[SOLVED] QApplication::beep() - no sound on linux

_rth_

Hi.

I have simple application, which should play sound on button click. I am using QApplication::beep() function (Qt 5.4.1). Everything works fine on Windows, but on linux (Ubuntu 12, Debian 7.8) no sound is played.

I am not aware of any limitation for linux platforms.

Is there anyone, who can help me find the solution? Thanks in advance.

tarod.net

Please, check if pcspkr module is currently loaded:

$ lsmod | grep pcspkr

_rth_

I guess that it is. This is result from command:
pcspkr 12579 0

I have done some other tests and:

command echo -e "\a" from terminal plays the sound
if my application is console app and executed from terminal, sound can be heard
if my application is GUI app, no sound is played

EDIT: the sound, which is played, is from System settings -> Sound -> Sound effects.

tarod.net

@_rth_ I've been reading about your problem, and it seems a Qt/Linux issue.

Could you change your code to use QSound?

http://doc.qt.io/qt-5/qsound.html

If you write

cout << '\a';

in your GUI application, is the beep played?

_rth_

Hi.

Using count << "\a" << endl; gives sound only if application is executed from terminal. If it is launched e.g. from window (double-click) or from Qt Creator, no sound playing.

I have also tried system("echo -e \"\a\"");, but the result is the same as above.

EDIT:
Using QSound::play("/usr/share/sounds/gnome/default/alerts/bark.ogg") gives error: QSoundEffect(pulseaudio): Error decoding source. Funny.

tarod.net

@_rth_ Maybe QSound needs some extra Qt libraries.

Anyway, try using XBell.

I.e.:

#include <X11/Xlib.h>

int main(int argc, char** argv)
{
        Display *display=XOpenDisplay(NULL);

        XBell(display, 1000);
        XFlush(display);
}

You will need to link X11 library:

gcc xbell.cpp -lX11

_rth_

I tried your example, compiled without any error, executed from terminal. Unfortunately no sound played.

tarod.net

@_rth_ You have more information about XBell In this page:

https://bugzilla.redhat.com/show_bug.cgi?id=607393

But in any case, if your code is working in Windows and not in Linux, I think is a problem with Linux more than Qt.

My last recommendation is to use your more suitable solution among the following ones:

http://doc.qt.io/qt-5/audiooverview.html

_rth_

QMediaPlayer works (at least on Debian 7.8).

QMediaPlayer player; 

...

//player.setMedia(QUrl::fromLocalFile("/usr/share/sounds/gnome/default/alerts/bark.ogg"));
//player.setMedia(QUrl::fromLocalFile("/usr/share/sounds/gnome/default/alerts/drip.ogg"));
//player.setMedia(QUrl::fromLocalFile("/usr/share/sounds/gnome/default/alerts/glass.ogg"));
//player.setMedia(QUrl::fromLocalFile("/usr/share/sounds/gnome/default/alerts/sonar.ogg"));

player.setMedia(QUrl::fromLocalFile("/usr/share/sounds/freedesktop/stereo/bell.oga")); //this seems to be default alert
player.setVolume(50); 

...

player.play();

tarod.net

@_rth_ So is your problem resolved?

_rth_

It hard to say ... I wanted to have platform independent, simple system alert to warn user about something. Right now, the only option is to add some sound (file) to app and use QMediaPlayer. QApplication::beep() is useless. It is not, what I expected.

tarod.net

@_rth_ Well, in my opinion, Qt and Linux have some things to talk about :) The fact is QApplication::beep() is not working in Ubuntu and Debian. QMediaPlayer is a good choice although you have to provide a file with your application.

_rth_

@tarod.net Thanks for help!

Marking as solved.