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tiff_common.h
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1 /*
2  * TIFF Common Routines
3  * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * TIFF Common Routines
25  * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
26  */
27 
28 #ifndef AVCODEC_TIFF_COMMON_H
29 #define AVCODEC_TIFF_COMMON_H
30 
31 #include "avcodec.h"
32 #include "tiff.h"
33 #include "bytestream.h"
34 #include "libavutil/bprint.h"
35 
36 /** data type identifiers for TIFF tags */
37 enum TiffTypes {
38  TIFF_BYTE = 1,
51 };
52 
53 /** sizes of various TIFF field types (string size = 100)*/
54 static const uint8_t type_sizes[14] = {
55  0, 1, 100, 2, 4, 8, 1, 1, 2, 4, 8, 4, 8, 4
56 };
57 
58 static const uint16_t ifd_tags[] = {
59  0x8769, // EXIF IFD
60  0x8825, // GPS IFD
61  0xA005 // Interoperability IFD
62 };
63 
64 
65 /** Returns a value > 0 if the tag is a known IFD-tag.
66  * The return value is the array index + 1 within ifd_tags[].
67  */
68 int ff_tis_ifd(unsigned tag);
69 
70 /** Reads a short from the bytestream using given endianness. */
71 unsigned ff_tget_short(GetByteContext *gb, int le);
72 
73 /** Reads a long from the bytestream using given endianness. */
74 unsigned ff_tget_long(GetByteContext *gb, int le);
75 
76 /** Reads a double from the bytestream using given endianness. */
77 double ff_tget_double(GetByteContext *gb, int le);
78 
79 /** Reads a byte from the bytestream using given endianness. */
80 unsigned ff_tget(GetByteContext *gb, int type, int le);
81 
82 /** Returns an allocated string containing count
83  * rational values using the given separator.
84  */
85 char *ff_trationals2str(int *rp, int count, const char *sep);
86 
87 /** Returns an allocated string containing count
88  * long values using the given separator.
89  */
90 char *ff_tlongs2str(int32_t *lp, int count, const char *sep);
91 
92 /** Returns an allocated string containing count
93  * double values using the given separator.
94  */
95 char *ff_tdoubles2str(double *dp, int count, const char *sep);
96 
97 /** Returns an allocated string containing count
98  * short values using the given separator.
99  */
100 char *ff_tshorts2str(int16_t *sp, int count, const char *sep);
101 
102 /** Adds count rationals converted to a string
103  * into the metadata dictionary.
104  */
105 int ff_tadd_rational_metadata(int count, const char *name, const char *sep,
106  GetByteContext *gb, int le, AVDictionary **metadata);
107 
108 /** Adds count longs converted to a string
109  * into the metadata dictionary.
110  */
111 int ff_tadd_long_metadata(int count, const char *name, const char *sep,
112  GetByteContext *gb, int le, AVDictionary **metadata);
113 
114 /** Adds count doubles converted to a string
115  * into the metadata dictionary.
116  */
117 int ff_tadd_doubles_metadata(int count, const char *name, const char *sep,
118  GetByteContext *gb, int le, AVDictionary **metadata);
119 
120 /** Adds count shorts converted to a string
121  * into the metadata dictionary.
122  */
123 int ff_tadd_shorts_metadata(int count, const char *name, const char *sep,
124  GetByteContext *gb, int le, int is_signed, AVDictionary **metadata);
125 
126 /** Adds count bytes converted to a string
127  * into the metadata dictionary.
128  */
129 int ff_tadd_bytes_metadata(int count, const char *name, const char *sep,
130  GetByteContext *gb, int le, int is_signed, AVDictionary **metadata);
131 
132 /** Adds a string of count characters
133  * into the metadata dictionary.
134  */
135 int ff_tadd_string_metadata(int count, const char *name,
136  GetByteContext *gb, int le, AVDictionary **metadata);
137 
138 /** Decodes a TIFF header from the input bytestream
139  * and sets the endianness in *le and the offset to
140  * the first IFD in *ifd_offset accordingly.
141  */
142 int ff_tdecode_header(GetByteContext *gb, int *le, int *ifd_offset);
143 
144 /** Reads the first 3 fields of a TIFF tag, which are
145  * the tag id, the tag type and the count of values for that tag.
146  * Afterwards the bytestream is located at the first value to read and
147  * *next holds the bytestream offset of the following tag.
148  */
149 int ff_tread_tag(GetByteContext *gb, int le, unsigned *tag, unsigned *type,
150  unsigned *count, int *next);
151 
152 #endif /* AVCODEC_TIFF_COMMON_H */