mirror of
https://github.com/python-pillow/Pillow.git
synced 2024-11-10 19:56:47 +03:00
bb1b3a532c
find * -type f "-(" -name "*.bdf" -o -name "*.c" -o -name "*.h" -o -name "*.py" -o -name "*.rst" -o -name "*.txt" "-)" -exec sed -e "s/[[:space:]]*$//" -i {} \;
139 lines
3.8 KiB
C
139 lines
3.8 KiB
C
/*
|
|
* The Python Imaging Library.
|
|
* $Id$
|
|
*
|
|
* decoder for packed bitfields (converts to floating point)
|
|
*
|
|
* history:
|
|
* 97-05-31 fl created (much more than originally intended)
|
|
*
|
|
* Copyright (c) Fredrik Lundh 1997.
|
|
* Copyright (c) Secret Labs AB 1997.
|
|
*
|
|
* See the README file for information on usage and redistribution.
|
|
*/
|
|
|
|
|
|
#include "Imaging.h"
|
|
|
|
#include "Bit.h"
|
|
|
|
|
|
int
|
|
ImagingBitDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
|
|
{
|
|
BITSTATE* bitstate = state->context;
|
|
UINT8* ptr;
|
|
|
|
if (state->state == 0) {
|
|
|
|
/* Initialize context variables */
|
|
|
|
/* this decoder only works for float32 image buffers */
|
|
if (im->type != IMAGING_TYPE_FLOAT32) {
|
|
state->errcode = IMAGING_CODEC_CONFIG;
|
|
return -1;
|
|
}
|
|
|
|
/* sanity check */
|
|
if (bitstate->bits < 1 || bitstate->bits >= 32) {
|
|
state->errcode = IMAGING_CODEC_CONFIG;
|
|
return -1;
|
|
}
|
|
|
|
bitstate->mask = (1<<bitstate->bits)-1;
|
|
|
|
if (bitstate->sign)
|
|
bitstate->signmask = (1<<(bitstate->bits-1));
|
|
|
|
/* check image orientation */
|
|
if (state->ystep < 0) {
|
|
state->y = state->ysize-1;
|
|
state->ystep = -1;
|
|
} else
|
|
state->ystep = 1;
|
|
|
|
state->state = 1;
|
|
|
|
}
|
|
|
|
ptr = buf;
|
|
|
|
while (bytes > 0) {
|
|
|
|
UINT8 byte = *ptr;
|
|
|
|
ptr++;
|
|
bytes--;
|
|
|
|
/* get a byte from the input stream and insert in the bit buffer */
|
|
if (bitstate->fill&1)
|
|
/* fill MSB first */
|
|
bitstate->bitbuffer |= (unsigned long) byte << bitstate->bitcount;
|
|
else
|
|
/* fill LSB first */
|
|
bitstate->bitbuffer = (bitstate->bitbuffer << 8) | byte;
|
|
|
|
bitstate->bitcount += 8;
|
|
|
|
while (bitstate->bitcount >= bitstate->bits) {
|
|
|
|
/* get a pixel from the bit buffer */
|
|
unsigned long data;
|
|
FLOAT32 pixel;
|
|
|
|
if (bitstate->fill&2) {
|
|
/* store LSB first */
|
|
data = bitstate->bitbuffer & bitstate->mask;
|
|
if (bitstate->bitcount > 32)
|
|
/* bitbuffer overflow; restore it from last input byte */
|
|
bitstate->bitbuffer = byte >> (8 - (bitstate->bitcount -
|
|
bitstate->bits));
|
|
else
|
|
bitstate->bitbuffer >>= bitstate->bits;
|
|
} else
|
|
/* store MSB first */
|
|
data = (bitstate->bitbuffer >> (bitstate->bitcount -
|
|
bitstate->bits))
|
|
& bitstate->mask;
|
|
|
|
bitstate->bitcount -= bitstate->bits;
|
|
|
|
if (bitstate->lutsize > 0) {
|
|
/* map through lookup table */
|
|
if (data <= 0)
|
|
pixel = bitstate->lut[0];
|
|
else if (data >= bitstate->lutsize)
|
|
pixel = bitstate->lut[bitstate->lutsize-1];
|
|
else
|
|
pixel = bitstate->lut[data];
|
|
} else {
|
|
/* convert */
|
|
if (data & bitstate->signmask)
|
|
/* image memory contains signed data */
|
|
pixel = (FLOAT32) (INT32) (data | ~bitstate->mask);
|
|
else
|
|
pixel = (FLOAT32) data;
|
|
}
|
|
|
|
*(FLOAT32*)(&im->image32[state->y][state->x]) = pixel;
|
|
|
|
/* step forward */
|
|
if (++state->x >= state->xsize) {
|
|
/* new line */
|
|
state->y += state->ystep;
|
|
if (state->y < 0 || state->y >= state->ysize) {
|
|
/* end of file (errcode = 0) */
|
|
return -1;
|
|
}
|
|
state->x = 0;
|
|
/* reset bit buffer */
|
|
if (bitstate->pad > 0)
|
|
bitstate->bitcount = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
return ptr - buf;
|
|
}
|