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614 | /* ============================================================
*
* This file is a part of digiKam project
* https://www.digikam.org
*
* Date : 2006-12-26
* Description : Multithreaded loader for previews
*
* SPDX-FileCopyrightText: 2006-2011 by Marcel Wiesweg <marcel dot wiesweg at gmx dot de>
* SPDX-FileCopyrightText: 2006-2025 by Gilles Caulier <caulier dot gilles at gmail dot com>
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* ============================================================ */
#include "previewtask.h"
// Qt includes
#include <QVariant>
#include <QScopedPointer>
// Local includes
#include "dimgloader.h"
#include "drawdecoder.h"
#include "digikam_debug.h"
#include "dmetadata.h"
#include "jpegutils.h"
#include "metaenginesettings.h"
#include "previewloadthread.h"
namespace Digikam
{
PreviewLoadingTask::PreviewLoadingTask(LoadSaveThread* const thread, const LoadingDescription& description)
: SharedLoadingTask(thread, description, LoadSaveThread::AccessModeRead, LoadingTaskStatusLoading)
{
}
void PreviewLoadingTask::execute()
{
if (m_loadingTaskStatus == LoadingTaskStatusStopping)
{
if (m_thread)
{
m_thread->taskHasFinished();
}
return;
}
// Check if preview is in cache first.
LoadingCache* const cache = LoadingCache::cache();
{
LoadingCache::CacheLock lock(cache);
// find possible cached images
DImg* cachedImg = nullptr;<--- Variable 'cachedImg' can be declared as pointer to const
QStringList lookupKeys = m_loadingDescription.lookupCacheKeys();
// lookupCacheKeys returns "best first". Prepend the cache key to make the list "fastest first":
// Scaling a full version takes longer!
lookupKeys.prepend(m_loadingDescription.cacheKey());
for (const QString& key : std::as_const(lookupKeys))
{
if ((cachedImg = cache->retrieveImage(key)))
{
if (m_loadingDescription.needCheckRawDecoding())
{
if (cachedImg->rawDecodingSettings() == m_loadingDescription.rawDecodingSettings)
{
break;
}
else
{
cachedImg = nullptr;
}
}
else
{
break;
}
}
}
if (cachedImg)
{
// image is found in image cache, loading is successful
m_img = *cachedImg;
}
else
{
// find possible running loading process
LoadingProcess* usedProcess = nullptr;
for (QStringList::const_iterator it = lookupKeys.constBegin() ; it != lookupKeys.constEnd() ; ++it)
{
if ((usedProcess = cache->retrieveLoadingProcess(*it)))
{<--- Consider using std::any_of algorithm instead of a raw loop.
break;
}
}
if (usedProcess)
{
// Other process is right now loading this image.
// Add this task to the list of listeners and
// attach this thread to the other thread, wait until loading
// has finished.
usedProcess->addListener(this);
// break loop when either the loading has completed, or this task is being stopped
// cppcheck-suppress knownConditionTrueFalse
while ((m_loadingTaskStatus != LoadingTaskStatusStopping) && !usedProcess->completed())
{
lock.timedWait();
}
// remove listener from process
usedProcess->removeListener(this);
// wake up the process which is waiting until all listeners have removed themselves
lock.wakeAll();
// m_img is now set to the result
}
}
}
if (continueQuery() && m_img.isNull())
{
{
LoadingCache::CacheLock lock(cache);
// Neither in cache, nor currently loading in different thread.
// Load it here and now, add this LoadingProcess to cache list.
cache->addLoadingProcess(this);
// Notify other processes that we are now loading this image.
// They might be interested - see notifyNewLoadingProcess below
cache->notifyNewLoadingProcess(this, m_loadingDescription);
}
// Preview is not in cache, we will load image from file.
DImg::FORMAT format = DImg::fileFormat(m_loadingDescription.filePath);
m_fromRawEmbeddedPreview = false;
if (format == DImg::RAW)
{
MetaEnginePreviews previews(m_loadingDescription.filePath);
// Check original image size using Exiv2.
QSize originalSize = previews.originalSize();
// If not valid, get original size from LibRaw
if (!originalSize.isValid())
{
DRawInfo container;
if (DRawDecoder::rawFileIdentify(container, m_loadingDescription.filePath))
{
originalSize = container.imageSize;
}
}
switch (m_loadingDescription.previewParameters.previewSettings.quality)
{
case PreviewSettings::FastPreview:
case PreviewSettings::FastButLargePreview:
{
// Size calculations
int sizeLimit = -1;
int bestSize = qMax(originalSize.width(), originalSize.height());
// for RAWs, the alternative is the half preview, so best size is already originalSize / 2
bestSize /= 2;
if (m_loadingDescription.previewParameters.previewSettings.quality == PreviewSettings::FastButLargePreview)
{
sizeLimit = qMin(m_loadingDescription.previewParameters.size, bestSize);
}
if (loadExiv2Preview(previews, sizeLimit))
{
break;
}
if (loadLibRawPreview(sizeLimit))
{
break;
}
loadHalfSizeRaw();
break;
}
case PreviewSettings::HighQualityPreview:
{
switch (m_loadingDescription.previewParameters.previewSettings.rawLoading)
{
case PreviewSettings::RawPreviewAutomatic:
{
// If we find a preview that is larger than half size (which is what we get from half-size original data), we take it
int acceptableSize = qMax(lround(originalSize.width() * 0.48), lround(originalSize.height() * 0.48));
if (loadExiv2Preview(previews, acceptableSize))
{
break;
}
if (loadLibRawPreview(acceptableSize))
{
break;
}
loadHalfSizeRaw();
break;
}
case PreviewSettings::RawPreviewFromEmbeddedPreview:
{
if (loadExiv2Preview(previews))
{
break;
}
if (loadLibRawPreview())
{
break;
}
loadHalfSizeRaw();
break;
}
case PreviewSettings::RawPreviewFromRawHalfSize:
{
loadHalfSizeRaw();
break;
}
case PreviewSettings::RawPreviewFromRawFullSize:
{
loadFullSizeRaw();
break;
}
}
}
}
// So far, everything loaded QImage. Convert to DImg.
convertQImageToDImg();
}
else // Non-RAW images
{
qCDebug(DIGIKAM_GENERAL_LOG) << "Try to get preview from" << m_loadingDescription.filePath;
qCDebug(DIGIKAM_GENERAL_LOG) << "Preview quality: " << m_loadingDescription.previewParameters.previewSettings.quality;
bool isFast = (m_loadingDescription.previewParameters.previewSettings.quality == PreviewSettings::FastPreview);
switch (m_loadingDescription.previewParameters.previewSettings.quality)
{
case PreviewSettings::FastPreview:
case PreviewSettings::FastButLargePreview:
{
if (isFast && loadImagePreview(m_loadingDescription.previewParameters.size))
{
convertQImageToDImg();
break;
}
// Set a hint to try to load a JPEG or PGF with the fast scale-before-decoding method
if (isFast)
{
m_img.setAttribute(QLatin1String("scaledLoadingSize"), m_loadingDescription.previewParameters.size);
}
m_img.load(m_loadingDescription.filePath, this, m_loadingDescription.rawDecodingSettings);
break;
}
case PreviewSettings::HighQualityPreview:
{
m_img.load(m_loadingDescription.filePath, this, m_loadingDescription.rawDecodingSettings);
break;
}
}
}
if (continueQuery() && !m_img.isNull())
{
if (needToScale())
{
QSize scaledSize = m_img.size();
scaledSize.scale(m_loadingDescription.previewParameters.size,
m_loadingDescription.previewParameters.size,
Qt::KeepAspectRatio);
m_img = m_img.smoothScale(scaledSize.width(), scaledSize.height());
}
if (MetaEngineSettings::instance()->settings().exifRotate)
{
m_img.exifRotate(m_loadingDescription.filePath);
}
if (needsPostProcessing())
{
postProcess();
}
}
{
LoadingCache::CacheLock lock(cache);
// remove this from the list of loading processes in cache
cache->removeLoadingProcess(this);
// put valid image into cache of loaded images
if (continueQuery() && !m_img.isNull())
{
cache->putImage(m_loadingDescription.cacheKey(), m_img,
m_loadingDescription.filePath);
// dispatch image to all listeners
for (int i = 0 ; i < m_listeners.count() ; ++i)
{
LoadingProcessListener* const l = m_listeners.at(i);
if (l->accessMode() == LoadSaveThread::AccessModeReadWrite)
{
// If a listener requested ReadWrite access, it gets a deep copy.
// DImg is explicitly shared.
l->setResult(m_loadingDescription, m_img.copy());
}
else
{
l->setResult(m_loadingDescription, m_img);
}
}
}
// indicate that loading has finished so that listeners can stop waiting
m_completed = true;
// wake all listeners waiting on cache condVar, so that they remove themselves
lock.wakeAll();
// wait until all listeners have removed themselves
while (m_listeners.count() != 0)
{
lock.timedWait();
}
}
}
// following the golden rule to avoid deadlocks, do this when CacheLock is not held
if (continueQuery() && !m_img.isNull())
{
// We check before to find out if we need to provide a deep copy
const bool needConvertToEightBit = m_loadingDescription.previewParameters.previewSettings.convertToEightBit;
if ((accessMode() == LoadSaveThread::AccessModeReadWrite) || needConvertToEightBit)
{
m_img.detach();
}
if (needConvertToEightBit)
{
m_img.convertToEightBit();
}
}
else if (continueQuery())
{
qCDebug(DIGIKAM_GENERAL_LOG) << "Cannot extract preview for" << m_loadingDescription.filePath;
}
else
{
m_img = DImg();
}
if (m_thread)
{
m_thread->taskHasFinished();
m_thread->imageLoaded(m_loadingDescription, m_img);
}
}
bool PreviewLoadingTask::needToScale()
{
switch (m_loadingDescription.previewParameters.previewSettings.quality)
{
case PreviewSettings::FastPreview:
{
if (m_loadingDescription.previewParameters.size > 0)
{
int maxSize = qMax(m_img.width(), m_img.height());
int acceptableUpperSize = lround(1.25 * (double)m_loadingDescription.previewParameters.size);
return (maxSize >= acceptableUpperSize);
}
break;
}
case PreviewSettings::FastButLargePreview:
case PreviewSettings::HighQualityPreview:
{
break;
}
}
return false;
}
// -- Exif/IPTC preview extraction using Exiv2 --------------------------------------------------------
bool PreviewLoadingTask::loadExiv2Preview(MetaEnginePreviews& previews, int sizeLimit)
{
if (previews.isEmpty() || !continueQuery())
{
return false;
}
if ((sizeLimit == -1) || (qMax(previews.width(), previews.height()) >= sizeLimit))
{
m_qimage = previews.image();
if (!m_qimage.isNull())
{
m_fromRawEmbeddedPreview = true;
return true;
}
}
return false;
}
bool PreviewLoadingTask::loadLibRawPreview(int sizeLimit)
{
if (!continueQuery())
{
return false;
}
QImage rawPreview;
DRawDecoder::loadEmbeddedPreview(rawPreview, m_loadingDescription.filePath);
if (!rawPreview.isNull() &&
((sizeLimit == -1) || (qMax(rawPreview.width(), rawPreview.height()) >= sizeLimit)))
{
m_qimage = rawPreview;
m_fromRawEmbeddedPreview = true;
return true;
}
return false;
}
bool PreviewLoadingTask::loadHalfSizeRaw()
{
if (!continueQuery())
{
return false;
}
DRawDecoder::loadHalfPreview(m_qimage, m_loadingDescription.filePath);
return (!m_qimage.isNull());
}
bool PreviewLoadingTask::loadFullSizeRaw()
{
if (!continueQuery())
{
return false;
}
DRawDecoder::loadFullImage(m_qimage, m_loadingDescription.filePath);
return (!m_qimage.isNull());
}
void PreviewLoadingTask::convertQImageToDImg()
{
if (!continueQuery())
{
return;
}
// convert from QImage
m_img = DImg(m_qimage);
DImg::FORMAT format = DImg::fileFormat(m_loadingDescription.filePath);
m_img.setAttribute(QLatin1String("detectedFileFormat"), format);
m_img.setAttribute(QLatin1String("originalFilePath"), m_loadingDescription.filePath);
QScopedPointer<DMetadata> metadata(new DMetadata(m_loadingDescription.filePath));
QSize orgSize = metadata->getPixelSize();
if ((format == DImg::RAW) && LoadSaveThread::infoProvider())
{
orgSize = LoadSaveThread::infoProvider()->dimensionsHint(m_loadingDescription.filePath);
}
// In case we don't get the original size from the metadata.
if (orgSize.isNull())
{
orgSize = QSize(m_img.width(), m_img.height());
}
else if (
((m_img.width() < m_img.height()) && (orgSize.width() > orgSize.height())) ||
((m_img.width() > m_img.height()) && (orgSize.width() < orgSize.height()))
)
{
// Set the ratio of width and height of the original
// size to the same ratio of the loaded image.
orgSize.transpose();
}
m_img.setAttribute(QLatin1String("originalSize"), orgSize);
m_img.setMetadata(metadata->data());
// mark as embedded preview (for Exif rotation)
if (m_fromRawEmbeddedPreview)
{
m_img.setAttribute(QLatin1String("fromRawEmbeddedPreview"), true);
// If we loaded the embedded preview, the Exif of the RAW indicates
// the color space of the preview (see bug 195950 for NEF files)
m_img.setIccProfile(metadata->getIccProfile());
}
// free memory
m_qimage = QImage();
}
bool PreviewLoadingTask::loadImagePreview(int sizeLimit)
{
QScopedPointer<DMetadata> metadata(new DMetadata(m_loadingDescription.filePath));
QImage previewImage;
if (metadata->getItemPreview(previewImage))
{
if (
(sizeLimit == -1) ||
(qMax(previewImage.width(), previewImage.height()) > sizeLimit)
)
{
m_qimage = previewImage;
return true;
}
}
qDebug(DIGIKAM_GENERAL_LOG) << "Try to load DImg preview from:" << m_loadingDescription.filePath;
DImg img;
DImgLoader::LoadFlags loadFlags = DImgLoader::LoadItemInfo |
DImgLoader::LoadMetadata |
DImgLoader::LoadICCData |
DImgLoader::LoadPreview;
if (img.load(m_loadingDescription.filePath, loadFlags, this))
{
if (
(sizeLimit == -1) ||
(qMax(img.width(), img.height()) > (uint)sizeLimit)
)
{
m_qimage = img.copyQImage();
return true;
}
}
return false;
}
} // namespace Digikam
|