65.QT-UDP组播实现多人共享桌面(同时支持收发显示)

这里我们只是简单学习下通过udp组播如何共享桌面demo.帧率上面比较低,毕竟没有用推流,只是简单的将图片发送到组播地址,而加入组播地址的客户端去取数据显示而已.

主要是为了学习udp知识而写的,真的想要做共享桌面的话,建议还是使用qt ffmpeg推流.速度上会快很多(后续有时间再来出)

1.demo介绍

截图如下所示:

gif效果如下所示(有点大,加载有点久):

功能介绍

• 一份代码同时支持收数据处理和发数据处理.
• 自动检查帧率和每帧图片字节大小
• 代码中使用了多线程和队列协助qwidget显示.
• 当接收共享时,会在线程中不停接收数据,直到接收到完整的一份数据时,则放到队列中,然后供qwidget提取数据.
• 当开启共享时,则在线程中抓取桌面数据,实时发送,并备份一个qpixmap供qwidget显示数据

 

代码和可以直接运行的程序都放在群里,需要的自行下载:

 

 

 

2.sharescreenthread.cpp代码如下所示

#include "sharescreenthread.h"

sharescreenthread::sharescreenthread(qthread *parent) : qthread(parent),
    m_state(sharescreen_none),
    groupaddress("239.255.43.21"),
    m_runcnt(0),
    m_canread(false),
    m_sendquality(20)
{
    m_recvqueue.clear();
}


bool sharescreenthread::startgrabwindow()
{
    qmutexlocker locker(&m_mutex);
    if (m_state == sharescreen_stop || m_state == sharescreen_sendrunning) {
        m_state = sharescreen_sendrunning;
        emit statechange();
        return true;
    }
    return false;
}

bool sharescreenthread::stopgrabwindow()
{
    qmutexlocker locker(&m_mutex);
    if (m_state == sharescreen_sendrunning || m_state == sharescreen_stop) {
        m_state = sharescreen_enterstop;
        return true;
    }

    return false;
}
void sharescreenthread::run()
{
    m_udp = new qudpsocket();
    qdebug()<<"绑定:"<<m_udp->bind(qhostaddress::anyipv4, 44544, qudpsocket::shareaddress | qudpsocket::reuseaddresshint);
    qdebug()<<"加入:"<<m_udp->joinmulticastgroup(groupaddress);

    while(1) {

        switch (m_state) {
            case sharescreen_none:
                m_runcnt++;
                if (m_runcnt > 100) {
                    m_state = sharescreen_stop;
                    m_pregetwindowmsec = qdatetime::currentdatetime().tomsecssinceepoch();     //记录时间
                    emit statechange();
                }
                msleep(10);
                if(m_udp->haspendingdatagrams() ) {
                    m_state = sharescreen_recvrunning;
                    emit statechange();
                    m_pregetwindowmsec = qdatetime::currentdatetime().tomsecssinceepoch();     //记录时间
                    getwindow();
                }
                break;
            case sharescreen_stop:
                if(m_udp->haspendingdatagrams()) {
                    m_state = sharescreen_recvrunning;
                    emit statechange();
                    getwindow();
                }
                break;
            case sharescreen_recvrunning:
                getwindow();
                break;
            case sharescreen_sendrunning:
                grabwindow();
                break;
            case sharescreen_enterstop:     // 由于广播,自己会受到自己消息,需要清空
                if (m_udp->haspendingdatagrams() ) {
                    m_udp->receivedatagram();
                } else {
                    m_state = sharescreen_stop;
                    emit statechange();
                }
                break;

            default: break;
        }

    }
}

3.widget.cpp代码如下所示

#include "widget.h"
#include "ui_widget.h"
widget::widget(qwidget *parent)
    : qwidget(parent),
      ui(new ui::widget)

{
    ui->setupui(this);
    connect(&m_thread, signal(statechange()), this, slot(onstatechange()));
    m_thread.start();

    connect(&m_updateshow, signal(timeout()), this, slot(onupdateshow()));

    setwindowtitle("udp共享屏幕");
}

widget::~widget()
{
    m_thread.terminate();
    delete ui;
}

void widget::onstatechange()
{
    qdebug()<<"onstatechange"<<m_thread.state();
    switch (m_thread.state()) {
        case sharescreenthread::sharescreen_none:  break;
        case sharescreenthread::sharescreen_stop: ui->labelhint->settext("等待共享..."); cleanshow(); ui->comboquality->setenabled(true); break;
        case sharescreenthread::sharescreen_recvrunning: ui->labelhint->settext("有人正在共享中☺");

            m_pressmsec = qdatetime::currentdatetime().tomsecssinceepoch();     //记录的时间
            m_updateshowcnt = 0;
            m_updateshow.start(25);
            ui->comboquality->setenabled(false);
            break;
        case sharescreenthread::sharescreen_sendrunning: ui->labelhint->settext("您正在共享中☺"); ui->comboquality->setenabled(true); break;
        default: break;
    }
}

void widget::cleanshow()
{
    ui->labelshow->clear();
    ui->labelbyte->settext(qstring("每帧: %1kb").arg(0));
    ui->labelfps->settext("当前fps: "+ qstring("%1").arg(0));

}


void widget::onupdateshow()
{
    bool getok = false;
    int size = 0;
    qpixmap pix(m_thread.getpixmap(getok, size));
    qsize imagesize =pix.size();
    if (size!=0)
        ui->labelbyte->settext(qstring("每帧: %1kb").arg(size/1024));

    if (getok == false)
        return;

    pix = pix.scaled(ui->labelshow->size(), qt::keepaspectratio);

    if (m_thread.state() == sharescreenthread::sharescreen_recvrunning) {
        qpainter painter(&pix);
        painter.setrenderhints(qpainter::antialiasing);
        qpixmap mouse(":/mouse");
        double xratio = pix.width() / (double)imagesize.width();
        double yratio = pix.height() / (double)imagesize.height();
        painter.drawpixmap(m_thread.getmousepos().x()*xratio, m_thread.getmousepos().y()*yratio , 25*xratio, 25*yratio, mouse);

    }

    ui->labelshow->setpixmap(pix);

    if (m_updateshowcnt++ >= 10) {
        qint64 tmp = qdatetime::currentdatetime().tomsecssinceepoch();
        qint64 durationms = tmp - m_pressmsec;

        int fps = m_updateshowcnt * 1000/durationms;
        ui->labelfps->settext("当前fps: "+ qstring("%1").arg(fps));

        m_updateshowcnt = 0;
        m_pressmsec = tmp;
    }

}

void widget::on_btnstartshare_clicked()
{
    bool question;
    switch (m_thread.state()) {
        case sharescreenthread::sharescreen_none: customdialog::showmessageerr(this,"提示", "正在初始化中!"); return;
        case sharescreenthread::sharescreen_stop: cleanshow(); break;
        case sharescreenthread::sharescreen_recvrunning: customdialog::showmessageinfo(this,"提示", "有人正在共享中!"); return;
        case sharescreenthread::sharescreen_sendrunning:  question = customdialog::showmessagequestion(this,"询问", "是否取消共享?");
            if (!question)
                return;
    }



    bool mystartd = ui->btnstartshare->text().contains("停止");

    if (mystartd) {
        m_thread.stopgrabwindow();
        ui->btnstartshare->settext("开始共享");
        ui->labelfps->settext("当前fps: 0");
        m_updateshow.stop();

        ui->labelshow->setpixmap(qpixmap());
    } else {
        m_thread.startgrabwindow();
        ui->btnstartshare->settext("停止共享");
        m_pressmsec = qdatetime::currentdatetime().tomsecssinceepoch();     //记录的时间
        m_updateshowcnt = 0;
        m_updateshow.start(12);
    }

}

void widget::keypressevent(qkeyevent *event)
{


   if (ui->control->ishidden() && event->key() == qt::key_escape) {
        ui->control->show();
        showmaximized();

   }

}


void widget::on_btnfull_clicked()
{
    ui->control->hide();
    showfullscreen();

}

void widget::on_comboquality_currentindexchanged(int index)
{

    switch (index) {
        case 0 : m_thread.setquality(20); break;
        case 1 : m_thread.setquality(38); break;
        case 2 : m_thread.setquality(50); break;
    }
}