Qt实现UVC摄像头捕获

一、环境配置

1. 开发环境： Qt 5.15+ (MSVC 2019编译器) Windows/Linux

2. 依赖配置：

   # .pro文件配置
   QT += multimedia multimediawidgets
   LIBS += -lQt5Multimedia
   

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二、核心代码实现

1. 设备枚举与选择

// 获取所有UVC摄像头设备
QList<QCameraInfo> cameras = QCameraInfo::availableCameras();
foreach (const QCameraInfo &cameraInfo, cameras) {if (cameraInfo.deviceName().contains("UVC")) {ui->cmbCamera->addItem(cameraInfo.description(), QVariant::fromValue(cameraInfo));}
}

2. 摄像头初始化

void MainWindow::initCamera() {QCameraInfo cameraInfo = ui->cmbCamera->currentData().value<QCameraInfo>();m_camera = new QCamera(cameraInfo, this);// 配置视频格式QCameraViewfinderSettings settings;settings.setResolution(1280, 720);settings.setPixelFormat(QVideoFrame::Format_YUYV);m_camera->setViewfinderSettings(settings);// 设置预览控件m_viewfinder = new QCameraViewfinder(this);m_camera->setViewfinder(m_viewfinder);ui->layout->addWidget(m_viewfinder);connect(m_camera, &QCamera::errorOccurred, this, &MainWindow::handleCameraError);
}

3. 视频帧捕获

// 自定义视频表面类
class VideoSurface : public QAbstractVideoSurface {
public:explicit VideoSurface(QWidget *parent = nullptr) : QAbstractVideoSurface(parent) {}QList<QVideoFrame::PixelFormat> supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType = QAbstractVideoBuffer::NoHandle) const override {return {QVideoFrame::Format_RGB32, QVideoFrame::Format_YUYV};}bool present(const QVideoFrame &frame) override {if (frame.isValid()) {QImage image(frame.bits(), frame.width(), frame.height(), QVideoFrame::imageFormatFromPixelFormat(frame.pixelFormat()));emit frameCaptured(image);  // 发射信号传递QImage}return true;}signals:void frameCaptured(const QImage &);
};// 在MainWindow中使用
VideoSurface *surface = new VideoSurface(this);
m_camera->setViewfinder(surface);
connect(surface, &VideoSurface::frameCaptured, this, &MainWindow::processFrame);

4. 图像处理与保存

void MainWindow::processFrame(const QImage &image) {ui->imageLabel->setPixmap(QPixmap::fromImage(image));// 保存图像示例static int frameCount = 0;if (ui->chkSave->isChecked()) {QString fileName = QString("frame_%1.jpg").arg(++frameCount);image.save(fileName, "JPG", 90);}
}

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三、高级功能实现

1. 多格式支持

// 查询摄像头支持的格式
QCameraViewfinderSettings settings = m_camera->viewfinderSettings();
QList<QSize> resolutions = m_camera->supportedViewfinderResolutions();
QList<QVideoFrame::PixelFormat> formats = m_camera->supportedViewfinderPixelFormats();

2. 曝光控制

// 自动曝光设置
m_camera->exposure()->setAutoExposure(QCameraExposure::ExposureAuto);// 手动调整曝光值
m_camera->exposure()->setManualExposure(0.5f);

3. 实时滤镜

// 添加色度偏移效果
QVideoProbe *probe = new QVideoProbe(this);
probe->setSource(m_camera);
connect(probe, &QVideoProbe::videoFrameProbed, [](const QVideoFrame &frame) {QVideoFrame filteredFrame(frame);// 实现自定义滤镜算法return filteredFrame;
});

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四、错误处理

void MainWindow::handleCameraError(QCamera::Error error) {QMessageBox::critical(this, "错误", QString("摄像头错误: %1\n错误描述: %2").arg(error).arg(m_camera->errorString()));
}// 权限检查
void MainWindow::checkPermissions() {#if defined(Q_OS_WIN)// Windows权限检查#elif defined(Q_OS_LINUX)if(!QFile::exists("/dev/video0")) {QMessageBox::warning(this, "警告", "未检测到UVC设备");}#endif
}

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五、性能优化

1. 多线程处理：

   // 使用QtConcurrent处理图像
   QtConcurrent::run([this](const QImage &img){// 后台处理图像emit processedImage(result);
   });
   

2. 硬件加速：

   // 启用GPU加速
   QSurfaceFormat format;
   format.setRenderableType(QSurfaceFormat::OpenGL);
   QSurfaceFormat::setDefaultFormat(format);
   

---

六、完整工程结构

UVC_Capture/
├── Src/
│   ├── main.cpp
│   ├── mainwindow.cpp
│   └── videoprocessor.cpp
├── Res/
│   └── mainwindow.ui
├── UVC_Capture.pro
└── CMakeLists.txt

参考代码 QT 捕获UVC摄像头，枚举摄像头设备，预览显示图像，拍照等 www.youwenfan.com/contentcnj/69957.html

七、调试技巧

1. 设备状态监控：

   qDebug() << "可用设备数:" << QCameraInfo::availableCameras().count();
   qDebug() << "当前分辨率:" << m_camera->viewfinderSettings().resolution();
   

2. 帧率测试：

   QElapsedTimer timer;
   timer.start();
   // 统计每秒帧数
   qDebug() << "实时帧率:" << 1000/timer.elapsed() << "FPS";