怎么获得一个免费的域名,陕西新站seo,虚拟货币网站建设,雅诗兰黛网络营销策划方案Windows操作系统提供了多种便捷的截图方式#xff0c;常见的有以下几种#xff1a;
全屏截图#xff1a;通过按下PrtSc键#xff08;Print Screen#xff09;#xff0c;可以截取整个屏幕的内容。截取的图像会保存在剪贴板中#xff0c;可以通过CtrlV粘贴到图片编辑工具…Windows操作系统提供了多种便捷的截图方式常见的有以下几种
全屏截图通过按下PrtSc键Print Screen可以截取整个屏幕的内容。截取的图像会保存在剪贴板中可以通过CtrlV粘贴到图片编辑工具或其他软件的输入框中。当前窗口截图同时按下Alt PrtSc键可以截取当前活动的窗口。同样截图内容会被保存在剪贴板中。矩形截图使用快捷键Windows Shift S可以选择矩形截图模式然后拖动鼠标选取屏幕上的任意矩形区域进行截图。自由形状截图同样使用Windows Shift S快捷键可以选择任意形状截图模式允许你自由绘制截图区域的形状。
libVLC 中通过libvlc_video_take_snapshot核心接口来截图。
以下是如何使用 libVLC 设置视频裁剪区域的基本步骤
1. 初始化 libVLC 和媒体播放器
首先你需要初始化 libVLC 实例和媒体播放器对象。
#include vlc/vlc.hint main(int argc, char* argv[])
{libvlc_instance_t* inst;libvlc_media_player_t* mp;libvlc_media_t* m;// 加载 libVLC 引擎inst libvlc_new(0, NULL);// 创建一个新的 itemm libvlc_media_new_location(inst, your_video_path_here);mp libvlc_media_player_new_from_media(m);// 不再需要媒体对象libvlc_media_release(m);
}
2. 播放视频
// 播放媒体播放器
libvlc_media_player_play(mp);// 保持程序运行直到视频播放完成
while (libvlc_media_player_is_playing(mp)) {// 可以在这里加入延时
}// 清理 libVLC
libvlc_media_player_stop(mp);
libvlc_media_player_release(mp);
libvlc_release(inst);return 0;
3.截图
这里为了方便路径写死了。 if (vlc_mediaPlayer){QString path ./snap.png;libvlc_video_take_snapshot(vlc_mediaPlayer, 0, path.toUtf8().data(), 0, 0);}
以下是VLC播放器中使用的截图界面我们仿照这个做一个界面。 以下是效果图。
菜单添加action并响应槽函数。
m_snapAction m_videoMenu-addAction(截图);
connect(m_snapAction, QAction::triggered, this, showWidget::slotSnap);
槽函数如下图所示为了方便路径写死了。
void showWidget::slotSnap()
{if (vlc_mediaPlayer){QString path ./snap.png;libvlc_video_take_snapshot(vlc_mediaPlayer, 0, path.toUtf8().data(), 0, 0);}
}
生成目录下snap.png。 完整源码
#pragma once
#define LIBVLC_USE_PTHREAD_CANCEL 1
#include QtWidgets/QWidget
#include ui_showWidget.h
#include QMenu
#include QActionGroup
#include vlc/vlc.h#include QDebug
#include QFileDialog
#include QThread
#include QMouseEvent
#include QKeyEventenum Rate
{Rate2X,Rate1_5X,Rate1_25X,Rate1_0X,Rate0_75X,Rate0_5X
};class showWidget : public QWidget
{Q_OBJECTpublic:showWidget(QWidget *parent nullptr);~showWidget();protected:virtual void mousePressEvent(QMouseEvent *event);virtual void mouseDoubleClickEvent(QMouseEvent *event);virtual void keyPressEvent(QKeyEvent *event);private slots:void slotOpenFile();void slotPlay();void slotPause();void slotStop();void slotValueChanged(int value);void slotCurrentIndexChanged(int index);void slotActionTriggered(QAction *action);void slotCropActionTriggered(QAction *action);void slotScaleActionTriggered(QAction *action);void slotSnap();private://事件处理回调static void vlcEvents(const libvlc_event_t *ev, void *param);//初始化menuvoid initMenu();private:Ui::showWidgetClass ui;private:libvlc_instance_t *vlc_base nullptr;libvlc_media_t *vlc_media nullptr;libvlc_media_player_t *vlc_mediaPlayer nullptr;QListfloat m_lstRate;QMenu *m_menu nullptr;QAction *m_video nullptr;QAction *m_scaleAction nullptr; //缩放QAction *m_aspectRatioAction nullptr; //宽高比QAction *m_cropAction nullptr; //裁剪QAction *m_snapAction nullptr;//截图QMenu *m_videoMenu nullptr;//宽高比QMenu *m_aspectRatioMenu nullptr;QAction *m_default nullptr;QAction *m_16_9 nullptr;QAction *m_4_3 nullptr;QAction *m_1_1 nullptr;QAction *m_16_10 nullptr;QAction *m_2_21_1 nullptr;QAction *m_2_35_1 nullptr;QAction *m_2_38_1 nullptr;QAction *m_5_4 nullptr;QActionGroup *m_group nullptr;QAction *m_preAspectRatio nullptr;//宽高比//裁剪QMenu *m_cropMenu nullptr;QAction *m__cropDefault nullptr;QAction *m__crop16_10 nullptr;QAction *m__crop16_9 nullptr;QAction *m__crop4_3 nullptr;QAction *m__crop1_85_1 nullptr;QAction *m__crop2_21_1 nullptr;QAction *m__crop2_35_1 nullptr;QAction *m__crop2_39_1 nullptr;QAction *m__crop5_3 nullptr;QAction *m__crop5_4 nullptr;QAction *m__crop1_1 nullptr;QActionGroup *m_cropGroup nullptr;QAction *m_preCrop nullptr;//裁剪//缩放QMenu *m_scaleMenu nullptr;QAction *m_scale1_4 nullptr;QAction *m_scale1_2 nullptr;QAction *m_scale1_1 nullptr;QAction *m_scale2_1 nullptr;QActionGroup *m_scaleGroup nullptr;QAction *m_preScale nullptr;//缩放char *m_defalutRate nullptr;char *m_defalutCrop nullptr;float m_defalutScale 0;
};cpp
#include showWidget.h
#include QTimer
#include QTime#pragma execution_character_set(utf-8)showWidget::showWidget(QWidget *parent): QWidget(parent)
{ui.setupUi(this);this-setWindowTitle(视频播放器);ui.cbxRate-setCurrentIndex(Rate1_0X);m_lstRate 2.0 1.5 1.25 1.0 0.75 0.5;initMenu();ui.btnOpen-setFocusPolicy(Qt::NoFocus);ui.btnPlay-setFocusPolicy(Qt::NoFocus);ui.btnPause-setFocusPolicy(Qt::NoFocus);ui.btnStop-setFocusPolicy(Qt::NoFocus);ui.hSliderVolumn-setFocusPolicy(Qt::NoFocus);ui.cbxRate-setFocusPolicy(Qt::NoFocus);connect(ui.btnOpen, QPushButton::clicked, this, showWidget::slotOpenFile);connect(ui.btnPlay, QPushButton::clicked, this, showWidget::slotPlay);connect(ui.btnPause, QPushButton::clicked, this, showWidget::slotPause);connect(ui.btnStop, QPushButton::clicked, this, showWidget::slotStop);connect(ui.btnSnap, QPushButton::clicked, this, showWidget::slotSnap);connect(ui.hSliderVolumn, QSlider::valueChanged, this, showWidget::slotValueChanged);connect(ui.cbxRate,SIGNAL(currentIndexChanged(int)), this, SLOT(slotCurrentIndexChanged(int)));
}showWidget::~showWidget()
{libvlc_release(vlc_base); //减少libvlc实例的引用计数并销毁
}void showWidget::mousePressEvent(QMouseEvent *event)
{switch (event-button()){case Qt::RightButton://this-setWindowState(Qt::WindowMinimized);m_menu-exec(event-globalPos());break;default:QWidget::mousePressEvent(event);}
}void showWidget::mouseDoubleClickEvent(QMouseEvent *event)
{if (this-isFullScreen()){this-showNormal();}else{this-showFullScreen();}
}void showWidget::keyPressEvent(QKeyEvent *event)
{if (!vlc_mediaPlayer)return;int value ui.hSliderVolumn-value();if (event-key() Qt::Key_W) //添加音量{qDebug() up;slotValueChanged(value10);}else if (event-key() Qt::Key_S) //减小音量{slotValueChanged(value - 10);}else if (event-key() Qt::Key_Space){if (vlc_mediaPlayer libvlc_media_player_get_state(vlc_mediaPlayer) libvlc_Playing){libvlc_media_player_pause(vlc_mediaPlayer);}else if (vlc_mediaPlayer libvlc_media_player_get_state(vlc_mediaPlayer) libvlc_Paused){libvlc_media_player_play(vlc_mediaPlayer);}}
}void showWidget::slotOpenFile()
{/*选择文件*/QString filename QFileDialog::getOpenFileName(this, 选择打开的文件, D:/, tr(*.*));std::replace(filename.begin(), filename.end(), QChar(/), QChar(\\));vlc_base libvlc_new(0, NULL);vlc_media libvlc_media_new_path(vlc_base, filename.toUtf8().data());if (!vlc_media) {return;}// 创建libvlc实例和媒体播放器vlc_mediaPlayer libvlc_media_player_new_from_media(vlc_media);if (!vlc_mediaPlayer) {return;}// 等待元数据加载完成libvlc_media_parse(vlc_media);m_defalutRate libvlc_video_get_aspect_ratio(vlc_mediaPlayer);m_defalutCrop libvlc_video_get_crop_geometry(vlc_mediaPlayer);libvlc_video_set_mouse_input(vlc_mediaPlayer, 0);libvlc_video_set_key_input(vlc_mediaPlayer, 0);// 获取各种元数据const char *title libvlc_media_get_meta(vlc_media, libvlc_meta_Title);const char *artist libvlc_media_get_meta(vlc_media, libvlc_meta_Artist);const char *album libvlc_media_get_meta(vlc_media, libvlc_meta_Album);const char *url libvlc_media_get_meta(vlc_media, libvlc_meta_URL);const char *date libvlc_media_get_meta(vlc_media, libvlc_meta_Date);const char *lang libvlc_media_get_meta(vlc_media, libvlc_meta_Language);int duration libvlc_media_get_duration(vlc_media); // 获取时长单位毫秒qDebug(Title: %s, title ? title : N/A);qDebug(Artist: %s, artist ? artist : N/A);qDebug(Album: %s, album ? album : N/A);qDebug(Duration: %d ms, duration);qDebug(url: %s, url ? url : N/A);qDebug(date: %s, date ? date : N/A);qDebug(lang: %s, lang ? lang : N/A);libvlc_media_track_t **tracks;int track_count libvlc_media_tracks_get(vlc_media,tracks);for (unsigned i 0; i track_count; i) {libvlc_media_track_t* track tracks[i];// 显示轨道信息printf(Track #%u: %s\n, i, track-psz_description);// 这里可以获取到每一个轨道的信息比如轨道类型 track-i_type// 可能是 libvlc_track_video, libvlc_track_audio 或者 libvlc_track_text (字幕)if (track-i_type libvlc_track_video) {// 处理视频轨道信息qDebug(width %d,track-video-i_width);qDebug(height %d, track-video-i_height);qDebug(rate_num %d, track-video-i_frame_rate_num);qDebug(rate_den %d, track-video-i_frame_rate_den);}else if (track-i_type libvlc_track_audio) {// 处理音频轨道信息qDebug(channels %d, track-audio-i_channels);qDebug(rate %d, track-audio-i_rate);}else if (track-i_type libvlc_track_text) {// 处理字幕轨道信息}}//获取事件管理器libvlc_event_manager_t *em libvlc_media_player_event_manager(vlc_mediaPlayer);// 注册事件监听器libvlc_event_attach(em, libvlc_MediaPlayerTimeChanged, vlcEvents, this);libvlc_event_attach(em, libvlc_MediaPlayerEndReached, vlcEvents, this);libvlc_event_attach(em, libvlc_MediaPlayerStopped, vlcEvents, this);libvlc_event_attach(em, libvlc_MediaPlayerPlaying, vlcEvents, this);libvlc_event_attach(em, libvlc_MediaPlayerPaused, vlcEvents, this);libvlc_media_player_set_hwnd(vlc_mediaPlayer, (void *)ui.widgetShow-winId());QTimer::singleShot(1000, this, showWidget::slotPlay);}void showWidget::slotPlay()
{if (vlc_mediaPlayer){libvlc_media_player_play(vlc_mediaPlayer);m_defalutScale libvlc_video_get_scale(vlc_mediaPlayer);}}void showWidget::slotPause()
{if (vlc_mediaPlayer)libvlc_media_player_pause(vlc_mediaPlayer);
}void showWidget::slotStop()
{if (vlc_mediaPlayer)libvlc_media_player_stop(vlc_mediaPlayer);
}void showWidget::slotValueChanged(int value)
{if (vlc_mediaPlayer)libvlc_audio_set_volume(vlc_mediaPlayer, value);
}void showWidget::slotCurrentIndexChanged(int index)
{if (vlc_mediaPlayer)libvlc_media_player_set_rate(vlc_mediaPlayer, m_lstRate[index]);
}void showWidget::slotActionTriggered(QAction *action)
{if (!vlc_mediaPlayer)return;if (action m_default)libvlc_video_set_aspect_ratio(vlc_mediaPlayer,m_defalutRate);else if(action m_16_9)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 16:9);else if (action m_4_3)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 4:3);else if (action m_1_1)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 1:1);else if (action m_16_10)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 16:10);else if (action m_2_21_1)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 221:100);else if (action m_2_35_1)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 235:100);else if (action m_2_38_1)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 238:100);else if (action m_5_4)libvlc_video_set_aspect_ratio(vlc_mediaPlayer, 5:4);action-setIcon(QIcon(:/image/images/point.png));m_preAspectRatio-setIcon(QIcon());m_preAspectRatio action;
}void showWidget::slotCropActionTriggered(QAction *action)
{if (!vlc_mediaPlayer)return;if (action m__cropDefault)libvlc_video_set_crop_geometry(vlc_mediaPlayer, m_defalutCrop);else if (action m__crop16_10)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 16:10);else if (action m__crop16_9)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 16:9);else if (action m__crop4_3)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 4:3);else if (action m__crop1_85_1)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 185:100);else if (action m__crop2_21_1)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 221:100);else if (action m__crop2_35_1)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 235:100);else if (action m__crop2_39_1)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 239:100);else if (action m__crop5_3)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 5:3);else if (action m__crop5_4)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 5:4);else if (action m__crop1_1)libvlc_video_set_crop_geometry(vlc_mediaPlayer, 1:1);action-setIcon(QIcon(:/image/images/point.png));m_preCrop-setIcon(QIcon());m_preCrop action;
}void showWidget::slotScaleActionTriggered(QAction *action)
{if (!vlc_mediaPlayer)return;if (action m_scale1_4)libvlc_video_set_scale(vlc_mediaPlayer, 0.25);else if (action m_scale1_2)libvlc_video_set_scale(vlc_mediaPlayer, 0.5);else if (action m_scale1_1)libvlc_video_set_scale(vlc_mediaPlayer, 1);else if (action m_scale2_1)libvlc_video_set_scale(vlc_mediaPlayer, 2);action-setIcon(QIcon(:/image/images/point.png));m_preScale-setIcon(QIcon());m_preScale action;
}void showWidget::slotSnap()
{if (vlc_mediaPlayer){QString path ./snap.png;libvlc_video_take_snapshot(vlc_mediaPlayer, 0, path.toUtf8().data(), 0, 0);}
}//事件回调
void showWidget::vlcEvents(const libvlc_event_t *ev, void *param)
{showWidget *w (showWidget*)param;//处理不同的事件switch (ev-type) {case libvlc_MediaPlayerTimeChanged:{//qDebug() VLC媒体播放器时间已更改;qint64 len libvlc_media_player_get_time(w-vlc_mediaPlayer);libvlc_time_t lenSec len / 1000;libvlc_time_t totalLen libvlc_media_player_get_length(w-vlc_mediaPlayer);libvlc_time_t totalLenSec totalLen / 1000;int thh, tmm, tss;thh lenSec / 3600;tmm (lenSec % 3600) / 60;tss (lenSec % 60);QTime time(thh, tmm, tss);w-ui.lbCurTime-setText(time.toString(hh:mm:ss));thh totalLenSec / 3600;tmm (totalLenSec % 3600) / 60;tss (totalLenSec % 60);QTime TotalTime(thh, tmm, tss);w-ui.lbTotalTime-setText(TotalTime.toString(hh:mm:ss));double pos (double)lenSec / totalLenSec * 100;w-ui.horizontalSlider-setValue(pos);}break;case libvlc_MediaPlayerEndReached:qDebug() VLC播放完毕.;break;case libvlc_MediaPlayerStopped:qDebug() VLC停止播放;break;case libvlc_MediaPlayerPlaying:qDebug() VLC开始播放;break;case libvlc_MediaPlayerPaused:qDebug() VLC暂停播放;break;}
}void showWidget::initMenu()
{//总菜单m_menu new QMenu(this);m_video m_menu-addAction(视频);//视频菜单m_videoMenu new QMenu(this);m_scaleAction m_videoMenu-addAction(缩放);m_aspectRatioAction m_videoMenu-addAction(宽高比);m_cropAction m_videoMenu-addAction(裁剪);m_snapAction m_videoMenu-addAction(截图);connect(m_snapAction, QAction::triggered, this, showWidget::slotSnap);m_video-setMenu(m_videoMenu);//宽高比菜单m_aspectRatioMenu new QMenu(this);m_aspectRatioAction-setMenu(m_aspectRatioMenu);//设置宽高比菜单m_default m_aspectRatioMenu-addAction(QIcon(:/image/images/point.png), 默认);m_16_9 m_aspectRatioMenu-addAction(16:9);m_4_3 m_aspectRatioMenu-addAction(4:3);m_1_1 m_aspectRatioMenu-addAction(1:1);m_16_10 m_aspectRatioMenu-addAction(16:10);m_2_21_1 m_aspectRatioMenu-addAction(2.21:1);m_2_35_1 m_aspectRatioMenu-addAction(2.35:1);m_2_38_1 m_aspectRatioMenu-addAction(2.38:1);m_5_4 m_aspectRatioMenu-addAction(5:4);m_preAspectRatio m_default;m_group new QActionGroup(this);m_group-addAction(m_default);m_group-addAction(m_16_9);m_group-addAction(m_4_3);m_group-addAction(m_1_1);m_group-addAction(m_16_10);m_group-addAction(m_2_21_1);m_group-addAction(m_2_35_1);m_group-addAction(m_2_38_1);m_group-addAction(m_5_4);connect(m_group, QActionGroup::triggered, this, showWidget::slotActionTriggered);//设置裁剪菜单m_cropMenu new QMenu(this);m_cropAction-setMenu(m_cropMenu);m__cropDefault m_cropMenu-addAction(QIcon(:/image/images/point.png), 默认);m__crop16_10 m_cropMenu-addAction(16:10);m__crop16_9 m_cropMenu-addAction(16:9);m__crop4_3 m_cropMenu-addAction(4:3);m__crop1_85_1 m_cropMenu-addAction(1.85:1);m__crop2_21_1 m_cropMenu-addAction(2.21:1);m__crop2_35_1 m_cropMenu-addAction(2.35:1);m__crop2_39_1 m_cropMenu-addAction(2.39:1);m__crop5_3 m_cropMenu-addAction(5:3);m__crop5_4 m_cropMenu-addAction(5:4);m__crop1_1 m_cropMenu-addAction(1:1);m_preCrop m__cropDefault;m_cropGroup new QActionGroup(this);m_cropGroup-addAction(m__cropDefault);m_cropGroup-addAction(m__crop16_10);m_cropGroup-addAction(m__crop16_9);m_cropGroup-addAction(m__crop4_3);m_cropGroup-addAction(m__crop1_85_1);m_cropGroup-addAction(m__crop2_21_1);m_cropGroup-addAction(m__crop2_35_1);m_cropGroup-addAction(m__crop2_39_1);m_cropGroup-addAction(m__crop5_3);m_cropGroup-addAction(m__crop5_4);m_cropGroup-addAction(m__crop1_1);connect(m_cropGroup, QActionGroup::triggered, this, showWidget::slotCropActionTriggered);//设置缩放菜单m_scaleMenu new QMenu(this);m_scaleAction-setMenu(m_scaleMenu);m_scale1_4 m_scaleMenu-addAction(1:4 四分之一);m_scale1_2 m_scaleMenu-addAction(1:2 二分之一);m_scale1_1 m_scaleMenu-addAction(QIcon(:/image/images/point.png),1:1 原始);m_scale2_1 m_scaleMenu-addAction(2:1 双倍);m_scaleGroup new QActionGroup(this);m_scaleGroup-addAction(m_scale1_4);m_scaleGroup-addAction(m_scale1_2);m_scaleGroup-addAction(m_scale1_1);m_scaleGroup-addAction(m_scale2_1);m_preScale m_scale1_1;connect(m_scaleGroup, QActionGroup::triggered, this, showWidget::slotScaleActionTriggered);
}更多参考
libVLC 事件机制-CSDN博客
libVLC windows开发环境搭建-CSDN博客
https://sunnnnnn666.blog.csdn.net/article/details/137023036
