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概念#xff1a;
视频帧#xff08;Video Frame#xff09;是组成视频的基本单元。它可以被视为一幅静止的图像#xff0c;它在一定的时间间隔内连续播放#xff0c;从而形成了流畅的视频。
Changes to Qt Multimedia
New features in Qt 6
Removed features
C…目录
概念
视频帧Video Frame是组成视频的基本单元。它可以被视为一幅静止的图像它在一定的时间间隔内连续播放从而形成了流畅的视频。
Changes to Qt Multimedia
New features in Qt 6
Removed features
Changed features
qt6中的正则表达式校验的应用 概念
视频帧Video Frame是组成视频的基本单元。它可以被视为一幅静止的图像它在一定的时间间隔内连续播放从而形成了流畅的视频。
视频帧由像素组成每个像素代表了图像中的一个点的颜色值。视频帧的大小通常以宽度和高度来描述例如 1920x1080 表示宽度为 1920 像素高度为 1080 像素。每个像素的颜色值可以通过不同的图像格式来表示例如 RGB、YUV 等。
视频帧之间的时间间隔称为帧率Frame Rate用于衡量每秒播放的视频帧数。常见的帧率有 24fps、30fps、60fps 等。较高的帧率可以提供更流畅的视频播放效果。
理解帧的概念可以类比为一本动画书每页都是一个静止画面当您快速翻动这些画面时就会产生连续的动画效果。同样地视频帧也是以相似的方式运作通过连续播放静止的视频帧我们感知到了动态的视频内容。
在视频处理和编辑中您可以对视频帧进行各种操作如剪辑、特效处理、颜色校正等。通过对视频帧的处理可以实现视频的编辑、修复和增强等功能。
总结起来视频帧是组成视频的静止图像通过连续播放这些图像我们可以观看到流畅的动态视频内容。
QVideoFrame 是 Qt Multimedia 模块中的一个类用于表示视频帧的数据。它提供了处理和操作视频帧的功能。
下面是 QVideoFrame 的一些常见用途和作用 获取视频帧数据通过 QVideoFrame您可以获取视频帧的原始数据包括像素数据、图像格式、图像大小等。这使得您可以进行视频处理、分析和编辑等操作。 格式转换QVideoFrame 提供了方法将视频帧转换为不同的图像格式以便与您的应用程序或其他模块兼容。您可以使用 QVideoFrame::map() 函数将帧数据映射到一个 QImage 或者 QPixmap 对象中然后进行格式转换。 视频播放和显示QVideoFrame 可以与其他 Qt 组件如 QImage、QLabel、QGraphicsView 等进行集成实现视频的播放和显示。通过将视频帧数据与相应的图像组件结合使用您可以在用户界面中实时显示视频。 视频输入输出通过 QVideoFrame您可以处理和传输视频帧数据。例如您可以将视频帧保存为文件或者从摄像头或其他视频源接收视频帧。
综上所述QVideoFrame 类提供了对视频帧的访问和处理功能使您能够灵活地处理视频数据以满足应用程序的需求。 在Qt项目中.pri文件是一种特殊的文件类型称为包含文件Include File主要用于将共享的构建设置和规则抽象成一个可复用的模块方便在其他项目中重复使用。.pri文件可以包含编译器选项、头文件路径、库依赖关系以及其他自定义构建规则等信息。
要创建一个.pri文件您可以按照以下步骤操作 打开Qt Creator并且打开您要将.pri文件添加到的项目。 在项目视图中右键单击您想要创建.pri文件的文件夹选择新建文件New File。 在弹出的对话框中选择其他Other- Pro 文件Pro File然后点击下一步。 输入文件名并选择保存位置例如myproject.pri然后点击下一步。 在下一个对话框中确认文件属性并且选择添加需要的模块或者库并且可以在此处定义全局变量、宏定义、编译器选项等设置。然后点击完成来创建文件。 在您的项目文件例如.pro文件中包含该.pri文件在您的项目文件中加入如下语句 include(myproject.pri)这样就可以在您的项目中使用.pri文件中定义的构建规则和设置了。需要注意的是.pri文件中定义的变量或宏在引入该文件的项目中是全局可见的。因此如果您有多个.pri文件建议将它们放在独立文件夹中以便管理和维护。
官网中说明
Changes to Qt Multimedia
Qt 6 is a result of the conscious effort to make the framework more efficient and easy to use.
We try to maintain binary and source compatibility for all the public APIs in each release. But some changes were inevitable in an effort to make Qt a better framework.
The module has been refactored significantly and has changed classification, from essential to add-on. The Qt Multimedia module in Qt 6 replaces the Qt Multimedia module from Qt 5.x. Existing code that uses Qt Multimedia from Qt 5 can be ported with limited effort.
New features in Qt 6
There are a number of new features in Qt Multimedia:
QMediaCaptureSession class is the central object for media capture.QMediaRecorder class is now a class limited to recording audio and video. It handles encoding of data produced in a capture session.Using QMediaFormat and QMediaRecorder, setting up the desired encoding when recording has changed significantly.You can now also monitor the audio recorded by a capture session.Support for selection of audio, video and subtitle tracks when playing back media files has been added.QAudioDecoder is now supported on all platforms.
Removed features
Removed featureNotes or suggested alternativePlaylist in QMediaPlayerQMediaPlayer does not do any playlist handling anymore in Qt 6.QMediaPlayListThis class has been removed from the API. It does however still exist as part of the Media Player Example.QAudioProbe and QVideoProbeThe audio and video probing API has been removed.QAudioRecorderUse the QMediaCaptureSession or CaptureSession QML type.Audio QML typeUse MediaPlayer QML type.QMediaObject and QMediaBindableInterfaceThese classes have been removed in favor of a more direct API for setting up connections between objects using, for example, setVideoOutput and QMediaCaptureSession.QCameraViewFinderSettingsThis class has been removed. Use QCameraFormat to define the resolution and frame rate the camera should be using.QMediaContentThe class has been removed. Use QUrl for individual media files instead.QSoundUse QSoundEffect instead.QVideoFilterRunnableUse shader effects in QML instead or access the QVideoFrames content in C.Public back-end APIThe back-end API of Qt Multimedia is private in Qt 6. This improves response time for supporting new multimedia use cases. Any classes that contain the words Control or Abstract in the class name in Qt 5 are now private in Qt 6.Back-end pluginsQt Multimedia in Qt 6 does not use a plugin infrastructure for its back ends anymore. This means that users no longer need to ship those back ends with their application. Instead, the back end being used is determined at compile time based on the underlying operating system. Qt uses gstreamer on Linux, WMF on Windows, AVFoundation on macOS and iOS and the Android multimedia APIs on Android.
Changed features
A number of classes previously offered in Qt Multimedia have changed in ways that may affect previously written code. The following table highlights these changes.
Changed featureNotesHandling of Camera resolutions and frame ratesHandling of these has been simplified and a new QCameraFormat class helps with selecting the correct resolution and frame rate for the camera.Video output handling on the C side has changed significantly.QAbstractVideoSurface has been replaced by the QVideoSink class, and generic rendering support has been enhanced to cover all pixel formats supported by Qt Multimedia.Metadata typesQMediaMetaData has changed significantly: mainly moving from string based to enum based keys, and reducing the set of supported keys to the ones that can be supported on most platforms.QMediaFormatHandling of formats for encoded media and the settings for the media recorder have changed significantly. Qt 5 provides a string-based API, a separated file format, and audio and video codecs into three classes. However, Qt 6 unifies the formats in the QMediaFormat class. Additional settings are directly specified in QMediaRecorder. Setting up file formats and codecs is now implemented with enums and no longer uses strings. This puts some limitations on the set of codecs that can be used, but helps provide a consistent cross-platform API.QCameraImageCapture renamed QImageCaptureNoneAudio inputs and outputsQMediaPlayer and QMediaCaptureSession (and the corresponding QML types MediaPlayer and CaptureSession) are not connected to any audio devices by default. Explicitly connect them to a QAudioInput/AudioInput or QAudioOutput/AudioOutput to capture or play back audio.Capturing videoA capture session is by default not connected to a Camera. Connect it to a QCamera object (Camera item) to be able to capture video or still images.
qt6中的正则表达式校验的应用 项目中涉及IP地址校验等需求qt6 正则表达式和qt5有一定差异见下面的代码
#ifndef CLINEEDIT_H
#define CLINEEDIT_H#include QLineEdit
#include QEventclass QLabel;class QIPLineEdit : public QLineEdit
{Q_OBJECTpublic:QIPLineEdit(QWidget *parent 0);~QIPLineEdit();void setText(const QString strIP);QString text() const;
protected:bool eventFilter(QObject *obj, QEvent *ev);int getIndex(QLineEdit *pEdit);bool isTextValid(const QString strIP);
private:QLineEdit *m_lineEidt[4];
};/
class QMacLineEdit : public QLineEdit
{Q_OBJECTpublic:QMacLineEdit(QWidget *parent 0);~QMacLineEdit();void setText(const QString strMac);QString text() const;
protected:
// void paintEvent(QPaintEvent *event);bool eventFilter(QObject *obj, QEvent *ev);int getIndex(QLineEdit *pEdit);bool isTextValid(const QString strIP);
private:QLineEdit *m_lineEidt[6];
};class QIconLineEdit : public QLineEdit {Q_OBJECT
public:QIconLineEdit(QWidget *parent 0);~QIconLineEdit();void SetIcon(const QPixmap pixmap);
private:QLabel *labelPixmap;
};#endif // QIPLINEEDIT_H#include clineedit.h
#include ipvalidator.h
#include QLabel
#include QRegularExpressionValidator
#include QRegularExpression
#include QValidator
#include QPainter
#include QHBoxLayout
#include QKeyEvent
#include QMessageBox
#include QDebug
#include QRegularExpression
#include QValidatorQIPLineEdit::QIPLineEdit(QWidget *parent): QLineEdit(parent)
{QRegularExpression rx((25[0-5]|2[0-4][0-9]|1?[0-9]{1,2}));//QRegExp rx((25[0-5]|2[0-4][0-9]|1?[0-9]{1,2}));QHBoxLayout *pHBox new QHBoxLayout(this);pHBox-setSpacing(2);pHBox-setContentsMargins(2, 2, 2, 2);QLabel *labelDot[3];for (int i 0; i 4; i){m_lineEidt[i] new QLineEdit(this);m_lineEidt[i]-setProperty(ip, true);m_lineEidt[i]-setFrame(false);m_lineEidt[i]-setMaxLength(3);m_lineEidt[i]-setAlignment(Qt::AlignCenter);m_lineEidt[i]-installEventFilter(this);//m_lineEidt[i]-setValidator(new QRegExpValidator(rx, this));m_lineEidt[i]-setValidator(new IPValidator(this));m_lineEidt[i]-setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);pHBox-addWidget(m_lineEidt[i]);if (i 3) {labelDot[i] new QLabel(this);labelDot[i]-setText(.);labelDot[i]-setFixedWidth(2);pHBox-addWidget(labelDot[i]);}}this-setReadOnly(true);m_lineEidt[0]-setFocus();m_lineEidt[0]-selectAll();
}QIPLineEdit::~QIPLineEdit()
{
}// 获取当前输入框索引
int QIPLineEdit::getIndex(QLineEdit *pEdit)
{int index -1;for (int i 0; i 4; i){if (pEdit m_lineEidt[i])index i;}return index;
}// 事件过滤器判断按键输入
bool QIPLineEdit::eventFilter(QObject *obj, QEvent *ev)
{if (children().contains(obj) QEvent::KeyPress ev-type()){QKeyEvent *keyEvent dynamic_castQKeyEvent *(ev);QLineEdit *pCurrentEdit qobject_castQLineEdit *(obj);switch (keyEvent-key()){case Qt::Key_0:case Qt::Key_1:case Qt::Key_2:case Qt::Key_3:case Qt::Key_4:case Qt::Key_5:case Qt::Key_6:case Qt::Key_7:case Qt::Key_8:case Qt::Key_9:{QString strText pCurrentEdit-text();if (pCurrentEdit-selectedText().length()){pCurrentEdit-text().replace(pCurrentEdit-selectedText(), QChar(keyEvent-key()));}else if (strText.length() 3 strText.toInt() * 10 255){int index getIndex(pCurrentEdit);if (index ! -1 index ! 3){m_lineEidt[index 1]-setFocus();m_lineEidt[index 1]-selectAll();}}else if (strText.length() 2 strText.toInt() * 10 255){if (Qt::Key_0 keyEvent-key() strText.toInt()){pCurrentEdit-setText(strText.insert(pCurrentEdit-cursorPosition(),QChar(Qt::Key_0)));}}return QLineEdit::eventFilter(obj, ev);}break;case Qt::Key_Backspace:{QString strText pCurrentEdit-text();if (strText.isEmpty()){int index getIndex(pCurrentEdit);if (index ! -1 index ! 0){m_lineEidt[index - 1]-setFocus();int length m_lineEidt[index - 1]-text().length();m_lineEidt[index - 1]-setCursorPosition(length ? length : 0);}}return QLineEdit::eventFilter(obj, ev);}case Qt::Key_Left:{if (!pCurrentEdit-cursorPosition()){int index getIndex(pCurrentEdit);if (index ! -1 index ! 0){m_lineEidt[index - 1]-setFocus();int length m_lineEidt[index - 1]-text().length();m_lineEidt[index - 1]-setCursorPosition(length ? length : 0);}}return QLineEdit::eventFilter(obj, ev);}case Qt::Key_Right:{if (pCurrentEdit-cursorPosition() pCurrentEdit-text().length()){int index getIndex(pCurrentEdit);if (index ! -1 index ! 3){m_lineEidt[index 1]-setFocus();m_lineEidt[index 1]-setCursorPosition(0);}}return QLineEdit::eventFilter(obj, ev);}// 小键盘的“.”号case Qt::Key_Period:{int index getIndex(pCurrentEdit);if (index ! -1 index ! 3){m_lineEidt[index 1]-setFocus();m_lineEidt[index 1]-setCursorPosition(0);}return QLineEdit::eventFilter(obj, ev);}break;default:break;}}return false;
}// 设置信息
void QIPLineEdit::setText(const QString strIP)
{// 是否是IP地址if (!isTextValid(strIP)){QMessageBox::warning(this, Attention,Your IP Address is Invalid!,QMessageBox::StandardButton::Ok);return;}else{int i 0;QStringList ipList strIP.split(.);foreach (QString ip ,ipList){m_lineEidt[i]-setText(ip);i;}}
}// 判断IP地址
bool QIPLineEdit::isTextValid(const QString strIP)
{//QRegExp rx2(\\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\b);QRegularExpression rx2(\\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\b);QRegularExpressionMatch match rx2.match(strIP);if (!match.hasMatch()) {return false;}// if (!rx2.exactMatch(strIP))
// return false;return true;
}// 获取IP地址
QString QIPLineEdit::text() const
{QString strIP;for (int i 0; i 4; i) {strIP.append(m_lineEidt[i]-text());if (3 ! i) {strIP.append(.);}}return strIP;
}QMacLineEdit::QMacLineEdit(QWidget *parent): QLineEdit(parent)
{//QRegExp rx(([0-9A-Fa-f]{2}));QRegularExpression rx(([0-9A-Fa-f]{2}));QHBoxLayout *pHBox new QHBoxLayout(this);pHBox-setSpacing(2);pHBox-setContentsMargins(2, 2, 2, 2);QLabel *labelDot[5];for (int i 0; i 6; i){m_lineEidt[i] new QLineEdit(this);m_lineEidt[i]-setFrame(false);m_lineEidt[i]-setMaxLength(2);m_lineEidt[i]-setAlignment(Qt::AlignCenter);m_lineEidt[i]-installEventFilter(this);//m_lineEidt[i]-setValidator(new QRegExpValidator(rx, this));//m_lineEidt[i]-setValidator(new QValidator (0,100,this));QRegularExpressionValidator* validator new QRegularExpressionValidator(QRegularExpression((25[0-5]|2[0-4][0-9]|1?[0-9]{1,2})), this);m_lineEidt[i]-setValidator(validator);m_lineEidt[i]-setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);pHBox-addWidget(m_lineEidt[i]);if (i 5) {labelDot[i] new QLabel(this);labelDot[i]-setText(-);labelDot[i]-setFixedWidth(2);pHBox-addWidget(labelDot[i]);}}this-setReadOnly(true);m_lineEidt[0]-setFocus();m_lineEidt[0]-selectAll();
}QMacLineEdit::~QMacLineEdit()
{
}int QMacLineEdit::getIndex(QLineEdit *pEdit)
{int index -1;for (int i 0; i 6; i){if (pEdit m_lineEidt[i])index i;}return index;
}//
bool QMacLineEdit::eventFilter(QObject *obj, QEvent *ev)
{if (children().contains(obj) QEvent::KeyPress ev-type()){QKeyEvent *keyEvent dynamic_castQKeyEvent *(ev);QLineEdit *pCurrentEdit qobject_castQLineEdit *(obj);switch (keyEvent-key()){case Qt::Key_0:case Qt::Key_1:case Qt::Key_2:case Qt::Key_3:case Qt::Key_4:case Qt::Key_5:case Qt::Key_6:case Qt::Key_7:case Qt::Key_8:case Qt::Key_9:case Qt::Key_A:case Qt::Key_B:case Qt::Key_C:case Qt::Key_D:case Qt::Key_E:case Qt::Key_F:{QString strText pCurrentEdit-text();if (pCurrentEdit-selectedText().length()){pCurrentEdit-text().replace(pCurrentEdit-selectedText(),QChar(keyEvent-key()).toUpper());}else if (strText.length() 2) {int index getIndex(pCurrentEdit);if (0 index index 5){m_lineEidt[index 1]-setFocus();m_lineEidt[index 1]-selectAll();}}return QLineEdit::eventFilter(obj, ev);}break;case Qt::Key_Backspace:{QString strText pCurrentEdit-text();if (strText.isEmpty()){int index getIndex(pCurrentEdit);if (index ! -1 index ! 0){m_lineEidt[index - 1]-setFocus();int length m_lineEidt[index - 1]-text().length();m_lineEidt[index - 1]-setCursorPosition(length ? length : 0);}}return QLineEdit::eventFilter(obj, ev);}case Qt::Key_Period:{int index getIndex(pCurrentEdit);QString strText pCurrentEdit-text();if (strText.length() 1) {pCurrentEdit-setText(strText.insert(0, QChar(Qt::Key_0)));}else if (strText.length() 0) {pCurrentEdit-setText(00);}if (index ! -1 index 5){m_lineEidt[index 1]-setFocus();m_lineEidt[index 1]-setCursorPosition(0);}return QLineEdit::eventFilter(obj, ev);}break;default:break;}}return false;
}//
void QMacLineEdit::setText(const QString strMac)
{if (!isTextValid(strMac)){QMessageBox::warning(this, Attention,Your MAC Address is Invalid!,QMessageBox::StandardButton::Ok);return;}else{int i 0;QStringList macList strMac.split(-);foreach (QString mac ,macList){m_lineEidt[i]-setText(mac);i;}}
}bool QMacLineEdit::isTextValid(const QString strIP)
{//qt6的写法QRegularExpression rx2(([0-9A-Za-z]{2})([0-9A-Za-z:-]{3}){5});QRegularExpressionMatch match rx2.match(strIP);return match.hasMatch();//qt5的写法//QRegExp rx2(([0-9A-Za-z]{2})([0-9A-Za-z:-]{3}){5});// if (!rx2.exactMatch(strIP))// return false;// return true;
}QString QMacLineEdit::text() const
{QString strMac;for (int i 0; i 5; i) {strMac.append(m_lineEidt[i]-text());if (3 ! i) {strMac.append(-);}}return strMac;
}QIconLineEdit::QIconLineEdit(QWidget *parent) :QLineEdit(parent)
{labelPixmap new QLabel(this);labelPixmap-setMinimumSize(16, 16);labelPixmap-setVisible(false);}QIconLineEdit::~QIconLineEdit()
{}void QIconLineEdit::SetIcon(const QPixmap pixmap)
{if (pixmap.isNull()) return;labelPixmap-setPixmap(pixmap);labelPixmap-setVisible(true);labelPixmap-setGeometry(5,(this-height() - pixmap.height()) / 2, 16, 16);this-setTextMargins(25, 1, 1, 1);
}
