Qt：投屏的发现和发送

发现：https://blog.csdn.net/sinat_33859977/article/details/113567847  

向固定地址端口发送查询信息

QHostAddress groupAddress;
QUdpSocket *socket;

{
    groupAddress = QHostAddress("239.255.255.250");
    socket = new QUdpSocket(this);
    auto ok = socket->bind(QHostAddress::AnyIPv4, 2068, QUdpSocket::ShareAddress);
    connect(socket, SIGNAL(readyRead()), this, SLOT(readMsg()));
    ok = socket->joinMulticastGroup(groupAddress);
}

void MainWindow::on_pushButton_discover_clicked()
{
    QByteArray BA("M-SEARCH * HTTP/1.1\r\n"
                  "HOST: 239.255.255.250:1900\r\n"
                  "ST: urn:schemas-upnp-org:service:AVTransport:1\r\n" //投屏
                  "MAN: \"ssdp:discover\"\r\n"
                  "MX: 3\r\n"
                  "\r\n");

    auto writeOk = socket->writeDatagram(BA.data(), groupAddress, 1900);
}

void MainWindow::readMsg()
{    
    while (socket->hasPendingDatagrams()) {
        QByteArray reply;
        reply.resize(socket->pendingDatagramSize());
        socket->readDatagram(reply.data(), reply.size());
        qDebug() << c;
        qDebug() << reply.data();        
}

每一个设备返回的信息

HTTP/1.1 200 OK
USN: uuid:8fa440b3-f312-4415-8640-f790a3845fcf::urn:schemas-upnp-org:service:AVTransport:1
LOCATION: http://192.168.2.104:1068/description.xml
ST: urn:schemas-upnp-org:service:AVTransport:1
EXT: 
SERVER: Linux/5.10.50-amd64-desktop UPnP/1.0 Macast/0.6
CACHE-CONTROL: max-age=66
DATE: Sat, 11 Sep 2021 11:49:18 GMT

打开 http://192.168.2.104:1068/description.xml，可以看到详情

    1
    0


    urn:schemas-upnp-org:device:MediaRenderer:1
    uuid:8fa440b3-f312-4415-8640-f790a3845fcf
    Macast(sonichy-PC)
    xfangfang
    https://github.com/xfangfang
    AVTransport Media Renderer
    Macast
    0.6
    https://xfangfang.github.io/Macast
    DMR-1.50
    
        
            urn:schemas-upnp-org:service:AVTransport:1
            urn:upnp-org:serviceId:AVTransport
            AVTransport/action
            AVTransport/event
            dlna/AVTransport.xml
        
        
            urn:schemas-upnp-org:service:RenderingControl:1
            urn:upnp-org:serviceId:RenderingControl
            RenderingControl/action
            RenderingControl/event
            dlna/RenderingControl.xml
        
        
            urn:schemas-upnp-org:service:ConnectionManager:1
            urn:upnp-org:serviceId:ConnectionManager
            ConnectionManager/action
            ConnectionManager/event
            dlna/ConnectionManager.xml
        
    

如何推送网址就比较难了，没人讲清楚，直到找到这个项目：

https://github.com/sYCH3L/TwitchTVDLNAPlayer/blob/master/dlnaclient.cpp#L111

在 UploadFileToPlay 的最后，增加几句，把请求内容写入文件，方便查看究竟写了些什么：

QString DLNAClient::UploadFileToPlay(QString ControlURL, QString UrlToPlay)
{
    //Later we will send a message to the DLNA server to start the file playing
    QString XML = XMLHead;
    XML += "\n";
    XML += "0\n";
    XML += "" + UrlToPlay.replace(" ", "%20") + "\n";
    XML += "\n" + Desc() + "\n";
    XML += "\n";
    XML += XMLFoot + "\n";
    QString Request = HelperDLNA::MakeRequest("POST", ControlURL, XML.length(), "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI", ip, StrPort) + XML;
    qDebug() << Request;
    QFile file("request.txt");
    if (file.open(QFile::WriteOnly)) {
        file.write(Request.toUtf8());
        file.close();
    }
    return HelperDLNA::makeSocketGetReply(ip, StrPort, Request);
}

打开 request.txt，一目了然

POST /AVTransport/action HTTP/1.1
Cache-Control: no-cache
Connection: Close
Pragma: no-cache
Host:  192.168.2.104:1068
User-Agent: Microsoft-Windows/6.3 UPnP/1.0 Microsoft-DLNA DLNADOC/1.50
FriendlyName.DLNA.ORG: sonichy-PC
Content-Length: 916
Content-Type: text/xml; charset="utf-8"
SOAPAction: "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI"





0
https://vod3.bdzybf3.com/20210523/Z14ku6y7/index.m3u8



Capital Edinburgh 373
object.item.audioItem.audioBroadcast
SA_RINCON65031_

 SOAPAction 请求头

 SOAP 的 XML

我改成了QNetworkRequest，注意  url 的协议要写，ContentType 要写。

QString DLNAClient::UploadFileToPlay(QString ControlURL, QString UrlToPlay)
{
    QString XML = "\n"
                  "\n"
                  "\n"
                  "\n"
                  "0\n";
    XML += "" + UrlToPlay.replace(" ", "%20") + "\n";
    XML += "\n";//" + Desc() + "
    XML += "\n";
    XML += "\n"
           "\n";
    QString surl = scheme + IP + ":" + port + "/" + ControlURL;
    qDebug() << surl;
    return postReply(surl, XML);
}

QByteArray DLNAClient::postReply(QString surl, QString spost)
{
    QNetworkAccessManager *NAM = new QNetworkAccessManager;
    QNetworkRequest request;
    request.setUrl(QUrl(surl));
    request.setHeader(QNetworkRequest::ContentTypeHeader, "text/xml; charset=\"utf-8\"");
    request.setRawHeader("SOAPAction", "urn:schemas-upnp-org:service:AVTransport:1#SetAVTransportURI");
    QByteArray BA_post;
    BA_post.append(spost.toUtf8());
    QNetworkReply *reply = NAM->post(request, BA_post);
    QEventLoop loop;
    connect(reply, &QNetworkReply::finished, &loop, &QEventLoop::quit);
    loop.exec();
    reply->deleteLater();
    return reply->readAll();
}

返回这个就成功了：

如何接收投屏还没头绪。

源码：sonichy/HTYDLNA