// ***************************************************************** -*- 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: gifimage.cpp
Author(s): Marco Piovanelli, Ovolab (marco)
History: 26-Feb-2007, marco: created
*/
// *****************************************************************************
// included header files
#include "config.h"
#include "gifimage.hpp"
#include "image.hpp"
#include "basicio.hpp"
#include "error.hpp"
#include "futils.hpp"
// + standard includes
#include <string>
#include <cstring>
#include <iostream>
// *****************************************************************************
// class member definitions
namespace Exiv2 {
GifImage::GifImage(BasicIo::AutoPtr io)
: Image(ImageType::gif, mdNone, io)
{
} // GifImage::GifImage
std::string GifImage::mimeType() const
{
return "image/gif";
}
void GifImage::setExifData(const ExifData& /*exifData*/)
{
// Todo: implement me!
throw(Error(kerInvalidSettingForImage, "Exif metadata", "GIF"));
}
void GifImage::setIptcData(const IptcData& /*iptcData*/)
{
// Todo: implement me!
throw(Error(kerInvalidSettingForImage, "IPTC metadata", "GIF"));
}
void GifImage::setComment(const std::string& /*comment*/)
{
// not supported
throw(Error(kerInvalidSettingForImage, "Image comment", "GIF"));
}
void GifImage::readMetadata()
{
#ifdef EXIV2_DEBUG_MESSAGES
std::cerr << "Exiv2::GifImage::readMetadata: Reading GIF 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 (!isGifType(*io_, true))
{
if (io_->error() || io_->eof()) throw Error(kerFailedToReadImageData);
throw Error(kerNotAnImage, "GIF");
}
clearMetadata();
byte buf[4];
if (io_->read(buf, sizeof(buf)) == sizeof(buf))
{
pixelWidth_ = getShort(buf, littleEndian);
pixelHeight_ = getShort(buf + 2, littleEndian);
}
} // GifImage::readMetadata
void GifImage::writeMetadata()
{
// Todo: implement me!
throw(Error(kerWritingImageFormatUnsupported, "GIF"));
} // GifImage::writeMetadata
// *************************************************************************
// free functions
Image::AutoPtr newGifInstance(BasicIo::AutoPtr io, bool /*create*/)
{
Image::AutoPtr image(new GifImage(io));
if (!image->good())
{
image.reset();
}
return image;
}
bool isGifType(BasicIo& iIo, bool advance)
{
const int32_t len = 6;
const unsigned char Gif87aId[8] = { 'G', 'I', 'F', '8', '7', 'a' };
const unsigned char Gif89aId[8] = { 'G', 'I', 'F', '8', '9', 'a' };
byte buf[len];
iIo.read(buf, len);
if (iIo.error() || iIo.eof())
{
return false;
}
bool matched = (memcmp(buf, Gif87aId, len) == 0)
|| (memcmp(buf, Gif89aId, len) == 0);
if (!advance || !matched)
{
iIo.seek(-len, BasicIo::cur);
}
return matched;
}
} // namespace Exiv2