// ***************************************************************** -*- C++ -*-
/*
* Copyright (C) 2004-2018 Exiv2 authors
* This program is part of the Exiv2 distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, 5th Floor, Boston, MA 02110-1301 USA.
*/
/*
File: bmpimage.cpp
Author(s): Marco Piovanelli, Ovolab (marco)
History: 05-Mar-2007, marco: created
*/
// *****************************************************************************
// included header files
#include "config.h"
#include "basicio.hpp"
#include "bmpimage.hpp"
#include "error.hpp"
#include "futils.hpp"
#include "image.hpp"
// + standard includes
#include <cstring>
#include <iostream>
#include <string>
// *****************************************************************************
// class member definitions
namespace Exiv2
{
BmpImage::BmpImage(BasicIo::AutoPtr io) : Image(ImageType::bmp, mdNone, io)
{
}
std::string BmpImage::mimeType() const
{
return "image/x-ms-bmp";
}
void BmpImage::setExifData(const ExifData& /*exifData*/)
{
// Todo: implement me!
throw(Error(kerInvalidSettingForImage, "Exif metadata", "BMP"));
}
void BmpImage::setIptcData(const IptcData& /*iptcData*/)
{
// Todo: implement me!
throw(Error(kerInvalidSettingForImage, "IPTC metadata", "BMP"));
}
void BmpImage::setComment(const std::string& /*comment*/)
{
// not supported
throw(Error(kerInvalidSettingForImage, "Image comment", "BMP"));
}
void BmpImage::readMetadata()
{
#ifdef EXIV2_DEBUG_MESSAGES
std::cerr << "Exiv2::BmpImage::readMetadata: Reading Windows bitmap file " << io_->path() << "\n";
#endif
if (io_->open() != 0) {
throw Error(kerDataSourceOpenFailed, io_->path(), strError());
}
IoCloser closer(*io_);
// Ensure that this is the correct image type
if (!isBmpType(*io_, false)) {
if (io_->error() || io_->eof()) throw Error(kerFailedToReadImageData);
throw Error(kerNotAnImage, "BMP");
}
clearMetadata();
/*
The Windows bitmap header goes as follows -- all numbers are in little-endian byte order:
offset length name description
====== ======= ===================== =======
0 2 bytes signature always 'BM'
2 4 bytes bitmap size
6 4 bytes reserved
10 4 bytes bitmap offset
14 4 bytes header size
18 4 bytes bitmap width
22 4 bytes bitmap height
26 2 bytes plane count
28 2 bytes depth
30 4 bytes compression 0 = none; 1 = RLE, 8 bits/pixel; 2 = RLE, 4 bits/pixel; 3 = bitfield; 4 = JPEG; 5 = PNG
34 4 bytes image size size of the raw bitmap data, in bytes
38 4 bytes horizontal resolution (in pixels per meter)
42 4 bytes vertical resolution (in pixels per meter)
46 4 bytes color count
50 4 bytes important colors number of "important" colors
*/
byte buf[54];
if (io_->read(buf, sizeof(buf)) == sizeof(buf)) {
pixelWidth_ = getLong(buf + 18, littleEndian);
pixelHeight_ = getLong(buf + 22, littleEndian);
}
}
void BmpImage::writeMetadata()
{
// Todo: implement me!
throw(Error(kerWritingImageFormatUnsupported, "BMP"));
}
// *************************************************************************
// free functions
Image::AutoPtr newBmpInstance(BasicIo::AutoPtr io, bool /*create*/)
{
Image::AutoPtr image(new BmpImage(io));
if (!image->good()) {
image.reset();
}
return image;
}
bool isBmpType(BasicIo& iIo, bool advance)
{
const int32_t len = 2;
const unsigned char BmpImageId[2] = {'B', 'M'};
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof()) {
return false;
}
bool matched = (memcmp(buf, BmpImageId, len) == 0);
if (!advance || !matched) {
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
}