网站发展历程,东莞企业网站建设制作,国际新闻哪个app好,河南郑州网站建设哪家公司好使用 libVLC 进行视频裁剪并不是直接支持的功能#xff0c;因为 libVLC 主要是一个媒体播放库。然而#xff0c;你可以通过调整播放窗口的大小和设置视频输出的区域来实现一种“视觉上的裁剪”。这意味着视频本身并没有被修改#xff0c;但可以控制显示给用户的视频区域。
…使用 libVLC 进行视频裁剪并不是直接支持的功能因为 libVLC 主要是一个媒体播放库。然而你可以通过调整播放窗口的大小和设置视频输出的区域来实现一种“视觉上的裁剪”。这意味着视频本身并没有被修改但可以控制显示给用户的视频区域。
如果你的目标是在播放时只显示视频的一部分你可以通过设置视频输出的裁剪区域来实现。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. 设置视频裁剪区域
你可以通过设置 libvlc_video_set_crop_geometry 来指定裁剪区域。这个函数允许你指定一个裁剪区域格式为 “NxN”例如“16:9”、“4:3” 等或者像素值例如 “640x480”。
// 设置裁剪区域
libvlc_video_set_crop_geometry(mp, 16:9);
3. 播放视频
最后播放视频。
// 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;
以下是VLC播放器中使用的视频裁剪我们仿照这个做一个界面。 以下是做出来的效果 首先做一个菜单
//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);
接受槽函数的响应事件
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;
}
设置鼠标右键弹出菜单重写鼠标点击事件弹出菜单。
首先设置libvlc忽略鼠标事件libvlc_video_set_mouse_input(vlc_mediaPlayer, 0);
再重写鼠标事件
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);}
}
完整代码
头文件。
#pragma once#include QtWidgets/QWidget
#include ui_showWidget.h
#include QMenu
#include QActionGroup
#include vlc/vlc.h
#include QDebug
#include QFileDialog
#include QThread
#include QMouseEventenum 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);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);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char *m_defalutRate nullptr;char *m_defalutCrop nullptr;
};cpp文件。
#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();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.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::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}}设置 logo 叠加//libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_enable, 1);//libvlc_video_set_logo_string(vlc_mediaPlayer, libvlc_logo_file, D:\\2.png);libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_position, libvlc_position_top_left);//libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_x, 100);//libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_y, 0);//libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_opacity, 255);//libvlc_video_set_logo_int(vlc_mediaPlayer, libvlc_logo_repeat, 1);创建并设置水印文本//libvlc_video_set_marquee_int(vlc_mediaPlayer, libvlc_marquee_Enable, 1);//libvlc_video_set_marquee_int(vlc_mediaPlayer, libvlc_marquee_Position, libvlc_position_center);//libvlc_video_set_marquee_int(vlc_mediaPlayer, libvlc_marquee_Refresh, 2000);//libvlc_video_set_marquee_int(vlc_mediaPlayer, libvlc_marquee_Size, 24);//libvlc_video_set_marquee_string(vlc_mediaPlayer, libvlc_marquee_Text, 这里是水印文本);libvlc_video_set_marquee_int(w-vlc_mediaPlayer, libvlc_marquee_Timeout, 5000);//libvlc_video_set_marquee_int(vlc_mediaPlayer, libvlc_marquee_Opacity, 255); // 不透明//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);
}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;
}//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_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);
}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/136854500
libVLC 元数据-CSDN博客
libVLC 添加图片和文本水印-CSDN博客
https://sunnnnnn666.blog.csdn.net/article/details/136920169
