterate over infile's scanlines
  //  for (int i = 0, biHeight = abs(bi.biHeight); i < biHeight; i++)
  //  {
        // iterate over pixels in scanline
      //  for (int j = 0; j < bi.biWidth; j++)
    //    {
            // temporary storage
        //    RGBTRIPLE triple;
 
            // read RGB triple from infile
          //  fread(&triple, sizeof(RGBTRIPLE), 1, inptr);
           // printf("biHeight=%d\n", biHeight);
           // printf("bi.biWidth=%ld\n", bi.biWidth);
//            printf("bf.bfOffBits=%ld\n",bf.bfOffBits);
//            if (triple.rgbtBlue == 0x00)
//            {
//            printf("triple.rgbtBlue=%x\n",triple.rgbtBlue);    
//            printf("triple.rgbtGreen=%x\n",triple.rgbtGreen);
//           }
           
           //  for (int i = 0; i < 4; i++)
            // {
          //   char buffer[512];
           //  fread(buffer, sizeof(BYTE), 1, inptr);
           //  printf("buffer=%c\n",buffer[0]);
           ///  if (buffer[j] == 0xff &&
            //    buffer[j+1] == 0xd8 &&
            //    buffer[j+2] == 0xff &&
            //    buffer[j+3] == 0xe1)
            //      return 0;
            // }
           //change red into white
            //if (triple.rgbtBlue == 0x00 && triple.rgbtGreen == 
           // 0x00 && triple.rgbtRed == 0xff)          
          //  {
            //  triple.rgbtBlue = 0xff;
             // triple.rgbtGreen = 0xff;
             // triple.rgbtRed = 0xff;
 
          //  }   
            // write RGB triple to outfile
            //fwrite(&triple, sizeof(RGBTRIPLE), 1, outptr);
      //  }
 
        // skip over padding, if any
        //fseek(inptr, padding, SEEK_CUR);
       // fseek(inptr, rgbtRed, SEEK_CUR);
        
        // write padding to outfile
       // for (int k = 0; k < padding; k++)
         //   fputc(0x00, outptr);
    
 
    // close infile
    fclose(inptr);
 
    // close outfile
    fclose(outptr);
 
    // that's all folks
    return 0;
}
[+][-]11.10.2008 at 01:50PM PST, ID: 22925941

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[+][-]11.10.2008 at 02:13PM PST, ID: 22926158

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[+][-]11.11.2008 at 06:59AM PST, ID: 22931043

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Zones: Programming Languages, Game Programming, Multimedia Programming
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Solution Provided By: jgordos
Participating Experts: 1
Solution Grade: A
 
 
[+][-]12.01.2008 at 11:15PM PST, ID: 23074967

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[+][-]12.06.2008 at 08:33AM PST, ID: 23112663

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