exiv2/src/mrwimage.cpp

// SPDX-License-Identifier: GPL-2.0-or-later

// included header files
#include "config.h"

#include "mrwimage.hpp"
#include "tiffimage.hpp"
#include "image.hpp"
#include "basicio.hpp"
#include "error.hpp"
#include "enforce.hpp"
#include "futils.hpp"

// + standard includes
#include <string>
#include <cstring>
#include <iostream>
#include <cassert>

// *****************************************************************************
// class member definitions
namespace Exiv2 {

    MrwImage::MrwImage(BasicIo::UniquePtr io, bool /*create*/)
        : Image(ImageType::mrw, mdExif | mdIptc | mdXmp, std::move(io))
    {
    } // MrwImage::MrwImage

    std::string MrwImage::mimeType() const
    {
        return "image/x-minolta-mrw";
    }

    uint32_t MrwImage::pixelWidth() const
    {
        auto imageWidth = exifData_.findKey(Exiv2::ExifKey("Exif.Image.ImageWidth"));
        if (imageWidth != exifData_.end() && imageWidth->count() > 0) {
            return imageWidth->toUint32();
        }
        return 0;
    }

    uint32_t MrwImage::pixelHeight() const
    {
        auto imageHeight = exifData_.findKey(Exiv2::ExifKey("Exif.Image.ImageLength"));
        if (imageHeight != exifData_.end() && imageHeight->count() > 0) {
            return imageHeight->toUint32();
        }
        return 0;
    }

    void MrwImage::setExifData(const ExifData& /*exifData*/)
    {
        // Todo: implement me!
        throw(Error(kerInvalidSettingForImage, "Exif metadata", "MRW"));
    }

    void MrwImage::setIptcData(const IptcData& /*iptcData*/)
    {
        // Todo: implement me!
        throw(Error(kerInvalidSettingForImage, "IPTC metadata", "MRW"));
    }

    void MrwImage::setComment(std::string_view /*comment*/)
    {
        // not supported
        throw(Error(kerInvalidSettingForImage, "Image comment", "MRW"));
    }

    void MrwImage::readMetadata()
    {
#ifdef EXIV2_DEBUG_MESSAGES
        std::cerr << "Reading MRW 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 (!isMrwType(*io_, false)) {
            if (io_->error() || io_->eof()) throw Error(kerFailedToReadImageData);
            throw Error(kerNotAnImage, "MRW");
        }
        clearMetadata();

        // Find the TTW block and read it into a buffer
        uint32_t const len = 8;
        byte tmp[len];
        io_->read(tmp, len);
        uint32_t pos = len;
        uint32_t const end = getULong(tmp + 4, bigEndian);

        pos += len;
        enforce(pos <= end, kerFailedToReadImageData);
        io_->read(tmp, len);
        if (io_->error() || io_->eof()) throw Error(kerFailedToReadImageData);

        while (memcmp(tmp + 1, "TTW", 3) != 0) {
            uint32_t const siz = getULong(tmp + 4, bigEndian);
            enforce(siz <= end - pos, kerFailedToReadImageData);
            pos += siz;
            io_->seek(siz, BasicIo::cur);
            enforce(!io_->error() && !io_->eof(), kerFailedToReadImageData);

            enforce(len <= end - pos, kerFailedToReadImageData);
            pos += len;
            io_->read(tmp, len);
            enforce(!io_->error() && !io_->eof(), kerFailedToReadImageData);
        }

        const uint32_t siz = getULong(tmp + 4, bigEndian);
        // First do an approximate bounds check of siz, so that we don't
        // get DOS-ed by a 4GB allocation on the next line. If siz is
        // greater than io_->size() then it is definitely invalid. But the
        // exact bounds checking is done by the call to io_->read, which
        // will fail if there are fewer than siz bytes left to read.
        enforce(siz <= io_->size(), kerFailedToReadImageData);
        DataBuf buf(siz);
        io_->read(buf.data(), buf.size());
        enforce(!io_->error() && !io_->eof(), kerFailedToReadImageData);

        ByteOrder bo = TiffParser::decode(exifData_,
                                          iptcData_,
                                          xmpData_,
                                          buf.c_data(),
                                          static_cast<uint32_t>(buf.size()));
        setByteOrder(bo);
    } // MrwImage::readMetadata

    void MrwImage::writeMetadata()
    {
        // Todo: implement me!
        throw(Error(kerWritingImageFormatUnsupported, "MRW"));
    } // MrwImage::writeMetadata

    // *************************************************************************
    // free functions
    Image::UniquePtr newMrwInstance(BasicIo::UniquePtr io, bool create)
    {
        auto image = std::make_unique<MrwImage>(std::move(io), create);
        if (!image->good()) {
            image.reset();
        }
        return image;
    }

    bool isMrwType(BasicIo& iIo, bool advance)
    {
        const int32_t len = 4;
        byte buf[len];
        iIo.read(buf, len);
        if (iIo.error() || iIo.eof()) {
            return false;
        }
        int rc = memcmp(buf, "\0MRM", 4);
        if (!advance || rc != 0) {
            iIo.seek(-len, BasicIo::cur);
        }
        return rc == 0;
    }

}                                       // namespace Exiv2