int JpegContent::dotsPerMeter(const QString& keyName) const
{
    Exiv2::ExifKey keyResUnit("Exif.Image.ResolutionUnit");
    Exiv2::ExifData::iterator it = d->mExifData.findKey(keyResUnit);
    if (it == d->mExifData.end()) {
        return 0;
    }
    int res = it->toLong();
    QString keyVal = "Exif.Image." + keyName;
    Exiv2::ExifKey keyResolution(keyVal.toAscii().data());
    it = d->mExifData.findKey(keyResolution);
    if (it == d->mExifData.end()) {
        return 0;
    }
    // The unit for measuring XResolution and YResolution. The same unit is used for both XResolution and YResolution.
    //     If the image resolution in unknown, 2 (inches) is designated.
    //         Default = 2
    //         2 = inches
    //         3 = centimeters
    //         Other = reserved
    const float INCHESPERMETER = (100. / 2.54);
    switch (res) {
    case 3:  // dots per cm
        return int(it->toLong() * 100);
    default:  // dots per inch
        return int(it->toLong() * INCHESPERMETER);
    }

    return 0;
}

    bool getExifDateTime(Exiv2::ExifData &exifData, QDateTime &dateTime) {
        bool anyFound = false;

        try {
            Exiv2::ExifKey key(EXIF_PHOTO_DATETIMEORIGINAL);
            Exiv2::ExifData::iterator it = exifData.findKey(key);
            if (it != exifData.end()) {
                dateTime = QDateTime::fromString(QString::fromLatin1(it->toString().c_str()), Qt::ISODate);
                anyFound = dateTime.isValid();
            }

            if (!anyFound) {
                Exiv2::ExifKey imageKey(EXIF_IMAGE_DATETIMEORIGINAL);
                Exiv2::ExifData::iterator imageIt = exifData.findKey(imageKey);
                if (imageIt != exifData.end()) {
                    dateTime = QDateTime::fromString(QString::fromLatin1(imageIt->toString().c_str()), Qt::ISODate);
                    anyFound = dateTime.isValid();
                }
            }
        }
        catch (Exiv2::Error &e) {
            LOG_WARNING << "Exiv2 error:" << e.what();
            anyFound = false;
        }
        catch (...) {
            LOG_WARNING << "Exception";
            anyFound = false;
#ifdef QT_DEBUG
            throw;
#endif
        }

        return anyFound;
    }

Orientation JpegContent::orientation() const
{
    Exiv2::ExifKey key("Exif.Image.Orientation");
    Exiv2::ExifData::iterator it = d->mExifData.findKey(key);

    // We do the same checks as in libexiv2's src/crwimage.cpp:
    // http://dev.exiv2.org/projects/exiv2/repository/entry/trunk/src/crwimage.cpp?rev=2681#L1336
    if (it == d->mExifData.end() || it->count() == 0 || it->typeId() != Exiv2::unsignedShort) {
        return NOT_AVAILABLE;
    }
    return Orientation(it->toLong());
}

 bool _getExiv2Value(Exiv2::ExifData& exifData, std::string keyName, float & value)
 {
     Exiv2::ExifData::iterator itr = exifData.findKey(Exiv2::ExifKey(keyName));
     if (itr != exifData.end() && itr->count())
     {
         value = itr->toFloat();
         return true;
     }
     else
     {
         return false;
     };
 };

static void EraseGpsTags(Exiv2::ExifData &ExifInfo)
{
	// Search through, find the keys that we want, and wipe them
	// Code below submitted by Marc Horowitz
	Exiv2::ExifData::iterator Iter;
	for (Exiv2::ExifData::iterator Iter = ExifInfo.begin();
		Iter != ExifInfo.end(); )
	{
		if (Iter->key().find("Exif.GPSInfo") == 0)
			Iter = ExifInfo.erase(Iter);
		else
			Iter++;
	}
}

QString Previewimage::getExifKey(QString key, Exiv2::ExifData *exifData){
    // returns string represented by exif key
    if(exifData == 0) return QString();
    QString ret;
    try {
        Exiv2::ExifData::iterator pos = exifData->findKey(
                    Exiv2::ExifKey(qPrintable(key)));
        if (pos == exifData->end()) return QString();
        else ret = QString().fromStdString(pos->value().toString());
    } catch (Exiv2::Error& e) {
        qCritical("[Rename] %s", e.what());
    }
    return ret;
}

// *****************************************************************************
void testCase(const std::string& file1,
              const std::string& file2,
              const std::string& thumb,
              const std::string& key,
              const std::string& value)
{
    Key1 ek(key);

    //Open first image
    Image::AutoPtr image1 = ImageFactory::open(file1);
    assert(image1.get() != 0);

    // Load existing metadata
    std::cerr << "---> Reading file " << file1 << "\n";
    image1->readMetadata();

    Exiv2::ExifData &ed1 = image1->exifData();
    std::cerr << "---> Modifying Exif data\n";
    Exiv2::ExifData::iterator pos = ed1.findKey(ek);
    if (pos == ed1.end()) {
        throw Error(1, "Metadatum with key = " + ek.key() + " not found");
    }
    pos->setValue(value);

    // Open second image
    Image::AutoPtr image2 = ImageFactory::open(file2);
    assert(image2.get() != 0);

    image2->setExifData(image1->exifData());

    std::cerr << "---> Writing Exif data to file " << file2 << "\n";
    image2->writeMetadata();

    std::cerr << "---> Reading file " << file2 << "\n";
    image2->readMetadata();

    Exiv2::ExifData &ed2 = image2->exifData();
    exifPrint(ed2);

    std::cerr << "---> Writing Exif thumbnail to file " << thumb << ".*\n";
    ExifThumbC et2(ed2);
    et2.writeFile(thumb);
}

 //for diagnostic
 void PrintTag(Exiv2::ExifData::iterator itr)
 {
     std::cout << itr->value() << " (" << itr->typeName() << ", size: " << itr->count() << ")" << std::endl;
     if(itr->count()>1)
     {
         std::cout << "[";
         for(long i=0; i<itr->count(); i++)
         {
             std::cout << itr->toFloat(i) << ",";
         }
         std::cout << "]" << std::endl;
     };
 };

//.........这里部分代码省略.........
        for ( size_t p = 0 ; !options.dryrun && p < gFiles.size() ; p++ ) {
            std::string arg = gFiles[p] ;
            std::string stamp ;
            try {
                time_t t       = readImageTime(arg,&stamp) ;
                Position* pPos = searchTimeDict(gTimeDict,t,Position::deltaMax_);
                Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(gFiles[p]);
                if ( image.get() ) {
                    image->readMetadata();
                    Exiv2::ExifData& exifData = image->exifData();
#if 0
                    /*
					char* keys[]={ "Exif.Image.GPSTag"
						         , "Exif.GPSInfo.GPSProcessingMethod"
					             , "Exif.GPSInfo.GPSAltitudeRef"
							     , "Exif.GPSInfo.GPSVersionID"
                                 , "Exif.GPSInfo.GPSProcessingMethod"
                                 , "Exif.GPSInfo.GPSVersionID"
                                 , "Exif.GPSInfo.GPSMapDatum"
                                 , "Exif.GPSInfo.GPSLatitude"
                                 , "Exif.GPSInfo.GPSLongitude"
                                 , "Exif.GPSInfo.GPSAltitude"
                                 , "Exif.GPSInfo.GPSAltitudeRef"
                                 , "Exif.GPSInfo.GPSLatitudeRef"
                                 , "Exif.GPSInfo.GPSLongitudeRef"
                                 , "Exif.GPSInfo.GPSDateStamp"
                                 , "Exif.GPSInfo.GPSTimeStamp"
					};
					static int bPrint = true ;
					for ( int k = 0 ; k < 15 ;   k++ ) {
						try {
							if ( bPrint ) printf("erasing %s\n",keys[k]);
							Exiv2::ExifKey  key = Exiv2::ExifKey(keys[k]);
							Exiv2::ExifData::iterator kk = exifData.findKey(key);
							if ( kk != exifData.end() ) exifData.erase(kk);
						} catch (...) {};
					}
					bPrint = false;
                    */
#endif
#if 0
					Exiv2::ExifData::const_iterator end = exifData.end();
					for (Exiv2::ExifData::iterator i = exifData.begin(); i != end; ++i) {
						char name[100];
						strcpy(name,i->key().c_str());
						// std::cout << "sniff " << i->key() << std::endl;
						if ( strstr(name,"GPS") )  {
							Exiv2::ExifData::iterator pos;
							Exiv2::ExifKey exifKey = Exiv2::ExifKey(name);
							pos = exifData.findKey(exifKey);
							while( pos != exifData.end()) {
								exifData.erase(pos);
							}
						}
					}
#endif
					if ( pPos ) {
						/*
						   struct _stat buf;
   int result;
   char timebuf[26];
   char* filename = "crt_stat.c";
   errno_t err;

   // Get data associated with "crt_stat.c":
   result = _stat( filename, &buf );

// *****************************************************************************
// Main
int main(int argc, char* const argv[])
try {

    if (argc != 2) {
        std::cout << "Usage: " << argv[0] << " file\n";
        return 1;
    }

    Exiv2::ExifData exifData;
    int rc = exifData.read(argv[1]);
    if (rc) {
        std::string error = Exiv2::ExifData::strError(rc, argv[1]);
        throw Exiv2::Error(error);
    }

    /*
      There are two pitfalls that we need to consider when setting the Exif user
      comment (Exif.Photo.UserComment) of an image:

      First, the type of the Exif user comment tag is "undefined" (and not
      ASCII) according to the Exif standard. This means that in Exiv2, we have
      to deal with a DataValue (and not an AsciiValue). DataValue has the usual
      two read methods, however, the one taking a const std::string& buf expects
      the string to contain a series of integers (e.g., "0 1 2") and not a text
      string. Thus, we need to use the read function that reads the value from a
      character buffer of a given length.

      Second, the Exif comment field starts with an eight character area that
      identifies the used character set. For ASCII, these eight characters are
      "ASCII\0\0\0". The actual comment follows after this code.

      Note: There is a more simple Exif tag for the title of an image. It is a
      20 byte string (type ASCII) and does not store two-byte characters.
      (Image.OtherTags.ImageDescription)
     */

    // Initialise a data value with the character set and comment
    std::string charset("ASCII\0\0\0", 8);
    std::string comment("A comment added to the Exif metadata through Exiv2");
    Exiv2::DataValue value;
    value.read(reinterpret_cast<const Exiv2::byte*>((charset + comment).data()), 
                8 + static_cast<long>(comment.size()));

    // Set the Exif comment
    Exiv2::ExifKey key("Exif.Photo.UserComment");
    Exiv2::ExifData::iterator pos = exifData.findKey(key);
    if (pos != exifData.end()) {
        // Use the existing Exif UserComment metadatum if there is one
        pos->setValue(&value);
    }
    else {
        // Otherwise add a new UserComment metadatum
        exifData.add(key, &value);
        pos = exifData.findKey(key);
    }

    // Now we should have a valid iterator in any case. We use the metadatum
    // output operator to print the formatted value
    std::cout << "Writing user comment '" << *pos << "' back to the image\n";

    rc = exifData.write(argv[1]);
    if (rc) {
        std::string error = Exiv2::ExifData::strError(rc, argv[1]);
        throw Exiv2::Error(error);
    }

   return rc;
}
catch (Exiv2::Error& e) {
    std::cout << "Caught Exiv2 exception '" << e << "'\n";
    return -1;
}

bool KExiv2::Private::saveOperations(const QFileInfo& finfo, Exiv2::Image::AutoPtr image) const
{
    try
    {
        Exiv2::AccessMode mode;
        bool wroteComment = false, wroteEXIF = false, wroteIPTC = false, wroteXMP = false;

        // We need to load target file metadata to merge with new one. It's mandatory with TIFF format:
        // like all tiff file structure is based on Exif.
        image->readMetadata();

        // Image Comments ---------------------------------

        mode = image->checkMode(Exiv2::mdComment);

        if ((mode == Exiv2::amWrite) || (mode == Exiv2::amReadWrite))
        {
            image->setComment(imageComments());
            wroteComment = true;
        }

        // Exif metadata ----------------------------------

        mode = image->checkMode(Exiv2::mdExif);

        if ((mode == Exiv2::amWrite) || (mode == Exiv2::amReadWrite))
        {
            if (image->mimeType() == "image/tiff")
            {
                Exiv2::ExifData orgExif = image->exifData();
                Exiv2::ExifData newExif;
                QStringList     untouchedTags;

                // With tiff image we cannot overwrite whole Exif data as well, because
                // image data are stored in Exif container. We need to take a care about
                // to not lost image data.
                untouchedTags << "Exif.Image.ImageWidth";
                untouchedTags << "Exif.Image.ImageLength";
                untouchedTags << "Exif.Image.BitsPerSample";
                untouchedTags << "Exif.Image.Compression";
                untouchedTags << "Exif.Image.PhotometricInterpretation";
                untouchedTags << "Exif.Image.FillOrder";
                untouchedTags << "Exif.Image.SamplesPerPixel";
                untouchedTags << "Exif.Image.StripOffsets";
                untouchedTags << "Exif.Image.RowsPerStrip";
                untouchedTags << "Exif.Image.StripByteCounts";
                untouchedTags << "Exif.Image.XResolution";
                untouchedTags << "Exif.Image.YResolution";
                untouchedTags << "Exif.Image.PlanarConfiguration";
                untouchedTags << "Exif.Image.ResolutionUnit";

                for (Exiv2::ExifData::iterator it = orgExif.begin(); it != orgExif.end(); ++it)
                {
                    if (untouchedTags.contains(it->key().c_str()))
                    {
                        newExif[it->key().c_str()] = orgExif[it->key().c_str()];
                    }
                }

                Exiv2::ExifData readedExif = exifMetadata();

                for (Exiv2::ExifData::iterator it = readedExif.begin(); it != readedExif.end(); ++it)
                {
                    if (!untouchedTags.contains(it->key().c_str()))
                    {
                        newExif[it->key().c_str()] = readedExif[it->key().c_str()];
                    }
                }

                image->setExifData(newExif);
            }
            else
            {
                image->setExifData(exifMetadata());
            }

            wroteEXIF = true;
        }

        // Iptc metadata ----------------------------------

        mode = image->checkMode(Exiv2::mdIptc);

        if ((mode == Exiv2::amWrite) || (mode == Exiv2::amReadWrite))
        {
            image->setIptcData(iptcMetadata());
            wroteIPTC = true;
        }

        // Xmp metadata -----------------------------------

        mode = image->checkMode(Exiv2::mdXmp);

        if ((mode == Exiv2::amWrite) || (mode == Exiv2::amReadWrite))
        {
#ifdef _XMP_SUPPORT_
            image->setXmpData(xmpMetadata());
            wroteXMP = true;
#endif
        }
//.........这里部分代码省略.........

bool ptImageHelper::WriteExif(const QString              &AFileName,
                              const std::vector<uint8_t> &AExifBuffer,
                              Exiv2::IptcData            &AIptcData,
                              Exiv2::XmpData             &AXmpData) {
  try {
#if EXIV2_TEST_VERSION(0,17,91)   /* Exiv2 0.18-pre1 */

    Exiv2::ExifData hInExifData;

    Exiv2::ExifParser::decode(hInExifData,
                              AExifBuffer.data() + CExifHeader.size(),
                              AExifBuffer.size() - CExifHeader.size());

    // Reset orientation
    Exiv2::ExifData::iterator pos = hInExifData.begin();
    if ((pos = hInExifData.findKey(Exiv2::ExifKey("Exif.Image.Orientation"))) != hInExifData.end()) {
      pos->setValue("1"); // Normal orientation
    }

    // Adapted from UFRaw, necessary for Tiff files
    QStringList ExifKeys;
    ExifKeys  << "Exif.Image.ImageWidth"
              << "Exif.Image.ImageLength"
              << "Exif.Image.BitsPerSample"
              << "Exif.Image.Compression"
              << "Exif.Image.PhotometricInterpretation"
              << "Exif.Image.FillOrder"
              << "Exif.Image.SamplesPerPixel"
              << "Exif.Image.StripOffsets"
              << "Exif.Image.RowsPerStrip"
              << "Exif.Image.StripByteCounts"
              << "Exif.Image.XResolution"
              << "Exif.Image.YResolution"
              << "Exif.Image.PlanarConfiguration"
              << "Exif.Image.ResolutionUnit";

    for (short i = 0; i < ExifKeys.count(); i++) {
      if ((pos = hInExifData.findKey(Exiv2::ExifKey(ExifKeys.at(i).toLocal8Bit().data()))) != hInExifData.end())
        hInExifData.erase(pos);
    }

    if (Settings->GetInt("EraseExifThumbnail")) {
      Exiv2::ExifThumb Thumb(hInExifData);
      Thumb.erase();
    }

    QStringList JpegExtensions;
    JpegExtensions << "jpg" << "JPG" << "Jpg" << "jpeg" << "Jpeg" << "JPEG";
    bool deleteDNGdata = false;
    for (short i = 0; i < JpegExtensions.count(); i++) {
      if (!AFileName.endsWith(JpegExtensions.at(i))) deleteDNGdata = true;
    }

    Exiv2::Image::AutoPtr Exiv2Image = Exiv2::ImageFactory::open(AFileName.toLocal8Bit().data());

    Exiv2Image->readMetadata();
    Exiv2::ExifData outExifData = Exiv2Image->exifData();

    for (auto hPos = hInExifData.begin(); hPos != hInExifData.end(); hPos++) {
      if (!deleteDNGdata || (*hPos).key() != "Exif.Image.DNGPrivateData") {
        outExifData.add(*hPos);
      }
    }

    // IPTC data

    QStringList Tags        = Settings->GetStringList("TagsList");
    QStringList DigikamTags = Settings->GetStringList("DigikamTagsList");

    Exiv2::StringValue StringValue;
    for (int i = 0; i < Tags.size(); i++) {
      StringValue.read(Tags.at(i).toStdString());
      AIptcData.add(Exiv2::IptcKey("Iptc.Application2.Keywords"), &StringValue);
    }


    // XMP data

    for (int i = 0; i < Tags.size(); i++) {
      AXmpData["Xmp.dc.subject"] = Tags.at(i).toStdString();
    }
    for (int i = 0; i < DigikamTags.size(); i++) {
      AXmpData["Xmp.digiKam.TagsList"] = DigikamTags.at(i).toStdString();
    }

    // Image rating
    outExifData["Exif.Image.Rating"] = Settings->GetInt("ImageRating");
    AXmpData["Xmp.xmp.Rating"]       = Settings->GetInt("ImageRating");

    // Program name
    outExifData["Exif.Image.ProcessingSoftware"]  = ProgramName;
    outExifData["Exif.Image.Software"]            = ProgramName;
    AIptcData["Iptc.Application2.Program"]        = ProgramName;
    AIptcData["Iptc.Application2.ProgramVersion"] = "idle";
    AXmpData["Xmp.xmp.CreatorTool"]               = ProgramName;
    AXmpData["Xmp.tiff.Software"]                 = ProgramName;

    // Title
    QString TitleWorking = Settings->GetString("ImageTitle");
    StringClean(TitleWorking);
//.........这里部分代码省略.........

bool KExiv2::setImageOrientation(ImageOrientation orientation, bool setProgramName) const
{
    if (!setProgramId(setProgramName))
        return false;

    try
    {
        if (orientation < ORIENTATION_UNSPECIFIED || orientation > ORIENTATION_ROT_270)
        {
            kDebug() << "Image orientation value is not correct!";
            return false;
        }

        // Set Exif values.

        d->exifMetadata()["Exif.Image.Orientation"] = static_cast<uint16_t>(orientation);
        kDebug() << "Exif.Image.Orientation tag set to: " << (int)orientation;

        // Set Xmp values.

#ifdef _XMP_SUPPORT_

        setXmpTagString("Xmp.tiff.Orientation", QString::number((int)orientation), false);

#endif // _XMP_SUPPORT_

        // -- Minolta/Sony Cameras ----------------------------------

        // Minolta and Sony camera store image rotation in Makernote.
        // We remove these information to prevent duplicate values.

        Exiv2::ExifData::iterator it;

        Exiv2::ExifKey minoltaKey1("Exif.MinoltaCs7D.Rotation");
        it = d->exifMetadata().findKey(minoltaKey1);
        if (it != d->exifMetadata().end())
        {
            d->exifMetadata().erase(it);
            kDebug() << "Removing Exif.MinoltaCs7D.Rotation tag";
        }

        Exiv2::ExifKey minoltaKey2("Exif.MinoltaCs5D.Rotation");
        it = d->exifMetadata().findKey(minoltaKey2);
        if (it != d->exifMetadata().end())
        {
            d->exifMetadata().erase(it);
            kDebug() << "Removing Exif.MinoltaCs5D.Rotation tag";
        }

        // -- Exif embedded thumbnail ----------------------------------

        Exiv2::ExifKey thumbKey("Exif.Thumbnail.Orientation");
        it = d->exifMetadata().findKey(thumbKey);
        if (it != d->exifMetadata().end() && it->count())
        {
            RotationMatrix operation((KExiv2Iface::KExiv2::ImageOrientation)it->toLong());
            operation *= orientation;
            (*it) = static_cast<uint16_t>(operation.exifOrientation());
        }

        return true;
    }
    catch( Exiv2::Error& e )
    {
        d->printExiv2ExceptionError("Cannot set Exif Orientation tag using Exiv2 ", e);
    }
    catch(...)
    {
        kError() << "Default exception from Exiv2";
    }

    return false;
}

KExiv2::ImageOrientation KExiv2::getImageOrientation() const
{
    try
    {
        Exiv2::ExifData exifData(d->exifMetadata());
        Exiv2::ExifData::iterator it;
        long orientation;
        ImageOrientation imageOrient = ORIENTATION_NORMAL;

        // -- Standard Xmp tag --------------------------------

#ifdef _XMP_SUPPORT_

        bool ok = false;
        QString str = getXmpTagString("Xmp.tiff.Orientation");
        if (!str.isEmpty())
        {
            orientation = str.toLong(&ok);
            if (ok)
            {
                kDebug() << "Orientation => Xmp.tiff.Orientation => " << (int)orientation;
                return (ImageOrientation)orientation;
            }
        }

#endif // _XMP_SUPPORT_

        // Because some camera set a wrong standard exif orientation tag,
        // We need to check makernote tags in first!

        // -- Minolta Cameras ----------------------------------

        Exiv2::ExifKey minoltaKey1("Exif.MinoltaCs7D.Rotation");
        it = exifData.findKey(minoltaKey1);

        if (it != exifData.end() && it->count())
        {
            orientation = it->toLong();
            kDebug() << "Orientation => Exif.MinoltaCs7D.Rotation => " << (int)orientation;
            switch(orientation)
            {
                case 76:
                    imageOrient = ORIENTATION_ROT_90;
                    break;
                case 82:
                    imageOrient = ORIENTATION_ROT_270;
                    break;
            }
            return imageOrient;
        }

        Exiv2::ExifKey minoltaKey2("Exif.MinoltaCs5D.Rotation");
        it = exifData.findKey(minoltaKey2);

        if (it != exifData.end() && it->count())
        {
            orientation = it->toLong();
            kDebug() << "Orientation => Exif.MinoltaCs5D.Rotation => " << (int)orientation;
            switch(orientation)
            {
                case 76:
                    imageOrient = ORIENTATION_ROT_90;
                    break;
                case 82:
                    imageOrient = ORIENTATION_ROT_270;
                    break;
            }
            return imageOrient;
        }

        // -- Standard Exif tag --------------------------------

        Exiv2::ExifKey keyStd("Exif.Image.Orientation");
        it = exifData.findKey(keyStd);

        if (it != exifData.end() && it->count())
        {
            orientation = it->toLong();
            kDebug() << "Orientation => Exif.Image.Orientation => " << (int)orientation;
            return (ImageOrientation)orientation;
        }

    }
    catch( Exiv2::Error& e )
    {
        d->printExiv2ExceptionError("Cannot parse Exif Orientation tag using Exiv2 ", e);
    }
    catch(...)
    {
        kError() << "Default exception from Exiv2";
    }

    return ORIENTATION_UNSPECIFIED;
}

long GalleryUtil::GetNaturalRotation(const QString &filePathString)
{
    long rotateAngle = 0;
#ifdef EXIF_SUPPORT
    QByteArray filePathBA = filePathString.toLocal8Bit();
    const char *filePath = filePathBA.constData();

    try
    {
        char *exifvalue = new char[1024];
        ExifData *data = exif_data_new_from_file (filePath);
        if (data)
        {
            for (int i = 0; i < EXIF_IFD_COUNT; i++)
            {
                ExifEntry *entry = exif_content_get_entry (data->ifd[i],
                                                        EXIF_TAG_ORIENTATION);
                ExifByteOrder byteorder = exif_data_get_byte_order (data);

                if (entry)
                {
                    ExifShort v_short = exif_get_short (entry->data, byteorder);
                    VERBOSE(VB_GENERAL|VB_EXTRA, QString("Exif entry=%1").arg(v_short));
                    /* See http://sylvana.net/jpegcrop/exif_orientation.html*/
                    if (v_short == 8)
                    {
                        rotateAngle = -90;
                    }
                    else if (v_short == 6)
                    {
                        rotateAngle = 90;
                    }
                    break;
                }
            }
            exif_data_free(data);
        }
        else
        {
            VERBOSE(VB_FILE, LOC_ERR +
                    QString("Could not load exif data from '%1'")
                    .arg(filePath));
        }
        
        delete [] exifvalue;
        
#if 0
        Exiv2::ExifData exifData;
        int rc = exifData.read(filePath);
        if (!rc)
        {
            Exiv2::ExifKey key = Exiv2::ExifKey("Exif.Image.Orientation");
            Exiv2::ExifData::iterator pos = exifData.findKey(key);
            if (pos != exifData.end())
            {
                long orientation = pos->toLong();
                switch (orientation)
                {
                    case 6:
                        rotateAngle = 90;
                        break;
                    case 8:
                        rotateAngle = -90;
                        break;
                    default:
                        rotateAngle = 0;
                        break;
                }
            }
        }
#endif
    }
    catch (...)
    {
        VERBOSE(VB_IMPORTANT, LOC_ERR +
                QString("Failed to extract EXIF headers from '%1'")
                .arg(filePathString));
    }

#else
    // Shut the compiler up about the unused argument
    (void)filePathString;
#endif // EXIF_SUPPORT
    return rotateAngle;
}

QgsPoint QgsExifTools::getGeoTag( const QString &imagePath, bool &ok )
{
  ok = false;
  if ( !QFileInfo::exists( imagePath ) )
    return QgsPoint();
  try
  {
    std::unique_ptr< Exiv2::Image > image( Exiv2::ImageFactory::open( imagePath.toStdString() ) );
    if ( !image )
      return QgsPoint();

    image->readMetadata();
    Exiv2::ExifData &exifData = image->exifData();

    if ( exifData.empty() )
      return QgsPoint();

    Exiv2::ExifData::iterator itLatRef = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLatitudeRef" ) );
    Exiv2::ExifData::iterator itLatVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLatitude" ) );
    Exiv2::ExifData::iterator itLonRef = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLongitudeRef" ) );
    Exiv2::ExifData::iterator itLonVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSLongitude" ) );

    if ( itLatRef == exifData.end() || itLatVal == exifData.end() ||
         itLonRef == exifData.end() || itLonVal == exifData.end() )
      return QgsPoint();

    auto readCoord = []( const QString & coord )->double
    {
      double res = 0;
      double div = 1;
      const QStringList parts = coord.split( QRegularExpression( QStringLiteral( "\\s+" ) ) );
      for ( const QString &rational : parts )
      {
        const QStringList pair = rational.split( '/' );
        if ( pair.size() != 2 )
          break;
        res += ( pair[0].toDouble() / pair[1].toDouble() ) / div;
        div *= 60;
      }
      return res;
    };

    auto readRationale = []( const QString & rational )->double
    {
      const QStringList pair = rational.split( '/' );
      if ( pair.size() != 2 )
        return std::numeric_limits< double >::quiet_NaN();
      return pair[0].toDouble() / pair[1].toDouble();
    };

    double lat = readCoord( QString::fromStdString( itLatVal->value().toString() ) );
    double lon = readCoord( QString::fromStdString( itLonVal->value().toString() ) );

    const QString latRef = QString::fromStdString( itLatRef->value().toString() );
    const QString lonRef = QString::fromStdString( itLonRef->value().toString() );
    if ( latRef.compare( QLatin1String( "S" ), Qt::CaseInsensitive ) == 0 )
    {
      lat *= -1;
    }
    if ( lonRef.compare( QLatin1String( "W" ), Qt::CaseInsensitive ) == 0 )
    {
      lon *= -1;
    }

    ok = true;

    Exiv2::ExifData::iterator itElevVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSAltitude" ) );
    Exiv2::ExifData::iterator itElevRefVal = exifData.findKey( Exiv2::ExifKey( "Exif.GPSInfo.GPSAltitudeRef" ) );
    if ( itElevVal != exifData.end() )
    {
      double elev = readRationale( QString::fromStdString( itElevVal->value().toString() ) );
      if ( itElevRefVal != exifData.end() )
      {
        const QString elevRef = QString::fromStdString( itElevRefVal->value().toString() );
        if ( elevRef.compare( QLatin1String( "1" ), Qt::CaseInsensitive ) == 0 )
        {
          elev *= -1;
        }
      }
      return QgsPoint( lon, lat, elev );
    }
    else
    {
      return QgsPoint( lon, lat );
    }
  }
  catch ( ... )
  {
    return QgsPoint();
  }
}

// Overwrites existing value if found, otherwise creates a new one.
// Passing invalidTypeId causes the type to be guessed.
// Guessing types is accurate for IPTC, but not for EXIF.
// Returns 0 on success
EXIVSIMPLE_API int ModifyMeta(HIMAGE img, const char *key, const char *val, DllTypeId type)
{
    assert(img && key && val);
    if (img==0 || key==0 || val==0) return -1;
    ImageWrapper *imgWrap = (ImageWrapper*)img;
    int rc = 2;

    Exiv2::IptcData &iptcData = imgWrap->image->iptcData();
    Exiv2::ExifData &exifData = imgWrap->image->exifData();

    std::string data(val);
    // if data starts and ends with quotes, remove them
    if (data.at(0) == '\"' && data.at(data.size()-1) == '\"') {
        data = data.substr(1, data.size()-2);
    }

    try {
        Exiv2::IptcKey iptcKey(key);
        rc = 1;

        if (type == invalidTypeId)
            type = (DllTypeId)Exiv2::IptcDataSets::dataSetType(iptcKey.tag(), iptcKey.record());
        Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
        value->read(data);

        Exiv2::IptcData::iterator iter = iptcData.findKey(iptcKey);
        if (iter != iptcData.end()) {
            iter->setValue(value.get());
            rc = 0;
        }
        else {
            rc = iptcData.add(iptcKey, value.get());
        }
    } 
    catch(const Exiv2::AnyError&) {
    }

    if (rc) {
        // Failed with iptc, so try exif
        try {
            Exiv2::ExifKey exifKey(key);
            rc = 1;

            // No way to get value type for exif... string is the most common
            if (type == invalidTypeId)
                type = asciiString;
            Exiv2::Value::AutoPtr value = Exiv2::Value::create((Exiv2::TypeId)type);
            value->read(data);

            Exiv2::ExifData::iterator iter = exifData.findKey(exifKey);
            if (iter != exifData.end()) {
                iter->setValue(value.get());
                rc = 0;
            }
            else {
                exifData.add(exifKey, value.get());
                rc = 0;
            }
        }
        catch(const Exiv2::AnyError&) {
        }
    }

    return rc;
}

QDateTime MetaEngine::getDigitizationDateTime(bool fallbackToCreationTime) const
{
    try
    {
        // In first, trying to get Date & time from Exif tags.

        if (!d->exifMetadata().empty())
        {
            // Try Exif date time digitized.

            Exiv2::ExifData exifData(d->exifMetadata());
            Exiv2::ExifKey key("Exif.Photo.DateTimeDigitized");
            Exiv2::ExifData::iterator it = exifData.findKey(key);

            if (it != exifData.end())
            {
                QDateTime dateTime = QDateTime::fromString(QString::fromLatin1(it->toString().c_str()), Qt::ISODate);

                if (dateTime.isValid())
                {
                    qCDebug(DIGIKAM_METAENGINE_LOG) << "DateTime (Exif digitalized): " << dateTime.toString().toLatin1().constData();
                    return dateTime;
                }
            }
        }

        // In second, we trying XMP

#ifdef _XMP_SUPPORT_

        if (!d->xmpMetadata().empty())
        {
            Exiv2::XmpData xmpData(d->xmpMetadata());
            {
                Exiv2::XmpKey key("Xmp.exif.DateTimeDigitized");
                Exiv2::XmpData::iterator it = xmpData.findKey(key);

                if (it != xmpData.end())
                {
                    QDateTime dateTime = QDateTime::fromString(QString::fromLatin1(it->toString().c_str()), Qt::ISODate);

                    if (dateTime.isValid())
                    {
                        qCDebug(DIGIKAM_METAENGINE_LOG) << "DateTime (XMP-Exif digitalized): " << dateTime.toString().toLatin1().constData();
                        return dateTime;
                    }
                }
            }
            {
                Exiv2::XmpKey key("Xmp.video.DateTimeDigitized");
                Exiv2::XmpData::iterator it = xmpData.findKey(key);

                if (it != xmpData.end())
                {
                    QDateTime dateTime = QDateTime::fromString(QString::fromLatin1(it->toString().c_str()), Qt::ISODate);

                    if (dateTime.isValid())
                    {
                        qCDebug(DIGIKAM_METAENGINE_LOG) << "DateTime (XMP-Video digitalized): " << dateTime.toString().toLatin1().constData();
                        return dateTime;
                    }
                }
            }
        }

#endif // _XMP_SUPPORT_

        // In third, trying to get Date & time from Iptc tags.

        if (!d->iptcMetadata().empty())
        {
            // Try digitization Iptc date time entries.

            Exiv2::IptcData iptcData(d->iptcMetadata());
            Exiv2::IptcKey keyDigitizationDate("Iptc.Application2.DigitizationDate");
            Exiv2::IptcData::iterator it = iptcData.findKey(keyDigitizationDate);

            if (it != iptcData.end())
            {
                QString IptcDateDigitization(QString::fromLatin1(it->toString().c_str()));

                Exiv2::IptcKey keyDigitizationTime("Iptc.Application2.DigitizationTime");
                Exiv2::IptcData::iterator it2 = iptcData.findKey(keyDigitizationTime);

                if (it2 != iptcData.end())
                {
                    QString IptcTimeDigitization(QString::fromLatin1(it2->toString().c_str()));

                    QDate date = QDate::fromString(IptcDateDigitization, Qt::ISODate);
                    QTime time = QTime::fromString(IptcTimeDigitization, Qt::ISODate);
                    QDateTime dateTime = QDateTime(date, time);

                    if (dateTime.isValid())
                    {
                        qCDebug(DIGIKAM_METAENGINE_LOG) << "Date (IPTC digitalized): " << dateTime.toString().toLatin1().constData();
                        return dateTime;
                    }
                }
            }
        }
//.........这里部分代码省略.........