qwindowsimagecapture.cpp

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// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qwindowsimagecapture_p.h"
 
#include <mediacapture/qwindowsmediacapture_p.h>
#include <mediacapture/qwindowsmediadevicesession_p.h>
 
#include <QtMultimedia/private/qmediastoragelocation_p.h>
#include <QtGui/qimagewriter.h>
#include <QtConcurrent/qtconcurrentrun.h>
 
QT_BEGIN_NAMESPACE
 
using namespace Qt::StringLiterals;
 
QWindowsImageCapture::QWindowsImageCapture(QImageCapture *parent)
    : QPlatformImageCapture(parent)
{
}
 
QWindowsImageCapture::~QWindowsImageCapture() = default;
 
bool QWindowsImageCapture::isReadyForCapture() const
{
    if (!m_mediaDeviceSession)
        return false;
    return !m_capturing && m_mediaDeviceSession->isActive() && !m_mediaDeviceSession->activeCamera().isNull();
}
 
int QWindowsImageCapture::capture(const QString &fileName)
{
    auto ext = writerFormat(m_settings.format());
    auto path = QMediaStorageLocation::generateFileName(fileName, QStandardPaths::PicturesLocation, ext);
    return doCapture(path);
}
 
int QWindowsImageCapture::captureToBuffer()
{
    return doCapture(QString());
}
 
int QWindowsImageCapture::doCapture(const QString &fileName)
{
    if (!isReadyForCapture())
        return -1;
    m_fileName = fileName;
    m_capturing = true;
    return m_captureId;
}
 
QImageEncoderSettings QWindowsImageCapture::imageSettings() const
{
    return m_settings;
}
 
void QWindowsImageCapture::setImageSettings(const QImageEncoderSettings &settings)
{
    m_settings = settings;
}
 
void QWindowsImageCapture::setCaptureSession(QPlatformMediaCaptureSession *session)
{
    QWindowsMediaCaptureService *captureService = static_cast<QWindowsMediaCaptureService *>(session);
    if (m_captureService == captureService)
        return;
 
    auto readyForCapture = isReadyForCapture();
    if (m_mediaDeviceSession)
        disconnect(m_mediaDeviceSession, nullptr, this, nullptr);
 
    m_captureService = captureService;
    if (!m_captureService) {
        if (readyForCapture)
            emit readyForCaptureChanged(false);
        m_mediaDeviceSession = nullptr;
        return;
    }
 
    m_mediaDeviceSession = m_captureService->session();
    Q_ASSERT(m_mediaDeviceSession);
 
    if (isReadyForCapture() != readyForCapture)
        emit readyForCaptureChanged(isReadyForCapture());
 
    connect(m_mediaDeviceSession, &QWindowsMediaDeviceSession::readyForCaptureChanged,
            this, &QWindowsImageCapture::readyForCaptureChanged);
 
    connect(m_mediaDeviceSession, &QWindowsMediaDeviceSession::videoFrameChanged,
            this, &QWindowsImageCapture::handleVideoFrameChanged);
}
 
void QWindowsImageCapture::handleVideoFrameChanged(const QVideoFrame &frame)
{
    if (m_capturing) {
 
        QImage image = frame.toImage();
 
        QSize size = m_settings.resolution();
        if (size.isValid() && image.size() != size) {
            image = image.scaled(size, Qt::KeepAspectRatioByExpanding);
            if (image.size() != size) {
                int xoff = (image.size().width() - size.width()) / 2;
                int yoff = (image.size().height() - size.height()) / 2;
                image = image.copy(xoff, yoff, size.width(), size.height());
            }
        }
 
        emit imageExposed(m_captureId);
        emit imageAvailable(m_captureId, frame);
        emit imageCaptured(m_captureId, image);
 
        QMediaMetaData metaData = this->metaData();
        metaData.insert(QMediaMetaData::Date, QDateTime::currentDateTime());
        metaData.insert(QMediaMetaData::Resolution, size);
 
        emit imageMetadataAvailable(m_captureId, metaData);
 
        if (!m_fileName.isEmpty()) {
 
            (void)QtConcurrent::run(&QWindowsImageCapture::saveImage, this,
                                    m_captureId, m_fileName, image, metaData, m_settings);
        }
 
        ++m_captureId;
        m_capturing = false;
    }
}
 
void QWindowsImageCapture::saveImage(int captureId, const QString &fileName,
                                           const QImage &image, const QMediaMetaData &metaData,
                                           const QImageEncoderSettings &settings)
{
    QImageWriter imageWriter;
    imageWriter.setFileName(fileName);
 
    QString format = writerFormat(settings.format());
    imageWriter.setFormat(format.toUtf8());
 
    int quality = writerQuality(format, settings.quality());
    if (quality > -1)
        imageWriter.setQuality(quality);
 
    for (auto key : metaData.keys())
        imageWriter.setText(QMediaMetaData::metaDataKeyToString(key),
                            metaData.stringValue(key));
 
    imageWriter.write(image);
 
    QMetaObject::invokeMethod(this, [this, captureId, fileName] {
        emit imageSaved(captureId, fileName);
    }, Qt::QueuedConnection);
}
 
QString QWindowsImageCapture::writerFormat(QImageCapture::FileFormat reqFormat)
{
    QString format;
 
    switch (reqFormat) {
    case QImageCapture::FileFormat::JPEG:
        format = u"jpg"_s;
        break;
    case QImageCapture::FileFormat::PNG:
        format = u"png"_s;
        break;
    case QImageCapture::FileFormat::WebP:
        format = u"webp"_s;
        break;
    case QImageCapture::FileFormat::Tiff:
        format = u"tiff"_s;
        break;
    default:
        format = u"jpg"_s;
    }
 
    auto supported = QImageWriter::supportedImageFormats();
    for (const auto &f : supported)
        if (format.compare(QString::fromUtf8(f), Qt::CaseInsensitive) == 0)
            return format;
 
    return u"jpg"_s;
}
 
int QWindowsImageCapture::writerQuality(const QString &writerFormat,
                                              QImageCapture::Quality quality)
{
    if (writerFormat.compare(u"jpg", Qt::CaseInsensitive) == 0 ||
            writerFormat.compare(u"jpeg", Qt::CaseInsensitive) == 0) {
 
        switch (quality) {
        case QImageCapture::Quality::VeryLowQuality:
            return 10;
        case QImageCapture::Quality::LowQuality:
            return 30;
        case QImageCapture::Quality::NormalQuality:
            return 75;
        case QImageCapture::Quality::HighQuality:
            return 90;
        case QImageCapture::Quality::VeryHighQuality:
            return 98;
        default:
            return 75;
        }
    }
    return -1;
}
 
QT_END_NAMESPACE
 
#include "moc_qwindowsimagecapture_p.cpp"