QT中调用mplayer显示视频并加透明文字

 之前使用QT的多媒体库phonon播放视频，后来发现在跨平台时也比较麻烦，不如直接带一个mplayer播放。CPU占用还可以。

#include <QApplication>

#include <QtGui>

 

#ifdef Q_WS_WIN

const QString mplayerPath("C:\\Program Files\\SMPlayer\\mplayer\\mplayer.exe");

const QString movieFile("c:/traffic.mpg");

#else

const QString mplayerPath("/usr/bin/mplayer");

const QString movieFile("/home/anderson/test.avi");

#endif

 

class MaskedLabel : public QLabel

{

public:

    MaskedLabel(QWidget *parent = 0):QLabel(parent)

    {

    }

 

protected:

    void resizeEvent(QResizeEvent* event)

    {

        QLabel::resizeEvent(event);

 

        QPixmap pixmap(size());

        pixmap.fill(Qt::transparent);

        QPainter::setRedirected(this, &pixmap);

        QPaintEvent pe(rect());

        paintEvent(&pe);

        QPainter::restoreRedirected(this);

        setMask(pixmap.mask());

    }

};

 

class PlayerWidget : public QWidget

{

    Q_OBJECT

 

public:

    virtual ~PlayerWidget() {}

    PlayerWidget(QWidget *parent =0): QWidget(parent)

    {

        controller = new QPushButton("Play");

 

        renderTarget = new QWidget(this);

        renderTarget->setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred));

        renderTarget->setAttribute(Qt::WA_OpaquePaintEvent );

        renderTarget->setMinimumSize(g00, g00);

 

        timeLine = new QSlider(Qt::Horizontal);

 

        log = new QTextEdit;

        log->setReadOnly(true);

 

        QVBoxLayout *layout = new QVBoxLayout;

        layout->addWidget(controller);

        layout->addWidget(renderTarget);

        layout->addWidget(timeLine);

        layout->addWidget(log);

        setLayout(layout);

 

        mplayerProcess = new QProcess(this);

 

        poller = new QTimer(this);

 

        connect(controller, SIGNAL(clicked()), this, SLOT(switchPlayState())); //switchPlayState在后面

        connect(mplayerProcess, SIGNAL(readyReadStandardOutput()),

                this, SLOT(catchOutput())); //catchOutput在后面

        connect(mplayerProcess, SIGNAL(finished(int, QProcess::ExitStatus)),

                this, SLOT(mplayerEnded(int, QProcess::ExitStatus))); //mplayerEnded在后面

        connect(poller, SIGNAL(timeout()), this, SLOT(pollCurrentTime())); //pollCurrentTime在后面

        connect(timeLine, SIGNAL(sliderMoved(int)), this, SLOT(timeLineChanged(int))); //timeLineChanged在后面

 

        QLabel* label = new MaskedLabel();

        label->setText("<font color=\"#0000e0\" size=\"22\"> <b> 1Now there was a man of the Pharisees named Nicodemus, a member of the Jewish ruling council. 2He came to Jesus at night and said, \"Rabbi, we know you are a teacher who has come from God. For no one could perform the miraculous signs you are doing if God were not with him.\" 3In reply Jesus declared, \"I tell you the truth, no one can see the kingdom of God unless he is born again.[a]\"  4\"How can a man be born when he is old?\" Nicodemus asked. \"Surely he cannot enter a second time into his mother's womb to be born!\" </b></font>");

        //label->setGeometry(renderTarget->geometry());

        label->setWordWrap(true);

        label->show();

 

    }

 

private:

    QPushButton *controller;

    QWidget *renderTarget;

    QProcess *mplayerProcess; //main thing

    bool isPlaying;

    QSlider *timeLine;

    QTimer *poller;

    QTextEdit *log;

 

 

protected:

    void closeEvent(QCloseEvent *e)

    {

        stopMPlayer();

        e->accept();

    }

 

private:

    bool startMPlayer()

    {

        if(isPlaying)

            return true;

 

        QStringList args; //运行mplayer需求的参数parameter

 

        // On demande ? utiliser mplayer comme backend

        // are asked to use mplayer as backend

        args << "-slave";

        // Et on veut ne pas avoir trop de chose ? parser :)

        //And we want to not having too many things to parser:)

        args << "-quiet";

#ifdef Q_WS_WIN

        // reinterpret_cast obligatoire, winId() ne se laissant pas convertir gentiment ;)

        //reinterpret_cast mandatory winId () not allowing convert nicely;)

        args << "-wid" << QString::number(reinterpret_cast<long>(renderTarget->winId()));

        args << "-vo" << "directx:noaccel";

     //   args << "-nocache";

     //   args << "-framedrop";

#else

        // Sur linux, aucun driver n'a ?t? n?cessaire et pas de manip pour Wid :)

        //On linux, no driver has been necessary and no manip for Wid:)

        args << "-wid" << QString::number(renderTarget->winId());

 

        log->append("Video output driver may not be necessary for your platform.Check: http://www.mplayerhq.hu/DOCS/man/en/mplayer.1.html at the VIDEO OUTPUT DRIVERS section.");

#endif

 

        args << movieFile;

 

        // On parse la stdout et stderr au m?me endroit, donc on demande ? "fusionnner" les 2 flux

        //parse the stdout and stderr in the same place, so we are asking "fusionnner"

        mplayerProcess->setProcessChannelMode(QProcess::MergedChannels);

        mplayerProcess->start(mplayerPath, args); //开端运行那个进程

        if(!mplayerProcess->waitForStarted(100))

        {

            qDebug("can not start mplayer !");

            return false;

        }

 

        //retrieve basic information

        mplayerProcess->write("get_video_resolution ");

        mplayerProcess->write("get_time_length ");

 

        poller->start(0);

 

        isPlaying = true;

 

        return true;

    }

 

    bool stopMPlayer()

    {

        if(!isPlaying)

            return true;

 

        mplayerProcess->write("quit ");

        if(!mplayerProcess->waitForFinished(100))

        {

            qDebug("ZOMG, ?a plante :(");

            return false;

        }

 

        return true;

    }

 

private slots:

 

    //响应readyReadStandardOutput消息

    void catchOutput()

    {

        while(mplayerProcess->canReadLine())

        {

            QByteArray buffer(mplayerProcess->readLine());

            log->append(QString(buffer));

 

            // On v?rifie si on a eu des r?ponses

            //It checks if we had answers

            // r?ponse ? get_video_resolution : ANS_VIDEO_RESOLUTION=' x '

            //response to get_video_resolution: ANS_VIDEO_RESOLUTION

            if(buffer.startsWith("ANS_VIDEO_RESOLUTION"))

            {

                buffer.remove(0, 21); // vire ANS_VIDEO_RESOLUTION=

                buffer.replace(QByteArray("'"), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                int sepIndex = buffer.indexOf('x');

                int resX = buffer.left(sepIndex).toInt();

                int resY = buffer.mid(sepIndex+1).toInt();

                renderTarget->setMinimumSize(resX, resY);

            }

            // r?ponse ? get_time_length : ANS_LENGTH=xx.yy

            //response to get_time_length: ANS_LENGTH =

            else if(buffer.startsWith("ANS_LENGTH"))

            {

                buffer.remove(0, 11); // vire ANS_LENGTH=

                buffer.replace(QByteArray("'"), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                float maxTime = buffer.toFloat();

                timeLine->setMaximum(static_cast<long>(maxTime+1));

            }

            // r?ponse ? get_time_pos : ANS_TIME_POSITION=xx.y

            //response to get_time_pos: ANS_TIME_POSITION = 2.4

            else if(buffer.startsWith("ANS_TIME_POSITION"))

            {

                buffer.remove(0, 18); // vire ANS_TIME_POSITION=

                buffer.replace(QByteArray("'"), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                buffer.replace(QByteArray(" "), QByteArray(""));

                float currTime = buffer.toFloat();

                timeLine->setValue(static_cast<long>(currTime+1));

            }

            //qApp->processEvents();

        }

    }

 

    void pollCurrentTime()

    {

        mplayerProcess->write("get_time_pos ");

    }

 

    // Dirige la timeline

    //Directs the timeline

    void timeLineChanged(int pos)

    {

        mplayerProcess->write(QString("seek " + QString::number(pos) + " 2 ").toUtf8());

    }

 

    // Play/stop

    void switchPlayState()

    {

        if(!isPlaying)

        {

            if(!startMPlayer())

                return;

 

            log->clear();

            controller->setText("Stop");

            isPlaying = true;

        }

        else

        {

            if(!stopMPlayer())

                return;

 

            poller->stop();

            log->clear();

            controller->setText("Play");

            isPlaying = false;

        }

    }

 

    void mplayerEnded(int exitCode, QProcess::ExitStatus exitStatus)

    {

        isPlaying = false;

        controller->setText("Play");

        poller->stop();

    }

 

 

};

 

int main(int argc, char **argv)

{

    QApplication app(argc, argv);

 

    PlayerWidget *pw = new PlayerWidget;

    pw->show();

 

    return app.exec();

}

 

#include "hello.moc"