problem with QMediaPlayer

[valeriy]

i created resourse file and added mp3 file
write 3 lines:

QMediaPlayer* player = new QMediaPlayer();
player->setMedia(QUrl("qrc:/sounds/psk.mp3"));
player->play();

application is started, there is win process, but does not appear on the screen
later, i changed code:

QMediaPlayer* player = new QMediaPlayer();
player->setMedia(QUrl(":/sounds/psk.mp3"));
player->play();

application is run on the screen, but now sound not play

my .pro file

QT += core gui multimedia

TARGET = test_cpp
CONFIG += console c++11
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp \
    Figure.cpp \
    GameField.cpp

HEADERS += \
    Figure.h \
    GameField.h

RESOURCES += \
    res.qrc

what am I doing wrong?

[SGaist]

Hi,

Do you mean that with qrc:/ the sound is playing but you have no UI ?

[valeriy]

@SGaist said:

Hi,

Do you mean that with qrc:/ the sound is playing but you have no UI ?

sound isn't playing and the application does not appear on the screen.
If i change qrc:/ to :/, sound isn`t playing, but application is running normally.
I noticed that happens only in this class:

class Button : public QObject, public QGraphicsPixmapItem
{
    Q_OBJECT
private:
    QPixmap *state1, *state2;
    void mousePressEvent(QGraphicsSceneMouseEvent *event);
    void hoverEnterEvent(QGraphicsSceneHoverEvent *event);
    void hoverLeaveEvent(QGraphicsSceneHoverEvent *event);
 
    //QMediaPlayer *hoverSound;
 
public:
    Button(const QPixmap& pixmap1, const QPixmap& pixmap2);
    ~Button();
 
signals:
    void clicked();
};

ps. sorry for my english :(

[SGaist]

Depending on your target platform reading from qrc is not possible. That's not a Qt limitation but a platform constraint. The native API used are not able to access data from Qt's resource. You should copy the file to a temporary folder provided by QStandardPaths and play it from there.

[MajidKamali]

I had the same problem.
It's because QMediaPlayer needs a QUrl and QUrl must start with something like qrc:/ or http:/ etc. otherwise string is an invalid QUrl and QUrl becomes empty.

QUrl url1("qrc:/path to your file in resources");
QUrl url2(":/path to your file in resources");
qDebug() << url1;
qDebug() << url2;

url2 is empty. because it's not a valid url.
I don't know if it is possible to disable validation in QUrl or not.
I add a "qrc" manually to my string when passing to QUrl

QUrl url("qrc" + ":/path to file in resources");

@SGaist why there is no access to library or binary file in some platforms? resources are internal and are in application binary.

[SGaist]

Your url1 should be correct.

What Version of Qt are you using ? On what platform ?

I've doubled checked the implementation of QMediaPlayer, if you have a recent enough Qt, it should do the temporary file trick automatically for you.

It's because the native API don't know how to handle files in Qt's resources.

[MajidKamali]

@SGaist I use Qt 5.4.1 on Ubuntu 14.04 64-bit

[SGaist]

It's been added to Qt 5.5.0