});
connect(ui->reset_meters_button, &QPushButton::clicked, this, &MainWindow::reset_meters_button_clicked);
mixer->set_audio_level_callback(bind(&MainWindow::audio_level_callback, this, _1, _2, _3, _4, _5, _6, _7, _8));
});
connect(ui->reset_meters_button, &QPushButton::clicked, this, &MainWindow::reset_meters_button_clicked);
mixer->set_audio_level_callback(bind(&MainWindow::audio_level_callback, this, _1, _2, _3, _4, _5, _6, _7, _8));