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#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <errno.h>
#include <endian.h>
#include "readers.h"
/* ---------------------------------------------------------------------- */
typedef unsigned int uint32;
typedef unsigned short uint16;
/* bitmap files are little endian */
#if BYTE_ORDER == LITTLE_ENDIAN
# define le16_to_cpu(x) (x)
# define le32_to_cpu(x) (x)
#elif BYTE_ORDER == BIG_ENDIAN
# define le16_to_cpu(x) (((x>>8) & 0x00ff) |\
((x<<8) & 0xff00))
# define le32_to_cpu(x) (((x>>24) & 0x000000ff) |\
((x>>8) & 0x0000ff00) |\
((x<<8) & 0x00ff0000) |\
((x<<24) & 0xff000000))
#else
# error "Oops: unknown byte order"
#endif
/* ---------------------------------------------------------------------- */
/* load */
struct bmp_hdr {
uint32 foobar;
uint32 size; /* == BitMapInfoHeader */
uint32 width;
uint32 height;
uint16 planes;
uint16 bit_cnt;
char compression[4];
uint32 image_size;
uint32 xpels_meter;
uint32 ypels_meter;
uint32 num_colors; /* used colors */
uint32 imp_colors; /* important colors */
/* may be more for some codecs */
};
struct bmp_cmap {
unsigned char blue;
unsigned char green;
unsigned char red;
unsigned char unused;
};
struct bmp_state {
struct bmp_hdr hdr;
struct bmp_cmap cmap[256];
FILE *fp;
};
static void*
bmp_init(FILE *fp, char *filename, unsigned int page,
struct ida_image_info *i, int thumbnail)
{
struct bmp_state *h;
h = malloc(sizeof(*h));
memset(h,0,sizeof(*h));
h->fp = fp;
fseek(fp,10,SEEK_SET);
fread(&h->hdr,sizeof(struct bmp_hdr),1,fp);
#if BYTE_ORDER == BIG_ENDIAN
h->hdr.foobar = le32_to_cpu(h->hdr.foobar);
h->hdr.size = le32_to_cpu(h->hdr.size);
h->hdr.width = le32_to_cpu(h->hdr.width);
h->hdr.height = le32_to_cpu(h->hdr.height);
h->hdr.planes = le16_to_cpu(h->hdr.planes);
h->hdr.bit_cnt = le16_to_cpu(h->hdr.bit_cnt);
h->hdr.image_size = le32_to_cpu(h->hdr.image_size);
h->hdr.xpels_meter = le32_to_cpu(h->hdr.xpels_meter);
h->hdr.ypels_meter = le32_to_cpu(h->hdr.ypels_meter);
h->hdr.num_colors = le32_to_cpu(h->hdr.num_colors);
h->hdr.imp_colors = le32_to_cpu(h->hdr.imp_colors);
#endif
if (debug)
fprintf(stderr,"bmp: hdr=%d size=%dx%d planes=%d"
" bits=%d size=%d res=%dx%d colors=%d/%d | %d\n",
h->hdr.size,h->hdr.width,h->hdr.height,
h->hdr.planes,h->hdr.bit_cnt,h->hdr.image_size,
h->hdr.xpels_meter,h->hdr.ypels_meter,
h->hdr.num_colors,h->hdr.imp_colors,h->hdr.foobar);
if (h->hdr.bit_cnt != 1 &&
h->hdr.bit_cnt != 4 &&
h->hdr.bit_cnt != 8 &&
h->hdr.bit_cnt != 24) {
fprintf(stderr,"bmp: can't handle depth [%d]\n",h->hdr.bit_cnt);
goto oops;
}
if (h->hdr.compression[0] || h->hdr.compression[1] ||
h->hdr.compression[2] || h->hdr.compression[3]) {
fprintf(stderr,"bmp: can't handle compressed bitmaps [%c%c%c%c]\n",
h->hdr.compression[0],
h->hdr.compression[1],
h->hdr.compression[2],
h->hdr.compression[3]);
goto oops;
}
if (0 == h->hdr.num_colors && h->hdr.bit_cnt <= 8)
h->hdr.num_colors = (1 << h->hdr.bit_cnt);
if (h->hdr.num_colors > 256)
h->hdr.num_colors = 256;
if (h->hdr.num_colors) {
fseek(fp,14+h->hdr.size,SEEK_SET);
fread(&h->cmap,sizeof(struct bmp_cmap),h->hdr.num_colors,fp);
}
i->width = h->hdr.width;
i->height = h->hdr.height;
if (h->hdr.xpels_meter)
i->dpi = res_m_to_inch(h->hdr.xpels_meter);
i->npages = 1;
return h;
oops:
free(h);
return NULL;
}
static void
bmp_read(unsigned char *dst, unsigned int line, void *data)
{
struct bmp_state *h = data;
unsigned int ll,y,x,pixel,byte = 0;
ll = (((h->hdr.width * h->hdr.bit_cnt + 31) & ~0x1f) >> 3);
y = h->hdr.height - line - 1;
fseek(h->fp,h->hdr.foobar + y * ll,SEEK_SET);
switch (h->hdr.bit_cnt) {
case 1:
for (x = 0; x < h->hdr.width; x++) {
if (0 == (x & 0x07))
byte = fgetc(h->fp);
pixel = byte & (0x80 >> (x & 0x07)) ? 1 : 0;
*(dst++) = h->cmap[pixel].red;
*(dst++) = h->cmap[pixel].green;
*(dst++) = h->cmap[pixel].blue;
}
break;
case 4:
for (x = 0; x < h->hdr.width; x++) {
if (x & 1) {
pixel = byte & 0xf;
} else {
byte = fgetc(h->fp);
pixel = byte >> 4;
}
*(dst++) = h->cmap[pixel].red;
*(dst++) = h->cmap[pixel].green;
*(dst++) = h->cmap[pixel].blue;
}
break;
case 8:
for (x = 0; x < h->hdr.width; x++) {
pixel = fgetc(h->fp);
*(dst++) = h->cmap[pixel].red;
*(dst++) = h->cmap[pixel].green;
*(dst++) = h->cmap[pixel].blue;
}
break;
case 24:
for (x = 0; x < h->hdr.width; x++) {
dst[2] = fgetc(h->fp);
dst[1] = fgetc(h->fp);
dst[0] = fgetc(h->fp);
dst += 3;
}
break;
default:
memset(dst,128,h->hdr.width*3);
break;
}
}
static void
bmp_done(void *data)
{
struct bmp_state *h = data;
fclose(h->fp);
free(h);
}
static struct ida_loader bmp_loader = {
magic: "BM",
moff: 0,
mlen: 2,
name: "bmp",
init: bmp_init,
read: bmp_read,
done: bmp_done,
};
static void __init init_rd(void)
{
load_register(&bmp_loader);
}
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