1 #define _DEFAULT_SOURCE /* New name for SVID & BSD source defines */
2 #define _BSD_SOURCE /* Make sure string.h containst strcasecmp() */
3 #include <stdlib.h>
4 #include <string.h>
5 #include <limits.h>
6
7 #include "pm.h"
8
9 #include "global_variables.h"
10 #include "util.h"
11 #include "decode.h"
12 #include "bayer.h"
13 #include "stdio_nofail.h"
14
15 #include "ljpeg.h"
16
17
18 /*
19 Not a full implementation of Lossless JPEG, just
20 enough to decode Canon, Kodak and Adobe DNG images.
21 */
22
23 int
ljpeg_start(FILE * const ifP,struct jhead * const jhP)24 ljpeg_start(FILE * const ifP,
25 struct jhead * const jhP) {
26
27 int i, tag;
28 unsigned char data[256], *dp;
29
30 init_decoder();
31 for (i=0; i < 4; i++)
32 jhP->huff[i] = free_decode;
33 fread_nofail (data, 2, 1, ifP);
34 if (data[0] != 0xff || data[1] != 0xd8) return 0;
35 do {
36 unsigned int len;
37
38 fread_nofail (data, 2, 2, ifP);
39 tag = data[0] << 8 | data[1];
40 len = data[2] << 8 | data[3];
41
42 if (len < 2)
43 pm_error("Length field is %u; must be at least 2", len);
44 else {
45 unsigned int const dataLen = len - 2;
46
47 if (tag <= 0xff00 || dataLen > 255) return 0;
48 fread_nofail (data, 1, dataLen, ifP);
49 switch (tag) {
50 case 0xffc3:
51 jhP->bits = data[0];
52 jhP->high = data[1] << 8 | data[2];
53 jhP->wide = data[3] << 8 | data[4];
54 jhP->clrs = data[5];
55 break;
56 case 0xffc4:
57 for (dp = data; dp < data + dataLen && *dp < 4; ) {
58 jhP->huff[*dp] = free_decode;
59 dp = make_decoder (++dp, 0);
60 }
61 }
62 }
63 } while (tag != 0xffda);
64 jhP->row = calloc (jhP->wide*jhP->clrs, 2);
65 if (jhP->row == NULL)
66 pm_error("Out of memory in ljpeg_start()");
67 for (i=0; i < 4; i++)
68 jhP->vpred[i] = 1 << (jhP->bits-1);
69 zero_after_ff = 1;
70 getbits(ifP, -1);
71 return 1;
72 }
73
74
75
76 int
ljpeg_diff(FILE * const ifP,struct decode * const dindexHeadP)77 ljpeg_diff(FILE * const ifP,
78 struct decode * const dindexHeadP) {
79
80 int len;
81 int diff;
82 struct decode * dindexP;
83
84 for (dindexP = dindexHeadP; dindexP->branch[0]; )
85 dindexP = dindexP->branch[getbits(ifP, 1)];
86
87 diff = getbits(ifP, len = dindexP->leaf);
88
89 if ((diff & (1 << (len-1))) == 0)
90 diff -= (1 << len) - 1;
91
92 return diff;
93 }
94
95
96
97 void
ljpeg_row(FILE * const ifP,struct jhead * const jhP)98 ljpeg_row(FILE * const ifP,
99 struct jhead * const jhP) {
100
101 int col, c, diff;
102 unsigned short *outp=jhP->row;
103
104 for (col=0; col < jhP->wide; col++)
105 for (c=0; c < jhP->clrs; c++) {
106 diff = ljpeg_diff(ifP, jhP->huff[c]);
107 *outp = col ? outp[-jhP->clrs]+diff : (jhP->vpred[c] += diff);
108 outp++;
109 }
110 }
111
112
113
114 void
lossless_jpeg_load_raw(Image const image)115 lossless_jpeg_load_raw(Image const image) {
116
117 int jwide, jrow, jcol, val, jidx, i, row, col;
118 struct jhead jh;
119 int min=INT_MAX;
120
121 if (!ljpeg_start (ifp, &jh)) return;
122 jwide = jh.wide * jh.clrs;
123
124 for (jrow=0; jrow < jh.high; jrow++) {
125 ljpeg_row (ifp, &jh);
126 for (jcol=0; jcol < jwide; jcol++) {
127 val = curve[jh.row[jcol]];
128 jidx = jrow*jwide + jcol;
129 if (raw_width == 5108) {
130 i = jidx / (1680*jh.high);
131 if (i < 2) {
132 row = jidx / 1680 % jh.high;
133 col = jidx % 1680 + i*1680;
134 } else {
135 jidx -= 2*1680*jh.high;
136 row = jidx / 1748;
137 col = jidx % 1748 + 2*1680;
138 }
139 } else if (raw_width == 3516) {
140 row = jidx / 1758;
141 col = jidx % 1758;
142 if (row >= raw_height) {
143 row -= raw_height;
144 col += 1758;
145 }
146 } else {
147 row = jidx / raw_width;
148 col = jidx % raw_width;
149 }
150 if ((unsigned) (row-top_margin) >= height) continue;
151 if ((unsigned) (col-left_margin) < width) {
152 BAYER(row-top_margin,col-left_margin) = val;
153 if (min > val) min = val;
154 } else
155 black += val;
156 }
157 }
158 free (jh.row);
159 if (raw_width > width)
160 black /= (raw_width - width) * height;
161 if (!strcasecmp(make,"KODAK"))
162 black = min;
163 }
164