mirror of
https://github.com/python-pillow/Pillow.git
synced 2024-12-26 18:06:18 +03:00
93 lines
1.5 KiB
C
93 lines
1.5 KiB
C
/*
|
|
* The Python Imaging Library.
|
|
* $Id$
|
|
*
|
|
* decoder for PackBits image data.
|
|
*
|
|
* history:
|
|
* 96-04-19 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"
|
|
|
|
int
|
|
ImagingPackbitsDecode(Imaging im, ImagingCodecState state,
|
|
UINT8* buf, int bytes)
|
|
{
|
|
UINT8 n;
|
|
UINT8* ptr;
|
|
int i;
|
|
|
|
ptr = buf;
|
|
|
|
for (;;) {
|
|
|
|
if (bytes < 1)
|
|
return ptr - buf;
|
|
|
|
if (ptr[0] & 0x80) {
|
|
|
|
if (ptr[0] == 0x80) {
|
|
/* Nop */
|
|
ptr++; bytes--;
|
|
continue;
|
|
}
|
|
|
|
/* Run */
|
|
if (bytes < 2)
|
|
return ptr - buf;
|
|
|
|
for (n = 257 - ptr[0]; n > 0; n--) {
|
|
if (state->x >= state->bytes) {
|
|
/* state->errcode = IMAGING_CODEC_OVERRUN; */
|
|
break;
|
|
}
|
|
state->buffer[state->x++] = ptr[1];
|
|
}
|
|
|
|
ptr += 2; bytes -= 2;
|
|
|
|
} else {
|
|
|
|
/* Literal */
|
|
n = ptr[0]+2;
|
|
|
|
if (bytes < n)
|
|
return ptr - buf;
|
|
|
|
for (i = 1; i < n; i++) {
|
|
if (state->x >= state->bytes) {
|
|
/* state->errcode = IMAGING_CODEC_OVERRUN; */
|
|
break;
|
|
}
|
|
state->buffer[state->x++] = ptr[i];
|
|
}
|
|
|
|
ptr += n; bytes -= n;
|
|
|
|
}
|
|
|
|
if (state->x >= state->bytes) {
|
|
|
|
/* Got a full line, unpack it */
|
|
state->shuffle((UINT8*) im->image[state->y + state->yoff] +
|
|
state->xoff * im->pixelsize, state->buffer,
|
|
state->xsize);
|
|
|
|
state->x = 0;
|
|
|
|
if (++state->y >= state->ysize) {
|
|
/* End of file (errcode = 0) */
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
}
|
|
}
|