QMediaplayer randomly plays part of the audio in a loop

Andrey Vasilyev

Hello!
I ran into an unexpected problem while using QMediplayer. Sometimes, when receiving a signal "play", the player starts to play a part of the audio file in a loop for a while . I have not been able to figure out what exactly affects this.
I also added the logging on the call of the signal to play, and I am sure that this signal comes only once.

I tried moving both QMediplayer instances to separate threads, but that didn't solve the problem.
Build with Qt 5.12.6 MinGW 32bit

#include <QApplication>
#include <QMediaPlayer>
#include <QThread>
#include <QMetaType>

#include "logger.h"
#include "routemanager.h"
#include "mqttclient.h"
#include "windowmanager.h"
#include "routewindow.h"

int main(int argc, char *argv[])
{
    qRegisterMetaType<Enums::MqttCommand>("Enums::MqttCommand");
    qRegisterMetaType<Enums::RouteState>("Enums::RouteState");

    QApplication a(argc, argv);

    Logger          logger;
    RouteManager    routeManager;
    WindowManager   windowManager;
    QMediaPlayer    clickPlayer;
    QMediaPlayer    alarmPlayer;

    MQTTclient      *mqttClient = new MQTTclient;
    QThread         *mqttThread = new QThread;

    clickPlayer.setMedia(QUrl("qrc:/sounds/click.wav"));
    alarmPlayer.setMedia(QUrl("qrc:/sounds/alarm.wav"));

    alarmPlayer.setVolume(0);

    mqttClient->moveToThread(mqttThread);
    QObject::connect(mqttThread, &QThread::started, mqttClient, &MQTTclient::initClient);
    QObject::connect(mqttThread, &QThread::finished, mqttClient, &MQTTclient::deleteLater);
    QObject::connect(mqttThread, &QThread::finished, mqttThread, &QThread::deleteLater);

    QObject::connect(&windowManager, &WindowManager::addToLog,              &logger,       &Logger::addToLog);
    QObject::connect(&windowManager, &WindowManager::checkSound,            &alarmPlayer,  &QMediaPlayer::play);
    QObject::connect(&windowManager, &WindowManager::setVolume,             &alarmPlayer,  &QMediaPlayer::setVolume);
    QObject::connect(&windowManager, &WindowManager::click,                 &clickPlayer,  &QMediaPlayer::play);

    QObject::connect(&routeManager, &RouteManager::playAlarm,           &alarmPlayer,   &QMediaPlayer::play);

    QObject::connect(&a, &QApplication::lastWindowClosed, mqttThread, &QThread::quit);
    QObject::connect(&a, &QApplication::aboutToQuit,      mqttThread, &QThread::quit);

    windowManager.initWindows();
    routeManager.initRoutes();

    mqttThread->start();

    return a.exec();
}

Andrey Vasilyev

It seems that the problem is somehow related to the work of the Windows defender. After disabling it, the problem did not appear yet.

Andrey Vasilyev

The problem was in the Windows firewall. I still don't understand why this was affecting the sound, but disabling the firewall did the trick.