Pillow/libImaging/RawDecode.c
2010-07-30 22:52:47 -04:00

90 lines
1.5 KiB
C

/*
* The Python Imaging Library.
* $Id$
*
* decoder for raw (uncompressed) image data
*
* history:
* 96-03-07 fl rewritten
*
* Copyright (c) Fredrik Lundh 1996.
* Copyright (c) Secret Labs AB 1997.
*
* See the README file for information on usage and redistribution.
*/
#include "Imaging.h"
#include "Raw.h"
int
ImagingRawDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
{
enum { LINE = 1, SKIP };
RAWSTATE* rawstate = state->context;
UINT8* ptr;
if (state->state == 0) {
/* Initialize context variables */
/* get size of image data and padding */
state->bytes = (state->xsize * state->bits + 7) / 8;
rawstate->skip = (rawstate->stride) ?
rawstate->stride - state->bytes : 0;
/* check image orientation */
if (state->ystep < 0) {
state->y = state->ysize-1;
state->ystep = -1;
} else
state->ystep = 1;
state->state = LINE;
}
ptr = buf;
for (;;) {
if (state->state == SKIP) {
/* Skip padding between lines */
if (bytes < rawstate->skip)
return ptr - buf;
ptr += rawstate->skip;
bytes -= rawstate->skip;
state->state = LINE;
}
if (bytes < state->bytes)
return ptr - buf;
/* Unpack data */
state->shuffle((UINT8*) im->image[state->y + state->yoff] +
state->xoff * im->pixelsize, ptr, state->xsize);
ptr += state->bytes;
bytes -= state->bytes;
state->y += state->ystep;
if (state->y < 0 || state->y >= state->ysize) {
/* End of file (errcode = 0) */
return -1;
}
state->state = SKIP;
}
}