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企业网站建设存在的问题,泰州市靖靖建设局网站,部队网站建设报告,wordpress 性能有时候需要在视频上画图#xff0c;所以需要能获取到每一帧视频数据。 以前从视频文件或视频流中得到帧#xff0c;一般都是使用qt ffmpeg或qt vlc。 qt对显示处理视频大体有以下方法#xff1a; QMediaPlayer QVideoWidget 这种方法只适合简单的显示视频功能#xff…有时候需要在视频上画图所以需要能获取到每一帧视频数据。 以前从视频文件或视频流中得到帧一般都是使用qt ffmpeg或qt vlc。 qt对显示处理视频大体有以下方法 QMediaPlayer QVideoWidget 这种方法只适合简单的显示视频功能不适合对视频进行处理比如画图 QMediaPlayer QGraphicsVideoItem QGraphicsScene QGraphicsView 这种方法功能强大除了显示视频功能还可以做复杂的图形处理(具体可以查看QGraphicsScene的使用) QMediaPlayer QAbstractVideoSurface 这种方法比较简单是我下面要介给的。可以获取到每一帧视频数据基本可以实现与qt ffmpeg或qt vlc相同的效果。 自定义VideoSurface class VideoSurface : public QAbstractVideoSurface {Q_OBJECTpublic:VideoSurface(QObject *parent Q_NULLPTR);~VideoSurface();QListQVideoFrame::PixelFormat supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType QAbstractVideoBuffer::NoHandle) const;bool present(const QVideoFrame frame);signals:void frameAvailable(QVideoFrame frame);};实现如下 VideoSurface::VideoSurface(QObject *parent): QAbstractVideoSurface(parent) { }VideoSurface::~VideoSurface() { }QListQVideoFrame::PixelFormat VideoSurface::supportedPixelFormats(QAbstractVideoBuffer::HandleType handleType) const {QListQVideoFrame::PixelFormat listPixelFormats;listPixelFormats QVideoFrame::Format_ARGB32 QVideoFrame::Format_ARGB32_Premultiplied QVideoFrame::Format_RGB32 QVideoFrame::Format_RGB24 QVideoFrame::Format_RGB565 QVideoFrame::Format_RGB555 QVideoFrame::Format_ARGB8565_Premultiplied QVideoFrame::Format_BGRA32 QVideoFrame::Format_BGRA32_Premultiplied QVideoFrame::Format_BGR32 QVideoFrame::Format_BGR24 QVideoFrame::Format_BGR565 QVideoFrame::Format_BGR555 QVideoFrame::Format_BGRA5658_Premultiplied QVideoFrame::Format_AYUV444 QVideoFrame::Format_AYUV444_Premultiplied QVideoFrame::Format_YUV444 QVideoFrame::Format_YUV420P QVideoFrame::Format_YV12 QVideoFrame::Format_UYVY QVideoFrame::Format_YUYV QVideoFrame::Format_NV12 QVideoFrame::Format_NV21 QVideoFrame::Format_IMC1 QVideoFrame::Format_IMC2 QVideoFrame::Format_IMC3 QVideoFrame::Format_IMC4 QVideoFrame::Format_Y8 QVideoFrame::Format_Y16 QVideoFrame::Format_Jpeg QVideoFrame::Format_CameraRaw QVideoFrame::Format_AdobeDng;//qDebug() listPixelFormats;// Return the formats you will supportreturn listPixelFormats; }bool VideoSurface::present(const QVideoFrame frame) {// Handle the frame and do your processingif (frame.isValid()){QVideoFrame cloneFrame(frame);emit frameAvailable(cloneFrame);return true;}return false; }看了上面的代码就知道只需要外部连接frameAvailable信号就可以获取到每一帧数据。 具体使用 QMediaPlayer *mediaPlayer new QMediaPlayer; VideoSurface *videoSurface new VideoSurface; mediaPlayer-setVideoOutput(videoSurface); mediaPlayer-setMedia(QUrl(rtsp://admin:admin192.168.1.112)); mediaPlayer-play();把frameAvailable信号与显示窗口的槽连接比如 connect(videoSurface, SIGNAL(frameAvailable(QVideoFrame )), this, SLOT(ProcessFrame(QVideoFrame ))); void QtVideoTest::ProcessFrame(QVideoFrame frame) {qDebug() ProcessFrame;qDebug() width : frame.width() height : frame.height();qDebug() start time : frame.startTime()/1000 ms;qDebug() end time : frame.endTime()/1000 ms;qDebug() pixelFormat : frame.pixelFormat();frame.map(QAbstractVideoBuffer::ReadOnly);QImage recvImage(frame.bits(), frame.width(), frame.height(), QVideoFrame::imageFormatFromPixelFormat(frame.pixelFormat()));qDebug() frame data size : frame.mappedBytes();frame.unmap(); }如上QVideoFrame转QImage拿QImage进行画图操作就简单了。 Qt6.2.3获取摄像头录制YUV文件逐帧获取录制使用QVideoSink Qt6.2.3获取摄像头录制YUV文件逐帧获取录制使用QVideoSink 必须要使用到QVideoSink相应的依赖模块有QMediaCaptureSession、QMediaDevices、QCamera、QVideoFrame 具体的使用方法是 1、创建一个QMediaCaptureSession QMediaCaptureSession m_captureSession; 2、设置摄像头 m_captureSession.setCamera(new QCamera(QMediaDevices::defaultVideoInput())); 3、设置YUV逐帧输出 m_captureSession.setVideoSink(new QVideoSink m_videoSink); 4、设置YUV格式 void QVideoSink::setVideoFrame(const QVideoFrame frame) 5、主动获取一帧YUV数据 QVideoFrame QVideoSink::videoFrame() const 6、被动接收每一帧 connect(m_videoSink, QVideoSink::videoFrameChanged, YourClass, yourParseFunction); 7、获取帧数据 videoFrame.map(QVideoFrame::ReadOnly); m_file.write((const char *)videoFrame.bits(0和1), videoFrame.mappedBytes(0和1)); mainwindow.cpp: #include mainwindow.h #include ui_mainwindow.h #include QCameraFormatMainWindow::MainWindow(QWidget parent): QMainWindow(parent), ui(new Ui::MainWindow) {ui-setupUi(this);m_camera new QCamera(QMediaDevices::defaultVideoInput());m_captureSession.setCamera(m_camera);m_captureSession.setVideoSink(m_videoSink);connect(m_videoSink, QVideoSink::videoFrameChanged, this, MainWindow::on_frame_changed);m_camera-start();m_file.setFileName(test.nv12);m_file.open(QIODevice::WriteOnly | QIODevice::Truncate); }MainWindow::~MainWindow() {m_camera-stop();m_file.close();delete ui; }void MainWindow::on_frame_changed(const QVideoFrame frame) {QVideoFrame videoFrame frame;/** 我的电脑上返回的格式是Format_NV1218每个像素1.5字节一帧1382400字节* 如果你需要用别的YUV或者RGB格式则需要自己设置QVideoSink或者QCamera格式*/QVideoFrameFormat::PixelFormat pixelFormat videoFrame.pixelFormat();int width videoFrame.width();int height videoFrame.height();int planeCount videoFrame.planeCount();uchar *pdata nullptr;int len 0;videoFrame.map(QVideoFrame::ReadOnly);for (int i 0; i planeCount; i) {pdata videoFrame.bits(i);len videoFrame.mappedBytes(i);m_file.write((const char *)pdata, len);}frame_num;qDebug(%d, %d, %d, %d, %d, %p, %d, frame_num,pixelFormat, width, height, planeCount, pdata, len);videoFrame.unmap(); }mainwindow.h: #ifndef MAINWINDOW_H #define MAINWINDOW_H#include QMainWindow #include QCamera #include QMediaCaptureSession #include QMediaDevices #include QVideoSink #include QVideoFrame #include QFileQT_BEGIN_NAMESPACE namespace Ui { class MainWindow; } QT_END_NAMESPACEclass MainWindow : public QMainWindow {Q_OBJECTpublic:MainWindow(QWidget *parent nullptr);~MainWindow();private:Ui::MainWindow *ui;QMediaCaptureSession m_captureSession;QVideoSink m_videoSink;QCamera m_camera;QFile m_file;int frame_num 0;private slots:void on_frame_changed(const QVideoFrame frame); // 一帧视频到来的信号 }; #endif // MAINWINDOW_Hmain.cpp: /** \brief Qt6.2.3要逐帧获取YUV需要使用QVideoSink和QMediaCaptureSession* \details 编译运行后窗口弹出即开始录制YUV文件关闭窗口后文件保存* \note 保存的文件在本工程文件夹上级目录中的debug目录下的test.nv12 我的电脑摄像头默认输出是YUV NV12格式1280 * 720* 播放方式是安装ffmpeg软件后在test.nv12文件目录下使用命令* ffplay -f rawvideo -pix_fmt nv12 -video_size 1280x720 test.nv12*/#include mainwindow.h #include QApplicationint main(int argc, char *argv[]) {QApplication a(argc, argv);MainWindow w;w.show();return a.exec(); }005_yuv_input_save_file.pro: QT core gui QT multimediagreaterThan(QT_MAJOR_VERSION, 4): QT widgetsCONFIG c17# You can make your code fail to compile if it uses deprecated APIs.

In order to do so, uncomment the following line.

#DEFINES QT_DISABLE_DEPRECATED_BEFORE0x060000 # disables all the APIs deprecated before Qt 6.0.0SOURCES \main.cpp \mainwindow.cppHEADERS \mainwindow.hFORMS \mainwindow.ui# Default rules for deployment. qnx: target.path /tmp/$\({TARGET}/bin else: unix:!android: target.path /opt/\)${TARGET}/bin !isEmpty(target.path): INSTALLS targetmainwindow.ui: ?xml version1.0 encodingUTF-8? ui version4.0classMainWindow/classwidget classQMainWindow nameMainWindowproperty namegeometryrectx0/xy0/ywidth800/widthheight600/height/rect/propertyproperty namewindowTitlestringMainWindow/string/propertywidget classQWidget namecentralwidgetlayout classQVBoxLayout nameverticalLayoutitemwidget classQPushButton namepushButtonproperty nametextstring窗口不要开太久开几秒就够了否则存储的YUV文件会把你的硬盘塞满/string/property/widget/item/layout/widgetwidget classQMenuBar namemenubarproperty namegeometryrectx0/xy0/ywidth800/widthheight22/height/rect/property/widgetwidget classQStatusBar namestatusbar//widgetresources/connections/ /ui报错QVideoFrame::unmap() was called more times then QVideoFrame::map() 原因格式对不上QVideoFrame转QImage格式对照表 QVideoFrame Class 参考QT——QCamera摄像头的切换、分辨率切换、截图显示 cv::QVideoFrame转QImage失败原因及解决方案