Qt5视频播放器QtMultimedia QGraphicsVideoItem
Qt5视频播放器QtMultimedia QGraphicsVideoItem
提问于 2013-09-03 11:36:22
目前，stackies正在尝试创建一些基本代码，这些代码只会从本地源播放一个视频文件(试图使其正常工作，然后尝试并实现rtsp)。下面是我的当前代码。如果有人能告诉我我哪里出了问题那就太好了。
当前，代码由于错误而失败。
C:\Qt\Qt5.1.0\5.1.0\msvc2010_opengl\examples\multimediawidgets\videographicsitem\main.cpp:58:错误: C2664：'QGraphicsScene::addItem‘：无法将参数1从“QGraphicsVideoItem*”转换为指向的“QGraphicsItem*”类型，这些类型是不相关的；转换需要reinterpret_cast、C风格的强制转换或函数样式的转换
我想我必须键入插入到additem中的变量。但是，不知道如何使用两个Qclasses来完成这个任务。如果有人有一个基本播放器的例子，其中只包含一个视频帧，并播放第二，你启动程序(甚至没有一个播放按钮，最好是)。如果有人有类似的事情，请告诉我，这样我的生活就容易多了。Main.cpp
#include "videoplayer.h"
#include <QApplication>
#include <QGraphicsView>
int main(int argc, char **argv)
{
QApplication app(argc, argv);
//VideoPlayer player;
//QGraphicsView graphicsView;
QMediaPlayer *player ;
QGraphicsVideoItem *item;
QGraphicsView *graphicsView;
QGraphicsScene *scene;
player->setVideoOutput(item);
// scene->addItem(item);
graphicsView->scene()->addItem(item);
graphicsView->show();
player->setMedia(QUrl("rtsp://192.168.100.58:8554/stream"));
player->play();
graphicsView->show();
return app.exec();
}Videoplayer.cpp
#include "videoplayer.h"
#include <QtWidgets>
#include <QVideoSurfaceFormat>
#include <QGraphicsVideoItem>
VideoPlayer::VideoPlayer(QWidget *parent)
: QWidget(parent)
, mediaPlayer(0, QMediaPlayer::VideoSurface)
, videoItem(0)
, playButton(0)
, positionSlider(0)
{
videoItem = new QGraphicsVideoItem;
videoItem->setSize(QSizeF(640, 480));
QGraphicsScene *scene = new QGraphicsScene(this);
QGraphicsView *graphicsView = new QGraphicsView(scene);
scene->addItem(videoItem);
QSlider *rotateSlider = new QSlider(Qt::Horizontal);
rotateSlider->setRange(-180, 180);
rotateSlider->setValue(0);
connect(rotateSlider, SIGNAL(valueChanged(int)),
this, SLOT(rotateVideo(int)));
QAbstractButton *openButton = new QPushButton(tr("Open..."));
connect(openButton, SIGNAL(clicked()), this, SLOT(openFile()));
playButton = new QPushButton;
playButton->setEnabled(false);
playButton->setIcon(style()->standardIcon(QStyle::SP_MediaPlay));
connect(playButton, SIGNAL(clicked()),
this, SLOT(play()));
positionSlider = new QSlider(Qt::Horizontal);
positionSlider->setRange(0, 0);
connect(positionSlider, SIGNAL(sliderMoved(int)),
this, SLOT(setPosition(int)));
QBoxLayout *controlLayout = new QHBoxLayout;
controlLayout->setMargin(0);
controlLayout->addWidget(openButton);
controlLayout->addWidget(playButton);
controlLayout->addWidget(positionSlider);
QBoxLayout *layout = new QVBoxLayout;
layout->addWidget(graphicsView);
layout->addWidget(rotateSlider);
layout->addLayout(controlLayout);
setLayout(layout);
mediaPlayer.setVideoOutput(videoItem);
connect(&mediaPlayer, SIGNAL(stateChanged(QMediaPlayer::State)),
this, SLOT(mediaStateChanged(QMediaPlayer::State)));
connect(&mediaPlayer, SIGNAL(positionChanged(qint64)), this, SLOT(positionChanged(qint64)));
connect(&mediaPlayer, SIGNAL(durationChanged(qint64)), this, SLOT(durationChanged(qint64)));
}
VideoPlayer::~VideoPlayer()
{
}
void VideoPlayer::openFile()
{
QString fileName = QFileDialog::getOpenFileName(this, tr("Open Movie"),QDir::homePath());
//QString fileName = "rtsp://192.168.100.58:8554/stream";
if (!fileName.isEmpty()) {
mediaPlayer.setMedia(QUrl::fromLocalFile(fileName));
playButton->setEnabled(true);
}
}
void VideoPlayer::play()
{
switch(mediaPlayer.state()) {
case QMediaPlayer::PlayingState:
mediaPlayer.pause();
break;
default:
mediaPlayer.play();
break;
}
}Videoplayer.h
#ifndef VIDEOPLAYER_H
#define VIDEOPLAYER_H
#include <QMediaPlayer>
#include <QMovie>
#include <QWidget>
class QAbstractButton;
class QSlider;
class QGraphicsVideoItem;
class VideoPlayer : public QWidget
{
Q_OBJECT
public:
VideoPlayer(QWidget *parent = 0);
~VideoPlayer();
QSize sizeHint() const { return QSize(800, 600); }
public slots:
void openFile();
void play();
private slots:
void mediaStateChanged(QMediaPlayer::State state);
void positionChanged(qint64 position);
void durationChanged(qint64 duration);
void setPosition(int position);
void rotateVideo(int angle);
private:
QMediaPlayer mediaPlayer;
QGraphicsVideoItem *videoItem;
QAbstractButton *playButton;
QSlider *positionSlider;
};
#endif.pro
TEMPLATE = app
TARGET = videographicsitem
QT += multimedia multimediawidgets
HEADERS += videoplayer.h
SOURCES += main.cpp \
videoplayer.cpp
target.path = $$[QT_INSTALL_EXAMPLES]/multimediawidgets/videographicsitem
INSTALLS += target
QT+=widgets也刚试过这个
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
QMediaPlayer media;
const QString file = "C:/Users/nick.herniman/Downloads/big_buck_bunny_1080p_h264.mov";
QUrl url(QFileInfo(file).absoluteFilePath());
media.setMedia(url);
media.play();
return a.exec();
}它可以工作，但只播放文件的音频，任何人都知道我在这里做了什么(它需要在gui窗口中，还是只在控制台应用程序中就可以了)？
回答 3
Stack Overflow用户
回答已采纳
发布于 2013-09-03 12:18:55
没什么奇怪的。:-)
当编译器知道QGraphicsVideoItem是QGraphicsItem时，它会有所帮助。为了让编译器知道这一点，#include <QGraphicsVideoItem>应该是存在的。
我明白了，你在Videoplayer.cpp里有。但是main.cpp只看到有一个类QGraphicsVideoItem声明了。你做了一个很好的前瞻性声明。但这堂课是..。无法了解main.cpp中的编译器。将#include <QGraphicsVideoItem>添加到main.cpp中。
Stack Overflow用户
发布于 2014-08-21 10:49:21
在Qt5中尝试以下最简单的示例：
QMediaPlayer *mediaPlayer = new QMediaPlayer(this, QMediaPlayer::VideoSurface);
QGraphicsVideoItem *videoItem = new QGraphicsVideoItem;
videoItem->setPos(100,100);
QGraphicsScene *scene = new QGraphicsScene(this);
ui->GV_VideoPlayer->setScene(scene);
scene->addItem(videoItem);
QString fileName = "/root/sampleVideos/videoplayback.mp4";
if(!fileName.isEmpty())
{
mediaPlayer->setMedia(QUrl::fromLocalFile(fileName));
}
mediaPlayer->play();
mediaPlayer->setVideoOutput(videoItem);Stack Overflow用户
发布于 2013-09-03 12:00:55
QT文档描述了一个非常相似的示例( http://qt-project.org/doc/qt-5.0/qtmultimedia/qgraphicsvideoitem.html )，而对象实际上并不相关，这实际上是非常奇怪的。除此之外，查看一下QT文档，因为我已经有一段时间没有使用QT了--创建一个虚拟QGraphicsItem，将其设置为QGraphicsVideoItem的父级，然后将虚拟项添加到场景中会有帮助吗？我想应该是这样的
QGraphicsItem* dummy = new QGraphicsItem;
item = new QGraphicsVideoItem(dummy);
graphicsView->scene()->addItem(dummy);页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/18591306
复制相关文章
相似问题
腾讯云开发者
