1 /*
2 * Copyright 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef IMG_UTILS_TIFF_HELPERS_H
18 #define IMG_UTILS_TIFF_HELPERS_H
19
20 #include <stdint.h>
21
22 namespace android {
23 namespace img_utils {
24
25 const uint8_t ZERO_WORD[] = {0, 0, 0, 0};
26
27 #define BAIL_ON_FAIL(x, flag) \
28 if (((flag) = (x)) != OK) return flag;
29
30 #define BYTES_TILL_WORD(index) \
31 ((TIFF_WORD_SIZE - ((index) % TIFF_WORD_SIZE)) % TIFF_WORD_SIZE)
32
33 #define WORD_ALIGN(count) \
34 count += BYTES_TILL_WORD(count);
35
36 #define ZERO_TILL_WORD(output, index, ret) \
37 { \
38 size_t remaining = BYTES_TILL_WORD(index); \
39 if (remaining > 0) { \
40 BAIL_ON_FAIL((output)->write(ZERO_WORD, 0, remaining), ret); \
41 } \
42 }
43
44 /**
45 * Basic TIFF header constants.
46 */
47 enum {
48 BAD_OFFSET = 0,
49 TIFF_WORD_SIZE = 4, // Size in bytes
50 IFD_HEADER_SIZE = 2, // Size in bytes
51 IFD_FOOTER_SIZE = 4, // Size in bytes
52 TIFF_ENTRY_SIZE = 12, // Size in bytes
53 MAX_IFD_ENTRIES = UINT16_MAX,
54 FILE_HEADER_SIZE = 8, // Size in bytes
55 ENDIAN_MARKER_SIZE = 2, // Size in bytes
56 TIFF_MARKER_SIZE = 2, // Size in bytes
57 OFFSET_MARKER_SIZE = 4, // Size in bytes
58 TIFF_FILE_MARKER = 42,
59 BIG_ENDIAN_MARKER = 0x4D4Du,
60 LITTLE_ENDIAN_MARKER = 0x4949u
61 };
62
63 /**
64 * Constants for the TIFF tag types.
65 */
66 enum TagType {
67 UNKNOWN_TAGTYPE = 0,
68 BYTE=1,
69 ASCII,
70 SHORT,
71 LONG,
72 RATIONAL,
73 SBYTE,
74 UNDEFINED,
75 SSHORT,
76 SLONG,
77 SRATIONAL,
78 FLOAT,
79 DOUBLE
80 };
81
82 /**
83 * Sizes of the TIFF entry fields (in bytes).
84 */
85 enum {
86 TAG_SIZE = 2,
87 TYPE_SIZE = 2,
88 COUNT_SIZE = 4,
89 OFFSET_SIZE = 4
90 };
91
92 /**
93 * Convenience IFD id constants.
94 */
95 enum {
96 IFD_0 = 0,
97 RAW_IFD,
98 PROFILE_IFD,
99 PREVIEW_IFD
100 };
101
getTypeSize(TagType type)102 inline size_t getTypeSize(TagType type) {
103 switch(type) {
104 case UNDEFINED:
105 case ASCII:
106 case BYTE:
107 case SBYTE:
108 return 1;
109 case SHORT:
110 case SSHORT:
111 return 2;
112 case LONG:
113 case SLONG:
114 case FLOAT:
115 return 4;
116 case RATIONAL:
117 case SRATIONAL:
118 case DOUBLE:
119 return 8;
120 default:
121 return 0;
122 }
123 }
124
calculateIfdSize(size_t numberOfEntries)125 inline uint32_t calculateIfdSize(size_t numberOfEntries) {
126 return IFD_HEADER_SIZE + IFD_FOOTER_SIZE + TIFF_ENTRY_SIZE * numberOfEntries;
127 }
128
129 } /*namespace img_utils*/
130 } /*namespace android*/
131
132 #endif /*IMG_UTILS_TIFF_HELPERS_H*/
133