QT应用编程:基于VLC开发音视频播放器(句柄方式)

#include "widget.h"
#include "ui_widget.h"

Widget* Widget::pThis = nullptr;

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    pThis=this;

    ui->setupUi(this);
    this->setWindowTitle("视频播放器");

    //VLC相关的初始化
    vlc_base=libvlc_new(0, nullptr); //创建并初始化libvlc实例
    if(!vlc_base)
    {
        qDebug()<<"libvlc_new 执行错误.";
    }


    //播放速度设置
    ui->MediaSpeedBtn->setCheckable(true);
    m_TimeSpeedGrp = new QActionGroup(this);

    QStringList strSpeedItems;
    strSpeedItems << tr("0.03X") << tr("0.06X") << tr("0.1X") << tr("0.15X") << tr("0.2X") << tr("0.3X") << tr("0.4X") << tr("0.5X") << tr("0.6X") << tr("0.8X") << tr("1.0X") << tr("1.25X") << tr("1.5X") << tr("2.0X") << tr("4.0X") << tr("8.0X");
    float speeds[] = { 0.03, 0.06, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5,0.6,0.8,1.0,1.25,1.5,2.0,4.0,8.0};

    for (int i = 0; i < strSpeedItems.size(); i++)
    {
        QAction *pSpeedItem = m_SpeedMenu.addAction(strSpeedItems.at(i));
        pSpeedItem->setData(QVariant::fromValue(speeds[i]));
        pSpeedItem->setCheckable(true);
        m_TimeSpeedGrp->addAction(pSpeedItem);
        if (i == 10)
        {
            pSpeedItem->setChecked(true);
        }
    }
    connect(m_TimeSpeedGrp, SIGNAL(triggered(QAction *)), this, SLOT(slot_onSetTimeSpeed(QAction *)));

    //事件监听
    ui->horizontalSlider_pos->installEventFilter(this);
    ui->horizontalSlider_volume->installEventFilter(this);
}


Widget::~Widget()
{
    delete ui;
    libvlc_release(vlc_base); //减少libvlc实例的引用计数，并销毁它
}


bool Widget::eventFilter(QObject *obj, QEvent *event)
{
    if(obj==ui->horizontalSlider_pos)
    {
        if (event->type()==QEvent::MouseButtonPress)           //判断类型
        {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
            if (mouseEvent->button() == Qt::LeftButton)	//判断左键
            {
               int value = QStyle::sliderValueFromPosition(ui->horizontalSlider_pos->minimum(), ui->horizontalSlider_pos->maximum(), mouseEvent->pos().x(), ui->horizontalSlider_pos->width());
               ui->horizontalSlider_pos->setValue(value);

               //跳转播放器
               float f_value=(float)value/(float)ui->horizontalSlider_pos->maximum();
               libvlc_media_player_set_position(vlc_mediaPlayer,f_value);
            }
        }
    }

    if(obj==ui->horizontalSlider_volume)
    {
        if (event->type()==QEvent::MouseButtonPress)           //判断类型
        {
            QMouseEvent *mouseEvent = static_cast<QMouseEvent *>(event);
            if (mouseEvent->button() == Qt::LeftButton)	//判断左键
            {
               int value = QStyle::sliderValueFromPosition(ui->horizontalSlider_volume->minimum(), ui->horizontalSlider_volume->maximum(), mouseEvent->pos().x(), ui->horizontalSlider_volume->width());
               ui->horizontalSlider_volume->setValue(value);
               //设置音量
               if(vlc_mediaPlayer)libvlc_audio_set_volume(vlc_mediaPlayer,value);
            }
        }
    }
    return QWidget::eventFilter(obj, event);
}


/*
工程: QtVLC_Player
日期: 2021-03-24
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 打开本地文件
*/
void Widget::on_pushButton_open_clicked()
{
    /*选择文件*/
    QString filename=QFileDialog::getOpenFileName(this,"选择打开的文件","D:/",tr("*.*"));

    /* 将 / 转为windows下的右斜杆 */
    std::replace(filename.begin(), filename.end(), QChar('/'), QChar('\\'));
    qDebug()<<"播放的媒体:"<<filename;

    /*为特定文件路径创建媒体*/
    if(vlc_media)libvlc_media_release(vlc_media);
    vlc_media=libvlc_media_new_path(vlc_base,filename.toUtf8().data());
    if(vlc_media==nullptr)
    {
        qDebug()<<"libvlc_media_new_path 执行错误.";
        return;
    }

    /*根据给定的媒体对象创建一个播放器对象*/
    if(vlc_mediaPlayer)libvlc_media_player_release(vlc_mediaPlayer);
    vlc_mediaPlayer=libvlc_media_player_new_from_media(vlc_media);

    /*解析媒体实例*/
    // libvlc_media_parse(vlc_media);

    /*获取媒体播放器事件管理器*/
    libvlc_event_manager_t *em = libvlc_media_player_event_manager(vlc_mediaPlayer);
    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);

    /*设置给予媒体播放器媒体输出的win32/win64窗口句柄*/
    libvlc_media_player_set_hwnd(vlc_mediaPlayer, (void *)ui->widget_VideoPlay->winId());
    //如果不使用句柄方式,VLC也支持回调方式处理图像,这种方式可以自己提取图像数据,自己渲染显示处理. libvlc_video_set_callbacks

    /*播放媒体文件*/
    if(vlc_mediaPlayer)libvlc_media_player_play(vlc_mediaPlayer);

    //等待VLC解析文件.否则下面的时间获取不成功
    QThread::msleep(100);

    //获取媒体文件总长度 ms
    libvlc_time_t length = libvlc_media_player_get_length(vlc_mediaPlayer);
    qDebug()<<"媒体文件总长度:"<<length;
    ui->label_t2->setText(QString("%1").arg(length));
    ui->horizontalSlider_pos->setMaximum(length);
    ui->horizontalSlider_pos->setMinimum(0);

    //获取当前媒体播放的位置
    libvlc_time_t current_movie_time=libvlc_media_player_get_time(vlc_mediaPlayer);
    qDebug()<<"获取当前媒体播放的位置:"<<current_movie_time;


    unsigned int width=0,height=0;
    libvlc_video_get_size(vlc_mediaPlayer,0,&width,&height);
    qDebug()<<"视频尺寸:"<<"width:"<<width<<"height:"<<height;

    /*获取媒体播放器使用的媒体。*/
    ui->label_video_name->setText(QString("%1:%2x%3").arg(filename).arg(width).arg(height));

    //暂停: 停留在第一帧画面
    if(vlc_mediaPlayer)libvlc_media_player_pause(vlc_mediaPlayer);
}


/*
工程: QtVLC_Player
日期: 2021-03-24
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: VLC的事件回调
*/
void Widget::vlcEvents(const libvlc_event_t *ev, void *param)
{
     qint64 pos;
    switch (ev->type){
    case libvlc_MediaPlayerTimeChanged:
         qDebug() << "VLC媒体播放器时间已更改";
         //获取当前媒体播放的位置
         pos=libvlc_media_player_get_time(pThis->vlc_mediaPlayer);
         pThis->ui->label_t1->setText(QString("%1").arg(pos));
         pThis->ui->horizontalSlider_pos->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;
    }
}


/*
工程: QtVLC_Player
日期: 2021-03-24
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 暂停
*/
void Widget::on_pushButton_pause_clicked()
{
     if(vlc_mediaPlayer)libvlc_media_player_pause(vlc_mediaPlayer);
}

/*
工程: QtVLC_Player
日期: 2021-03-24
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 停止
*/
void Widget::on_pushButton_stop_clicked()
{
    if(vlc_mediaPlayer)libvlc_media_player_stop(vlc_mediaPlayer);
}

/*
工程: QtVLC_Player
日期: 2021-03-24
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 速率
*/
void Widget::slot_onSetTimeSpeed(QAction *action)
{
    action->setChecked(true);
    ui->MediaSpeedBtn->setToolTip(action->text());
    ui->MediaSpeedBtn->setText(action->text());

    /*设置播放速率*/
    if(vlc_mediaPlayer)libvlc_media_player_set_rate(vlc_mediaPlayer,float(action->data().toFloat()));
}

void Widget::on_MediaSpeedBtn_clicked()
{
    QPoint ptWgt = ui->MediaSpeedBtn->mapToGlobal(QPoint(0, 0));
    ptWgt -= QPoint(10, 180);
    QAction *pSelect = m_SpeedMenu.exec(ptWgt);
    if (pSelect == nullptr)
        return;
}

void Widget::on_pushButton_get_state_clicked()
{
    if(vlc_mediaPlayer)
    {
        //4表示暂停  3表示继续   5表示停止
        qDebug()<<"播放状态:"<<libvlc_media_player_get_state(vlc_mediaPlayer);
    }
}


void Widget::on_pushButton_reset_clicked()
{
    /*需要先停止才可以继续重头播放*/
    if(vlc_mediaPlayer)libvlc_media_player_stop(vlc_mediaPlayer);
    /*播放媒体文件*/
    if(vlc_mediaPlayer)libvlc_media_player_play(vlc_mediaPlayer);
}

//静音切换
void Widget::on_pushButton_volume_clicked()
{
    static bool state=false;
    state=!state;
    if(state)
    {
        //静音
        if(vlc_mediaPlayer)libvlc_audio_set_volume(vlc_mediaPlayer,0);
    }
    else
    {
        int val=ui->horizontalSlider_volume->value();
        qDebug()<<"设置音量:"<<val;
        if(vlc_mediaPlayer)libvlc_audio_set_volume(vlc_mediaPlayer,val);
    }
}

//音量滑块
void Widget::on_horizontalSlider_volume_valueChanged(int value)
{
    //设置音量
    if(vlc_mediaPlayer)libvlc_audio_set_volume(vlc_mediaPlayer,value);
}

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <vlc/vlc.h>
#include <QFileDialog>
#include <QDebug>
#include <QThread>
#include <QActionGroup>
#include <QMenu>
#include <QMouseEvent>
#include <QStyle>
#include <QTimer>


QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();


private slots:
    void on_pushButton_open_clicked();
    void on_pushButton_pause_clicked();
    void on_pushButton_stop_clicked();
    void slot_onSetTimeSpeed(QAction *action);
    void on_MediaSpeedBtn_clicked();

    void on_pushButton_get_state_clicked();

    void on_pushButton_reset_clicked();
    void on_pushButton_volume_clicked();

    void on_horizontalSlider_volume_valueChanged(int value);

protected:
    bool eventFilter(QObject *obj, QEvent *event);
    static void vlcEvents(const libvlc_event_t *ev, void *param);
private:
    Ui::Widget *ui;

    libvlc_instance_t *vlc_base=nullptr;
    libvlc_media_t *vlc_media=nullptr;
    libvlc_media_player_t *vlc_mediaPlayer=nullptr;

    QActionGroup *m_TimeSpeedGrp;
    QMenu		m_SpeedMenu;

    static Widget *pThis;
};
#endif // WIDGET_H