1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
|
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include "Exif.hxx"
#include <memory>
#include <tools/stream.hxx>
Exif::Exif() :
maOrientation(TOP_LEFT),
mbExifPresent(false)
{}
Exif::~Exif()
{}
void Exif::setOrientation(Orientation aOrientation) {
maOrientation = aOrientation;
}
Orientation Exif::convertToOrientation(sal_Int32 value)
{
switch(value) {
case 1: return TOP_LEFT;
case 2: return TOP_RIGHT;
case 3: return BOTTOM_RIGHT;
case 4: return BOTTOM_LEFT;
case 5: return LEFT_TOP;
case 6: return RIGHT_TOP;
case 7: return RIGHT_BOTTOM;
case 8: return LEFT_BOTTOM;
}
return TOP_LEFT;
}
sal_Int32 Exif::getRotation()
{
switch(maOrientation) {
case TOP_LEFT:
return 0;
case BOTTOM_RIGHT:
return 1800;
case RIGHT_TOP:
return 2700;
case LEFT_BOTTOM:
return 900;
default:
break;
}
return 0;
}
bool Exif::read(SvStream& rStream)
{
sal_Int32 nStreamPosition = rStream.Tell();
bool result = processJpeg(rStream, false);
rStream.Seek( nStreamPosition );
return result;
}
void Exif::write(SvStream& rStream)
{
sal_Int32 nStreamPosition = rStream.Tell();
processJpeg(rStream, true);
rStream.Seek( nStreamPosition );
}
bool Exif::processJpeg(SvStream& rStream, bool bSetValue)
{
sal_uInt16 aMagic16;
sal_uInt16 aLength;
sal_uInt32 aSize = rStream.TellEnd();
rStream.Seek(STREAM_SEEK_TO_BEGIN);
rStream.SetEndian( SvStreamEndian::BIG );
rStream.ReadUInt16( aMagic16 );
// Compare JPEG magic bytes
if( 0xFFD8 != aMagic16 )
{
return false;
}
sal_uInt32 aPreviousPosition = STREAM_SEEK_TO_BEGIN;
while(true)
{
sal_uInt8 aMarker = 0xD9;
sal_Int32 aCount;
for (aCount = 0; aCount < 7; aCount++)
{
rStream.ReadUChar( aMarker );
if (aMarker != 0xFF)
{
break;
}
if (aCount >= 6)
{
return false;
}
}
rStream.ReadUInt16( aLength );
if (aLength < 8 || aLength > rStream.remainingSize())
{
return false;
}
if (aMarker == 0xE1)
{
return processExif(rStream, aLength, bSetValue);
}
else if (aMarker == 0xD9)
{
return false;
}
else
{
sal_uInt32 aCurrentPosition = rStream.SeekRel(aLength-1);
if (aCurrentPosition == aPreviousPosition || aCurrentPosition > aSize)
{
return false;
}
aPreviousPosition = aCurrentPosition;
}
}
return false;
}
void Exif::processIFD(sal_uInt8* pExifData, sal_uInt16 aLength, sal_uInt16 aOffset, sal_uInt16 aNumberOfTags, bool bSetValue, bool bSwap)
{
ExifIFD* ifd = nullptr;
while (aOffset <= aLength - 12 && aNumberOfTags > 0)
{
ifd = reinterpret_cast<ExifIFD*>(&pExifData[aOffset]);
sal_uInt16 tag = ifd->tag;
if (bSwap)
{
tag = OSL_SWAPWORD(ifd->tag);
}
if (tag == ORIENTATION)
{
if(bSetValue)
{
ifd->tag = ORIENTATION;
ifd->type = 3;
ifd->count = 1;
ifd->offset = maOrientation;
if (bSwap)
{
ifd->tag = OSL_SWAPWORD(ifd->tag);
ifd->offset = OSL_SWAPWORD(ifd->offset);
}
}
else
{
sal_uInt32 nIfdOffset = ifd->offset;
if (bSwap)
nIfdOffset = OSL_SWAPWORD(ifd->offset);
maOrientation = convertToOrientation(nIfdOffset);
}
}
aNumberOfTags--;
aOffset += 12;
}
}
bool Exif::processExif(SvStream& rStream, sal_uInt16 aSectionLength, bool bSetValue)
{
sal_uInt32 aMagic32;
sal_uInt16 aMagic16;
rStream.ReadUInt32( aMagic32 );
rStream.ReadUInt16( aMagic16 );
// Compare EXIF magic bytes
if( 0x45786966 != aMagic32 || 0x0000 != aMagic16)
{
return false;
}
sal_uInt16 aLength = aSectionLength - 6; // Length = Section - Header
std::unique_ptr<sal_uInt8[]> aExifData(new sal_uInt8[aLength]);
sal_uInt32 aExifDataBeginPosition = rStream.Tell();
rStream.ReadBytes(aExifData.get(), aLength);
// Exif detected
mbExifPresent = true;
TiffHeader* aTiffHeader = reinterpret_cast<TiffHeader*>(&aExifData[0]);
bool bIntel = aTiffHeader->byteOrder == 0x4949; //big-endian
bool bMotorola = aTiffHeader->byteOrder == 0x4D4D; //little-endian
if (!bIntel && !bMotorola)
{
return false;
}
bool bSwap = false;
#ifdef OSL_BIGENDIAN
if (bIntel)
bSwap = true;
#else
if (bMotorola)
bSwap = true;
#endif
if (bSwap)
{
aTiffHeader->tagAlign = OSL_SWAPWORD(aTiffHeader->tagAlign);
aTiffHeader->offset = OSL_SWAPDWORD(aTiffHeader->offset);
}
if (aTiffHeader->tagAlign != 0x002A) // TIFF tag
{
return false;
}
sal_uInt16 aOffset = aTiffHeader->offset;
sal_uInt16 aNumberOfTags = aExifData[aOffset];
if (bSwap)
{
aNumberOfTags = ((aExifData[aOffset] << 8) | aExifData[aOffset+1]);
}
processIFD(aExifData.get(), aLength, aOffset+2, aNumberOfTags, bSetValue, bSwap);
if (bSetValue)
{
rStream.Seek(aExifDataBeginPosition);
rStream.WriteBytes(aExifData.get(), aLength);
}
return true;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
