/*
* The Python Imaging Library.
* $Id: HexDecode.c 2134 2004-10-06 08:55:20Z fredrik $
*
* decoder for hex encoded image data
*
* history:
* 96-05-16 fl Created
*
* Copyright (c) Fredrik Lundh 1996.
* Copyright (c) Secret Labs AB 1997.
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
#define HEX(v) ((v >= '0' && v <= '9') ? v - '0' :\
(v >= 'a' && v <= 'f') ? v - 'a' + 10 :\
(v >= 'A' && v <= 'F') ? v - 'A' + 10 : -1)
int
ImagingHexDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
{
UINT8* ptr;
int a, b;
ptr = buf;
for (;;) {
if (bytes < 2)
return ptr - buf;
a = HEX(ptr[0]);
b = HEX(ptr[1]);
if (a < 0 || b < 0) {
ptr++;
bytes--;
} else {
ptr += 2;
bytes -= 2;
state->buffer[state->x] = (a<<4) + b;
if (++state->x >= state->bytes) {
/* Got a full line, unpack it */
state->shuffle((UINT8*) im->image[state->y], state->buffer,
state->xsize);
state->x = 0;
if (++state->y >= state->ysize) {
/* End of file (errcode = 0) */
return -1;
}
}
}
}
}
