1 // ***************************************************************** -*- C++ -*-
2 // mrwthumb.cpp
3 // Sample program to extract a Minolta thumbnail from the makernote
4 /*
5 * Copyright (C) 2004-2021 Exiv2 authors
6 * This program is part of the Exiv2 distribution.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
21 */
22
23 #include <exiv2/exiv2.hpp>
24 #include <cassert>
25 #include <iostream>
26
main(int argc,char * const argv[])27 int main(int argc, char* const argv[])
28 {
29 Exiv2::XmpParser::initialize();
30 ::atexit(Exiv2::XmpParser::terminate);
31 #ifdef EXV_ENABLE_BMFF
32 Exiv2::enableBMFF();
33 #endif
34
35 try {
36 if (argc != 2) {
37 std::cout << "Usage: " << argv[0] << " file\n";
38 return 1;
39 }
40
41 Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(argv[1]);
42 assert(image.get() != 0);
43 image->readMetadata();
44
45 Exiv2::ExifData& exifData = image->exifData();
46 if (exifData.empty()) {
47 std::string error(argv[1]);
48 error += ": No Exif data found in the file";
49 throw Exiv2::Error(Exiv2::kerErrorMessage, error);
50 }
51
52 Exiv2::ExifKey key("Exif.Minolta.ThumbnailOffset");
53 Exiv2::ExifData::const_iterator format = exifData.findKey(key);
54
55 if (format != exifData.end()) {
56 Exiv2::DataBuf buf = format->dataArea();
57
58 // The first byte of the buffer needs to be patched
59 buf.pData_[0] = 0xff;
60
61 Exiv2::FileIo file("img_thumb.jpg");
62
63 file.open("wb");
64 file.write(buf.pData_, buf.size_);
65 file.close();
66 }
67
68 return 0;
69 } catch (Exiv2::AnyError& e) {
70 std::cout << "Caught Exiv2 exception '" << e << "'\n";
71 return -1;
72 }
73 }
74