diff options
| author | Antonin Descampe <antonin@gmail.com> | 2011-03-20 22:45:24 +0000 |
|---|---|---|
| committer | Antonin Descampe <antonin@gmail.com> | 2011-03-20 22:45:24 +0000 |
| commit | 19f9147e1076d83dd1111609ca93a01085dbfb4f (patch) | |
| tree | 8ba9fe2ac562b474f627c3ae8c90eefb7d0435a3 /thirdparty/libtiff/tif_lzw.c | |
| parent | 6bda73eeb2134963f64c3d67fdd11c1304cb14f9 (diff) | |
Removed the libs directory containing win32 compiled versions of libpng, libtiff and liblcms. Added a thirdparty directory to include main source files of libtiff, libpng, libz and liblcms to enable support of these formats in the codec executables. CMake will try to statically build these libraries if they are not found on the system. Note that these third party libraries are not required to build libopenjpeg (which has no dependencies).
Diffstat (limited to 'thirdparty/libtiff/tif_lzw.c')
| -rw-r--r-- | thirdparty/libtiff/tif_lzw.c | 1129 |
1 files changed, 1129 insertions, 0 deletions
diff --git a/thirdparty/libtiff/tif_lzw.c b/thirdparty/libtiff/tif_lzw.c new file mode 100644 index 00000000..d4238663 --- /dev/null +++ b/thirdparty/libtiff/tif_lzw.c @@ -0,0 +1,1129 @@ +/* $Id: tif_lzw.c,v 1.29.2.6 2010-06-08 18:50:42 bfriesen Exp $ */ + +/* + * Copyright (c) 1988-1997 Sam Leffler + * Copyright (c) 1991-1997 Silicon Graphics, Inc. + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that (i) the above copyright notices and this permission notice appear in + * all copies of the software and related documentation, and (ii) the names of + * Sam Leffler and Silicon Graphics may not be used in any advertising or + * publicity relating to the software without the specific, prior written + * permission of Sam Leffler and Silicon Graphics. + * + * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, + * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY + * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + * + * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR + * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, + * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, + * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF + * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#include "tiffiop.h" +#ifdef LZW_SUPPORT +/* + * TIFF Library. + * Rev 5.0 Lempel-Ziv & Welch Compression Support + * + * This code is derived from the compress program whose code is + * derived from software contributed to Berkeley by James A. Woods, + * derived from original work by Spencer Thomas and Joseph Orost. + * + * The original Berkeley copyright notice appears below in its entirety. + */ +#include "tif_predict.h" + +#include <stdio.h> + +/* + * NB: The 5.0 spec describes a different algorithm than Aldus + * implements. Specifically, Aldus does code length transitions + * one code earlier than should be done (for real LZW). + * Earlier versions of this library implemented the correct + * LZW algorithm, but emitted codes in a bit order opposite + * to the TIFF spec. Thus, to maintain compatibility w/ Aldus + * we interpret MSB-LSB ordered codes to be images written w/ + * old versions of this library, but otherwise adhere to the + * Aldus "off by one" algorithm. + * + * Future revisions to the TIFF spec are expected to "clarify this issue". + */ +#define LZW_COMPAT /* include backwards compatibility code */ +/* + * Each strip of data is supposed to be terminated by a CODE_EOI. + * If the following #define is included, the decoder will also + * check for end-of-strip w/o seeing this code. This makes the + * library more robust, but also slower. + */ +#define LZW_CHECKEOS /* include checks for strips w/o EOI code */ + +#define MAXCODE(n) ((1L<<(n))-1) +/* + * The TIFF spec specifies that encoded bit + * strings range from 9 to 12 bits. + */ +#define BITS_MIN 9 /* start with 9 bits */ +#define BITS_MAX 12 /* max of 12 bit strings */ +/* predefined codes */ +#define CODE_CLEAR 256 /* code to clear string table */ +#define CODE_EOI 257 /* end-of-information code */ +#define CODE_FIRST 258 /* first free code entry */ +#define CODE_MAX MAXCODE(BITS_MAX) +#define HSIZE 9001L /* 91% occupancy */ +#define HSHIFT (13-8) +#ifdef LZW_COMPAT +/* NB: +1024 is for compatibility with old files */ +#define CSIZE (MAXCODE(BITS_MAX)+1024L) +#else +#define CSIZE (MAXCODE(BITS_MAX)+1L) +#endif + +/* + * State block for each open TIFF file using LZW + * compression/decompression. Note that the predictor + * state block must be first in this data structure. + */ +typedef struct { + TIFFPredictorState predict; /* predictor super class */ + + unsigned short nbits; /* # of bits/code */ + unsigned short maxcode; /* maximum code for lzw_nbits */ + unsigned short free_ent; /* next free entry in hash table */ + long nextdata; /* next bits of i/o */ + long nextbits; /* # of valid bits in lzw_nextdata */ + + int rw_mode; /* preserve rw_mode from init */ +} LZWBaseState; + +#define lzw_nbits base.nbits +#define lzw_maxcode base.maxcode +#define lzw_free_ent base.free_ent +#define lzw_nextdata base.nextdata +#define lzw_nextbits base.nextbits + +/* + * Encoding-specific state. + */ +typedef uint16 hcode_t; /* codes fit in 16 bits */ +typedef struct { + long hash; + hcode_t code; +} hash_t; + +/* + * Decoding-specific state. + */ +typedef struct code_ent { + struct code_ent *next; + unsigned short length; /* string len, including this token */ + unsigned char value; /* data value */ + unsigned char firstchar; /* first token of string */ +} code_t; + +typedef int (*decodeFunc)(TIFF*, tidata_t, tsize_t, tsample_t); + +typedef struct { + LZWBaseState base; + + /* Decoding specific data */ + long dec_nbitsmask; /* lzw_nbits 1 bits, right adjusted */ + long dec_restart; /* restart count */ +#ifdef LZW_CHECKEOS + long dec_bitsleft; /* available bits in raw data */ +#endif + decodeFunc dec_decode; /* regular or backwards compatible */ + code_t* dec_codep; /* current recognized code */ + code_t* dec_oldcodep; /* previously recognized code */ + code_t* dec_free_entp; /* next free entry */ + code_t* dec_maxcodep; /* max available entry */ + code_t* dec_codetab; /* kept separate for small machines */ + + /* Encoding specific data */ + int enc_oldcode; /* last code encountered */ + long enc_checkpoint; /* point at which to clear table */ +#define CHECK_GAP 10000 /* enc_ratio check interval */ + long enc_ratio; /* current compression ratio */ + long enc_incount; /* (input) data bytes encoded */ + long enc_outcount; /* encoded (output) bytes */ + tidata_t enc_rawlimit; /* bound on tif_rawdata buffer */ + hash_t* enc_hashtab; /* kept separate for small machines */ +} LZWCodecState; + +#define LZWState(tif) ((LZWBaseState*) (tif)->tif_data) +#define DecoderState(tif) ((LZWCodecState*) LZWState(tif)) +#define EncoderState(tif) ((LZWCodecState*) LZWState(tif)) + +static int LZWDecode(TIFF*, tidata_t, tsize_t, tsample_t); +#ifdef LZW_COMPAT +static int LZWDecodeCompat(TIFF*, tidata_t, tsize_t, tsample_t); +#endif +static void cl_hash(LZWCodecState*); + +/* + * LZW Decoder. + */ + +#ifdef LZW_CHECKEOS +/* + * This check shouldn't be necessary because each + * strip is suppose to be terminated with CODE_EOI. + */ +#define NextCode(_tif, _sp, _bp, _code, _get) { \ + if ((_sp)->dec_bitsleft < nbits) { \ + TIFFWarningExt(_tif->tif_clientdata, _tif->tif_name, \ + "LZWDecode: Strip %d not terminated with EOI code", \ + _tif->tif_curstrip); \ + _code = CODE_EOI; \ + } else { \ + _get(_sp,_bp,_code); \ + (_sp)->dec_bitsleft -= nbits; \ + } \ +} +#else +#define NextCode(tif, sp, bp, code, get) get(sp, bp, code) +#endif + +static int +LZWSetupDecode(TIFF* tif) +{ + LZWCodecState* sp = DecoderState(tif); + static const char module[] = " LZWSetupDecode"; + int code; + + if( sp == NULL ) + { + /* + * Allocate state block so tag methods have storage to record + * values. + */ + tif->tif_data = (tidata_t) _TIFFmalloc(sizeof(LZWCodecState)); + if (tif->tif_data == NULL) + { + TIFFErrorExt(tif->tif_clientdata, "LZWPreDecode", "No space for LZW state block"); + return (0); + } + + DecoderState(tif)->dec_codetab = NULL; + DecoderState(tif)->dec_decode = NULL; + + /* + * Setup predictor setup. + */ + (void) TIFFPredictorInit(tif); + + sp = DecoderState(tif); + } + + assert(sp != NULL); + + if (sp->dec_codetab == NULL) { + sp->dec_codetab = (code_t*)_TIFFmalloc(CSIZE*sizeof (code_t)); + if (sp->dec_codetab == NULL) { + TIFFErrorExt(tif->tif_clientdata, module, + "No space for LZW code table"); + return (0); + } + /* + * Pre-load the table. + */ + code = 255; + do { + sp->dec_codetab[code].value = code; + sp->dec_codetab[code].firstchar = code; + sp->dec_codetab[code].length = 1; + sp->dec_codetab[code].next = NULL; + } while (code--); + /* + * Zero-out the unused entries + */ + _TIFFmemset(&sp->dec_codetab[CODE_CLEAR], 0, + (CODE_FIRST - CODE_CLEAR) * sizeof (code_t)); + } + return (1); +} + +/* + * Setup state for decoding a strip. + */ +static int +LZWPreDecode(TIFF* tif, tsample_t s) +{ + LZWCodecState *sp = DecoderState(tif); + + (void) s; + assert(sp != NULL); + if( sp->dec_codetab == NULL ) + { + tif->tif_setupdecode( tif ); + } + + /* + * Check for old bit-reversed codes. + */ + if (tif->tif_rawdata[0] == 0 && (tif->tif_rawdata[1] & 0x1)) { +#ifdef LZW_COMPAT + if (!sp->dec_decode) { + TIFFWarningExt(tif->tif_clientdata, tif->tif_name, + "Old-style LZW codes, convert file"); + /* + * Override default decoding methods with + * ones that deal with the old coding. + * Otherwise the predictor versions set + * above will call the compatibility routines + * through the dec_decode method. + */ + tif->tif_decoderow = LZWDecodeCompat; + tif->tif_decodestrip = LZWDecodeCompat; + tif->tif_decodetile = LZWDecodeCompat; + /* + * If doing horizontal differencing, must + * re-setup the predictor logic since we + * switched the basic decoder methods... + */ + (*tif->tif_setupdecode)(tif); + sp->dec_decode = LZWDecodeCompat; + } + sp->lzw_maxcode = MAXCODE(BITS_MIN); +#else /* !LZW_COMPAT */ + if (!sp->dec_decode) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "Old-style LZW codes not supported"); + sp->dec_decode = LZWDecode; + } + return (0); +#endif/* !LZW_COMPAT */ + } else { + sp->lzw_maxcode = MAXCODE(BITS_MIN)-1; + sp->dec_decode = LZWDecode; + } + sp->lzw_nbits = BITS_MIN; + sp->lzw_nextbits = 0; + sp->lzw_nextdata = 0; + + sp->dec_restart = 0; + sp->dec_nbitsmask = MAXCODE(BITS_MIN); +#ifdef LZW_CHECKEOS + sp->dec_bitsleft = tif->tif_rawcc << 3; +#endif + sp->dec_free_entp = sp->dec_codetab + CODE_FIRST; + /* + * Zero entries that are not yet filled in. We do + * this to guard against bogus input data that causes + * us to index into undefined entries. If you can + * come up with a way to safely bounds-check input codes + * while decoding then you can remove this operation. + */ + _TIFFmemset(sp->dec_free_entp, 0, (CSIZE-CODE_FIRST)*sizeof (code_t)); + sp->dec_oldcodep = &sp->dec_codetab[-1]; + sp->dec_maxcodep = &sp->dec_codetab[sp->dec_nbitsmask-1]; + return (1); +} + +/* + * Decode a "hunk of data". + */ +#define GetNextCode(sp, bp, code) { \ + nextdata = (nextdata<<8) | *(bp)++; \ + nextbits += 8; \ + if (nextbits < nbits) { \ + nextdata = (nextdata<<8) | *(bp)++; \ + nextbits += 8; \ + } \ + code = (hcode_t)((nextdata >> (nextbits-nbits)) & nbitsmask); \ + nextbits -= nbits; \ +} + +static void +codeLoop(TIFF* tif) +{ + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Bogus encoding, loop in the code table; scanline %d", + tif->tif_row); +} + +static int +LZWDecode(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s) +{ + LZWCodecState *sp = DecoderState(tif); + char *op = (char*) op0; + long occ = (long) occ0; + char *tp; + unsigned char *bp; + hcode_t code; + int len; + long nbits, nextbits, nextdata, nbitsmask; + code_t *codep, *free_entp, *maxcodep, *oldcodep; + + (void) s; + assert(sp != NULL); + assert(sp->dec_codetab != NULL); + /* + * Restart interrupted output operation. + */ + if (sp->dec_restart) { + long residue; + + codep = sp->dec_codep; + residue = codep->length - sp->dec_restart; + if (residue > occ) { + /* + * Residue from previous decode is sufficient + * to satisfy decode request. Skip to the + * start of the decoded string, place decoded + * values in the output buffer, and return. + */ + sp->dec_restart += occ; + do { + codep = codep->next; + } while (--residue > occ && codep); + if (codep) { + tp = op + occ; + do { + *--tp = codep->value; + codep = codep->next; + } while (--occ && codep); + } + return (1); + } + /* + * Residue satisfies only part of the decode request. + */ + op += residue, occ -= residue; + tp = op; + do { + int t; + --tp; + t = codep->value; + codep = codep->next; + *tp = t; + } while (--residue && codep); + sp->dec_restart = 0; + } + + bp = (unsigned char *)tif->tif_rawcp; + nbits = sp->lzw_nbits; + nextdata = sp->lzw_nextdata; + nextbits = sp->lzw_nextbits; + nbitsmask = sp->dec_nbitsmask; + oldcodep = sp->dec_oldcodep; + free_entp = sp->dec_free_entp; + maxcodep = sp->dec_maxcodep; + + while (occ > 0) { + NextCode(tif, sp, bp, code, GetNextCode); + if (code == CODE_EOI) + break; + if (code == CODE_CLEAR) { + free_entp = sp->dec_codetab + CODE_FIRST; + _TIFFmemset(free_entp, 0, + (CSIZE - CODE_FIRST) * sizeof (code_t)); + nbits = BITS_MIN; + nbitsmask = MAXCODE(BITS_MIN); + maxcodep = sp->dec_codetab + nbitsmask-1; + NextCode(tif, sp, bp, code, GetNextCode); + if (code == CODE_EOI) + break; + if (code == CODE_CLEAR) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + *op++ = (char)code, occ--; + oldcodep = sp->dec_codetab + code; + continue; + } + codep = sp->dec_codetab + code; + + /* + * Add the new entry to the code table. + */ + if (free_entp < &sp->dec_codetab[0] || + free_entp >= &sp->dec_codetab[CSIZE]) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + + free_entp->next = oldcodep; + if (free_entp->next < &sp->dec_codetab[0] || + free_entp->next >= &sp->dec_codetab[CSIZE]) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + free_entp->firstchar = free_entp->next->firstchar; + free_entp->length = free_entp->next->length+1; + free_entp->value = (codep < free_entp) ? + codep->firstchar : free_entp->firstchar; + if (++free_entp > maxcodep) { + if (++nbits > BITS_MAX) /* should not happen */ + nbits = BITS_MAX; + nbitsmask = MAXCODE(nbits); + maxcodep = sp->dec_codetab + nbitsmask-1; + } + oldcodep = codep; + if (code >= 256) { + /* + * Code maps to a string, copy string + * value to output (written in reverse). + */ + if(codep->length == 0) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Wrong length of decoded string: " + "data probably corrupted at scanline %d", + tif->tif_row); + return (0); + } + if (codep->length > occ) { + /* + * String is too long for decode buffer, + * locate portion that will fit, copy to + * the decode buffer, and setup restart + * logic for the next decoding call. + */ + sp->dec_codep = codep; + do { + codep = codep->next; + } while (codep && codep->length > occ); + if (codep) { + sp->dec_restart = occ; + tp = op + occ; + do { + *--tp = codep->value; + codep = codep->next; + } while (--occ && codep); + if (codep) + codeLoop(tif); + } + break; + } + len = codep->length; + tp = op + len; + do { + int t; + --tp; + t = codep->value; + codep = codep->next; + *tp = t; + } while (codep && tp > op); + if (codep) { + codeLoop(tif); + break; + } + op += len, occ -= len; + } else + *op++ = (char)code, occ--; + } + + tif->tif_rawcp = (tidata_t) bp; + sp->lzw_nbits = (unsigned short) nbits; + sp->lzw_nextdata = nextdata; + sp->lzw_nextbits = nextbits; + sp->dec_nbitsmask = nbitsmask; + sp->dec_oldcodep = oldcodep; + sp->dec_free_entp = free_entp; + sp->dec_maxcodep = maxcodep; + + if (occ > 0) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Not enough data at scanline %d (short %ld bytes)", + tif->tif_row, occ); + return (0); + } + return (1); +} + +#ifdef LZW_COMPAT +/* + * Decode a "hunk of data" for old images. + */ +#define GetNextCodeCompat(sp, bp, code) { \ + nextdata |= (unsigned long) *(bp)++ << nextbits; \ + nextbits += 8; \ + if (nextbits < nbits) { \ + nextdata |= (unsigned long) *(bp)++ << nextbits;\ + nextbits += 8; \ + } \ + code = (hcode_t)(nextdata & nbitsmask); \ + nextdata >>= nbits; \ + nextbits -= nbits; \ +} + +static int +LZWDecodeCompat(TIFF* tif, tidata_t op0, tsize_t occ0, tsample_t s) +{ + LZWCodecState *sp = DecoderState(tif); + char *op = (char*) op0; + long occ = (long) occ0; + char *tp; + unsigned char *bp; + int code, nbits; + long nextbits, nextdata, nbitsmask; + code_t *codep, *free_entp, *maxcodep, *oldcodep; + + (void) s; + assert(sp != NULL); + /* + * Restart interrupted output operation. + */ + if (sp->dec_restart) { + long residue; + + codep = sp->dec_codep; + residue = codep->length - sp->dec_restart; + if (residue > occ) { + /* + * Residue from previous decode is sufficient + * to satisfy decode request. Skip to the + * start of the decoded string, place decoded + * values in the output buffer, and return. + */ + sp->dec_restart += occ; + do { + codep = codep->next; + } while (--residue > occ); + tp = op + occ; + do { + *--tp = codep->value; + codep = codep->next; + } while (--occ); + return (1); + } + /* + * Residue satisfies only part of the decode request. + */ + op += residue, occ -= residue; + tp = op; + do { + *--tp = codep->value; + codep = codep->next; + } while (--residue); + sp->dec_restart = 0; + } + + bp = (unsigned char *)tif->tif_rawcp; + nbits = sp->lzw_nbits; + nextdata = sp->lzw_nextdata; + nextbits = sp->lzw_nextbits; + nbitsmask = sp->dec_nbitsmask; + oldcodep = sp->dec_oldcodep; + free_entp = sp->dec_free_entp; + maxcodep = sp->dec_maxcodep; + + while (occ > 0) { + NextCode(tif, sp, bp, code, GetNextCodeCompat); + if (code == CODE_EOI) + break; + if (code == CODE_CLEAR) { + free_entp = sp->dec_codetab + CODE_FIRST; + _TIFFmemset(free_entp, 0, + (CSIZE - CODE_FIRST) * sizeof (code_t)); + nbits = BITS_MIN; + nbitsmask = MAXCODE(BITS_MIN); + maxcodep = sp->dec_codetab + nbitsmask; + NextCode(tif, sp, bp, code, GetNextCodeCompat); + if (code == CODE_EOI) + break; + if (code == CODE_CLEAR) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecode: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + *op++ = code, occ--; + oldcodep = sp->dec_codetab + code; + continue; + } + codep = sp->dec_codetab + code; + + /* + * Add the new entry to the code table. + */ + if (free_entp < &sp->dec_codetab[0] || + free_entp >= &sp->dec_codetab[CSIZE]) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecodeCompat: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + + free_entp->next = oldcodep; + if (free_entp->next < &sp->dec_codetab[0] || + free_entp->next >= &sp->dec_codetab[CSIZE]) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecodeCompat: Corrupted LZW table at scanline %d", + tif->tif_row); + return (0); + } + free_entp->firstchar = free_entp->next->firstchar; + free_entp->length = free_entp->next->length+1; + free_entp->value = (codep < free_entp) ? + codep->firstchar : free_entp->firstchar; + if (++free_entp > maxcodep) { + if (++nbits > BITS_MAX) /* should not happen */ + nbits = BITS_MAX; + nbitsmask = MAXCODE(nbits); + maxcodep = sp->dec_codetab + nbitsmask; + } + oldcodep = codep; + if (code >= 256) { + char *op_orig = op; + /* + * Code maps to a string, copy string + * value to output (written in reverse). + */ + if(codep->length == 0) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecodeCompat: Wrong length of decoded " + "string: data probably corrupted at scanline %d", + tif->tif_row); + return (0); + } + if (codep->length > occ) { + /* + * String is too long for decode buffer, + * locate portion that will fit, copy to + * the decode buffer, and setup restart + * logic for the next decoding call. + */ + sp->dec_codep = codep; + do { + codep = codep->next; + } while (codep->length > occ); + sp->dec_restart = occ; + tp = op + occ; + do { + *--tp = codep->value; + codep = codep->next; + } while (--occ); + break; + } + op += codep->length, occ -= codep->length; + tp = op; + do { + *--tp = codep->value; + } while( (codep = codep->next) != NULL && tp > op_orig); + } else + *op++ = code, occ--; + } + + tif->tif_rawcp = (tidata_t) bp; + sp->lzw_nbits = nbits; + sp->lzw_nextdata = nextdata; + sp->lzw_nextbits = nextbits; + sp->dec_nbitsmask = nbitsmask; + sp->dec_oldcodep = oldcodep; + sp->dec_free_entp = free_entp; + sp->dec_maxcodep = maxcodep; + + if (occ > 0) { + TIFFErrorExt(tif->tif_clientdata, tif->tif_name, + "LZWDecodeCompat: Not enough data at scanline %d (short %ld bytes)", + tif->tif_row, occ); + return (0); + } + return (1); +} +#endif /* LZW_COMPAT */ + +/* + * LZW Encoding. + */ + +static int +LZWSetupEncode(TIFF* tif) +{ + LZWCodecState* sp = EncoderState(tif); + static const char module[] = "LZWSetupEncode"; + + assert(sp != NULL); + sp->enc_hashtab = (hash_t*) _TIFFmalloc(HSIZE*sizeof (hash_t)); + if (sp->enc_hashtab == NULL) { + TIFFErrorExt(tif->tif_clientdata, module, "No space for LZW hash table"); + return (0); + } + return (1); +} + +/* + * Reset encoding state at the start of a strip. + */ +static int +LZWPreEncode(TIFF* tif, tsample_t s) +{ + LZWCodecState *sp = EncoderState(tif); + + (void) s; + assert(sp != NULL); + + if( sp->enc_hashtab == NULL ) + { + tif->tif_setupencode( tif ); + } + + sp->lzw_nbits = BITS_MIN; + sp->lzw_maxcode = MAXCODE(BITS_MIN); + sp->lzw_free_ent = CODE_FIRST; + sp->lzw_nextbits = 0; + sp->lzw_nextdata = 0; + sp->enc_checkpoint = CHECK_GAP; + sp->enc_ratio = 0; + sp->enc_incount = 0; + sp->enc_outcount = 0; + /* + * The 4 here insures there is space for 2 max-sized + * codes in LZWEncode and LZWPostDecode. + */ + sp->enc_rawlimit = tif->tif_rawdata + tif->tif_rawdatasize-1 - 4; + cl_hash(sp); /* clear hash table */ + sp->enc_oldcode = (hcode_t) -1; /* generates CODE_CLEAR in LZWEncode */ + return (1); +} + +#define CALCRATIO(sp, rat) { \ + if (incount > 0x007fffff) { /* NB: shift will overflow */\ + rat = outcount >> 8; \ + rat = (rat == 0 ? 0x7fffffff : incount/rat); \ + } else \ + rat = (incount<<8) / outcount; \ +} +#define PutNextCode(op, c) { \ + nextdata = (nextdata << nbits) | c; \ + nextbits += nbits; \ + *op++ = (unsigned char)(nextdata >> (nextbits-8)); \ + nextbits -= 8; \ + if (nextbits >= 8) { \ + *op++ = (unsigned char)(nextdata >> (nextbits-8)); \ + nextbits -= 8; \ + } \ + outcount += nbits; \ +} + +/* + * Encode a chunk of pixels. + * + * Uses an open addressing double hashing (no chaining) on the + * prefix code/next character combination. We do a variant of + * Knuth's algorithm D (vol. 3, sec. 6.4) along with G. Knott's + * relatively-prime secondary probe. Here, the modular division + * first probe is gives way to a faster exclusive-or manipulation. + * Also do block compression with an adaptive reset, whereby the + * code table is cleared when the compression ratio decreases, + * but after the table fills. The variable-length output codes + * are re-sized at this point, and a CODE_CLEAR is generated + * for the decoder. + */ +static int +LZWEncode(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s) +{ + register LZWCodecState *sp = EncoderState(tif); + register long fcode; + register hash_t *hp; + register int h, c; + hcode_t ent; + long disp; + long incount, outcount, checkpoint; + long nextdata, nextbits; + int free_ent, maxcode, nbits; + tidata_t op, limit; + + (void) s; + if (sp == NULL) + return (0); + + assert(sp->enc_hashtab != NULL); + + /* + * Load local state. + */ + incount = sp->enc_incount; + outcount = sp->enc_outcount; + checkpoint = sp->enc_checkpoint; + nextdata = sp->lzw_nextdata; + nextbits = sp->lzw_nextbits; + free_ent = sp->lzw_free_ent; + maxcode = sp->lzw_maxcode; + nbits = sp->lzw_nbits; + op = tif->tif_rawcp; + limit = sp->enc_rawlimit; + ent = sp->enc_oldcode; + + if (ent == (hcode_t) -1 && cc > 0) { + /* + * NB: This is safe because it can only happen + * at the start of a strip where we know there + * is space in the data buffer. + */ + PutNextCode(op, CODE_CLEAR); + ent = *bp++; cc--; incount++; + } + while (cc > 0) { + c = *bp++; cc--; incount++; + fcode = ((long)c << BITS_MAX) + ent; + h = (c << HSHIFT) ^ ent; /* xor hashing */ +#ifdef _WINDOWS + /* + * Check hash index for an overflow. + */ + if (h >= HSIZE) + h -= HSIZE; +#endif + hp = &sp->enc_hashtab[h]; + if (hp->hash == fcode) { + ent = hp->code; + continue; + } + if (hp->hash >= 0) { + /* + * Primary hash failed, check secondary hash. + */ + disp = HSIZE - h; + if (h == 0) + disp = 1; + do { + /* + * Avoid pointer arithmetic 'cuz of + * wraparound problems with segments. + */ + if ((h -= disp) < 0) + h += HSIZE; + hp = &sp->enc_hashtab[h]; + if (hp->hash == fcode) { + ent = hp->code; + goto hit; + } + } while (hp->hash >= 0); + } + /* + * New entry, emit code and add to table. + */ + /* + * Verify there is space in the buffer for the code + * and any potential Clear code that might be emitted + * below. The value of limit is setup so that there + * are at least 4 bytes free--room for 2 codes. + */ + if (op > limit) { + tif->tif_rawcc = (tsize_t)(op - tif->tif_rawdata); + TIFFFlushData1(tif); + op = tif->tif_rawdata; + } + PutNextCode(op, ent); + ent = c; + hp->code = free_ent++; + hp->hash = fcode; + if (free_ent == CODE_MAX-1) { + /* table is full, emit clear code and reset */ + cl_hash(sp); + sp->enc_ratio = 0; + incount = 0; + outcount = 0; + free_ent = CODE_FIRST; + PutNextCode(op, CODE_CLEAR); + nbits = BITS_MIN; + maxcode = MAXCODE(BITS_MIN); + } else { + /* + * If the next entry is going to be too big for + * the code size, then increase it, if possible. + */ + if (free_ent > maxcode) { + nbits++; + assert(nbits <= BITS_MAX); + maxcode = (int) MAXCODE(nbits); + } else if (incount >= checkpoint) { + long rat; + /* + * Check compression ratio and, if things seem + * to be slipping, clear the hash table and + * reset state. The compression ratio is a + * 24+8-bit fractional number. + */ + checkpoint = incount+CHECK_GAP; + CALCRATIO(sp, rat); + if (rat <= sp->enc_ratio) { + cl_hash(sp); + sp->enc_ratio = 0; + incount = 0; + outcount = 0; + free_ent = CODE_FIRST; + PutNextCode(op, CODE_CLEAR); + nbits = BITS_MIN; + maxcode = MAXCODE(BITS_MIN); + } else + sp->enc_ratio = rat; + } + } + hit: + ; + } + + /* + * Restore global state. + */ + sp->enc_incount = incount; + sp->enc_outcount = outcount; + sp->enc_checkpoint = checkpoint; + sp->enc_oldcode = ent; + sp->lzw_nextdata = nextdata; + sp->lzw_nextbits = nextbits; + sp->lzw_free_ent = free_ent; + sp->lzw_maxcode = maxcode; + sp->lzw_nbits = nbits; + tif->tif_rawcp = op; + return (1); +} + +/* + * Finish off an encoded strip by flushing the last + * string and tacking on an End Of Information code. + */ +static int +LZWPostEncode(TIFF* tif) +{ + register LZWCodecState *sp = EncoderState(tif); + tidata_t op = tif->tif_rawcp; + long nextbits = sp->lzw_nextbits; + long nextdata = sp->lzw_nextdata; + long outcount = sp->enc_outcount; + int nbits = sp->lzw_nbits; + + if (op > sp->enc_rawlimit) { + tif->tif_rawcc = (tsize_t)(op - tif->tif_rawdata); + TIFFFlushData1(tif); + op = tif->tif_rawdata; + } + if (sp->enc_oldcode != (hcode_t) -1) { + PutNextCode(op, sp->enc_oldcode); + sp->enc_oldcode = (hcode_t) -1; + } + PutNextCode(op, CODE_EOI); + if (nextbits > 0) + *op++ = (unsigned char)(nextdata << (8-nextbits)); + tif->tif_rawcc = (tsize_t)(op - tif->tif_rawdata); + return (1); +} + +/* + * Reset encoding hash table. + */ +static void +cl_hash(LZWCodecState* sp) +{ + register hash_t *hp = &sp->enc_hashtab[HSIZE-1]; + register long 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 void +LZWCleanup(TIFF* tif) +{ + (void)TIFFPredictorCleanup(tif); + + assert(tif->tif_data != 0); + + if (DecoderState(tif)->dec_codetab) + _TIFFfree(DecoderState(tif)->dec_codetab); + + if (EncoderState(tif)->enc_hashtab) + _TIFFfree(EncoderState(tif)->enc_hashtab); + + _TIFFfree(tif->tif_data); + tif->tif_data = NULL; + + _TIFFSetDefaultCompressionState(tif); +} + +int +TIFFInitLZW(TIFF* tif, int scheme) +{ + assert(scheme == COMPRESSION_LZW); + /* + * Allocate state block so tag methods have storage to record values. + */ + tif->tif_data = (tidata_t) _TIFFmalloc(sizeof (LZWCodecState)); + if (tif->tif_data == NULL) + goto bad; + DecoderState(tif)->dec_codetab = NULL; + DecoderState(tif)->dec_decode = NULL; + EncoderState(tif)->enc_hashtab = NULL; + LZWState(tif)->rw_mode = tif->tif_mode; + + /* + * Install codec methods. + */ + tif->tif_setupdecode = LZWSetupDecode; + tif->tif_predecode = LZWPreDecode; + tif->tif_decoderow = LZWDecode; + tif->tif_decodestrip = LZWDecode; + tif->tif_decodetile = LZWDecode; + tif->tif_setupencode = LZWSetupEncode; + tif->tif_preencode = LZWPreEncode; + tif->tif_postencode = LZWPostEncode; + tif->tif_encoderow = LZWEncode; + tif->tif_encodestrip = LZWEncode; + tif->tif_encodetile = LZWEncode; + tif->tif_cleanup = LZWCleanup; + /* + * Setup predictor setup. + */ + (void) TIFFPredictorInit(tif); + return (1); +bad: + TIFFErrorExt(tif->tif_clientdata, "TIFFInitLZW", + "No space for LZW state block"); + return (0); +} + +/* + * Copyright (c) 1985, 1986 The Regents of the University of California. + * All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * James A. Woods, derived from original work by Spencer Thomas + * and Joseph Orost. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ +#endif /* LZW_SUPPORT */ + +/* vim: set ts=8 sts=8 sw=8 noet: */ +/* + * Local Variables: + * mode: c + * c-basic-offset: 8 + * fill-column: 78 + * End: + */ |
