mpv_qt.cpp

#include "mpv_qt.h"

//唤醒函数
static void wakeup(void *ctx){
	//此回调可从任何MPV线程调用(也可从调用MPV API的线程递归返回)
	//只是需要通知要唤醒的Qt GUI线程(以便它可以使用mpv_wait_event())，并尽快返回
    MpvPlayer *mpvPlayer = (MpvPlayer *)ctx;
    emit mpvPlayer->mpv_events();
}

MpvPlayer::MpvPlayer(QWidget *parent):
    QWidget(parent)
{
    create_mpvPlayer(parent);	//创建MpvPlayer
}

MpvPlayer::~MpvPlayer(){
    if(mpv) mpv_terminate_destroy(mpv);
}

//创建MPV
void MpvPlayer::create_mpvPlayer(QWidget *videoWin){
    //创建MPV实例
	mpv=mpv_create();
    if(!mpv)
        throw std::runtime_error("Can't create mpv instance");
	
	//将视频子窗口ID传给MPV win选项
    int64_t wid=videoWin->winId();
    mpv_set_option(mpv,"wid",MPV_FORMAT_INT64,&wid);

	//通过MPV_EVENT_PROPERTY_CHANGE接收属性更改事件，如属性更改
    mpv_observe_property(mpv,0,"time-pos",MPV_FORMAT_DOUBLE);
	
	//从此开始调用唤醒功能。回调可以来自任何线程，因此使用QueuedConnection机制以线程安全的方式中继唤醒
    connect(this, &MpvPlayer::mpv_events, this, &MpvPlayer::on_mpv_events,
                Qt::QueuedConnection);
    mpv_set_wakeup_callback(mpv,wakeup,this);

	//判断MPV实例是否成功初始化
    if(mpv_initialize(mpv)<0)
        throw std::runtime_error("mpv failed to initialize");
}

//设置MPV属性
void MpvPlayer::setProperty(const QString &name, const QString &value){
    mpv_set_option_string(mpv,name.toLatin1().data(),value.toLatin1().data());
}

//获得MPV属性
QString MpvPlayer::getProperty(const QString &name) const{
    return (QString)mpv_get_property_string(mpv,name.toLatin1().data());
}

//播放
void MpvPlayer::play(QString filename){
    if(mpv){
        const QByteArray c_filename=filename.toUtf8();
        const char *args[]={"loadfile",c_filename.data(),NULL};
		//与mpv_command相同，但异步运行命令来避免阻塞，直到进程终止
        mpv_command_async(mpv,0,args);
    }
}

//此槽函数由wakeup()调用(通过mpv_events信号)
void MpvPlayer::on_mpv_events(){
	//处理所有事件，直到事件队列为空
    while(mpv){
        mpv_event *event=mpv_wait_event(mpv,0);
        if(event->event_id==MPV_EVENT_NONE) break;
        handle_mpv_event(event);
    }
}

//处理MPV事件
void MpvPlayer::handle_mpv_event(mpv_event *event)
{
    switch (event->event_id)
    {
        //属性改变事件发生
        case MPV_EVENT_PROPERTY_CHANGE:
        {
            mpv_event_property *prop = (mpv_event_property *)event->data;

            if (strcmp(prop->name, "time-pos") == 0)
            {
                if (prop->format == MPV_FORMAT_DOUBLE)
                {
                    //获得播放时间
                    //double time = *(double *)prop->data;
                    //qDebug() << "播放时间: " << QString::number(time, 10, 2);
                }
                else if (prop->format == MPV_FORMAT_NONE)
                {
                    //该属性不可用，可能意味着播放已停止
                    emit mpv_palyEnd();
                    qDebug() << "Finished";
                }
            }
        }
        break;

        //退出事件发生
        case MPV_EVENT_SHUTDOWN:
        {
            mpv_terminate_destroy(mpv);
            mpv = NULL;
        }
        break;

        default: ;
    }
}