#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
/////////////////////////////////////////////////////////////////////////
_inline size_t stepToNextMarker(unsigned char* mem, size_t j, size_t len)
{
size_t tmp = j + (mem[j] << 8 | mem[j + 1]);
if(tmp < len && 0xff == mem[tmp]) //check if in range and next marker exists
j = tmp;
return j;
}
/////////////////////////////////////////////////////////////////////////
size_t scanJpeg(unsigned char* mem, size_t len, unsigned char** outPtr)
{
size_t j, ret, tmp;
unsigned char c, *ptr = NULL, *lastEoi = NULL;
for(ret = j = 0; j < len; )
{
if(0xff == mem[j++])
{
if(j >= len)
break;
c = mem[j++];
if(j >= len)
break;
switch(c)
{
case 0xd8:
printf("SOI (ffd8)\t@%p\n", j - 2);
break;
case 0xe0:
case 0xe1:
case 0xe2:
case 0xe3:
case 0xe4:
case 0xe5:
case 0xe6:
case 0xe7:
case 0xe8:
case 0xe9:
case 0xea:
case 0xeb:
case 0xec:
case 0xed:
case 0xee:
case 0xef:
printf("APP%d(ffe%x)\t@%p\n", c & 0xf, c & 0xf, j - 2);
j = stepToNextMarker(mem, j, len);
break;
case 0xc4:
printf("DHT (ffc4)\t@%p\n", j - 2);
j = stepToNextMarker(mem, j, len);
break;
case 0xdb:
printf("DQT (ffdb)\t@%p\n", j - 2);
j = stepToNextMarker(mem, j, len);
break;
case 0xd9:
printf("EOI (ffd9)\t@%p\n", j - 2); //end of image is the last marker
ptr = lastEoi;
lastEoi = &mem[j - 2];
break;
case 0xc0: //most markers except c0 and c2 are unused
case 0xc1:
case 0xc2:
case 0xc3:
case 0xc5:
case 0xc6:
case 0xc7:
case 0xc9:
case 0xca:
case 0xcb:
case 0xcd:
case 0xce:
case 0xcf:
printf("SOF%d(ffc%x)\t@%p\tx=%d, y=%d\n", c & 0xf, c & 0xf, j - 2, mem[j + 5] << 8 | mem[j + 6], mem[j + 3] << 8 | mem[j + 4]);
j = stepToNextMarker(mem, j, len);
break;
case 0xda:
printf("SOS (ffda)\t@%p\n", j - 2);
tmp = j + (mem[j] << 8 | mem[j + 1]); //the compressed stream follows, no next marker
if(tmp < len)
j = tmp;
break;
case 0xfe:
printf("COM (fffe)\t@%p\n", j - 2);
j = stepToNextMarker(mem, j, len);
break;
case 0xdd:
printf("DRI (ffdd)\t@%p\n", j - 2);
j = stepToNextMarker(mem, j, len);
break;
}
}
}
if(ptr)
{
ret = lastEoi - ptr + 2;
*outPtr = ptr;
}
return ret;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////
int repairJpg(char* fName)
{
HANDLE h;
size_t len, tmp;
unsigned char *mem, *ptr;
h = CreateFile(fName, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if(h == INVALID_HANDLE_VALUE)
{
printf("Error while opening a \"%s\"\n", fName);
return -1;
}
len = GetFileSize(h, NULL);
mem = VirtualAlloc(NULL, len, MEM_COMMIT, PAGE_READWRITE);
ReadFile(h, mem, len, &tmp, NULL);
len = scanJpeg(mem, len, &ptr);
if(len)
{
ptr[1] = 0xd8;
SetFilePointer(h, 0, NULL, FILE_BEGIN);
WriteFile(h, ptr, len, &tmp, NULL);
SetEndOfFile(h);
}
VirtualFree(mem, 0, MEM_RELEASE);
CloseHandle(h);
return 0;
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////
int main()
{
char buf[MAX_PATH];
int len;
WIN32_FIND_DATA fd;
HANDLE h;
len = GetModuleFileName(NULL, buf, sizeof(buf));
for( ; len && buf[len] != '\\'; --len)
;
strcpy(&buf[len], "\\*.jpg");
h = FindFirstFile(buf, &fd);
if(INVALID_HANDLE_VALUE == h)
{
printf("Jpg file(s) not found.\nCopy a parseJpg.exe to directory with jpg file(s) and run again.\n");
getch();
return -1;
}
do {
strcpy(&buf[len + 1], fd.cFileName);
printf("Repairing \"%s\"\n", buf);
repairJpg(buf);
} while(FindNextFile(h, &fd));
FindClose(h);
printf("\nDone.\n");
return 0;
}
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