mirror of https://github.com/opencv/opencv.git
Open Source Computer Vision Library
https://opencv.org/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1080 lines
28 KiB
1080 lines
28 KiB
15 years ago
|
/* $Id: tif_lzw.c,v 1.1 2005-06-17 13:54:52 vp153 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) { \
|
||
|
TIFFWarning(_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)
|
||
|
{
|
||
|
TIFFError("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) {
|
||
|
TIFFError(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--);
|
||
|
}
|
||
|
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);
|
||
|
/*
|
||
|
* Check for old bit-reversed codes.
|
||
|
*/
|
||
|
if (tif->tif_rawdata[0] == 0 && (tif->tif_rawdata[1] & 0x1)) {
|
||
|
#ifdef LZW_COMPAT
|
||
|
if (!sp->dec_decode) {
|
||
|
TIFFWarning(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) {
|
||
|
TIFFError(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)
|
||
|
{
|
||
|
TIFFError(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);
|
||
|
/*
|
||
|
* 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;
|
||
|
nbits = BITS_MIN;
|
||
|
nbitsmask = MAXCODE(BITS_MIN);
|
||
|
maxcodep = sp->dec_codetab + nbitsmask-1;
|
||
|
NextCode(tif, sp, bp, code, GetNextCode);
|
||
|
if (code == CODE_EOI)
|
||
|
break;
|
||
|
*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]) {
|
||
|
TIFFError(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]) {
|
||
|
TIFFError(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) {
|
||
|
TIFFError(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) {
|
||
|
TIFFError(tif->tif_name,
|
||
|
"LZWDecode: Not enough data at scanline %d (short %d 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;
|
||
|
nbits = BITS_MIN;
|
||
|
nbitsmask = MAXCODE(BITS_MIN);
|
||
|
maxcodep = sp->dec_codetab + nbitsmask;
|
||
|
NextCode(tif, sp, bp, code, GetNextCodeCompat);
|
||
|
if (code == CODE_EOI)
|
||
|
break;
|
||
|
*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]) {
|
||
|
TIFFError(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]) {
|
||
|
TIFFError(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) {
|
||
|
/*
|
||
|
* Code maps to a string, copy string
|
||
|
* value to output (written in reverse).
|
||
|
*/
|
||
|
if(codep->length == 0) {
|
||
|
TIFFError(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);
|
||
|
} 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) {
|
||
|
TIFFError(tif->tif_name,
|
||
|
"LZWDecodeCompat: Not enough data at scanline %d (short %d 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) {
|
||
|
TIFFError(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);
|
||
|
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);
|
||
|
/*
|
||
|
* 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)
|
||
|
{
|
||
|
if (tif->tif_data) {
|
||
|
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;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
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:
|
||
|
TIFFError("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: */
|