ref: 440ccbc06007422f04943378260f250f9efa5331
dir: /sys/src/cmd/jpg/readtif.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 lzw help: * http://www.remotesensing.org/libtiff/ */ #include <u.h> #include <libc.h> #include <bio.h> #include <draw.h> #include "imagefile.h" enum { II = 0x4949, /* little-endian */ MM = 0x4d4d, /* big-endian */ TIF = 0x002a /* tiff magic number */ }; enum { Byte = 1, Short = 3, Long = 4 }; enum { Width = 0x0100, Length = 0x0101, Bits = 0x0102, Compression = 0x0103, Nocomp = 0x0001, Huffman = 0x0002, T4enc = 0x0003, T6enc = 0x0004, Lzwenc = 0x0005, Packbits = 0x8005, Photometric = 0x0106, Whitezero = 0x0000, Blackzero = 0x0001, Rgb = 0x0002, Palette = 0x0003, Fill = 0x010a, Strips = 0x0111, Orientation = 0x0112, Samples = 0x0115, Rows = 0x0116, Counts = 0x0117, Planar = 0x011c, T4opts = 0x0124, T6opts = 0x0125, Predictor = 0x13d, Color = 0x0140 }; enum { Nfaxcodes = 10, Nfaxtab = 105 }; enum { Clrcode = 256, Eoicode = 257, Tabsz = 1<<12 }; typedef struct Tab Tab; typedef struct Fax Fax; typedef struct Code Code; typedef struct Lzw Lzw; typedef struct Fld Fld; typedef struct Tif Tif; struct Tab { int len; int code; int run; /* run length */ }; struct Fax { ulong n; int m; int st; /* state */ Tab *tab[2]; int ntab; /* position in tab */ Tab *eol; int eolfill; int (*getbit)(Fax *); ulong *l1; ulong *l2; ulong nl; uchar *data; ulong next; /* next strip offset in data */ }; struct Code { uchar val; Code *next; }; struct Lzw { Code tab[Tabsz]; int ntab; int len; /* code length */ ulong n; int m; uchar *data; ulong next; /* next strip offset in data */ /* remaining allocated codes */ Code *first; Code *last; }; struct Fld { uint tag; uint typ; ulong cnt; ulong off; /* value offset */ ulong *val; ulong nval; }; struct Tif { Biobuf *fd; uint end; /* endianness */ uchar tmp[4]; uchar *buf; ulong nbuf; int eof; /* reached end of image */ ulong n; /* offset in buf array */ ulong off; uint nfld; Fld *fld; ulong (*byte2)(uchar *); ulong (*byte4)(uchar *); /* field data */ ulong dx; ulong dy; ulong depth; ulong comp; uchar *(*uncompress)(Tif *); ulong orientation; ulong photo; int (*decode)(Tif *, Rawimage *, uchar *); ulong fill; ulong *strips; ulong nstrips; ulong samples; ulong rows; ulong *counts; ulong ncounts; ulong planar; ulong *color; /* color map */ ulong ncolor; ulong t4; ulong t6; ulong predictor; /* image data */ uchar *data; ulong ndata; }; /* * 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] = { {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, 0x12, 128}, /* 1001 0 */ {5, 0x13, 8}, /* 1001 1 */ {5, 0x14, 9}, /* 1010 0 */ {5, 0x1b, 64}, /* 1101 1 */ {5, 0x7, 10}, /* 0011 1 */ {5, 0x8, 11}, /* 0100 0 */ {6, 0x17, 192}, /* 0101 11 */ {6, 0x18, 1664}, /* 0110 00 */ {6, 0x2a, 16}, /* 1010 10 */ {6, 0x2b, 17}, /* 1010 11 */ {6, 0x3, 13}, /* 0000 11 */ {6, 0x34, 14}, /* 1101 00 */ {6, 0x35, 15}, /* 1101 01 */ {6, 0x7, 1}, /* 0001 11 */ {6, 0x8, 12}, /* 0010 00 */ {7, 0x13, 26}, /* 0010 011 */ {7, 0x17, 21}, /* 0010 111 */ {7, 0x18, 28}, /* 0011 000 */ {7, 0x24, 27}, /* 0100 100 */ {7, 0x27, 18}, /* 0100 111 */ {7, 0x28, 24}, /* 0101 000 */ {7, 0x2b, 25}, /* 0101 011 */ {7, 0x3, 22}, /* 0000 011 */ {7, 0x37, 256}, /* 0110 111 */ {7, 0x4, 23}, /* 0000 100 */ {7, 0x8, 20}, /* 0001 000 */ {7, 0xc, 19}, /* 0001 100 */ {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, 0x1a, 31}, /* 0001 1010 */ {8, 0x1b, 32}, /* 0001 1011 */ {8, 0x2, 29}, /* 0000 0010 */ {8, 0x24, 53}, /* 0010 0100 */ {8, 0x25, 54}, /* 0010 0101 */ {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, 0x3, 30}, /* 0000 0011 */ {8, 0x32, 61}, /* 0011 0010 */ {8, 0x33, 62}, /* 0011 0011 */ {8, 0x34, 63}, /* 0011 0100 */ {8, 0x35, 0}, /* 0011 0101 */ {8, 0x36, 320}, /* 0011 0110 */ {8, 0x37, 384}, /* 0011 0111 */ {8, 0x4, 45}, /* 0000 0100 */ {8, 0x4a, 59}, /* 0100 1010 */ {8, 0x4b, 60}, /* 0100 1011 */ {8, 0x5, 46}, /* 0000 0101 */ {8, 0x52, 49}, /* 0101 0010 */ {8, 0x53, 50}, /* 0101 0011 */ {8, 0x54, 51}, /* 0101 0100 */ {8, 0x55, 52}, /* 0101 0101 */ {8, 0x58, 55}, /* 0101 1000 */ {8, 0x59, 56}, /* 0101 1001 */ {8, 0x5a, 57}, /* 0101 1010 */ {8, 0x5b, 58}, /* 0101 1011 */ {8, 0x64, 448}, /* 0110 0100 */ {8, 0x65, 512}, /* 0110 0101 */ {8, 0x67, 640}, /* 0110 0111 */ {8, 0x68, 576}, /* 0110 1000 */ {8, 0xa, 47}, /* 0000 1010 */ {8, 0xb, 48}, /* 0000 1011 */ {9, 0x98, 1472}, /* 0100 1100 0 */ {9, 0x99, 1536}, /* 0100 1100 1 */ {9, 0x9a, 1600}, /* 0100 1101 0 */ {9, 0x9b, 1728}, /* 0100 1101 1 */ {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 */ {11, 0x8, 1792}, /* 0000 0001 000 */ {11, 0xc, 1856}, /* 0000 0001 100 */ {11, 0xd, 1920}, /* 0000 0001 101 */ {12, 0x1, -1}, /* 0000 0000 0001 */ {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 */ }; static Tab faxblack[Nfaxtab] = { {2, 0x2, 3}, /* 10 */ {2, 0x3, 2}, /* 11 */ {3, 0x2, 1}, /* 010 */ {3, 0x3, 4}, /* 011 */ {4, 0x2, 6}, /* 0010 */ {4, 0x3, 5}, /* 0011 */ {5, 0x3, 7}, /* 0001 1 */ {6, 0x4, 9}, /* 0001 00 */ {6, 0x5, 8}, /* 0001 01 */ {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, 0x37, 0}, /* 0000 1101 11 */ {10, 0x8, 18}, /* 0000 0010 00 */ {10, 0xf, 64}, /* 0000 0011 11 */ {11, 0x17, 24}, /* 0000 0010 111 */ {11, 0x18, 25}, /* 0000 0011 000 */ {11, 0x28, 23}, /* 0000 0101 000 */ {11, 0x37, 22}, /* 0000 0110 111 */ {11, 0x67, 19}, /* 0000 1100 111 */ {11, 0x68, 20}, /* 0000 1101 000 */ {11, 0x6c, 21}, /* 0000 1101 100 */ {11, 0x8, 1792}, /* 0000 0001 000 */ {11, 0xc, 1856}, /* 0000 0001 100 */ {11, 0xd, 1920}, /* 0000 0001 101 */ {12, 0x1, -1}, /* 0000 0000 0001 */ {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, 0x24, 52}, /* 0000 0010 0100 */ {12, 0x27, 55}, /* 0000 0010 0111 */ {12, 0x28, 56}, /* 0000 0010 1000 */ {12, 0x2b, 59}, /* 0000 0010 1011 */ {12, 0x2c, 60}, /* 0000 0010 1100 */ {12, 0x33, 320}, /* 0000 0011 0011 */ {12, 0x34, 384}, /* 0000 0011 0100 */ {12, 0x35, 448}, /* 0000 0011 0101 */ {12, 0x37, 53}, /* 0000 0011 0111 */ {12, 0x38, 54}, /* 0000 0011 1000 */ {12, 0x52, 50}, /* 0000 0101 0010 */ {12, 0x53, 51}, /* 0000 0101 0011 */ {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, 0x58, 57}, /* 0000 0101 1000 */ {12, 0x59, 58}, /* 0000 0101 1001 */ {12, 0x5a, 61}, /* 0000 0101 1010 */ {12, 0x5b, 256}, /* 0000 0101 1011 */ {12, 0x64, 48}, /* 0000 0110 0100 */ {12, 0x65, 49}, /* 0000 0110 0101 */ {12, 0x66, 62}, /* 0000 0110 0110 */ {12, 0x67, 63}, /* 0000 0110 0111 */ {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, 0x6c, 40}, /* 0000 0110 1100 */ {12, 0x6d, 41}, /* 0000 0110 1101 */ {12, 0xc8, 128}, /* 0000 1100 1000 */ {12, 0xc9, 192}, /* 0000 1100 1001 */ {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, 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, 0xda, 42}, /* 0000 1101 1010 */ {12, 0xdb, 43}, /* 0000 1101 1011 */ {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, 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 */ {13, 0x6c, 512}, /* 0000 0011 0110 0 */ {13, 0x6d, 576}, /* 0000 0011 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 */ }; static Tab faxcodes[Nfaxcodes] = { {1, 0x1, 0}, /* 1 */ {3, 0x1, 0}, /* 001 */ {3, 0x2, 0}, /* 010 */ {3, 0x3, 0}, /* 011 */ {4, 0x1, 0}, /* 0001 */ {6, 0x2, 0}, /* 0000 10 */ {6, 0x3, 0}, /* 0000 11 */ {7, 0x2, 0}, /* 0000 010 */ {7, 0x3, 0}, /* 0000 011 */ {12, 0x1, -1} /* 0000 0000 0001 */ }; static int typesizes[] = {0, 1, 0, 2, 4}; static int vcodeval[] = {0, 0, 0, 1, 0, 0, 2, 3}; static ulong byte2le(uchar *); static ulong byte4le(uchar *); static ulong byte2be(uchar *); static ulong byte4be(uchar *); static void readdata(Tif *, ulong); static void readnbytes(Tif *, ulong); static ulong readbyte(Tif *); static ulong readshort(Tif *); static ulong readlong(Tif *); static int gototif(Tif *, ulong); static int readheader(Tif *); static uchar *nocomp(Tif *); static int getbit1(Fax *); static int getbit2(Fax *); static Tab *findtab(Fax *, int, int, Tab *, int); static Tab *gettab(Fax *, int); static Tab *geteol(Fax *); static int faxfill(Fax *, uchar *, ulong, ulong *, ulong *, ulong, int); static void fillbits(Fax *); static int faxalloclines(Fax *); static Tab *getfax1d(Fax *, uchar *, ulong, ulong *, ulong *, ulong); static Tab *getfax2d(Fax *, uchar *, ulong, ulong *, ulong *, ulong); static int faxstrip(Tif *, Fax *, uchar *, ulong, ulong, ulong *); static uchar *fax(Tif *); static void tabinit(Lzw *); static Code *newcode(Lzw *, Code *); static void listadd(Lzw *, Code *); static Code *tabadd(Lzw *, Code *, Code *); static int getcode(Lzw *); static int wstr(uchar *, ulong, ulong *, Code *, long *); static void predict1(Tif *, uchar *); static void predict8(Tif *, uchar *); static int lzwstrip(Lzw *, uchar *, ulong, ulong *, long); static uchar *lzw(Tif *); static uchar *packbits(Tif *); static int faxdecode(Tif *, Rawimage *, uchar *); static int greydecode(Tif *, Rawimage *, uchar *); static int rgbdecode(Tif *, Rawimage *, uchar *); static int paldecode(Tif *, Rawimage *, uchar *); static int parsefield(Tif *, Fld *); static int readfield(Tif *, Fld *); static int checkfields(Tif *); static int readstrips(Tif *); static Rawimage *decode(Tif *); static void freefields(Tif *); static Rawimage *readslave(Tif *); static ulong byte2le(uchar *buf) { return (buf[1] << 8) | buf[0]; } static ulong byte4le(uchar *buf) { return (byte2le(buf+2) << 16) | byte2le(buf); } static ulong byte2be(uchar *buf) { return (buf[0] << 8) | buf[1]; } static ulong byte4be(uchar *buf) { return (byte2be(buf) << 16) | byte2be(buf+2); } static void readdata(Tif *t, ulong offset) { long n, m; ulong size; if(offset < t->nbuf) offset = t->nbuf; m = offset + 4096 - t->nbuf; size = (m + t->nbuf) * sizeof *t->buf; if(t->buf == nil) { if((t->buf = malloc(size)) == nil) sysfatal("malloc: %r"); } else { if((t->buf = realloc(t->buf, size)) == nil) sysfatal("realloc: %r"); } if((n = Bread(t->fd, t->buf+t->nbuf, m)) < 0) sysfatal("Bread: %r"); if(n != m) t->eof = 1; t->nbuf += n; } static void readnbytes(Tif *t, ulong n) { if(n <= 0 || n > 4) sysfatal("cannot read %lud bytes", n); if(t->n+n > t->nbuf) { if(t->eof) sysfatal("reached end of file"); readdata(t, 0); } memmove(t->tmp, t->buf+t->n, n); t->n += n; } static ulong readbyte(Tif *t) { readnbytes(t, 1); return t->tmp[0]; } static ulong readshort(Tif *t) { readnbytes(t, 2); return (*t->byte2)(t->tmp); } static ulong readlong(Tif *t) { readnbytes(t, 4); return (*t->byte4)(t->tmp); } static int gototif(Tif *t, ulong n) { if(n < 8) { werrstr("offset pointing to header"); return -1; } if(n > t->nbuf) readdata(t, n); t->n = n; return 0; } static int readheader(Tif *t) { uint n; t->end = readshort(t); switch(t->end) { case II: break; case MM: t->byte2 = byte2be; t->byte4 = byte4be; break; default: werrstr("illegal byte order: %#.4x", t->end); return -1; } if((n = readshort(t)) != TIF) { werrstr("illegal tiff magic: %#.4x", n); return -1; } t->off = readlong(t); return gototif(t, t->off); } static uchar * nocomp(Tif *t) { return t->data; } static int getbit1(Fax *f) { int bit; if(f->n >= f->next) return -1; bit = (f->data[f->n] >> f->m) & 0x1; f->m--; if(f->m < 0) { f->n++; f->m = 7; } return bit; } static int getbit2(Fax *f) { int bit; if(f->n >= f->next) return -1; bit = (f->data[f->n] >> f->m) & 0x1; f->m++; if(f->m >= 8) { f->n++; f->m = 0; } return bit; } static Tab * findtab(Fax *f, int code, int len, Tab *tab, int max) { Tab *p; while(f->ntab < max) { p = &tab[f->ntab]; if(p->len > len) break; if(p->code == code) { f->ntab = 0; return p; } f->ntab++; } return nil; } static Tab * gettab(Fax *f, int mode) { int i, n, maxlen, bit, code; Tab *p, *tab; code = 0; if(mode) { n = Nfaxcodes; tab = faxcodes; } else { n = Nfaxtab; tab = f->tab[f->st]; } maxlen = tab[n-1].len; for(i = 1; i <= maxlen; i++) { if((bit = (*f->getbit)(f)) < 0) { f->st = -1; return nil; } code = (code << 1) | bit; if((p = findtab(f, code, i, tab, n)) != nil) return p; } werrstr("code not found"); return nil; } static Tab * geteol(Fax *f) { int i, bit; Tab *p; if(f->eol == nil) { if(f->eolfill) { for(i = 0; i < 4; i++) { if((*f->getbit)(f) < 0) { f->st = -1; return nil; } } } if((p = gettab(f, 0)) == nil || p->run >= 0) { werrstr("first eol"); return nil; } f->eol = p; return p; } for(i = 0; (bit = (*f->getbit)(f)) == 0; i++) ; if(bit < 0) { f->st = -1; return nil; } if(i < 11) { werrstr("eol"); return nil; } return f->eol; } static int faxfill(Fax *f, uchar *data, ulong size, ulong *i, ulong *x, ulong dx, int n) { if((*x += n) > dx) { werrstr("fax row overflow"); return -1; } if((*i += n) > size) return -1; if(f->st != 0) memset(data+*i-n, f->st, n); return 0; } static void fillbits(Fax *f) { if(f->getbit == getbit1) { if(f->m != 7) { f->n++; f->m = 7; } } else { if(f->m != 0) { f->n++; f->m = 0; } } } static int faxalloclines(Fax *f) { f->nl *= 2; f->l1 = realloc(f->l1, f->nl*sizeof *f->l1); if(f->l1 == nil) return -1; f->l2 = realloc(f->l2, f->nl*sizeof *f->l2); if(f->l2 == nil) { free(f->l1); return -1; } return 0; } static Tab * getfax1d(Fax *f, uchar *data, ulong size, ulong *i, ulong *x, ulong dx) { int j, n; Tab *p; for(j = n = 0; *x < dx;) { if((p = gettab(f, 0)) == nil) return nil; if((n = p->run) < 0) { f->l1[j] = dx; return f->eol; } if(faxfill(f, data, size, i, x, dx, n) < 0) return nil; if(n < 64) { f->l1[j++] = *x; f->st ^= 1; } if(j >= f->nl) faxalloclines(f); } if(n >= 64) { f->l1[j] = dx; if((p = gettab(f, 0)) == nil) return nil; if((n = p->run) < 0) return f->eol; if(n != 0) { werrstr("no terminating code"); return nil; } } return nil; } static Tab * getfax2d(Fax *f, uchar *data, ulong size, ulong *i, ulong *x, ulong dx) { int j, k, n, code, len, v; long a0, a1, b1, b2; Tab *p; a0 = -1; for(j = 0; *x < dx;) { for(k = 0;; k++) { b1 = f->l1[k]; if(b1 > a0 && f->st == k%2) break; if(b1 >= dx) break; } if((b2 = b1) < dx) b2 = f->l1[k+1]; if((p = gettab(f, 1)) == nil) return nil; /* early eofb */ if(p->run < 0) { f->st = -1; return nil; } if(j+1 >= f->nl) faxalloclines(f); len = p->len; code = p->code; if(code == 1 && len == 3) { /* horizontal */ for(k = 0; k < 2;) { if((p = gettab(f, 0)) == nil) return nil; if((n = p->run) < 0) { werrstr("2d eol"); return nil; } if(faxfill(f, data, size, i, x, dx, n) < 0) return nil; if(n < 64) { f->l2[j++] = *x; f->st ^= 1; k++; } } } else if(code == 1 && len == 4) { /* pass */ n = b2 - *x; if(faxfill(f, data, size, i, x, dx, n) < 0) return nil; if(*x == dx) f->l2[j++] = *x; } else { /* vertical */ switch(code) { case 1: case 2: v = -vcodeval[len]; break; case 3: v = vcodeval[len]; break; default: werrstr("mode"); return nil; } a1 = b1 + v; n = a1 - *x; if(faxfill(f, data, size, i, x, dx, n) < 0) return nil; f->l2[j++] = *x; f->st ^= 1; } a0 = *x; } memmove(f->l1, f->l2, j*sizeof *f->l1); return nil; } static int faxstrip(Tif *t, Fax *f, uchar *data, ulong size, ulong rows, ulong *i) { int d1; ulong x, y; Tab *p; d1 = t->comp != T6enc; p = nil; for(x = y = 0; x < t->dx || y < rows;) { f->st = 0; if(t->comp == T4enc) { if(p == nil && geteol(f) == nil) { if(f->st >= 0) return -1; break; } if(y > 0) { *i += t->dx - x; if(*i > size) break; } if(t->t4 & 1) { d1 = (*f->getbit)(f); if(d1 < 0) break; } } x = 0; y++; if(d1) { p = getfax1d(f, data, size, i, &x, t->dx); } else { p = getfax2d(f, data, size, i, &x, t->dx); } if(t->comp == Huffman) fillbits(f); if(p == nil && x != t->dx) { if(f->st >= 0) return -1; if(x > t->dx) return -1; break; } } if(*i > size) { werrstr("fax data overflow"); return -1; } return 0; } /* i've encountered t4 images that did not have rtcs */ static uchar * fax(Tif *t) { int m; ulong i, j, datasz, r, dy; uchar *data; Fax f; datasz = t->dx * t->dy * sizeof *data; data = mallocz(datasz, 1); f.nl = t->dx + 1; f.l1 = mallocz(f.nl*sizeof *f.l1, 1); f.l2 = mallocz(f.nl*sizeof *f.l2, 1); if(data == nil || f.l1 == nil || f.l2 == nil) { free(t->data); if(data != nil) free(data); if(f.l1 != nil) free(f.l1); if(f.l2 != nil) free(f.l2); return nil; } if(t->fill == 1) { f.getbit = getbit1; m = 7; } else { f.getbit = getbit2; m = 0; } f.tab[0] = faxwhite; f.tab[1] = faxblack; f.ntab = 0; f.eol = nil; if(t->comp == T4enc && t->t4 & (1<<1)) f.eolfill = 1; else f.eolfill = 0; f.data = t->data; for(i = j = 0, dy = t->dy; i < t->nstrips; i++) { f.l1[0] = t->dx; f.n = t->strips[i]; f.m = m; if(i < t->nstrips-1) f.next = t->strips[i+1]; else f.next = t->ndata; r = dy < t->rows? dy: t->rows; if(faxstrip(t, &f, data, datasz, r, &j) < 0) break; dy -= t->rows; } if(i < t->nstrips) { free(data); data = nil; } free(t->data); free(f.l1); free(f.l2); return data; } static void tabinit(Lzw *l) { l->ntab = Eoicode + 1; l->len = 9; } static Code * newcode(Lzw *l, Code *p) { Code *q; if(p == nil) return nil; if(l->first != nil) { q = l->first; if((l->first = l->first->next) == nil) l->last = nil; } else if((q = malloc(sizeof *q)) == nil) return nil; q->val = p->val; q->next = nil; return q; } static void listadd(Lzw *l, Code *p) { if(p == nil) return; if(l->last != nil) l->last->next = p; else l->first = l->last = p; while(l->last->next != nil) l->last = l->last->next; } static Code * tabadd(Lzw *l, Code *p, Code *q) { Code *r, *s; r = s = &l->tab[l->ntab]; switch(l->ntab) { case 510: case 1022: case 2046: l->len++; break; default: break; } if(l->ntab++ >= Tabsz-3) { werrstr("lzw table full"); return nil; } s->val = p->val; while((p = p->next) != nil) { if(s->next != nil) s->next->val = p->val; else if((s->next = newcode(l, p)) == nil) return nil; s = s->next; } if(s->next != nil) { s->next->val = q->val; s = s->next; if(s->next != nil) { listadd(l, s->next); s->next = nil; } } else if((s->next = newcode(l, q)) == nil) return nil; return r; } static int getcode(Lzw *l) { int i, c, code; if(l->n >= l->next) { eof: werrstr("lzw eof"); return -1; } code = 0; for(i = l->len-1; i >= 0; i--) { c = (l->data[l->n] >> l->m) & 0x1; code |= c << i; l->m--; if(l->m < 0) { l->m = 7; if(++l->n >= l->next && i > 0) goto eof; } } return code; } static int wstr(uchar *data, ulong size, ulong *i, Code *p, long *striplen) { for(; p != nil; p = p->next, ++*i, --*striplen) { if(*i >= size || *striplen < 0) { werrstr("lzw overflow"); return -1; } data[*i] = p->val; } return 0; } static void predict1(Tif *t, uchar *data) { int bpl, pix, b[8], d, m, n, j; ulong x, y; d = t->depth; bpl = bytesperline(Rect(0, 0, t->dx, t->dy), d); m = (1 << d) - 1; n = 8 / d; for(y = 0; y < t->dy; y++) { for(x = 0; x < bpl; x++, data++) { pix = *data; b[n-1] = (pix >> d*(n-1)) & m; if(x > 0) b[n-1] += *(data-1) & m; for(j = n-2; j >= 0; j--) { b[j] = (pix >> d*j) & m; b[j] += b[j+1]; } for(j = pix = 0; j < n; j++) pix |= (b[j] & m) << d*j; *data = pix; } } } static void predict8(Tif *t, uchar *data) { ulong j, s, x, y; s = t->samples; for(y = 0; y < t->dy; y++) { for(x = 1, data += s; x < t->dx; x++) { for(j = 0; j < s; j++, data++) *data += *(data-s); } } } static int lzwstrip(Lzw *l, uchar *data, ulong size, ulong *i, long striplen) { int c, oc; Code *p, *q; if((c = getcode(l)) != Clrcode) { werrstr("clear code"); return -1; } for(oc = -1; c != Eoicode;) { if(c < 0) return -1; if(c == Clrcode) { if(oc >= 0) tabinit(l); if((c = getcode(l)) == Eoicode) break; if(c < 0) return -1; if(c >= l->ntab) { werrstr("table overflow"); return -1; } if(wstr(data, size, i, &l->tab[c], &striplen) < 0) return -1; } else if(c < l->ntab) { p = &l->tab[c]; if(wstr(data, size, i, p, &striplen) < 0) return -1; q = &l->tab[oc]; if(tabadd(l, q, p) == nil) return -1; } else if(c == l->ntab) { q = &l->tab[oc]; if((p = tabadd(l, q, q)) == nil) return -1; if(wstr(data, size, i, p, &striplen) < 0) return -1; } else { werrstr("table overflow"); return -1; } if(striplen <= 0) break; oc = c; c = getcode(l); } return 0; } static uchar * lzw(Tif *t) { ulong i, j, size, r, dy; long striplen; uchar *data; Lzw l; Code *p, *q; size = ((t->dx*t->dy*t->depth + 7) / 8) * sizeof *data; if((data = malloc(size)) == nil) { free(t->data); return nil; } for(i = 0; i < Tabsz; i++) { l.tab[i].val = i; l.tab[i].next = nil; } l.data = t->data; l.first = l.last = nil; for(i = j = 0, dy = t->dy; i < t->nstrips; i++) { tabinit(&l); l.n = t->strips[i]; l.m = 7; if(i < t->nstrips-1) l.next = t->strips[i+1]; else l.next = t->ndata; r = dy < t->rows? dy: t->rows; striplen = (t->dx*r*t->depth + 7) / 8; if(lzwstrip(&l, data, size, &j, striplen) < 0) break; dy -= t->rows; } if(i < t->nstrips) { free(data); data = nil; } for(i = 0; i < Tabsz; i++) { for(p = l.tab[i].next; (q = p) != nil;) { p = p->next; free(q); } } for(p = l.first; (q = p) != nil;) { p = p->next; free(q); } free(t->data); if(data != nil && t->predictor == 2) { if(t->depth < 8) predict1(t, data); else predict8(t, data); } return data; } static uchar * packbits(Tif *t) { char n; ulong i, j, k, size; uchar *data; size = ((t->dx*t->dy*t->depth + 7) / 8) * sizeof *data; if((data = malloc(size)) == nil) { free(t->data); return nil; } for(i = 0, j = 0; i < t->ndata;) { n = (char)t->data[i++]; if(n >= 0) { k = n + 1; if((j += k) > size || (i += k) > t->ndata) break; memmove(data+j-k, t->data+i-k, k); } else if(n > -128 && n < 0) { k = j - n + 1; if(k > size || i >= t->ndata) break; for(; j < k; j++) data[j] = t->data[i]; i++; } } if(i < t->ndata) { werrstr("packbits overflow"); free(data); data = nil; } free(t->data); return data; } static int faxdecode(Tif *t, Rawimage *im, uchar *data) { ulong n; for(n = 0; n < im->chanlen; n++) { if(t->photo == Whitezero) data[n] ^= 1; im->chans[0][n] = data[n] * 0xff; } return 0; } static int greydecode(Tif *t, Rawimage *im, uchar *data) { int pix, pmask, xmask; ulong i, n, x, y; pmask = (1 << t->depth) - 1; xmask = 7 >> log2[t->depth]; for(y = 0, n = 0; y < t->dy; y++) { i = y * bytesperline(im->r, t->depth); for(x = 0; x < t->dx; x++, n++) { if(n >= im->chanlen) { werrstr("grey overflow"); return -1; } pix = (data[i] >> t->depth*((xmask - x) & xmask)) & pmask; if(((x + 1) & xmask) == 0) i++; if(t->photo == Whitezero) pix ^= pmask; pix = (pix * 0xff) / pmask; im->chans[0][n] = pix; } } return 0; } static int rgbdecode(Tif *t, Rawimage *im, uchar *data) { ulong i, n, x, y; for(y = 0, n = 0; y < t->dy; y++) { for(x = 0; x < t->dx; x++, n += 3) { if(n >= im->chanlen) { werrstr("rgb overflow"); return -1; } i = (y*t->dx + x) * 3; im->chans[0][n] = data[i+2]; im->chans[0][n+1] = data[i+1]; im->chans[0][n+2] = data[i]; } } return 0; } static int paldecode(Tif *t, Rawimage *im, uchar *data) { int pix, pmask, xmask; ulong i, n, x, y, *r, *g, *b, max; pmask = (1 << t->depth) - 1; xmask = 7 >> log2[t->depth]; for(i = 0, max = 1; i < t->ncolor; i++) { if(t->color[i] > max) max = t->color[i]; } for(i = 0; i < t->ncolor; i++) t->color[i] = (t->color[i] * 0xff) / max; r = t->color; g = r + pmask + 1; b = g + pmask + 1; for(y = 0, n = 0; y < t->dy; y++) { i = y * bytesperline(im->r, t->depth); for(x = 0; x < t->dx; x++, n += 3) { if(n >= im->chanlen) { werrstr("palette overflow"); return -1; } pix = (data[i] >> t->depth*((xmask - x) & xmask)) & pmask; if(((x + 1) & xmask) == 0) i++; im->chans[0][n] = b[pix]; im->chans[0][n+1] = g[pix]; im->chans[0][n+2] = r[pix]; } } return 0; } static int parsefield(Tif *t, Fld *f) { ulong v; v = f->val[0]; switch(f->tag) { case Width: t->dx = v; break; case Length: t->dy = v; break; case Bits: t->depth = v; if(f->cnt == 3) t->depth += f->val[1] + f->val[2]; break; case Compression: t->comp = v; break; case Photometric: t->photo = v; switch(t->photo) { case Whitezero: case Blackzero: t->decode = greydecode; break; case Rgb: t->decode = rgbdecode; break; case Palette: t->decode = paldecode; break; default: break; } break; case Strips: t->strips = f->val; t->nstrips = f->cnt; break; case Fill: t->fill = v; break; case Orientation: t->orientation = v; break; case Samples: t->samples = v; break; case Rows: t->rows = v; break; case Counts: t->counts = f->val; t->ncounts = f->cnt; break; case Planar: t->planar = v; break; case T4opts: t->t4 = v; break; case T6opts: t->t6 = v; break; case Predictor: t->predictor = v; break; case Color: t->color = f->val; t->ncolor = f->cnt; break; default: werrstr("shouldn't reach"); return -1; } return 0; } static int readfield(Tif *t, Fld *f) { int size; ulong i, j, n, off; ulong (*readval)(Tif *); f->tag = readshort(t); f->typ = readshort(t); f->cnt = readlong(t); f->val = nil; switch(f->tag) { case Width: case Length: case Compression: case Photometric: case Fill: case Orientation: case Samples: case Rows: case Planar: case T4opts: case T6opts: case Predictor: if(f->cnt != 1) { werrstr("field count"); return -1; } break; case Bits: if(f->cnt != 1 && f->cnt != 3) { werrstr("field count"); return -1; } break; case Strips: case Counts: case Color: break; default: readlong(t); return 0; } switch(f->typ) { case Byte: readval = readbyte; break; case Short: readval = readshort; break; case Long: readval = readlong; break; default: werrstr("unsupported type\n"); return -1; } if((f->val = malloc(f->cnt*sizeof *f->val)) == nil) return -1; size = typesizes[f->typ]; if((n = size*f->cnt) <= 4) { for(i = 0; i < f->cnt; i++) f->val[i] = (*readval)(t); f->off = 0x0; f->nval = i; for(j = n; j < 4; j += size) (*readval)(t); } else { f->off = readlong(t); off = t->n; if(gototif(t, f->off) < 0) return -1; for(i = 0; i < f->cnt; i++) f->val[i] = (*readval)(t); f->nval = i; if(gototif(t, off) < 0) return -1; } return parsefield(t, f); } static int checkfields(Tif *t) { ulong n, size; if(t->dx == 0) { werrstr("image width"); return -1; } if(t->dy == 0) { werrstr("image length"); return -1; } switch(t->depth) { case 1: case 4: case 8: case 24: break; default: werrstr("bits per sample"); return -1; } switch(t->comp) { case Nocomp: t->uncompress = nocomp; break; case Huffman: case T4enc: case T6enc: t->uncompress = fax; if(t->decode != nil) t->decode = faxdecode; if((t->comp == T4enc && t->t4 & (1<<1)) || (t->comp == T6enc && t->t6 & (1<<1))) { werrstr("uncompressed mode"); return -1; } break; case Lzwenc: t->uncompress = lzw; break; case Packbits: t->uncompress = packbits; break; default: werrstr("compression"); return -1; } if(t->decode == nil) { werrstr("photometric interpretation"); return -1; } if(t->depth > 1 && (t->comp == Huffman || t->comp == T4enc || t->comp == T6enc)) { werrstr("compression"); return -1; } if(t->fill != 1 && t->fill != 2) { werrstr("fill order"); return -1; } if(t->fill == 2 && t->depth != 1) { werrstr("depth should be 1 with fill order 2"); return -1; } if(t->orientation != 1) { werrstr("orientation"); return -1; } if(t->rows == 0) { werrstr("rows per strip"); return -1; } n = (t->dy + t->rows - 1) / t->rows; if(t->strips == nil || t->nstrips != n) { werrstr("strip offsets"); return -1; } if(t->samples == 1 && t->photo == Rgb) { werrstr("not enough samples per pixel"); return -1; } if(t->samples == 3 && t->photo != Rgb) { werrstr("too many samples per pixel"); return -1; } if(t->samples != 1 && t->samples != 3) { werrstr("samples per pixel"); return -1; } /* * strip byte counts should not be missing, * but we can guess correctly in this case */ size = sizeof *t->counts; if(t->counts == nil && t->comp == Nocomp && t->nstrips == 1 && (t->counts = malloc(size)) != nil) { t->counts[0] = (t->dx*t->dy*t->depth + 7) / 8; t->ncounts = t->nstrips; } if(t->counts == nil || t->ncounts != t->nstrips) { werrstr("strip byte counts"); return -1; } if(t->planar != 1) { werrstr("planar configuration"); return -1; } if(t->photo == Palette && (t->color == nil || t->ncolor != 3*(1<<t->depth))) { werrstr("color map"); return -1; } return 0; } static int readstrips(Tif *t) { int i, j, n; ulong off; t->data = nil; t->ndata = 0; for(i = 0; i < t->nstrips; i++) t->ndata += t->counts[i]; if(t->ndata == 0) { werrstr("no image data"); return -1; } if((t->data = malloc(t->ndata*sizeof *t->data)) == nil) return -1; off = t->n; for(i = n = 0; i < t->nstrips; i++) { if(gototif(t, t->strips[i]) < 0) return -1; /* * we store each strip's offset in t->data * in order to skip the final rtc or eofb * during fax decoding. t->strips is used * to save on memory allocation. these * offsets are also used in lzw as a * preventive measure. */ t->strips[i] = n; for(j = 0; j < t->counts[i]; j++, n++) t->data[n] = readbyte(t); } return gototif(t, off); } static Rawimage * decode(Tif *t) { ulong size; uchar *data; Rawimage *im; if((im = malloc(sizeof *im)) == nil) return nil; im->r = Rect(0, 0, t->dx, t->dy); im->cmap = nil; im->cmaplen = 0; im->chanlen = t->dx * t->dy; if(t->photo == Rgb || t->photo == Palette) { im->chandesc = CRGB24; im->chanlen *= 3; } else im->chandesc = CY; im->nchans = 1; size = im->chanlen * sizeof *im->chans[0]; if((im->chans[0] = malloc(size)) == nil) return nil; /* unused members */ im->fields = 0; im->gifflags = 0; im->gifdelay = 0; im->giftrindex = 0; im->gifloopcount = 1; if((data = (*t->uncompress)(t)) == nil) return nil; if((*t->decode)(t, im, data) < 0) { free(im->chans[0]); free(im); im = nil; } free(data); return im; } static void freefields(Tif *t) { uint i; for(i = 0; i < t->nfld; i++) { if(t->fld[i].val != nil) free(t->fld[i].val); } free(t->fld); } static Rawimage * readslave(Tif *t) { uint i, j; Rawimage *r; if(readheader(t) < 0) return nil; if((t->nfld = readshort(t)) <= 0) { werrstr("illegal field number: %#.4x", t->nfld); return nil; } if((t->fld = malloc(t->nfld*sizeof *t->fld)) == nil) return nil; for(i = 0; i < t->nfld; i++) { if(readfield(t, &t->fld[i]) < 0) { if(t->fld[i].val != nil) free(t->fld[i].val); break; } } if(i < t->nfld) { for(j = 0; j < i; j++) { if(t->fld[j].val != nil) free(t->fld[j].val); } free(t->fld); return nil; } readlong(t); if(checkfields(t) < 0) { freefields(t); return nil; } if(readstrips(t) < 0) { freefields(t); if(t->data != nil) free(t->data); return nil; } free(t->buf); r = decode(t); freefields(t); return r; } Rawimage ** Breadtif(Biobuf *b, int colorspace) { Rawimage **array, *r; Tif *t; if(colorspace != CRGB24) { werrstr("unknown color space: %d", colorspace); return nil; } if((t = malloc(sizeof *t)) == nil) return nil; if((array = malloc(2*sizeof *array)) == nil) return nil; t->fd = b; t->buf = nil; t->nbuf = t->eof = t->n = 0; /* order doesn't matter for the first two bytes */ t->byte2 = byte2le; t->byte4 = byte4le; /* defaults */ t->dx = 0; t->dy = 0; t->depth = 1; t->comp = 1; t->uncompress = nil; t->photo = 0; t->decode = nil; t->fill = 1; t->orientation = 1; t->strips = nil; t->nstrips = 0; t->samples = 1; t->rows = 0xffffffff; /* entire image is one strip */ t->counts = nil; t->ncounts = 0; t->planar = 1; t->t4 = 0; t->t6 = 0; t->predictor = 1; t->color = nil; t->ncolor = 0; r = readslave(t); free(t); array[0] = r; array[1] = nil; return array; } Rawimage ** readtif(int fd, int colorspace) { Rawimage **a; Biobuf b; if(Binit(&b, fd, OREAD) < 0) return nil; a = Breadtif(&b, colorspace); Bterm(&b); return a; }