QT应用编程: 基于mdk-sdk开发视频播放器(简单框架测试)

一、环境介绍

操作系统: win10 64位

QT版本:  QT5.12.6

编译器:  MinGW 32

二、mdk-sdk 介绍

github 首页地址:  https://github.com/wang-bin/mdk-sdk

Features

• Simple and powerful API set
• Cross platform: Windows, UWP, Linux, macOS, Android, iOS, Raspberry Pi
• Hardware accelerated decoding and 0-copy GPU rendering for all platforms
• OpenGL, D3D11, Vulkan and Metal rendering w/ or w/o user provided context
• Integrated with any gui toolkits or apps via OpenGL, D3D11, Vulkan and Metal (OBS, Qt, SDL, glfw, SFML etc.) easily
• Seamless/Gapless media and bitrate switch for any media
• HDR rendering in GPU
• Optimized Continuous seeking. As fast as mpv, but much lower cpu, memory and gpu load. Suitable for timeline preview
• Smart FFmpeg runtime. See https://github.com/wang-bin/mdk-sdk/wiki/FFmpeg-Runtime

mdk-sdk的API使用介绍:  https://github.com/wang-bin/mdk-sdk/wiki/Player-APIs

mdk-sdk的使用例子(CSDN):  https://download.csdn.net/download/xiaolong1126626497/16273881

mdk-sdk的SDK包(CSDN)--截止当前是最新版本:  https://download.csdn.net/download/xiaolong1126626497/16273875

mdk-sdk的使用例子(GitHub):https://github.com/wang-bin/mdk-examples

三、工程源码

3.1 运行效果

 这个Demo只是简单的测试播放器，很多功能没去写，简单测试下性能；所以界面没有怎么去弄。

3.2  pro工程文件

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets opengl

CONFIG += c++17 utf8_source

MDK_SDK = $$PWD/mdk-sdk
INCLUDEPATH += $$MDK_SDK/include

MDK_ARCH = x86

LIBS += -L$$MDK_SDK/lib/$$MDK_ARCH -lmdk
LIBS += -L$$MDK_SDK/bin/$$MDK_ARCH

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    QMDKWidget.cpp \
    main.cpp \
    widget.cpp

HEADERS += \
    QMDKWidget.h \
    widget.h

FORMS += \
    widget.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

3.3 QMDKWidget.cpp

/*
 * Copyright (c) 2020 WangBin <wbsecg1 at gmail.com>
 * MDK SDK with QOpenGLWidget example
 */
#include "QMDKWidget.h"
#include "mdk/Player.h"
#include <QCoreApplication>
#include <QDebug>
#include <QDir>
#include <QKeyEvent>
#include <QOpenGLContext>
#include <QStringList>
#include <QScreen>

using namespace MDK_NS;
QMDKWidget::QMDKWidget(QWidget *parent, Qt::WindowFlags f)
    : QOpenGLWidget(parent, f)
    , player_(std::make_shared<Player>())
{
    player_->setVideoDecoders({"VT", "VAAPI", "MFT:d3d=11", "DXVA", "MMAL", "AMediaCodec:java=1:copy=0:surface=1:async=0", "FFmpeg"});

    player_->setRenderCallback([this](void*){
        QMetaObject::invokeMethod(this, "update", Qt::QueuedConnection);
    });


}

QMDKWidget::~QMDKWidget()
{
    makeCurrent();
    player_->setVideoSurfaceSize(-1, -1); // cleanup gl renderer resources
}

void QMDKWidget::setDecoders(const QStringList &dec)
{
    std::vector<std::string> v;
    foreach (QString d, dec) {
        v.push_back(d.toStdString());
    }
    player_->setVideoDecoders(v);
}

void QMDKWidget::setMedia(const QString &url)
{
    player_->setMedia(url.toUtf8().constData());
}

void QMDKWidget::play()
{
    player_->setState(State::Playing);
}

void QMDKWidget::pause()
{
    player_->setState(State::Paused);
}

void QMDKWidget::stop()
{
    player_->setState(State::Stopped);
}

bool QMDKWidget::isPaused() const
{
    return player_->state() == State::Paused;
}

void QMDKWidget::seek(qint64 ms)
{
    player_->seek(ms);
}

qint64 QMDKWidget::position() const
{
    return player_->position();
}

void QMDKWidget::snapshot() {
    Player::SnapshotRequest sr{};
    player_->snapshot(&sr, [](Player::SnapshotRequest *_sr, double frameTime) {
        const QString path = QDir::toNativeSeparators(
            QString("%1/%2.png")
                .arg(QCoreApplication::applicationDirPath())
                .arg(frameTime));
        return path.toStdString();
        // Here's how to convert SnapshotRequest to QImage and save it to disk.
        /*if (_sr) {
            const QImage img = QImage(_sr->data, _sr->width, _sr->height,
                                      QImage::Format_RGBA8888);
            if (img.save(path)) {
                qDebug() << "Snapshot saved:" << path;
            } else {
                qDebug() << "Failed to save:" << path;
            }
        } else {
            qDebug() << "Snapshot failed.";
        }
        return "";*/
    });
}

void QMDKWidget::resizeGL(int w, int h)
{
    //auto s = screen();
    //qDebug("resizeGL>>>>>dpr: %f, logical dpi: (%f,%f), phy dpi: (%f,%f)", s->devicePixelRatio(), s->logicalDotsPerInchX(), s->logicalDotsPerInchY(), s->physicalDotsPerInchX(), s->physicalDotsPerInchY());
    player_->setVideoSurfaceSize(w*devicePixelRatio(), h*devicePixelRatio());
}

void QMDKWidget::paintGL()
{
    player_->renderVideo();
}

void QMDKWidget::keyPressEvent(QKeyEvent *e)
{
    switch (e->key()) {
    case Qt::Key_Space: {
        if (isPaused())
            play();
        else
            pause();
    }
        break;
    case Qt::Key_Right:
        seek(position() + 10000);
        break;
    case Qt::Key_Left:
        seek(position() - 10000);
        break;
    case Qt::Key_Q:
        qApp->quit();
        break;
    case Qt::Key_C:
        //if (QKeySequence(e->modifiers() | e->key()) == QKeySequence::Copy) {
            snapshot();
        //}
        break;
    default:
        break;
    }
}

3.4 QMDKWidget.h

/*
 * Copyright (c) 2020 WangBin <wbsecg1 at gmail.com>
 * MDK SDK with QOpenGLWindow example
 */
#pragma once
#include <QOpenGLWidget>
#include <memory>

namespace mdk {
class Player;
}
class QMDKWidget : public QOpenGLWidget
{
public:
    QMDKWidget(QWidget *parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
    ~QMDKWidget();
    void setDecoders(const QStringList& dec);
    void setMedia(const QString& url);
    void play();
    void pause();
    void stop();
    bool isPaused() const;
    void seek(qint64 ms);
    qint64 position() const;
    void snapshot();

protected:
    void resizeGL(int w, int h) override;
    void paintGL() override;
    void keyPressEvent(QKeyEvent *) override;
private:
    std::shared_ptr<mdk::Player> player_;
};

3.5 widget.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);

}

Widget::~Widget()
{
    delete ui;
}


/*
工程: QMDK_Player
日期: 2021-03-31
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 加载视频文件
*/
void Widget::on_pushButton_load_clicked()
{
    QString filename=QFileDialog::getOpenFileName(this,"选择打开的文件","C:/",tr("*.*"));
    ui->AV_player->setMedia(filename);
    ui->AV_player->play();
}


/*
工程: QMDK_Player
日期: 2021-03-31
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 暂停/继续
*/
void Widget::on_pushButton_pause_clicked()
{
    ui->AV_player->pause();
}


/*
工程: QMDK_Player
日期: 2021-03-31
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 重新播放
*/
void Widget::on_pushButton_reset_clicked()
{

}


/*
工程: QMDK_Player
日期: 2021-03-31
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 播放
*/
void Widget::on_pushButton_play_clicked()
{
    ui->AV_player->play();
}


/*
工程: QMDK_Player
日期: 2021-03-31
作者: DS小龙哥
环境: win10 QT5.12.6 MinGW32
功能: 停止播放
*/
void Widget::on_pushButton_stop_clicked()
{
    ui->AV_player->stop();
}

3.6 widget.h代码

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QOpenGLWidget>
#include <memory>
#include "QMDKWidget.h"
#include <QFileDialog>

namespace mdk {
class Player;
}

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
private slots:
    void on_pushButton_load_clicked();

    void on_pushButton_pause_clicked();

    void on_pushButton_reset_clicked();

    void on_pushButton_play_clicked();

    void on_pushButton_stop_clicked();

private:
    Ui::Widget *ui;
};
#endif // WIDGET_H

3.7 ui文件