解决QCamera使用QCameraImageCapture截图卡顿问题

最新推荐文章于 2025-07-05 16:54:56 发布

SDU-Leon

最新推荐文章于 2025-07-05 16:54:56 发布

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分类专栏： Qt 文章标签： QCamera QCameraImageCapture 截图卡顿

本文链接：https://blog.youkuaiyun.com/lell3538/article/details/79485255

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本文介绍了解决QCameraImageCapture在使用时出现卡顿的问题。通过将图片捕获到内存缓冲区而非直接存盘，有效提高了捕获速度。文章提供了具体的实现步骤和关键代码。

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卡顿原因：

QCameraImageCapture每次调用capture，无论你是否输入路径，都会将捕获的图片存盘，存盘的速度慢导致卡顿。

解决思路：

将捕获的图片输出到内存缓冲区而不存盘

具体操作：

1、确保支持输出到缓冲区

isCaptureDestinationSupported(QCameraImageCapture::CaptureToBuffer)

2、设置截图输出、缓冲区格式、分辨率

image_capture_->setCaptureDestination(QCameraImageCapture::CaptureToBuffer);
image_capture_->setBufferFormat(QVideoFrame::PixelFormat::Format_Jpeg);
QImageEncoderSettings iamge_setting;
iamge_setting.setResolution(640,360);
image_capture_->setEncodingSettings(iamge_setting);

3、开始截图，通过imageCaptured信号获取图像数据

关键代码如下：

WidgetCamera::WidgetCamera(QWidget *parent) :
    QWidget(parent)
{
    ui_ = new UI::WidgetCamera(this);

    camera_pc_ = new QCamera(this);
    camera_pc_->setViewfinder(ui_->getViewFinderOri());
    camera_pc_->setCaptureMode(QCamera::CaptureStillImage);
    camera_pc_->start();

    image_capture_ = new QCameraImageCapture(camera_pc_);
    if (image_capture_->isCaptureDestinationSupported(QCameraImageCapture::CaptureToBuffer)) {
        image_capture_->setCaptureDestination(QCameraImageCapture::CaptureToBuffer);
        qDebug() << image_capture_->supportedBufferFormats();
        image_capture_->setBufferFormat(QVideoFrame::PixelFormat::Format_Jpeg);
        qDebug() << image_capture_->supportedResolutions(image_capture_->encodingSettings());
        QImageEncoderSettings iamge_setting;
        iamge_setting.setResolution(640,360);
        image_capture_->setEncodingSettings(iamge_setting);
        connect(image_capture_,&QCameraImageCapture::imageCaptured,this,&WidgetAiCamera::processCapturedImage);
    }

    timer_image_capture_ = new QTimer(this);
    connect(timer_image_capture_,&QTimer::timeout,this,&WidgetAiCamera::captureImage);
    timer_image_capture_->start(90);
}

void WidgetCamera::captureImage()
{
    image_capture_->capture();
}

void WidgetCamera::processCapturedImage(int request_id, const QImage &img)
{
    qDebug() << "processCapturedImage" << request_id;
    ui_->setQImage(img);
}

注意：如果要连续截图，最好不要用计时器，可以在processCapturedImage中处理完图片再次调用capture()