How to play sounds using QMediaPlayer

8Observer8

Hello. Why can't I play sound using the following code?

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QtWidgets/QWidget>
#include <QtMultimedia/QMediaPlayer>

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();

private slots:
    void play();

private:
    QMediaPlayer mediaPlayer;
};
#endif // WIDGET_H

widget.cpp

#include "widget.h"
#include <QtCore/QUrl>
#include <QtWidgets/QPushButton>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    mediaPlayer.setSource(QUrl("qrc:/assets/audio/music.wav"));

    QPushButton *playButton = new QPushButton("Play", this);
    connect(playButton, &QPushButton::pressed, this, &Widget::play);
}

Widget::~Widget()
{
}

void Widget::play()
{
    mediaPlayer.play();
    qDebug() << "play";
}

CPPUIX

@8Observer8

From Changes to Qt Multimedia in Qt 6:

Audio inputs and output QMediaPlayer and QMediaCaptureSession (and the corresponding QML types MediaPlayer and CaptureSession) are not connected to any audio devices by default. Explicitly connect them to a QAudioInput/AudioInput or QAudioOutput/AudioOutput to capture or play back audio.

You're not doing that in your code and I forgot to mention that I did so in my test; something like:

mediaPlayer.setAudioOutput(new QAudioOutput);

If this still does not fix it, try an absolute path just to verify it's a file access issue or not.

CPPUIX

Hi,

Try what's suggested here on Audio not playing from .qrc resources:

try "qrc://music/sound.mp3" and "qrc:/music/sound.mp3"

qrc:// worked for me using your code.

8Observer8

Unfortunately it didn't help.

mediaPlayer.setSource(QUrl("qrc://assets/audio/music.wav"));

JonB

@8Observer8
There are several other suggestions in @Abderrahmene_Rayene's linked thread, at least for troubleshooting. Including

Listen for the mediaStatusChanged() and error() signals to be notified when the media is loaded and when an error occurs during loading.

8Observer8

I added this:

    connect(&mediaPlayer, &QMediaPlayer::mediaStatusChanged, this, [this] (QMediaPlayer::MediaStatus status) -> void  {
        qDebug() << "QMediaPlayer::mediaStatusChanged" << status;
    });

But I see this message only:

widget.cpp:13: warning: Lambda capture 'this' is not used (fix available)

8Observer8

My example from the topic works with Qt5 but doesn't work with Qt6.

CPPUIX

@8Observer8

From Changes to Qt Multimedia in Qt 6:

Audio inputs and output QMediaPlayer and QMediaCaptureSession (and the corresponding QML types MediaPlayer and CaptureSession) are not connected to any audio devices by default. Explicitly connect them to a QAudioInput/AudioInput or QAudioOutput/AudioOutput to capture or play back audio.

You're not doing that in your code and I forgot to mention that I did so in my test; something like:

mediaPlayer.setAudioOutput(new QAudioOutput);

If this still does not fix it, try an absolute path just to verify it's a file access issue or not.

8Observer8

@Abderrahmene_Rayene said in How to play sounds using QMediaPlayer:

new QAudioOutput

Yes, it helped! Thank you very much! Interesting that this didn't work with qrc:// and works with qrc:/

#include "widget.h"
#include <QtCore/QUrl>
#include <QtWidgets/QPushButton>
#include <QtMultimedia/QAudioOutput>

Widget::Widget(QWidget *parent)
    : QWidget(parent)
{
    mediaPlayer.setSource(QUrl("qrc:/assets/audio/music.wav"));
    mediaPlayer.setAudioOutput(new QAudioOutput);

    QPushButton *playButton = new QPushButton("Play", this);
    connect(playButton, &QPushButton::pressed, this, &Widget::play);

    connect(&mediaPlayer, &QMediaPlayer::mediaStatusChanged, this, [this] (QMediaPlayer::MediaStatus status) -> void  {
        qDebug() << "QMediaPlayer::mediaStatusChanged" << status;
    });
}

Widget::~Widget()
{
}

void Widget::play()
{
    mediaPlayer.play();
    qDebug() << "play";
}

JoeCFD

@8Observer8 said in How to play sounds using QMediaPlayer:

connect(&mediaPlayer, &QMediaPlayer::mediaStatusChanged, this, [this] (QMediaPlayer::MediaStatus status) -> void  {
    qDebug() << "QMediaPlayer::mediaStatusChanged" << status;
});

Does the following work?

connect(&mediaPlayer, &QMediaPlayer::mediaStatusChanged, 
        [=](QMediaPlayer::MediaStatus status) -> void{ qDebug() << "QMediaPlayer::mediaStatusChanged" << status;}
       );

8Observer8

@JoeCFD Yes! Thanks a lot!

8Observer8

Hello guys again. I want to rewrite the example above to PySide6 and PyQt6:

from PySide6.QtCore import QUrl
from PySide6.QtMultimedia import QAudioOutput, QMediaPlayer
from PySide6.QtWidgets import QPushButton, QWidget


class Widget(QWidget):
    def __init__(self):
        super().__init__()

        self.mediaPlayer = QMediaPlayer()
        self.mediaPlayer.setSource(QUrl("assets/audio/music.wav"))
        self.mediaPlayer.setAudioOutput(QAudioOutput())
        self.mediaPlayer.mediaStatusChanged.connect(lambda status : print(status))

        playButton = QPushButton("Play", self)
        playButton.clicked.connect(self.play)

    def play(self):
        self.mediaPlayer.play()
        print("play")

main.py

import sys

from PySide6.QtCore import Qt
from PySide6.QtWidgets import QApplication

from widget import Widget

if __name__ == "__main__":
    app = QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec())

But I have these errors:

MediaStatus.InvalidMedia
MediaStatus.LoadingMedia
play
MediaStatus.InvalidMedia

The path to the audio file is correct:

8Observer8

I tried to use fromLocalFile but I have the same result:

self.mediaPlayer.setSource(QUrl.fromLocalFile("assets/audio/music.wav"))

JonB

@8Observer8

QUrl("assets/audio/music.wav")

Test with an absolute path rather than a relative one. Not sure what the current directory is when running Python script, so check this is not the issue?

8Observer8

@JonB I tried, but no, it doesn't work. The result is the same as above

8Observer8

But if I write the wrong path, I get a different error message:

self.mediaPlayer.setSource(QUrl("wrong_path/audio/music.wav"))

handleSourceError: 0x80070003
MediaStatus.InvalidMedia
MediaStatus.LoadingMedia
play
handleSourceError: 0x80070003
MediaStatus.InvalidMedia

8Observer8

I solved the problem! I found the solution here: https://zhuanlan.zhihu.com/p/521028351

        self.audioOutput = QAudioOutput()
        self.mediaPlayer.setAudioOutput(self.audioOutput)