ref: 39f18c9d88f52a22373790dec5721fa3521d3f00
dir: /sys/src/cmd/jpg/writetif.c/
/*
* code/documentation:
* http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
* http://www.fileformat.info/format/tiff/egff.htm
* http://www.fileformat.info/mirror/egff/ch09_05.htm
* http://www.itu.int/rec/T-REC-T.4-199904-S/en
* http://www.itu.int/rec/T-REC-T.6-198811-I/en
*
* many thanks to paul bourke for a simple description of tiff:
* http://paulbourke.net/dataformats/tiff/
*
* copy-pasted fax codes and copy-pasted lzw encoding
* hash table implementation:
* http://www.remotesensing.org/libtiff/
*/
#include <u.h>
#include <libc.h>
#include <bio.h>
#include <draw.h>
#include <memdraw.h>
#include "imagefile.h"
enum {
Tbyte = 0x0001,
Tascii = 0x0002,
Tshort = 0x0003,
Tlong = 0x0004,
Trational = 0x0005,
Tnocomp = 0x0001,
Thuffman = 0x0002,
Tt4enc = 0x0003,
Tt6enc = 0x0004,
Tlzw = 0x0005,
Tpackbits = 0x8005
};
enum {
Twidth,
Tlength,
Tbits,
Tcomp,
Tphoto,
Tfill,
Tdesc,
Tstrips,
Tsamples,
Trows,
Tcounts,
Txres,
Tyres,
T4opt,
Tresunit,
Tpredictor,
Tcolor
};
enum {
Kpar = 2,
Nfaxtab = 105
};
enum {
Clrcode = 256,
Eoicode = 257,
Tabsz = 1<<12,
Hshift = 13 - 8,
Hsize = 9001L
};
typedef struct Tab Tab;
typedef struct Fax Fax;
typedef struct Hash Hash;
typedef struct Lzw Lzw;
typedef struct Pkb Pkb;
typedef struct Fld Fld;
typedef struct Tif Tif;
struct Tab {
int len;
int code;
int run;
};
struct Fax {
int st;
Tab *tab[2];
int byte;
int nbyte;
ulong *l1;
ulong *l2;
uchar *data;
ulong ndata;
ulong n;
};
struct Hash {
long hash;
u16int code;
};
struct Lzw {
Hash hash[Hsize];
int ntab;
int len;
int byte;
int nbyte;
uchar *data;
ulong ndata;
ulong n;
};
struct Pkb {
uchar *data;
ulong ndata;
ulong n;
};
struct Fld {
ushort tag;
ushort typ;
};
struct Tif {
ulong dx;
ulong dy;
ushort depth[3];
ushort comp;
ulong opt;
char *(*compress)(Tif *);
ushort photo;
char *desc;
ulong *strips;
ulong nstrips;
ushort samples;
ulong rows;
ulong *counts;
ushort *color;
ulong ncolor;
uchar *data;
ulong ndata;
ushort nfld;
int bpl;
};
static Fld flds[] = {
[Twidth] {0x0100, Tlong},
[Tlength] {0x0101, Tlong},
[Tbits] {0x0102, Tshort},
[Tcomp] {0x0103, Tshort},
[Tphoto] {0x0106, Tshort},
[Tfill] {0x010a, Tshort},
[Tdesc] {0x010e, Tascii},
[Tstrips] {0x0111, Tlong},
[Tsamples] {0x0115, Tshort},
[Trows] {0x0116, Tlong},
[Tcounts] {0x0117, Tlong},
[Txres] {0x011a, Trational},
[Tyres] {0x011b, Trational},
[T4opt] {0x0124, Tlong},
[Tresunit] {0x0128, Tshort},
[Tpredictor] {0x013d, Tshort},
[Tcolor] {0x0140, Tshort}
};
/*
* imported from libdraw/arith.c to permit
* extern log2 function
*/
static int log2[] = {
-1, 0, 1, -1, 2, -1, -1, -1, 3,
-1, -1, -1, -1, -1, -1, -1, 4,
-1, -1, -1, -1, -1, -1, -1, 4 /* BUG */,
-1, -1, -1, -1, -1, -1, -1, 5
};
static Tab faxwhite[Nfaxtab] = {
{8, 0x35, 0}, /* 0011 0101 */
{6, 0x7, 1}, /* 0001 11 */
{4, 0x7, 2}, /* 0111 */
{4, 0x8, 3}, /* 1000 */
{4, 0xb, 4}, /* 1011 */
{4, 0xc, 5}, /* 1100 */
{4, 0xe, 6}, /* 1110 */
{4, 0xf, 7}, /* 1111 */
{5, 0x13, 8}, /* 1001 1 */
{5, 0x14, 9}, /* 1010 0 */
{5, 0x7, 10}, /* 0011 1 */
{5, 0x8, 11}, /* 0100 0 */
{6, 0x8, 12}, /* 0010 00 */
{6, 0x3, 13}, /* 0000 11 */
{6, 0x34, 14}, /* 1101 00 */
{6, 0x35, 15}, /* 1101 01 */
{6, 0x2a, 16}, /* 1010 10 */
{6, 0x2b, 17}, /* 1010 11 */
{7, 0x27, 18}, /* 0100 111 */
{7, 0xc, 19}, /* 0001 100 */
{7, 0x8, 20}, /* 0001 000 */
{7, 0x17, 21}, /* 0010 111 */
{7, 0x3, 22}, /* 0000 011 */
{7, 0x4, 23}, /* 0000 100 */
{7, 0x28, 24}, /* 0101 000 */
{7, 0x2b, 25}, /* 0101 011 */
{7, 0x13, 26}, /* 0010 011 */
{7, 0x24, 27}, /* 0100 100 */
{7, 0x18, 28}, /* 0011 000 */
{8, 0x2, 29}, /* 0000 0010 */
{8, 0x3, 30}, /* 0000 0011 */
{8, 0x1a, 31}, /* 0001 1010 */
{8, 0x1b, 32}, /* 0001 1011 */
{8, 0x12, 33}, /* 0001 0010 */
{8, 0x13, 34}, /* 0001 0011 */
{8, 0x14, 35}, /* 0001 0100 */
{8, 0x15, 36}, /* 0001 0101 */
{8, 0x16, 37}, /* 0001 0110 */
{8, 0x17, 38}, /* 0001 0111 */
{8, 0x28, 39}, /* 0010 1000 */
{8, 0x29, 40}, /* 0010 1001 */
{8, 0x2a, 41}, /* 0010 1010 */
{8, 0x2b, 42}, /* 0010 1011 */
{8, 0x2c, 43}, /* 0010 1100 */
{8, 0x2d, 44}, /* 0010 1101 */
{8, 0x4, 45}, /* 0000 0100 */
{8, 0x5, 46}, /* 0000 0101 */
{8, 0xa, 47}, /* 0000 1010 */
{8, 0xb, 48}, /* 0000 1011 */
{8, 0x52, 49}, /* 0101 0010 */
{8, 0x53, 50}, /* 0101 0011 */
{8, 0x54, 51}, /* 0101 0100 */
{8, 0x55, 52}, /* 0101 0101 */
{8, 0x24, 53}, /* 0010 0100 */
{8, 0x25, 54}, /* 0010 0101 */
{8, 0x58, 55}, /* 0101 1000 */
{8, 0x59, 56}, /* 0101 1001 */
{8, 0x5a, 57}, /* 0101 1010 */
{8, 0x5b, 58}, /* 0101 1011 */
{8, 0x4a, 59}, /* 0100 1010 */
{8, 0x4b, 60}, /* 0100 1011 */
{8, 0x32, 61}, /* 0011 0010 */
{8, 0x33, 62}, /* 0011 0011 */
{8, 0x34, 63}, /* 0011 0100 */
{5, 0x1b, 64}, /* 1101 1 */
{5, 0x12, 128}, /* 1001 0 */
{6, 0x17, 192}, /* 0101 11 */
{7, 0x37, 256}, /* 0110 111 */
{8, 0x36, 320}, /* 0011 0110 */
{8, 0x37, 384}, /* 0011 0111 */
{8, 0x64, 448}, /* 0110 0100 */
{8, 0x65, 512}, /* 0110 0101 */
{8, 0x68, 576}, /* 0110 1000 */
{8, 0x67, 640}, /* 0110 0111 */
{9, 0xcc, 704}, /* 0110 0110 0 */
{9, 0xcd, 768}, /* 0110 0110 1 */
{9, 0xd2, 832}, /* 0110 1001 0 */
{9, 0xd3, 896}, /* 0110 1001 1 */
{9, 0xd4, 960}, /* 0110 1010 0 */
{9, 0xd5, 1024}, /* 0110 1010 1 */
{9, 0xd6, 1088}, /* 0110 1011 0 */
{9, 0xd7, 1152}, /* 0110 1011 1 */
{9, 0xd8, 1216}, /* 0110 1100 0 */
{9, 0xd9, 1280}, /* 0110 1100 1 */
{9, 0xda, 1344}, /* 0110 1101 0 */
{9, 0xdb, 1408}, /* 0110 1101 1 */
{9, 0x98, 1472}, /* 0100 1100 0 */
{9, 0x99, 1536}, /* 0100 1100 1 */
{9, 0x9a, 1600}, /* 0100 1101 0 */
{6, 0x18, 1664}, /* 0110 00 */
{9, 0x9b, 1728}, /* 0100 1101 1 */
{11, 0x8, 1792}, /* 0000 0001 000 */
{11, 0xc, 1856}, /* 0000 0001 100 */
{11, 0xd, 1920}, /* 0000 0001 101 */
{12, 0x12, 1984}, /* 0000 0001 0010 */
{12, 0x13, 2048}, /* 0000 0001 0011 */
{12, 0x14, 2112}, /* 0000 0001 0100 */
{12, 0x15, 2176}, /* 0000 0001 0101 */
{12, 0x16, 2240}, /* 0000 0001 0110 */
{12, 0x17, 2304}, /* 0000 0001 0111 */
{12, 0x1c, 2368}, /* 0000 0001 1100 */
{12, 0x1d, 2432}, /* 0000 0001 1101 */
{12, 0x1e, 2496}, /* 0000 0001 1110 */
{12, 0x1f, 2560}, /* 0000 0001 1111 */
{12, 0x1, -1} /* 0000 0000 0001 */
};
static Tab faxblack[Nfaxtab] = {
{10, 0x37, 0}, /* 0000 1101 11 */
{3, 0x2, 1}, /* 010 */
{2, 0x3, 2}, /* 11 */
{2, 0x2, 3}, /* 10 */
{3, 0x3, 4}, /* 011 */
{4, 0x3, 5}, /* 0011 */
{4, 0x2, 6}, /* 0010 */
{5, 0x3, 7}, /* 0001 1 */
{6, 0x5, 8}, /* 0001 01 */
{6, 0x4, 9}, /* 0001 00 */
{7, 0x4, 10}, /* 0000 100 */
{7, 0x5, 11}, /* 0000 101 */
{7, 0x7, 12}, /* 0000 111 */
{8, 0x4, 13}, /* 0000 0100 */
{8, 0x7, 14}, /* 0000 0111 */
{9, 0x18, 15}, /* 0000 1100 0 */
{10, 0x17, 16}, /* 0000 0101 11 */
{10, 0x18, 17}, /* 0000 0110 00 */
{10, 0x8, 18}, /* 0000 0010 00 */
{11, 0x67, 19}, /* 0000 1100 111 */
{11, 0x68, 20}, /* 0000 1101 000 */
{11, 0x6c, 21}, /* 0000 1101 100 */
{11, 0x37, 22}, /* 0000 0110 111 */
{11, 0x28, 23}, /* 0000 0101 000 */
{11, 0x17, 24}, /* 0000 0010 111 */
{11, 0x18, 25}, /* 0000 0011 000 */
{12, 0xca, 26}, /* 0000 1100 1010 */
{12, 0xcb, 27}, /* 0000 1100 1011 */
{12, 0xcc, 28}, /* 0000 1100 1100 */
{12, 0xcd, 29}, /* 0000 1100 1101 */
{12, 0x68, 30}, /* 0000 0110 1000 */
{12, 0x69, 31}, /* 0000 0110 1001 */
{12, 0x6a, 32}, /* 0000 0110 1010 */
{12, 0x6b, 33}, /* 0000 0110 1011 */
{12, 0xd2, 34}, /* 0000 1101 0010 */
{12, 0xd3, 35}, /* 0000 1101 0011 */
{12, 0xd4, 36}, /* 0000 1101 0100 */
{12, 0xd5, 37}, /* 0000 1101 0101 */
{12, 0xd6, 38}, /* 0000 1101 0110 */
{12, 0xd7, 39}, /* 0000 1101 0111 */
{12, 0x6c, 40}, /* 0000 0110 1100 */
{12, 0x6d, 41}, /* 0000 0110 1101 */
{12, 0xda, 42}, /* 0000 1101 1010 */
{12, 0xdb, 43}, /* 0000 1101 1011 */
{12, 0x54, 44}, /* 0000 0101 0100 */
{12, 0x55, 45}, /* 0000 0101 0101 */
{12, 0x56, 46}, /* 0000 0101 0110 */
{12, 0x57, 47}, /* 0000 0101 0111 */
{12, 0x64, 48}, /* 0000 0110 0100 */
{12, 0x65, 49}, /* 0000 0110 0101 */
{12, 0x52, 50}, /* 0000 0101 0010 */
{12, 0x53, 51}, /* 0000 0101 0011 */
{12, 0x24, 52}, /* 0000 0010 0100 */
{12, 0x37, 53}, /* 0000 0011 0111 */
{12, 0x38, 54}, /* 0000 0011 1000 */
{12, 0x27, 55}, /* 0000 0010 0111 */
{12, 0x28, 56}, /* 0000 0010 1000 */
{12, 0x58, 57}, /* 0000 0101 1000 */
{12, 0x59, 58}, /* 0000 0101 1001 */
{12, 0x2b, 59}, /* 0000 0010 1011 */
{12, 0x2c, 60}, /* 0000 0010 1100 */
{12, 0x5a, 61}, /* 0000 0101 1010 */
{12, 0x66, 62}, /* 0000 0110 0110 */
{12, 0x67, 63}, /* 0000 0110 0111 */
{10, 0xf, 64}, /* 0000 0011 11 */
{12, 0xc8, 128}, /* 0000 1100 1000 */
{12, 0xc9, 192}, /* 0000 1100 1001 */
{12, 0x5b, 256}, /* 0000 0101 1011 */
{12, 0x33, 320}, /* 0000 0011 0011 */
{12, 0x34, 384}, /* 0000 0011 0100 */
{12, 0x35, 448}, /* 0000 0011 0101 */
{13, 0x6c, 512}, /* 0000 0011 0110 0 */
{13, 0x6d, 576}, /* 0000 0011 0110 1 */
{13, 0x4a, 640}, /* 0000 0010 0101 0 */
{13, 0x4b, 704}, /* 0000 0010 0101 1 */
{13, 0x4c, 768}, /* 0000 0010 0110 0 */
{13, 0x4d, 832}, /* 0000 0010 0110 1 */
{13, 0x72, 896}, /* 0000 0011 1001 0 */
{13, 0x73, 960}, /* 0000 0011 1001 1 */
{13, 0x74, 1024}, /* 0000 0011 1010 0 */
{13, 0x75, 1088}, /* 0000 0011 1010 1 */
{13, 0x76, 1152}, /* 0000 0011 1011 0 */
{13, 0x77, 1216}, /* 0000 0011 1011 1 */
{13, 0x52, 1280}, /* 0000 0010 1001 0 */
{13, 0x53, 1344}, /* 0000 0010 1001 1 */
{13, 0x54, 1408}, /* 0000 0010 1010 0 */
{13, 0x55, 1472}, /* 0000 0010 1010 1 */
{13, 0x5a, 1536}, /* 0000 0010 1101 0 */
{13, 0x5b, 1600}, /* 0000 0010 1101 1 */
{13, 0x64, 1664}, /* 0000 0011 0010 0 */
{13, 0x65, 1728}, /* 0000 0011 0010 1 */
{11, 0x8, 1792}, /* 0000 0001 000 */
{11, 0xc, 1856}, /* 0000 0001 100 */
{11, 0xd, 1920}, /* 0000 0001 101 */
{12, 0x12, 1984}, /* 0000 0001 0010 */
{12, 0x13, 2048}, /* 0000 0001 0011 */
{12, 0x14, 2112}, /* 0000 0001 0100 */
{12, 0x15, 2176}, /* 0000 0001 0101 */
{12, 0x16, 2240}, /* 0000 0001 0110 */
{12, 0x17, 2304}, /* 0000 0001 0111 */
{12, 0x1c, 2368}, /* 0000 0001 1100 */
{12, 0x1d, 2432}, /* 0000 0001 1101 */
{12, 0x1e, 2496}, /* 0000 0001 1110 */
{12, 0x1f, 2560}, /* 0000 0001 1111 */
{12, 0x1, -1} /* 0000 0000 0001 */
};
static Tab faxcodes[] = {
{4, 0x1, 0}, /* 0001 */
{3, 0x1, 0}, /* 001 */
{1, 0x1, 0}, /* 1 */
{3, 0x2, 0}, /* 010 */
{6, 0x2, 0}, /* 0000 10 */
{7, 0x2, 0}, /* 0000 010 */
{3, 0x3, 0}, /* 011 */
{6, 0x3, 0}, /* 0000 11 */
{7, 0x3, 0} /* 0000 011 */
};
static int typesizes[] = {0, 1, 1, 2, 4, 8};
static char memerr[] = "WriteTIF: malloc failed";
static int
put1(Biobuf *b, uchar c)
{
return Bputc(b, c);
}
static int
put2(Biobuf *b, uint s)
{
if(put1(b, s>>8) < 0)
return -1;
return put1(b, s);
}
static int
put4(Biobuf *b, ulong l)
{
if(put2(b, l>>16) < 0)
return -1;
return put2(b, l);
}
static char *
nocomp(Tif *)
{
return nil;
}
static char *
faxputbyte(Fax *f)
{
if(f->n >= f->ndata) {
f->ndata *= 2;
f->data = realloc(f->data,
f->ndata*sizeof *f->data);
if(f->data == nil)
return memerr;
}
f->data[f->n++] = f->byte;
f->byte = f->nbyte = 0;
return nil;
}
static char *
faxputbit(Fax *f, int bit)
{
f->byte = (f->byte << 1) | bit;
f->nbyte++;
return f->nbyte >= 8? faxputbyte(f): nil;
}
static char *
faxbytealign(Fax *f)
{
char *err;
err = nil;
if(f->nbyte != 0) {
f->byte <<= 8 - f->nbyte;
err = faxputbyte(f);
}
return err;
}
static char *
faxputcode(Fax *f, Tab *tab)
{
int i, bit;
char *err;
for(i = tab->len-1; i >= 0; i--) {
bit = (tab->code >> i) & 0x1;
if((err = faxputbit(f, bit)) != nil)
return err;
}
return nil;
}
static int
faxgettab(int run)
{
if(run >= 0) {
if(run <= 64)
return run;
if(run <= 2560)
return 64 + run/64 - 1;
}
return Nfaxtab - 1;
}
static char *
faxputrun(Fax *f, long run)
{
char *err;
Tab *tab, *p;
tab = f->tab[f->st];
p = &tab[faxgettab(2560)];
while(run >= 2624) {
if((err = faxputcode(f, p)) != nil)
return err;
run -= 2560;
}
if(run >= 64) {
p = &tab[faxgettab(run)];
if((err = faxputcode(f, p)) != nil)
return err;
run -= p->run;
}
p = &tab[faxgettab(run)];
err = faxputcode(f, p);
f->st ^= 1;
return err;
}
static char *
faxputeol(Fax *f)
{
return faxputcode(f, &f->tab[0][faxgettab(-1)]);
}
static char *
fax1d(Fax *f, ulong dx)
{
ulong i;
long run;
char *err;
f->st = 0;
run = f->l2[0];
for(i = 0;;) {
if((err = faxputrun(f, run)) != nil)
return err;
if(f->l2[i++] >= dx)
break;
run = f->l2[i] - f->l2[i-1];
}
memmove(f->l1, f->l2, i*sizeof *f->l1);
return nil;
}
static char *
fax2d(Fax *f, ulong dx)
{
int j, v;
ulong i;
long a0, a1, a2, b1, b2;
char *err;
Tab *tab, *p;
f->st = 0;
a0 = a1 = -1;
tab = faxcodes;
for(i = 0, err = nil; err == nil;) {
while(a1 <= a0)
a1 = f->l2[i++];
for(j = 0;; j++) {
b1 = f->l1[j];
if(b1 > a0 && f->st == j%2)
break;
if(b1 >= dx)
break;
}
if((b2 = b1) < dx)
b2 = f->l1[j+1];
if(b2 < a1) {
/* pass */
p = &tab[0];
err = faxputcode(f, p);
a0 = b2;
} else if(abs(v = a1-b1) < 3) {
/* vertical */
p = &tab[2+(v>0?3:0)+abs(v)];
err = faxputcode(f, p);
f->st ^= 1;
a0 = a1;
} else {
/* horizontal */
if(a0 < 0)
a0 = 0;
p = &tab[1];
if((err = faxputcode(f, p)) != nil)
return err;
a2 = a1 < dx? f->l2[i++]: a1;
if((err = faxputrun(f, a1-a0)) != nil)
return err;
err = faxputrun(f, a2-a1);
a0 = a2;
}
if(a0 >= dx)
break;
}
memmove(f->l1, f->l2, i*sizeof *f->l1);
return err;
}
static char *
faxstrip(Tif *t, Fax *f, uchar *data, ulong n, ulong dx)
{
int k, s, d1, two;
ulong i, j, x;
char *err;
d1 = t->comp != Tt6enc;
two = 0;
if(t->comp == Tt4enc) {
if((err = faxputeol(f)) != nil)
return err;
if(t->opt && (err = faxputbit(f, 1)) != nil)
return err;
}
for(i = j = x = 0; i < n;) {
s = 7 - x++%8;
k = ((data[i] >> s) & 0x1) ^ 0x1;
if(s == 0)
i++;
if(k != f->st) {
f->l2[j++] = x - 1;
f->st ^= 1;
}
if(x == dx) {
f->l2[j] = dx;
if(d1) {
err = fax1d(f, dx);
if(t->comp == Tt4enc &&
t->opt) {
two = Kpar - 1;
d1 = 0;
}
} else {
err = fax2d(f, dx);
if(two > 0 && --two <= 0)
d1 = 1;
}
if(err != nil)
return err;
if(t->comp == Thuffman)
err = faxbytealign(f);
else if(t->comp == Tt4enc &&
t->opt) {
if((err = faxputeol(f)) != nil)
return err;
err = faxputbit(f, d1);
} else if(t->comp == Tt4enc)
err = faxputeol(f);
if(err != nil)
return err;
f->st = 0;
if(s != 0)
i++;
x = 0;
j = 0;
}
}
if(t->comp == Tt4enc || t->comp == Tt6enc) {
i = t->comp == Tt4enc? 5: 2;
for(; i > 0; i--) {
if((err = faxputeol(f)) != nil)
return err;
if(t->comp == Tt4enc && t->opt) {
err = faxputbit(f, 1);
if(err != nil)
return err;
}
}
}
return faxbytealign(f);
}
static char *
fax(Tif *t)
{
ulong i, m, n;
char *err;
uchar *data;
Fax f;
f.ndata = t->ndata;
if((f.data = malloc(f.ndata*sizeof *f.data)) == nil)
return memerr;
f.l1 = mallocz((t->dx+1)*sizeof *f.l1, 1);
f.l2 = mallocz((t->dx+1)*sizeof *f.l2, 1);
if(f.l1 == nil || f.l2 == nil) {
free(f.data);
if(f.l1 != nil)
free(f.l1);
if(f.l2 != nil)
free(f.l2);
return memerr;
}
f.tab[0] = faxwhite;
f.tab[1] = faxblack;
f.n = f.byte = f.nbyte = 0;
for(i = n = 0, data = t->data; i < t->nstrips; i++) {
f.st = 0;
f.l1[0] = t->dx;
m = t->counts[i];
if((err = faxstrip(t, &f, data, m, t->dx)) != nil) {
if(f.data != nil)
free(f.data);
return err;
}
data += m;
t->counts[i] = f.n - n;
n = f.n;
}
free(t->data);
free(f.l1);
free(f.l2);
t->data = f.data;
t->ndata = f.n;
return nil;
}
static void
lzwtabinit(Lzw *l)
{
long i;
Hash *hp;
l->ntab = Eoicode + 1;
l->len = 9;
hp = &l->hash[Hsize-1];
i = Hsize - 8;
do {
i -= 8;
hp[-7].hash = -1;
hp[-6].hash = -1;
hp[-5].hash = -1;
hp[-4].hash = -1;
hp[-3].hash = -1;
hp[-2].hash = -1;
hp[-1].hash = -1;
hp[0].hash = -1;
hp -= 8;
} while(i >= 0);
for(i += 8; i > 0; i--, hp--)
hp->hash = -1;
}
static char *
lzwputbyte(Lzw *l)
{
if(l->n >= l->ndata) {
l->ndata *= 2;
l->data = realloc(l->data,
l->ndata*sizeof *l->data);
if(l->data == nil)
return memerr;
}
l->data[l->n++] = l->byte;
l->byte = l->nbyte = 0;
return nil;
}
static char *
lzwbytealign(Lzw *l)
{
char *err;
err = nil;
if(l->nbyte != 0) {
l->byte <<= 8 - l->nbyte;
err = lzwputbyte(l);
}
return err;
}
static char *
lzwputcode(Lzw *l, int code)
{
int i, c;
char *err;
for(i = l->len-1; i >= 0; i--) {
c = (code >> i) & 0x1;
l->byte = (l->byte << 1) | c;
l->nbyte++;
if(l->nbyte >= 8) {
if((err = lzwputbyte(l)) != nil)
return err;
}
}
return nil;
}
static void
predict1(Tif *t)
{
int pix, b[8], d, m, n, j;
ulong x, y;
uchar *data, *p;
p = t->data;
d = *t->depth;
m = (1 << d) - 1;
n = 8 / d;
for(y = 0; y < t->dy; y++) {
data = p += t->bpl;
for(x = t->bpl; x > 0; x--) {
pix = *--data;
for(j = 0; j < n; j++) {
b[j] = (pix >> d*j) & m;
if(j > 0)
b[j-1] -= b[j];
}
if(x > 1)
b[n-1] -= *(data-1) & m;
for(j = pix = 0; j < n; j++)
pix |= (b[j] & m) << d*j;
*data = pix;
}
}
}
static void
predict8(Tif *t)
{
ulong j, s, x, y;
uchar *data, *p;
p = t->data;
s = t->samples;
for(y = 0; y < t->dy; y++) {
data = p += t->dx * s;
for(x = t->dx; x > 1; x--) {
for(j = 0; j < s; j++) {
data--;
*data -= *(data-s);
}
}
}
}
static char *
lzwstrip(Lzw *l, uchar *data, ulong n)
{
int k, h;
long fcode, disp;
ulong i;
char *err;
Hash *hp;
u16int ent;
if((err = lzwputcode(l, Clrcode)) != nil)
return err;
i = 0;
ent = data[i++];
for(; i < n; i++) {
k = data[i];
fcode = ((long)k << 12) + ent;
h = (k << Hshift) ^ ent;
hp = &l->hash[h];
if(hp->hash == fcode) {
hit:
ent = hp->code;
continue;
}
if(hp->hash >= 0) {
disp = h == 0? 1: Hsize - h;
do {
if((h -= disp) < 0)
h += Hsize;
hp = &l->hash[h];
if(hp->hash == fcode)
goto hit;
} while(hp->hash >= 0);
}
if((err = lzwputcode(l, ent)) != nil)
return err;
ent = k;
hp->hash = fcode;
switch(hp->code = l->ntab) {
case 511:
case 1023:
case 2047:
l->len++;
break;
default:
break;
}
if(l->ntab++ >= Tabsz-2) {
err = lzwputcode(l, Clrcode);
if(err != nil)
return err;
lzwtabinit(l);
}
}
if((err = lzwputcode(l, ent)) != nil)
return err;
if((err = lzwputcode(l, Eoicode)) != nil)
return err;
return lzwbytealign(l);
}
static char *
lzw(Tif *t)
{
ulong i, m, n;
char *err;
uchar *data;
Lzw l;
if(t->opt)
*t->depth < 8? predict1(t): predict8(t);
l.ndata = t->ndata;
if((l.data = malloc(l.ndata*sizeof *l.data)) == nil)
return memerr;
l.n = l.byte = l.nbyte = 0;
err = nil;
for(i = n = 0, data = t->data; i < t->nstrips; i++) {
lzwtabinit(&l);
m = t->counts[i];
if((err = lzwstrip(&l, data, m)) != nil)
break;
data += m;
t->counts[i] = l.n - n;
n = l.n;
}
if(err != nil) {
if(l.data != nil)
free(l.data);
return err;
}
free(t->data);
t->data = l.data;
t->ndata = l.n;
return nil;
}
static char *
pkbrow(Pkb *p, uchar *data, int ndata, long *buf)
{
int b, repl;
long i, j, k, n;
ulong m;
i = n = 0;
buf[n++] = i;
b = data[i++];
if(i < ndata)
repl = b == data[i]? 1: 0;
else
repl = 0;
for(; i < ndata; i++) {
k = data[i];
j = labs(buf[n-1]);
if(repl) {
if(b != k) {
repl ^= 1;
buf[n++] = -i;
}
} else {
if(b == k) {
repl ^= 1;
if(i-j > 1)
buf[n++] = i - 1;
}
}
b = k;
}
buf[n++] = repl? -i: i;
for(i = 1; i < n;) {
k = buf[i];
j = labs(buf[i-1]);
if(i < n-2 && k > 0 && buf[i+1] < 0 &&
buf[i+2] > 0 && -buf[i+1]-k <= 2) {
buf[i] = buf[i+1] = buf[i+2];
continue;
}
if((b = labs(k) - j) > 128) {
b = 128;
buf[i-1] += buf[i-1] < 0? -b: b;
} else
i++;
if(b == 0)
continue;
m = 1 + (k < 0? 1: b);
if(p->n+m > p->ndata) {
p->ndata = (p->n + m) * 2;
p->data = realloc(p->data,
p->ndata*sizeof *p->data);
if(p->data == nil)
return memerr;
}
if(k < 0) {
p->data[p->n++] = 1 - b;
p->data[p->n++] = data[j];
} else {
p->data[p->n++] = b - 1;
memmove(p->data+p->n, data+j, b);
p->n += b;
}
}
return nil;
}
static char *
packbits(Tif *t)
{
ulong i, j, n;
char *err;
uchar *data;
long *buf;
Pkb p;
p.ndata = t->ndata;
if((p.data = malloc(p.ndata*sizeof *p.data)) == nil)
return memerr;
if((buf = malloc((t->bpl+1)*sizeof *buf)) == nil) {
free(p.data);
return memerr;
}
p.n = 0;
data = t->data;
for(i = j = n = 0, err = nil; i < t->dy; i++) {
if((err = pkbrow(&p, data, t->bpl, buf)) != nil)
break;
data += t->bpl;
if(i%t->rows == t->rows-1) {
t->counts[j++] = p.n - n;
n = p.n;
}
}
free(buf);
if(err != nil) {
if(p.data != nil)
free(p.data);
return err;
}
if(j < t->nstrips)
t->counts[j] = p.n - n;
free(t->data);
t->data = p.data;
t->ndata = p.n;
return nil;
}
static char *
alloctif(Tif *t)
{
int rgb;
ulong i, count, n;
count = t->ndata < 0x2000? t->ndata: 0x2000;
t->rows = (count + t->bpl - 1) / t->bpl;
if(t->comp == Tt4enc && t->opt) {
if((n = t->rows%Kpar) != 0)
t->rows += Kpar - n;
}
t->nstrips = (t->dy + t->rows - 1) / t->rows;
t->strips = malloc(t->nstrips*sizeof *t->strips);
if(t->strips == nil)
return memerr;
t->counts = malloc(t->nstrips*sizeof *t->counts);
if(t->counts == nil) {
free(t->strips);
return memerr;
}
if(t->ncolor > 0) {
t->color = malloc(t->ncolor*sizeof *t->color);
if(t->color == nil) {
free(t->strips);
free(t->counts);
return memerr;
}
for(i = 0; i < 256; i++) {
rgb = cmap2rgb(i);
t->color[i] = (rgb >> 16) & 0xff;
t->color[i+256] = (rgb >> 8) & 0xff;
t->color[i+256*2] = rgb & 0xff;
}
}
count = t->rows * t->bpl;
for(i = 0, n = t->ndata; i < t->nstrips-1; i++) {
t->counts[i] = count;
n -= count;
}
t->counts[i] = n;
return nil;
}
static void
freetif(Tif *t)
{
free(t->strips);
free(t->counts);
if(t->color != nil)
free(t->color);
free(t->data);
}
static int
typesize(int fld)
{
return typesizes[flds[fld].typ];
}
static void
writefld(Biobuf *fd, int fld, ulong cnt, ulong val)
{
put2(fd, flds[fld].tag);
put2(fd, flds[fld].typ);
put4(fd, cnt);
put4(fd, val);
}
static void
writeflds(Biobuf *fd, Tif *t)
{
int n;
ulong i, off, slen, s, offs[7];
slen = t->desc == nil? 0: strlen(t->desc) + 1;
put2(fd, 0x4d4d);
put2(fd, 0x002a);
off = 0x00000008;
memset(offs, 0, sizeof offs);
n = 0;
offs[n++] = off;
if(t->samples > 1) {
off += t->samples * typesize(Tbits);
offs[n++] = off;
}
if(slen > 4) {
off += slen * typesize(Tdesc);
offs[n++] = off;
}
if(t->nstrips > 1) {
off += t->nstrips * typesize(Tstrips);
offs[n++] = off;
off += t->nstrips * typesize(Tcounts);
offs[n++] = off;
}
off += typesize(Txres);
offs[n++] = off;
off += typesize(Tyres);
offs[n] = off;
if(t->color != nil)
off += t->ncolor * typesize(Tcolor);
for(i = 0; i < t->nstrips-1; i++) {
t->strips[i] = off;
off += t->counts[i];
}
t->strips[i] = off;
off += t->counts[i];
put4(fd, off);
if(t->samples > 1) {
for(i = 0; i < t->samples; i++)
put2(fd, t->depth[i]);
}
if(slen > 4) {
Bwrite(fd, t->desc, slen-1);
put1(fd, 0x00);
}
if(t->nstrips > 1) {
for(i = 0; i < t->nstrips; i++)
put4(fd, t->strips[i]);
for(i = 0; i < t->nstrips; i++)
put4(fd, t->counts[i]);
}
put4(fd, t->dx);
put4(fd, 0x00000004);
put4(fd, t->dy);
put4(fd, 0x00000004);
if(t->color != nil) {
for(i = 0; i < t->ncolor; i++)
put2(fd, t->color[i]);
}
Bwrite(fd, t->data, t->ndata);
n = 0;
put2(fd, t->nfld);
writefld(fd, Twidth, 1, t->dx);
writefld(fd, Tlength, 1, t->dy);
if(t->samples > 1)
writefld(fd, Tbits, t->samples, offs[n++]);
else
writefld(fd, Tbits, t->samples, *t->depth<<16);
writefld(fd, Tcomp, 1, t->comp<<16);
writefld(fd, Tphoto, 1, t->photo<<16);
if(t->comp >= 2 && t->comp <= 4)
writefld(fd, Tfill, 1, 1<<16);
if(slen > 1) {
if(slen <= 4) {
for(i = s = 0; i < slen-1; i++)
s = (s << 8) | t->desc[i];
s <<= 8;
writefld(fd, Tdesc, slen, s);
} else
writefld(fd, Tdesc, slen, offs[n++]);
}
if(t->nstrips > 1)
writefld(fd, Tstrips, t->nstrips, offs[n++]);
else
writefld(fd, Tstrips, t->nstrips, *t->strips);
if(t->samples > 1)
writefld(fd, Tsamples, 1, t->samples<<16);
writefld(fd, Trows, 1, t->rows);
if(t->nstrips > 1)
writefld(fd, Tcounts, t->nstrips, offs[n++]);
else
writefld(fd, Tcounts, t->nstrips, *t->counts);
writefld(fd, Txres, 1, offs[n++]);
writefld(fd, Tyres, 1, offs[n++]);
if(t->comp == Tt4enc && t->opt)
writefld(fd, T4opt, 1, 1);
writefld(fd, Tresunit, 1, 2<<16);
if(t->comp == Tlzw && t->opt)
writefld(fd, Tpredictor, 1, 2<<16);
if(t->color != nil)
writefld(fd, Tcolor, t->ncolor, offs[n]);
put4(fd, 0x00000000);
}
static char *
writedata(Biobuf *fd, Image *i, Memimage *m, Tif *t)
{
char *err;
uchar *data;
int j, ndata, depth;
Rectangle r;
if(m != nil) {
r = m->r;
depth = m->depth;
} else {
r = i->r;
depth = i->depth;
}
t->dx = Dx(r);
t->dy = Dy(r);
for(j = 0; j < t->samples; j++)
t->depth[j] = depth / t->samples;
/*
* potentially one extra byte on each
* end of each scan line
*/
ndata = t->dy * (2 + t->dx*depth/8);
if((data = malloc(ndata)) == nil)
return memerr;
if(m != nil)
ndata = unloadmemimage(m, r, data, ndata);
else
ndata = unloadimage(i, r, data, ndata);
if(ndata < 0) {
free(data);
if((err = malloc(ERRMAX*sizeof *err)) == nil)
return memerr;
snprint(err, ERRMAX, "WriteTIF: %r");
} else {
t->data = data;
t->ndata = ndata;
t->bpl = bytesperline(r, depth);
err = alloctif(t);
if(err != nil) {
freetif(t);
return err;
}
if((err = (*t->compress)(t)) == nil)
writeflds(fd, t);
freetif(t);
}
return err;
}
static char *
writetif0(Biobuf *fd, Image *image, Memimage *memimage,
ulong chan, char *s, int comp, int opt)
{
Tif t;
t.nfld = 11;
t.color = nil;
if((t.desc = s) != nil)
t.nfld++;
t.opt = opt;
t.comp = comp;
switch(chan) {
case GREY1:
case GREY4:
case GREY8:
t.photo = 1;
t.samples = 1;
t.ncolor = 0;
break;
case CMAP8:
t.photo = 3;
t.samples = 1;
t.ncolor = 3 * 256;
t.nfld++;
break;
case BGR24:
t.photo = 2;
t.samples = 3;
t.ncolor = 0;
t.nfld++;
break;
default:
return "WriteTIF: can't handle channel type";
}
switch(t.comp) {
case Tnocomp:
t.compress = nocomp;
break;
case Thuffman:
case Tt4enc:
case Tt6enc:
t.photo = 0;
t.nfld++;
if(t.comp == Tt4enc && t.opt)
t.nfld++;
t.compress = fax;
break;
case Tlzw:
t.compress = lzw;
if(t.opt)
t.nfld++;
break;
case Tpackbits:
t.compress = packbits;
break;
default:
return "WriteTIF: unknown compression";
}
return writedata(fd, image, memimage, &t);
}
char *
writetif(Biobuf *fd, Image *i, char *s, int comp, int opt)
{
return writetif0(fd, i, nil, i->chan, s, comp, opt);
}
char *
memwritetif(Biobuf *fd, Memimage *m, char *s, int comp, int opt)
{
return writetif0(fd, nil, m, m->chan, s, comp, opt);
}