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Playing audio using thread

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  • G Offline
    G Offline
    goshantry
    wrote on last edited by
    #1

    I am trying to use qthread to play audio.
    My code runs fine for sometime but after a few minutes i get an error saying

    GStreamer-WARNING **: Failed to load plugin '/usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstximagesink.so': /usr/lib/x86_64-linux-gnu/gstreamer-1.0/libgstximagesink.so: cannot open shared object file: Too many open files

    my code is as follows

    audioclass.h

    #ifndef AUDIOCLASS_H
    #define AUDIOCLASS_H
    
    #include <QThread>
    #include <QMediaPlayer>
    
    
    class audioClass : public QThread
    {
    public:
        audioClass();
    
        void playSound(QString audioPath);
    
        void run();
    
    private:
        QMediaPlayer *player;
    };
    
    #endif // AUDIOCLASS_H
    
    

    audioclass.cpp

    #include "audioclass.h"
    
    #include <QMediaPlayer>
    #include <QDebug>
    #include <QMutex>
    #include <QtCore>
    
    QString path = "";
    audioClass::audioClass()
    {
        player = new QMediaPlayer(this);
    }
    
    void audioClass::playSound(QString audioPath)
    {
        path = audioPath;
        run();
    }
    
    void audioClass::run()
    {
    
        QMutex myMutex;
        qDebug() << "Thread started";
        player->setMedia(QUrl::fromLocalFile(path));
        myMutex.lock();
        player->play();
        myMutex.unlock();
        qDebug() << "audio thread" << QThread::currentThread();
    }
    
    

    mainwindow.h

    #ifndef MAINWINDOW_H
    #define MAINWINDOW_H
    
    #include <QMainWindow>
    #include <QMediaPlayer>
    
    namespace Ui {
    class MainWindow;
    }
    
    class MainWindow : public QMainWindow
    {
        Q_OBJECT
    
    public:
        explicit MainWindow(QWidget *parent = nullptr);
    
        QTimer *mainTimer;
        QTimer *timer1sec;
        void mainTimerInit();
        void timer1secinit();
    
        ~MainWindow();
    
    public slots:
        void mainTimerCallback();
        void timer1seccallback();
    
    private:
        Ui::MainWindow *ui;
        QMediaPlayer *player;
    };
    
    #endif // MAINWINDOW_H
    
    

    mainwindow.cpp

    #include "mainwindow.h"
    #include "ui_mainwindow.h"
    #include "audioclass.h"
    
    #include <QTimer>
    #include <QDebug>
    
    int i = 0;
    
    MainWindow::MainWindow(QWidget *parent) :
        QMainWindow(parent),
        ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
    }
    
    MainWindow::~MainWindow()
    {
        delete ui;
    }
    
    void MainWindow::mainTimerInit()
    {
        mainTimer = new QTimer(this);
        connect(mainTimer, SIGNAL(timeout()), this, SLOT(mainTimerCallback()));
        mainTimer->start(5000);
    }
    
    void MainWindow::timer1secinit()
    {
        timer1sec = new QTimer(this);
        connect(timer1sec, SIGNAL(timeout()), this, SLOT(timer1seccallback()));
        timer1sec->start(1000);
    }
    
    void MainWindow::mainTimerCallback()
    {
        audioClass audObj;
        audObj.playSound("/home/fiem/Sound/00_E.mp3");
    
        qDebug() << "Playing audio";
    
    
    }
    
    void MainWindow::timer1seccallback()
    {
        i++;
        qDebug() << "1 sec thread" << QThread::currentThread();
        ui->label->setNum(i);
    }
    
    

    main.cpp

    #include "mainwindow.h"
    #include "audioclass.h"
    #include <QApplication>
    
    int main(int argc, char *argv[])
    {
        QApplication a(argc, argv);
        MainWindow w;
        w.show();
    
        w.timer1secinit();
        w.mainTimerInit();
    
        // Run audio thread
        audioClass audioClassObj;
        audioClassObj.start(QThread::LowPriority);
    
        return a.exec();
    }
    
    

    i have created a thread in audioclass class and i am trying to play audio using the mainwindow.

    Any help would be appreciated.

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #2

      Hi and welcome to devnet,

      Are you closing all the files you are loading?

      Interested in AI ? www.idiap.ch
      Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

      1 Reply Last reply
      -1
      • G Offline
        G Offline
        goshantry
        wrote on last edited by goshantry
        #3

        Shouldn't the audio file close automatically after it is played by the player? Or is there any way to close the audio file? I am not opening the audio file manually using QFile so I did not think about closing that.

        Also i left my program to run overnight and i got these errors as well

        (PAPIS:19650): GStreamer-CRITICAL **: gst_poll_get_read_gpollfd: assertion 'set != NULL' failed

        (PAPIS:19650): GStreamer-CRITICAL **: gst_bus_create_watch: assertion 'bus->priv->poll != NULL' failed

        (PAPIS:19650): GStreamer-CRITICAL **: Creating bus watch failed

        Now the audio is also not playing and the system hangs a little as well.

        I checked the no. of threads in my program and they are as follows

        PID SPID TTY TIME CMD
        19650 19650 ? 00:27:04 PAPIS
        19650 19651 ? 00:00:01 Qt bearer threa
        19650 19652 ? 00:00:05 QDBusConnection
        19650 19653 ? 00:00:02 QXcbEventQueue
        19650 19654 ? 00:00:00 dconf worker
        19650 19655 ? 00:00:00 gmain
        19650 19656 ? 00:00:00 gdbus
        19650 25026 ? 00:00:00 typefind:sink
        19650 25067 ? 00:00:00 id3demux3958:si
        19650 25068 ? 00:00:00 mpegaudioparse3
        19650 25069 ? 00:00:00 aqueue:src
        19650 25070 ? 00:00:00 pool

        I am unable to understand where the problem lies.

        1 Reply Last reply
        0
        • Kent-DorfmanK Offline
          Kent-DorfmanK Offline
          Kent-Dorfman
          wrote on last edited by Kent-Dorfman
          #4

          It may or may not be related but I found leaks last year in the Qt multimedia module (gstreamer as default backend) where it did not close URL based video streams when I would switch between multiple video feeds. The result was that after 20 or 30 stream switches it would quit working. It's possible and probable that this resource leak still exists.

          1 Reply Last reply
          0
          • G Offline
            G Offline
            goshantry
            wrote on last edited by
            #5

            I tried using valgrind from qt to check for the memory leaks and the program crashes as soon as it starts. Also i tried to use it through terminal and it shows no leaks and errors.

            1 Reply Last reply
            0
            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #6

              @Kent-Dorfman Any chance of remembering the version you used ?

              @goshantry What version of Qt are you using ?

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

              G 1 Reply Last reply
              -1
              • Kent-DorfmanK Offline
                Kent-DorfmanK Offline
                Kent-Dorfman
                wrote on last edited by
                #7

                I still have the project directory so you are in luck:

                From the Makefile Generated by qmake (3.1) (Qt 5.9.4)

                The app was an operator console for an unmanned vehicle. It had four IP cameras and cycling through the feeds or toggling the same feed on and off many times eventually caused the feed to die.

                1 Reply Last reply
                0
                • SGaistS SGaist

                  @Kent-Dorfman Any chance of remembering the version you used ?

                  @goshantry What version of Qt are you using ?

                  G Offline
                  G Offline
                  goshantry
                  wrote on last edited by
                  #8

                  @SGaist I am using Qt creator 4.8.1

                  jsulmJ 1 Reply Last reply
                  0
                  • G goshantry

                    @SGaist I am using Qt creator 4.8.1

                    jsulmJ Offline
                    jsulmJ Offline
                    jsulm
                    Lifetime Qt Champion
                    wrote on last edited by
                    #9

                    @goshantry said in Playing audio using thread:

                    I am using Qt creator 4.8.1

                    The question was what Qt version you're using, not which QtCreator version.

                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                    G 1 Reply Last reply
                    0
                    • jsulmJ jsulm

                      @goshantry said in Playing audio using thread:

                      I am using Qt creator 4.8.1

                      The question was what Qt version you're using, not which QtCreator version.

                      G Offline
                      G Offline
                      goshantry
                      wrote on last edited by
                      #10

                      @jsulm Sorry for that
                      I am using Qt 5.12.0

                      1 Reply Last reply
                      0
                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #11

                        Can you check with Qt 5.12.1 ?

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        -1
                        • G Offline
                          G Offline
                          goshantry
                          wrote on last edited by
                          #12

                          checked with Qt 5.12.1
                          I am still facing the same error

                          jsulmJ 1 Reply Last reply
                          0
                          • G goshantry

                            checked with Qt 5.12.1
                            I am still facing the same error

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #13

                            @goshantry Is it working properly without threads?

                            https://forum.qt.io/topic/113070/qt-code-of-conduct

                            1 Reply Last reply
                            0
                            • G Offline
                              G Offline
                              goshantry
                              wrote on last edited by
                              #14

                              After much hit and trial I found that when the program goes into the mainTimerCallback function, it initializes audObj every time. This object gradually takes up the memory. If i block this function my code works fine.

                              Any idea as to why this object does not free the memory as soon as this function is completed?

                              I tried doing this without QThread and everything works fine

                              I also used audObj.deletelater() function but the system shows the same error

                              1 Reply Last reply
                              0
                              • SGaistS Offline
                                SGaistS Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on last edited by
                                #15

                                Because it's not how memory manager works necessarily.

                                By the way, with the code you shown, your QThread doesn't do anything as you call the run method explicitly except for the one in your main.cpp file.

                                Also note that your mutex isn't useful as it's local to the run method so it's created each time the method is called.

                                Interested in AI ? www.idiap.ch
                                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                1 Reply Last reply
                                1
                                • G Offline
                                  G Offline
                                  goshantry
                                  wrote on last edited by
                                  #16

                                  Is there any way to free up memory after an object has been created in Qt or does it automatically frees up memory after the function has been completed?

                                  jsulmJ 1 Reply Last reply
                                  0
                                  • G goshantry

                                    Is there any way to free up memory after an object has been created in Qt or does it automatically frees up memory after the function has been completed?

                                    jsulmJ Offline
                                    jsulmJ Offline
                                    jsulm
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #17

                                    @goshantry Variables allocated on the stack are freed automatically when the function/method finishes.
                                    If a variable was allocated on the heap (new) then it is either freed when the parent is deleted (if you're using Qt parent/child feature) or you have to delete it at some point.
                                    As @SGaist pointed out your mutex is useless the way you're using it...

                                    https://forum.qt.io/topic/113070/qt-code-of-conduct

                                    G 1 Reply Last reply
                                    1
                                    • jsulmJ jsulm

                                      @goshantry Variables allocated on the stack are freed automatically when the function/method finishes.
                                      If a variable was allocated on the heap (new) then it is either freed when the parent is deleted (if you're using Qt parent/child feature) or you have to delete it at some point.
                                      As @SGaist pointed out your mutex is useless the way you're using it...

                                      G Offline
                                      G Offline
                                      goshantry
                                      wrote on last edited by
                                      #18

                                      @jsulm I removed that part of my code and created a new function to play audio without thread. Everything works fine and I left to test it for 2 days. Now when I run the free -m command in the terminal it shows only around 250-300 mb remaining out of my 8Gb. The swap memory is also used to a great extent.

                                      Is this memory because of those objects which I declared with new() or with any object that has been created?

                                      Also do I use the delete later with every object that i created at the end of the function to release the memory?

                                      My application is supposed to run for long hours without having to shutdown or restart the system.

                                      jsulmJ 1 Reply Last reply
                                      0
                                      • G goshantry

                                        @jsulm I removed that part of my code and created a new function to play audio without thread. Everything works fine and I left to test it for 2 days. Now when I run the free -m command in the terminal it shows only around 250-300 mb remaining out of my 8Gb. The swap memory is also used to a great extent.

                                        Is this memory because of those objects which I declared with new() or with any object that has been created?

                                        Also do I use the delete later with every object that i created at the end of the function to release the memory?

                                        My application is supposed to run for long hours without having to shutdown or restart the system.

                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #19

                                        @goshantry You release the memory when you don't need it anymore.
                                        "Also do I use the delete later with every object that i created at the end of the function to release the memory?" - do you mean deleteLater() method?
                                        You should use Valgrind to analyse where your app is consuming memory.
                                        "Is this memory because of those objects which I declared with new() or with any object that has been created?" - any of course. Everything in use by your app.
                                        Can you show the code you're currently using?

                                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        G 1 Reply Last reply
                                        0
                                        • jsulmJ jsulm

                                          @goshantry You release the memory when you don't need it anymore.
                                          "Also do I use the delete later with every object that i created at the end of the function to release the memory?" - do you mean deleteLater() method?
                                          You should use Valgrind to analyse where your app is consuming memory.
                                          "Is this memory because of those objects which I declared with new() or with any object that has been created?" - any of course. Everything in use by your app.
                                          Can you show the code you're currently using?

                                          G Offline
                                          G Offline
                                          goshantry
                                          wrote on last edited by goshantry
                                          #20

                                          @jsulm I tried using valgrind in Qt and this is the output which I get everytime

                                          11:40:37: valgrind --child-silent-after-fork=yes --xml-socket=127.0.0.1:43171 --log-socket=127.0.0.1:46593 --xml=yes --smc-check=stack --tool=memcheck --gen-suppressions=all --track-origins=yes --leak-check=summary --num-callers=25 /home/fiem/workspace/build-PAPIS-Desktop_Qt_5_12_1_GCC_64bit-Debug/PAPIS
                                          11:41:11: The program has unexpectedly finished.
                                          11:41:11: Process exited with return value Process crashed
                                          11:41:11: Analyzing finished.
                                          

                                          Also I changed the Audio Playing function to

                                          // Constructor for class
                                          pisUser::pisUser(QWidget *parent) :
                                              QWidget(parent),
                                              ui(new Ui::pisUser)
                                          {
                                              ui->setupUi(this);
                                              player = new QMediaPlayer(this);
                                          }
                                          
                                          // Function to play audio
                                          void pisUser::playAudioDirect()
                                          {
                                          //    player->deleteLater();
                                              player->setMedia(QUrl::fromLocalFile(path));
                                              player->play();               // Play the audio sounds
                                          }
                                          

                                          also player->deleteLater(); always crashes the application no matter where i put it

                                          jsulmJ 1 Reply Last reply
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