1492 lines
22 KiB
C
1492 lines
22 KiB
C
/**
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** $Header: /roq/libim/imgiflzw.c 1 11/02/99 4:38p Zaphod $
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** Copyright (c) 1989-1995 San Diego Supercomputer Center (SDSC)
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** a division of General Atomics, San Diego, California, USA
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**
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** Users and possessors of this source code are hereby granted a
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** nonexclusive, royalty-free copyright and design patent license to
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** use this code in individual software. License is not granted for
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** commercial resale, in whole or in part, without prior written
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** permission from SDSC. This source is provided "AS IS" without express
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** or implied warranty of any kind.
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**
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** For further information contact:
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** E-Mail: info@sds.sdsc.edu
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**
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** Surface Mail: Information Center
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** San Diego Supercomputer Center
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** P.O. Box 85608
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** San Diego, CA 92138-5608
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** (619) 534-5000
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**/
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#define HEADER " $Header: /roq/libim/imgiflzw.c 1 11/02/99 4:38p Zaphod $"
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/**
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** FILE
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** imgiflzw.c - Do Lempel-Ziv & Welch uncompress/compress
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**
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** PROJECT
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** libim - SDSC image manipulation library
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**
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** DESCRIPTION
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** imlzw.c contains rountines for decoding and encoding bytes
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** using Lempel-Ziv & Welch uncompress/compress algorithm.
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**
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** PUBLIC CONTENTS
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** d =defined constant
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** f =function
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** m =defined macro
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** t =typedef/struct/union
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** v =variable
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** ? =other
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**
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** imLzwCompGif f
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**
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** PRIVATE CONTENTS
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**
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** imLzwGetCode f
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** imLzwError f
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** imLzwGifNextPixel f
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** imLzwPackBits f
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**
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** struct str_table_node t
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** struct str_table_node t
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** strTableNode t
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** strTableNodePtr t
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** strTable t
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**
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**
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** IMMAX_LWZ_BITS d maximum number of bits allowed by LWZ
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** IMMAXIMUMCODE d maximum code size
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** IMBLOCKSIZE d maximum block byte count plus one
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** IMNULLPREFIX d null prefix
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**
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** ImGifEasyFail m non fatal error ocurred. report the error.
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**
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** CODE CREDITS
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** David Koblas, 1990.
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** Custom development, Soraya Gonzales, Intevep S.A., Venzuela, 1991.
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** Extensions, Vinh Le, San Diego Supercomputer Center, 1992.
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** Extensions, Dave Nadeau, San Diego Supercomputer Center, 1993.
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**
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**
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** HISTORY
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** $Log: /roq/libim/imgiflzw.c $
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*
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* 1 11/02/99 4:38p Zaphod
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** Revision 1.11 1995/06/29 00:28:04 bduggan
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** updated copyright year
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**
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** Revision 1.10 1995/06/16 08:43:52 bduggan
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** cleaned up code formatting
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**
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** Revision 1.9 1995/01/10 23:25:55 bduggan
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** Updated copyright notice
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**
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** Revision 1.8 1994/10/03 11:29:39 nadeau
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** Updated to ANSI C and C++ compatibility.
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** Removed all use of register keyword.
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** Minimized use of custom SDSC types (e.g., uchar vs. unsigned char)
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** Changed all float arguments to double.
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** Added forward declarations.
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** Added misc. casts to passify SGI and DEC compilers.
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** Changed all macros and defined constants to have names
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** starting with IM.
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** Updated comments.
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** Updated indenting on some code.
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** Updated copyright message.
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**
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** Revision 1.7 92/08/31 17:24:09 vle
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** Updated copyright notice.
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**
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** Revision 1.6 91/10/03 09:03:23 nadeau
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** Fixed #includes.
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**
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** Revision 1.5 91/03/21 08:51:38 nadeau
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** ifdef-ed out inclusion of strings.h. Nothing seems
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** to need it and it confuses the compiler on SysV vs.
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** BSD machines (string.h vs. strings.h).
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**
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** Revision 1.4 91/03/13 17:11:53 soraya
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** *** empty log message ***
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**
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** Revision 1.3 91/03/11 09:19:07 soraya
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** Optimization and comment cleanup.
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**
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** Revision 1.2 91/01/31 08:34:42 soraya
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** Adding comments
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**
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**
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**
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**/
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#if 0
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The lines between the dashes are taken directly from the file jrdgif.c:
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-----------------------------------------------------------------------------
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/*
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* jrdgif.c
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*
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* Copyright (C) 1991, 1992, Thomas G. Lane.
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* This file is part of the Independent JPEG Group's software.
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* For conditions of distribution and use, see the accompanying README file.
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*
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* This file contains routines to read input images in GIF format.
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*
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* These routines may need modification for non-Unix environments or
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* specialized applications. As they stand, they assume input from
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* an ordinary stdio stream. They further assume that reading begins
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* at the start of the file; input_init may need work if the
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* user interface has already read some data (e.g., to determine that
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* the file is indeed GIF format).
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*
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* These routines are invoked via the methods get_input_row
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* and input_init/term.
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*/
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/*
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* This code is loosely based on giftoppm from the PBMPLUS distribution
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* of Feb. 1991. That file contains the following copyright notice:
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* +-------------------------------------------------------------------+
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* | Copyright 1990, David Koblas. |
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* | Permission to use, copy, modify, and distribute this software |
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* | and its documentation for any purpose and without fee is hereby |
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* | granted, provided that the above copyright notice appear in all |
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* | copies and that both that copyright notice and this permission |
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* | notice appear in supporting documentation. This software is |
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* | provided "as is" without express or implied warranty. |
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* +-------------------------------------------------------------------+
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*
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* We are also required to state that
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* "The Graphics Interchange Format(c) is the Copyright property of
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* CompuServe Incorporated. GIF(sm) is a Service Mark property of
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* CompuServe Incorporated."
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*/
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-----------------------------------------------------------------------------
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#endif
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/*
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* imLzwGetCode
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* imLzwReadByte
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*
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* Gif Image decompression - from LZW to Gif
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* Written by David Koblas.
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* Copyright 1989
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* Modified by Soraya Gonzalez
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* San Diego Supercomputer Center
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* to include it in the image library
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* ==================================================================
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* imLzwError
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* imLzwGifNextPixel
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* imLzwPackBits
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* imLzwCompGif
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*
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*
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* GIF Image compression - LZW algorithm implemented with Trie type
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* structure.
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* Written by Bailey Brown, Jr.
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* last change May 24, 1990
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* Modified by Soraya Gonzalez.
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* San Diego Supercomputer Center.
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* December 1990
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* to include it in the image library
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*
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*
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*/
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#ifdef USE_STDLIB_H
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#include <stdlib.h>
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#else
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#ifdef old
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#ifdef USE_STRING_H
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#include <string.h>
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#else
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#include <strings.h>
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#endif
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#endif
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#endif /* USE_STDLIB_H */
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#include "iminternal.h"
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/*
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* TYPEDEF & STRUCTURE
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* struct str_table_node
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* struct str_table_node
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* strTableNode
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* strTableNodePtr
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* strTable
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* DESCRIPTION
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*
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*/
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typedef struct str_table_entry {
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int code;
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int prefix;
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int suffix;
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} strTableEntry;
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typedef struct str_table_node {
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strTableEntry entry;
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struct str_table_node *left;
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struct str_table_node *right;
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struct str_table_node *children;
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} strTableNode, *strTableNodePtr, **strTable;
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/*
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* CONSTANTS
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*
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* IMMAX_LWZ_BITS - maximum number of bits allowed by LWZ
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* IMMAXIMUMCODE - maximum code size
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* IMBLOCKSIZE - maximum block byte count plus one
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* IMNULLPREFIX - null prefix
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*/
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#define IMMAX_LWZ_BITS 12
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#define IMMAXIMUMCODE 4095 /* 2**maximum_code_size */
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#define IMBLOCKSIZE 256 /* max block byte count + 1 */
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#define IMNULLPREFIX -1
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/*
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* MACROS
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* ImGifEasyFail - non fatal error occurred. report the error.
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*/
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#define ImGifEasyFail(str,status) \
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{ \
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ImErrorWarning(str,status,IMEUNKNOWN); \
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return(status); \
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}
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/*
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* FILE-WIDE VARIABLE
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*/
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static int RasterIndex; /* index over the rasterdata array */
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/*
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* FUNCTION
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* imLzwGetCode - return the next code from the input stream.
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*
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* DESCRIPTION
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* return the next code from the input stream. The code read
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* has code_size size. flag is used to initialize
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* the internal variables.
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*/
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static int
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#ifdef __STDC__
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imLzwGetCode(int ioType, int fd, FILE *fp, int code_size, int flag)
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#else
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imLzwGetCode(ioType, fd, fp, code_size, flag)
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int ioType; /* I/O flags */
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int fd; /* Input file descriptor */
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FILE *fp; /* Input file pointer */
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int code_size; /* current code size used */
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int flag; /* used for to initializations */
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#endif
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{
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static unsigned char buf[280];
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static int curbit,lastbit,done,last_byte;
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int i, j, ret;
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unsigned char count;
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if (flag)
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{
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curbit = 0;
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lastbit = 0;
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done = FALSE;
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return 0;
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}
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if ( (curbit+code_size) >= lastbit)
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{
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if (done)
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if (curbit>=lastbit)
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ImGifEasyFail("Ran off the end of my bits",-1);
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buf[0] = buf[last_byte-2];
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buf[1] = buf[last_byte-1];
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if ( ImBinRead( ioType,fd,fp,&count, UCHAR, 1, 1 ) == -1 )
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ImReturnBinError( );
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if (count == 0)
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done = TRUE;
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else if ( ImBinRead( ioType,fd,fp,&buf[2],UCHAR,1,count ) == -1 )
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ImReturnBinError( );
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last_byte = 2 + count;
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curbit = (curbit - lastbit) + 16;
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lastbit = (2+count)*8 ;
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}
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ret = 0;
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for( i = curbit, j = 0; j < code_size; i++, j++ )
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ret |= ((buf[ i / 8 ] & (1 << (i % 8))) != 0) << j;
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curbit += code_size;
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return ret;
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}
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/*
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* FUNCTION
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* ImLzwReadByte - return the next decoded pixel
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*
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* DESCRIPTION
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* Return the next decoded pixel value.
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*/
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int
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#ifdef __STDC__
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imLzwReadByte(int ioType,int fd,FILE *fp,int flag,int input_code_size)
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#else
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imLzwReadByte(ioType,fd,fp,flag,input_code_size)
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int ioType; /* I/O flags */
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int fd; /* Input file descriptor */
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FILE *fp; /* Input file pointer */
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int flag; /* to make intializations*/
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int input_code_size;/* code size */
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#endif
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{
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static int fresh=FALSE;
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int code,incode;
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unsigned char count,junk;
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static int code_size,set_code_size;
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static int max_code,max_code_size;
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static int firstcode,oldcode;
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static int clear_code,end_code;
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static int table[2][(1<< IMMAX_LWZ_BITS)];
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static int stack[(1<<(IMMAX_LWZ_BITS))*2],*sp;
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int i;
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if (flag)
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{
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set_code_size = input_code_size;
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code_size = set_code_size+1;
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clear_code = 1 << set_code_size ;
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end_code = clear_code + 1;
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max_code_size = 2*clear_code;
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max_code = clear_code+2;
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imLzwGetCode(ioType,fd,fp,NULL,TRUE);
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fresh=TRUE;
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for (i=0;i<clear_code;i++)
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{
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table[0][i] = 0;
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table[1][i] = i;
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}
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for (;i<(1<<IMMAX_LWZ_BITS);i++)
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table[0][i] = table[1][0] = 0;
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sp = stack;
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return 0;
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}
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else
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if (fresh)
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{
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fresh = FALSE;
|
|
|
|
do
|
|
|
|
{
|
|
|
|
firstcode=oldcode=
|
|
|
|
imLzwGetCode(ioType,fd,fp, code_size, FALSE);
|
|
|
|
} while (firstcode == clear_code);
|
|
|
|
return firstcode;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (sp > stack)
|
|
|
|
return *--sp;
|
|
|
|
|
|
|
|
while ((code=imLzwGetCode(ioType,fd,fp,code_size,FALSE))>=0)
|
|
|
|
{
|
|
|
|
if (code == clear_code)
|
|
|
|
{
|
|
|
|
for (i=0;i<clear_code;i++)
|
|
|
|
{
|
|
|
|
table[0][i] = 0;
|
|
|
|
table[1][i] = i;
|
|
|
|
}
|
|
|
|
for (;i<(1<<IMMAX_LWZ_BITS);i++)
|
|
|
|
table[0][i] = table[1][i] = 0;
|
|
|
|
code_size = set_code_size+1;
|
|
|
|
max_code_size = 2*clear_code;
|
|
|
|
max_code = clear_code+2;
|
|
|
|
sp = stack;
|
|
|
|
firstcode=oldcode=
|
|
|
|
imLzwGetCode(ioType,fd,fp,code_size,FALSE);
|
|
|
|
return firstcode;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
if (code == end_code)
|
|
|
|
{
|
|
|
|
while ( ImBinRead(ioType,fd,fp,&count,UCHAR,1,1) != -1 && (count!=0))
|
|
|
|
while (count-->0 && ImBinRead( ioType,fd,fp,&junk,UCHAR,1,1) != -1);
|
|
|
|
if (count!=0)
|
|
|
|
ImGifEasyFail("Missing EOD in data stream (common occurance)",-1);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
|
|
|
|
incode = code;
|
|
|
|
|
|
|
|
if (code >= max_code)
|
|
|
|
{
|
|
|
|
*sp++ = firstcode;
|
|
|
|
code = oldcode;
|
|
|
|
}
|
|
|
|
|
|
|
|
while (code >= clear_code)
|
|
|
|
{
|
|
|
|
*sp++ = table[1][code];
|
|
|
|
if (code == table[0][code])
|
|
|
|
ImGifEasyFail("Circular table entry BIG ERROR",-1);
|
|
|
|
code = table[0][code];
|
|
|
|
}
|
|
|
|
|
|
|
|
*sp++ = firstcode = table[1][code];
|
|
|
|
|
|
|
|
if ((code=max_code)<(1<<IMMAX_LWZ_BITS))
|
|
|
|
{
|
|
|
|
table[0][code] = oldcode;
|
|
|
|
table[1][code] = firstcode;
|
|
|
|
max_code++;
|
|
|
|
if ((max_code >= max_code_size) &&
|
|
|
|
(max_code_size < (1<<IMMAX_LWZ_BITS)))
|
|
|
|
{
|
|
|
|
max_code_size *= 2;
|
|
|
|
code_size++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
oldcode = incode;
|
|
|
|
|
|
|
|
if (sp > stack)
|
|
|
|
return *--sp;
|
|
|
|
}
|
|
|
|
return code;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* FUNCTION
|
|
|
|
* ImLzwError - prints the error ocurred in the standar error file
|
|
|
|
* and return with status equal to -1
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
#ifdef __STDC__
|
|
|
|
imLzwError(char *s)
|
|
|
|
#else
|
|
|
|
imLzwError(s)
|
|
|
|
char *s;
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
ImErrorFatal(s, -1, IMEUNKNOWN);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* FUNCTION
|
|
|
|
* ImLzwGifNextPixel - Return the next pixel from the raster data
|
|
|
|
*
|
|
|
|
* DESCRIPTION
|
|
|
|
* The pixel values are stored in the rasterdata buffer. This
|
|
|
|
* function returns the next pixel value.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static int
|
|
|
|
#ifdef __STDC__
|
|
|
|
imLzwGifNextPixel(unsigned char *rasterdata,int size)
|
|
|
|
#else
|
|
|
|
imLzwGifNextPixel( rasterdata,size)
|
|
|
|
unsigned char *rasterdata;
|
|
|
|
int size;
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
|
|
|
|
if ( RasterIndex == size )
|
|
|
|
return (EOF);
|
|
|
|
return( rasterdata[RasterIndex++] );
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* FUNCTION
|
|
|
|
* imLzwPackBits - packs the bits of the codes generated
|
|
|
|
* by imLzwCompGif.
|
|
|
|
* DESCRIPTION
|
|
|
|
* imLzwPackBits() packs the bits of the codes generated by ImLzwCompGif
|
|
|
|
* into a 1..256 byte output block. The first byte of the block is the
|
|
|
|
* number 0..255 of data bytes in the block. To flush or initialize
|
|
|
|
* the block, pass a negative argument.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static int
|
|
|
|
#ifdef __STDC__
|
|
|
|
imLzwPackBits(int compress_size, int prefix, int ioType, int fd, FILE *fp)
|
|
|
|
#else
|
|
|
|
imLzwPackBits(compress_size, prefix, ioType, fd, fp)
|
|
|
|
int compress_size;
|
|
|
|
int prefix;
|
|
|
|
int ioType;
|
|
|
|
int fd;
|
|
|
|
FILE *fp;
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
static int cur_bit = 8;
|
|
|
|
static unsigned char block[IMBLOCKSIZE] = { 0 };
|
|
|
|
int i, left_over_bits;
|
|
|
|
|
|
|
|
/* if we are about to excede the bounds of block or if the flush
|
|
|
|
code (code_bis < 0) we output the block */
|
|
|
|
if((cur_bit + compress_size > (IMBLOCKSIZE-1)*8) || (prefix < 0))
|
|
|
|
{
|
|
|
|
/* handle case of data overlapping blocks */
|
|
|
|
if ((left_over_bits = (((cur_bit>>3) +
|
|
|
|
((cur_bit & 7) != 0))<<3) - cur_bit) != 0)
|
|
|
|
{
|
|
|
|
for (i=0; i < left_over_bits; i++)
|
|
|
|
{
|
|
|
|
if (prefix & (1<<i))
|
|
|
|
block[cur_bit>>3] |= (char)(1<<(cur_bit & 7));
|
|
|
|
/* note n>>3 == n/8 and n & 7 == n % 8 */
|
|
|
|
cur_bit++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
compress_size -= left_over_bits;
|
|
|
|
prefix = prefix>>left_over_bits;
|
|
|
|
block[0] = (unsigned char)((cur_bit>>3) - 1);
|
|
|
|
if (block[0])
|
|
|
|
if ( ImBinWrite( ioType, fd, fp, block, UCHAR, 1, block[0]+1) == -1)
|
|
|
|
ImReturnBinError();
|
|
|
|
for(i=0; i < IMBLOCKSIZE; i++)
|
|
|
|
block[i] = 0;
|
|
|
|
cur_bit = 8;
|
|
|
|
}
|
|
|
|
if (prefix >= 0)
|
|
|
|
{
|
|
|
|
for (i=0; i < compress_size; i++)
|
|
|
|
{
|
|
|
|
if (prefix & (1<<i))
|
|
|
|
block[cur_bit>>3] |= (unsigned char)(1<<(cur_bit & 7));
|
|
|
|
/* note n>>3 == n/8 and n & 7 == n % 8 */
|
|
|
|
cur_bit++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return (1);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
* FUNCTION
|
|
|
|
* ImLzwCompGif - compresses and pack the pixels values that are
|
|
|
|
* stored in rasterdata buffer using the
|
|
|
|
* LZW algorithm.
|
|
|
|
* DESCRIPTION
|
|
|
|
* ImLzwCompGif () recieves pointers to a buffer and an output
|
|
|
|
* stream, and the code size as parameters and outputs successive
|
|
|
|
* blocks of LZW compressed gif data. The calling routine should
|
|
|
|
* have aready written the GIF file header out to the output file.
|
|
|
|
* It assumes that there will be no more than 8 bits/pixel and that
|
|
|
|
* each data item comes from successive bytes returned by
|
|
|
|
* ImLzwGifNextPixel().
|
|
|
|
*/
|
|
|
|
|
|
|
|
int
|
|
|
|
#ifdef __STDC__
|
|
|
|
imLzwCompGif(int ioType,int fd,FILE *fp,int code_size, unsigned char *rasterdata, int size)
|
|
|
|
#else
|
|
|
|
imLzwCompGif(ioType,fd,fp,code_size, rasterdata, size)
|
|
|
|
int ioType; /* I/O flags */
|
|
|
|
int fd; /* Input file descriptor */
|
|
|
|
FILE *fp; /* Input file pointer */
|
|
|
|
int code_size; /* i.e. for 8 bits/pixel code_size = 9; */
|
|
|
|
unsigned char *rasterdata; /* rasterdata to be compress */
|
|
|
|
int size; /* size of the raster data */
|
|
|
|
#endif
|
|
|
|
{
|
|
|
|
strTable heap; /* our very own memory manager */
|
|
|
|
int heap_index;
|
|
|
|
int clear_code, end_code, cur_code;
|
|
|
|
int i, found, num_colors, prefix, compress_size;
|
|
|
|
int cur_char, end_of_data, bits_per_pix;
|
|
|
|
strTableNodePtr cur_node;
|
|
|
|
strTable root; /* root of string table for LZW compression */
|
|
|
|
/* is an array of 2**bits_per_pix pointers
|
|
|
|
to atomic nodes */
|
|
|
|
heap_index = 0;
|
|
|
|
heap = (strTable)malloc(sizeof(strTableNodePtr)*IMMAXIMUMCODE);
|
|
|
|
if (heap == NULL)
|
|
|
|
imLzwError("can't allocate heap");
|
|
|
|
for (i=0; i < IMMAXIMUMCODE; i++)
|
|
|
|
{
|
|
|
|
heap[i] = (strTableNodePtr)malloc(sizeof(strTableNode));
|
|
|
|
if (heap[i] == NULL)
|
|
|
|
imLzwError("can't allocate heap");
|
|
|
|
}
|
|
|
|
bits_per_pix = code_size - 1;
|
|
|
|
compress_size = code_size;
|
|
|
|
num_colors = 1<<(bits_per_pix);
|
|
|
|
clear_code = num_colors;
|
|
|
|
end_code = clear_code + 1;
|
|
|
|
cur_code = end_code + 1;
|
|
|
|
RasterIndex = 0;
|
|
|
|
prefix = IMNULLPREFIX;
|
|
|
|
root = (strTable)malloc(sizeof(strTableNodePtr)*num_colors);
|
|
|
|
if (!root)
|
|
|
|
imLzwError("memory allocation failure (root)");
|
|
|
|
for(i=0; i<num_colors; i++)
|
|
|
|
{
|
|
|
|
root[i] = heap[heap_index++];
|
|
|
|
root[i]->entry.code = i;
|
|
|
|
root[i]->entry.prefix = IMNULLPREFIX;
|
|
|
|
root[i]->entry.suffix = i;
|
|
|
|
root[i]->left = NULL;
|
|
|
|
root[i]->right = NULL;
|
|
|
|
root[i]->children = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* initialize output block */
|
|
|
|
imLzwPackBits(compress_size, -1, ioType,fd,fp);
|
|
|
|
imLzwPackBits(compress_size, clear_code, ioType,fd,fp);
|
|
|
|
end_of_data = 0;
|
|
|
|
if ((cur_char = imLzwGifNextPixel(rasterdata,size)) == EOF)
|
|
|
|
imLzwError("premature end of data");
|
|
|
|
while (!end_of_data)
|
|
|
|
{
|
|
|
|
prefix = cur_char;
|
|
|
|
cur_node = root[prefix];
|
|
|
|
found = 1;
|
|
|
|
if ((cur_char = imLzwGifNextPixel(rasterdata,size)) == EOF)
|
|
|
|
{
|
|
|
|
end_of_data = 1;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
while(cur_node->children && found)
|
|
|
|
{
|
|
|
|
cur_node = cur_node->children;
|
|
|
|
while(cur_node->entry.suffix != cur_char)
|
|
|
|
{
|
|
|
|
if (cur_char < cur_node->entry.suffix)
|
|
|
|
{
|
|
|
|
if (cur_node->left)
|
|
|
|
cur_node = cur_node->left;
|
|
|
|
else
|
|
|
|
{
|
|
|
|
cur_node->left = heap[heap_index++];
|
|
|
|
cur_node = cur_node->left;
|
|
|
|
found = 0;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
if (cur_node->right)
|
|
|
|
cur_node = cur_node->right;
|
|
|
|
else
|
|
|
|
{
|
|
|
|
cur_node->right = heap[heap_index++];
|
|
|
|
cur_node = cur_node->right;
|
|
|
|
found = 0;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (found)
|
|
|
|
{
|
|
|
|
prefix = cur_node->entry.code;
|
|
|
|
if((cur_char = imLzwGifNextPixel(rasterdata,size)) == EOF)
|
|
|
|
{
|
|
|
|
end_of_data = 1;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (end_of_data)
|
|
|
|
break;
|
|
|
|
if (found)
|
|
|
|
{
|
|
|
|
cur_node->children = heap[heap_index++];
|
|
|
|
cur_node = cur_node->children;
|
|
|
|
}
|
|
|
|
cur_node->children = NULL;
|
|
|
|
cur_node->left = NULL;
|
|
|
|
cur_node->right = NULL;
|
|
|
|
cur_node->entry.code = cur_code;
|
|
|
|
cur_node->entry.prefix = prefix;
|
|
|
|
cur_node->entry.suffix = cur_char;
|
|
|
|
imLzwPackBits(compress_size, prefix, ioType,fd,fp);
|
|
|
|
if (cur_code > ((1<<(compress_size))-1))
|
|
|
|
compress_size++;
|
|
|
|
if (cur_code < IMMAXIMUMCODE)
|
|
|
|
{
|
|
|
|
cur_code++;
|
|
|
|
}
|
|
|
|
else
|
|
|
|
{
|
|
|
|
heap_index = num_colors; /* reinitialize string table */
|
|
|
|
for (i=0; i < num_colors; i++ )
|
|
|
|
root[i]->children = NULL;
|
|
|
|
imLzwPackBits(compress_size, clear_code, ioType,fd,fp);
|
|
|
|
compress_size = bits_per_pix + 1;
|
|
|
|
cur_code = end_code + 1;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
imLzwPackBits(compress_size, prefix, ioType,fd,fp);
|
|
|
|
imLzwPackBits(compress_size, end_code, ioType,fd,fp);
|
|
|
|
imLzwPackBits(compress_size, -1, ioType,fd,fp);
|
|
|
|
for (i=0; i < IMMAXIMUMCODE; i++)
|
|
|
|
free(heap[i]);
|
|
|
|
free(heap);
|
|
|
|
free(root);
|
|
|
|
return (1);
|
|
|
|
}
|
|
|
|
|
|
|