1 /*
2 * Gif extracting routines - derived from libungif
3 *
4 * Portions Copyright 2006 Mike McCormack
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19 */
20
21 /*
22 * Original copyright notice:
23 *
24 * The GIFLIB distribution is Copyright (c) 1997 Eric S. Raymond
25 *
26 * Permission is hereby granted, free of charge, to any person obtaining a copy
27 * of this software and associated documentation files (the "Software"), to deal
28 * in the Software without restriction, including without limitation the rights
29 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
30 * copies of the Software, and to permit persons to whom the Software is
31 * furnished to do so, subject to the following conditions:
32 *
33 * The above copyright notice and this permission notice shall be included in
34 * all copies or substantial portions of the Software.
35 */
36
37 /******************************************************************************
38 * In order to make life a little bit easier when using the GIF file format,
39 * this library was written, and which does all the dirty work...
40 *
41 * Written by Gershon Elber, Jun. 1989
42 * Hacks by Eric S. Raymond, Sep. 1992
43 ******************************************************************************
44 * History:
45 * 14 Jun 89 - Version 1.0 by Gershon Elber.
46 * 3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names)
47 * 15 Sep 90 - Version 2.0 by Eric S. Raymond (Changes to support GIF slurp)
48 * 26 Jun 96 - Version 3.0 by Eric S. Raymond (Full GIF89 support)
49 * 17 Dec 98 - Version 4.0 by Toshio Kuratomi (Fix extension writing code)
50 *****************************************************************************/
51
52 #ifndef _UNGIF_H_
53 #define _UNGIF_H_ 1
54
55 #define GIF_ERROR 0
56 #define GIF_OK 1
57
58 #ifndef TRUE
59 #define TRUE 1
60 #endif /* TRUE */
61 #ifndef FALSE
62 #define FALSE 0
63 #endif /* FALSE */
64
65 #ifndef NULL
66 #define NULL 0
67 #endif /* NULL */
68
69 #define GIF_STAMP "GIFVER" /* First chars in file - GIF stamp. */
70 #define GIF_STAMP_LEN sizeof(GIF_STAMP) - 1
71 #define GIF_VERSION_POS 3 /* Version first character in stamp. */
72 #define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */
73 #define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */
74
75 #define GIF_FILE_BUFFER_SIZE 16384 /* Files uses bigger buffers than usual. */
76
77 typedef int GifBooleanType;
78 typedef unsigned char GifPixelType;
79 typedef unsigned char *GifRowType;
80 typedef unsigned char GifByteType;
81 typedef unsigned int GifPrefixType;
82 typedef int GifWord;
83
84 typedef struct GifColorType {
85 GifByteType Red, Green, Blue;
86 } GifColorType;
87
88 typedef struct ColorMapObject {
89 int ColorCount;
90 int BitsPerPixel;
91 GifColorType *Colors;
92 } ColorMapObject;
93
94 typedef struct GifImageDesc {
95 GifWord Left, Top, Width, Height, /* Current image dimensions. */
96 Interlace; /* Sequential/Interlaced lines. */
97 ColorMapObject *ColorMap; /* The local color map */
98 } GifImageDesc;
99
100 typedef struct GifFileType {
101 GifWord SWidth, SHeight, /* Screen dimensions. */
102 SColorResolution, /* How many colors can we generate? */
103 SBackGroundColor, /* I hope you understand this one... */
104 SAspectRatio; /* Pixel aspect ratio, in 1/64 units, starting at 1:4. */
105 ColorMapObject *SColorMap; /* NULL if not exists. */
106 int ImageCount; /* Number of current image */
107 GifImageDesc Image; /* Block describing current image */
108 struct SavedImage *SavedImages; /* Use this to accumulate file state */
109 void *UserData; /* hook to attach user data (TVT) */
110 void *Private; /* Don't mess with this! */
111 } GifFileType;
112
113 typedef enum {
114 UNDEFINED_RECORD_TYPE,
115 SCREEN_DESC_RECORD_TYPE,
116 IMAGE_DESC_RECORD_TYPE, /* Begin with ',' */
117 EXTENSION_RECORD_TYPE, /* Begin with '!' */
118 TERMINATE_RECORD_TYPE /* Begin with ';' */
119 } GifRecordType;
120
121 /* func type to read gif data from arbitrary sources (TVT) */
122 typedef int (*InputFunc) (GifFileType *, GifByteType *, int);
123
124 /* GIF89 extension function codes */
125
126 #define COMMENT_EXT_FUNC_CODE 0xfe /* comment */
127 #define GRAPHICS_EXT_FUNC_CODE 0xf9 /* graphics control */
128 #define PLAINTEXT_EXT_FUNC_CODE 0x01 /* plaintext */
129 #define APPLICATION_EXT_FUNC_CODE 0xff /* application block */
130
131 /* public interface to ungif.c */
132 int DGifSlurp(GifFileType * GifFile);
133 GifFileType *DGifOpen(void *userPtr, InputFunc readFunc);
134 int DGifCloseFile(GifFileType * GifFile);
135
136 #define D_GIF_ERR_OPEN_FAILED 101 /* And DGif possible errors. */
137 #define D_GIF_ERR_READ_FAILED 102
138 #define D_GIF_ERR_NOT_GIF_FILE 103
139 #define D_GIF_ERR_NO_SCRN_DSCR 104
140 #define D_GIF_ERR_NO_IMAG_DSCR 105
141 #define D_GIF_ERR_NO_COLOR_MAP 106
142 #define D_GIF_ERR_WRONG_RECORD 107
143 #define D_GIF_ERR_DATA_TOO_BIG 108
144 #define D_GIF_ERR_NOT_ENOUGH_MEM 109
145 #define D_GIF_ERR_CLOSE_FAILED 110
146 #define D_GIF_ERR_NOT_READABLE 111
147 #define D_GIF_ERR_IMAGE_DEFECT 112
148 #define D_GIF_ERR_EOF_TOO_SOON 113
149
150 /******************************************************************************
151 * Support for the in-core structures allocation (slurp mode).
152 *****************************************************************************/
153
154 /* This is the in-core version of an extension record */
155 typedef struct {
156 int ByteCount;
157 char *Bytes;
158 int Function; /* Holds the type of the Extension block. */
159 } ExtensionBlock;
160
161 /* This holds an image header, its unpacked raster bits, and extensions */
162 typedef struct SavedImage {
163 GifImageDesc ImageDesc;
164 unsigned char *RasterBits;
165 int Function; /* DEPRECATED: Use ExtensionBlocks[x].Function instead */
166 int ExtensionBlockCount;
167 ExtensionBlock *ExtensionBlocks;
168 } SavedImage;
169
170 #endif /* _UNGIF_H_ */
171
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