使用 VLC-Qt 库实现流媒体及视频文件多画面显示程序，根据simple-player例子修改，使用VLC-Qt_1.0.1_win64_msvc2013版本。

GitHub - vlc-qt/examples: VLC-Qt Examples
https://github.com/vlc-qt/examples

Releases · vlc-qt/vlc-qt · GitHub
https://github.com/vlc-qt/vlc-qt/releases

有1x2、2x2、2x3、3x3多个选择，根据选择生成多个播放画面，3x3需要占用90%的CPU及500M以上内存，根据exe名称读取对应文本文件获得视频地址，需要播放的视频文件个数和能播放的画面个数需要进行取舍。在对音量进行控制的时候，由于VlcWidgetVolumeSlider控件需要关联到VlcMediaPlayer控件，实现的时候需要一个临时的播放器控件对音量控件进行接收。通过播放器控件的右键菜单控制播放功能，包括暂停、重新打开、音量选项。

提示：添加于2019年1月5号，想实现一个“除此之外全部静音”的功能，初始代码如下

void MainWindow::setOtherVolume0()
{
    for (int i = 0; i < mVlcMediaLst.size(); ++i)
    {
        ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(i));
        ui->volume->setVolume(0);
    }

    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(100);
}

但是一直不能实现效果，后根据如下网址修改

VlcAudio - setVolume(int volume) · Issue #54 · vlc-qt/vlc-qt · GitHub
https://github.com/vlc-qt/vlc-qt/issues/54

修改后的代码如下，实现了效果。

void MainWindow::setOtherVolume0()
{
    for (int i = 0; i < mVlcMediaLst.size(); ++i)
    {
        mVlcMediaPlayerLst.at(i)->audio()->setVolume(0);
    }

    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(100);
}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <VLCQtCore/Common.h>
#include <VLCQtCore/Instance.h>
#include <VLCQtCore/Media.h>
#include <VLCQtCore/MediaPlayer.h>
#include <VLCQtWidgets/WidgetVideo.h>
#include <QFile>
#include <QFileInfo>
#include <QTextStream>
#include <QDateTime>
#include <QTimer>
#include <QHBoxLayout>
#include <QMenu>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    QFont font;
    font.setPixelSize(14);
    setFont(font);
    mTitle = QStringLiteral("VLC-Qt 流媒体及视频文件多画面显示");
    setWindowTitle(mTitle);

    mTimer = new QTimer(this);
    connect(mTimer, SIGNAL(timeout()), this, SLOT(updateTimer()));
    mTimer->start(1000);

    ui->comboBox->setMaximumHeight(25);
    ui->pushButton->setMaximumHeight(25);
    ui->label->setMaximumHeight(25);

    ui->comboBox->insertItem(0, "1x2");
    ui->comboBox->insertItem(1, "2x2");
    ui->comboBox->insertItem(2, "2x3");
    ui->comboBox->insertItem(3, "3x3");

    mVlcInstance = new VlcInstance(VlcCommon::args(), this);

    mVlcMediaPlayerTmp = new VlcMediaPlayer(mVlcInstance);
    ui->volume->setVisible(false);
    ui->volume->setMediaPlayer(mVlcMediaPlayerTmp);
    ui->volume->setVolume(0);

    readUrls();
}

MainWindow::~MainWindow()
{
    freeVlcLst();

    delete mVlcMediaPlayerTmp;

    if (mVlcInstance != nullptr)
    {
        delete mVlcInstance;
    }

    if (mTimer->isActive())
    {
        mTimer->stop();
    }
    delete mTimer;

    delete ui;
}

void MainWindow::updateTimer()
{
    QString dateTime = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss");
    ui->label->setText(QStringLiteral("%1").arg(dateTime));
}

void MainWindow::readUrls()
{
    mUrlLst.clear();

    QFile file(QStringLiteral("%1.txt").arg(qApp->applicationDisplayName()));
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
    {
        return;
    }

    QTextStream in(&file);
    in.setCodec("UTF-8");

    while (!in.atEnd())
    {
        QString str = in.readLine();
        if (str.isEmpty() || str.startsWith("$$"))
        {
            continue;
        }

        mUrlLst.append(str.split("#")[1]);
    }
}

void MainWindow::freeVlcLst()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerTmp);
    ui->volume->setVolume(0);

    foreach (VlcMedia *media, mVlcMediaLst)
    {
        delete media;
    }

    foreach (VlcMediaPlayer *player, mVlcMediaPlayerLst)
    {
        delete player;
    }

    foreach (VlcWidgetVideo *widget, mVlcWidgetVideoLst)
    {
        delete widget;
    }

    mVlcMediaLst.clear();
    mVlcMediaPlayerLst.clear();
    mVlcWidgetVideoLst.clear();
}

void MainWindow::initVideoWidgets()
{
    int count = 0;
    QString str;
    QStringList strLst;
    for (int i = 0; i < mTotal; ++i)
    {
        strLst.append(QStringLiteral("%1").arg(i));
        count++;
        if (count % mColumn == 0)
        {
            str.append(strLst.join("|"));
            str.append(",");
            strLst.clear();
        }
    }
    str.remove(str.length() - 1, 1);

    foreach (QString row, str.split(","))
    {
        QHBoxLayout *layout = new QHBoxLayout;
        foreach (QString column, row.split("|"))
        {
            layout->addWidget(mVlcWidgetVideoLst.at(column.toInt()));
        }
        ui->verticalLayout->addLayout(layout);
    }
}

void MainWindow::on_pushButton_clicked()
{
    freeVlcLst();

    if (mIsPlaying)
    {
        ui->comboBox->setEnabled(true);
        ui->pushButton->setText(QStringLiteral("开始播放"));
        mIsPlaying = false;
    }
    else
    {
        ui->comboBox->setEnabled(false);
        ui->pushButton->setText(QStringLiteral("停止播放"));
        mIsPlaying = true;

        for (int i = 0; i < mTotal; ++i)
        {
            VlcWidgetVideo *widget = new VlcWidgetVideo(this);
            VlcMediaPlayer *vlcMediaPlayer = new VlcMediaPlayer(mVlcInstance);
            vlcMediaPlayer->setVideoWidget(widget);
            widget->setMediaPlayer(vlcMediaPlayer);
            mVlcWidgetVideoLst.append(widget);
            mVlcMediaPlayerLst.append(vlcMediaPlayer);

            widget->setObjectName(QStringLiteral("%1").arg(i));
            widget->setContextMenuPolicy(Qt::CustomContextMenu);
            connect(widget, SIGNAL(customContextMenuRequested(QPoint)), this, SLOT(menuDisplayed(QPoint)));
        }

        initVideoWidgets();

        int validSize = (mUrlLst.size() >= mTotal) ? mTotal : mUrlLst.size();
        for (int i = 0; i < validSize; ++i)
        {
            QString url = mUrlLst.at(i);
            QFileInfo file(url);
            if (file.isFile())
            {
                VlcMedia *vlcMedia = new VlcMedia(url, true, mVlcInstance);
                mVlcMediaLst.append(vlcMedia);
            }
            else
            {
                VlcMedia *vlcMedia = new VlcMedia(url, mVlcInstance);
                mVlcMediaLst.append(vlcMedia);
            }
        }

        for (int i = 0; i < validSize; ++i)
        {
            mVlcMediaPlayerLst.at(i)->open(mVlcMediaLst.at(i));
        }
    }
}

void MainWindow::on_comboBox_currentIndexChanged(const QString &arg1)
{
    QStringList lst = arg1.split("x");
    mRow = lst[0].toInt();
    mColumn = lst[1].toInt();
    mTotal = mRow * mColumn;
}

void MainWindow::menuDisplayed(const QPoint &pos)
{
    Q_UNUSED(pos);

    mChoosePlayerNum = sender()->objectName().toInt();

    if (mChoosePlayerNum >= mUrlLst.size())
    {
        return;
    }

    QMenu *menu = new QMenu(this);
    QAction *pause = new QAction(QStringLiteral("暂停"), this);
    QAction *reOpen = new QAction(QStringLiteral("重新打开"), this);
    QAction *volume100 = new QAction(QStringLiteral("音量100%"), this);
    QAction *volume75 = new QAction(QStringLiteral("音量75%"), this);
    QAction *volume50 = new QAction(QStringLiteral("音量50%"), this);
    QAction *volume25 = new QAction(QStringLiteral("音量25%"), this);
    QAction *volume0 = new QAction(QStringLiteral("音量0%"), this);
    menu->addAction(pause);
    menu->addSeparator();
    menu->addAction(reOpen);
    menu->addSeparator();
    menu->addAction(volume100);
    menu->addAction(volume75);
    menu->addAction(volume50);
    menu->addAction(volume25);
    menu->addAction(volume0);

    connect(pause, SIGNAL(triggered(bool)), this, SLOT(pause()));
    connect(reOpen, SIGNAL(triggered(bool)), this, SLOT(reOpen()));
    connect(volume100, SIGNAL(triggered(bool)), this, SLOT(volume100()));
    connect(volume75, SIGNAL(triggered(bool)), this, SLOT(volume75()));
    connect(volume50, SIGNAL(triggered(bool)), this, SLOT(volume50()));
    connect(volume25, SIGNAL(triggered(bool)), this, SLOT(volume25()));
    connect(volume0, SIGNAL(triggered(bool)), this, SLOT(volume0()));

    menu->exec(QCursor::pos());

    delete pause;
    delete reOpen;
    delete volume100;
    delete volume75;
    delete volume50;
    delete volume25;
    delete volume0;
    delete menu;
}

void MainWindow::pause()
{
    mVlcMediaPlayerLst.at(mChoosePlayerNum)->togglePause();
}

void MainWindow::reOpen()
{
    mVlcMediaPlayerLst.at(mChoosePlayerNum)->open(mVlcMediaLst.at(mChoosePlayerNum));
}

void MainWindow::volume100()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(100);
}

void MainWindow::volume75()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(75);
}

void MainWindow::volume50()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(50);
}

void MainWindow::volume25()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(25);
}

void MainWindow::volume0()
{
    ui->volume->setMediaPlayer(mVlcMediaPlayerLst.at(mChoosePlayerNum));
    ui->volume->setVolume(0);
}