Reverse reading WORD from a binary file?
- by Angel
Hi,
I have a structure:
struct JFIF_HEADER
{
WORD marker[2]; // = 0xFFD8FFE0
WORD length; // = 0x0010
BYTE signature[5]; // = "JFIF\0"
BYTE versionhi; // = 1
BYTE versionlo; // = 1
BYTE xyunits; // = 0
WORD xdensity; // = 1
WORD ydensity; // = 1
BYTE thumbnwidth; // = 0
BYTE thumbnheight; // = 0
};
This is how I read it from the file:
HANDLE file = CreateFile(filename, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
DWORD tmp = 0;
DWORD size = GetFileSize(file, &tmp);
BYTE *DATA = new BYTE[size];
ReadFile(file, DATA, size, &tmp, 0);
JFIF_HEADER header;
memcpy(&header, DATA, sizeof(JFIF_HEADER));
This is how the beginning of my file looks in hex editor:
0xFF 0xD8 0xFF 0xE0 0x00 0x10 0x4A 0x46 0x49 0x46 0x00 0x01 0x01 0x00 0x00 0x01
When I print header.marker, it shows exactly what it should (0xFFD8FFE0). But when I print header.length, it shows 0x1000 instead of 0x0010. The same thing is with xdensity and ydensity. Why do I get wrong data when reading a WORD?
Thank you.
