Playing Sound, Controlling The Volume

[speculatrix]

I have successfully played sound like this...

Code: [Select]

#include

QSound soundSample(Resource::findSound("wave"));
soundSample.play();

However, I am trying to set the volume control.. I have tried everything I can find from googling, but no joy!

If anyone has any ideas, I'd be terrible grateful!

Here's what I have so far:[/code]
    Config      cfgSound("Sound");
    cfgSound.setGroup("System");
    int oldVolume = cfgSound.readNumEntry("Volume", 0);
    cfgSound.writeEntry("Volume", 66);
    int newVolume = cfgSound.readNumEntry("Volume", 0);
    QCopEnvelope( "QPE/System", "volumeChange(bool)" ) << FALSE;
[/code]

the code runs but the volume doesn't change..

reading it and calling readNumEntry then writeEntry then readNumEntry reveals the new value is accepted, but the volume level doesn't change!

[Meanie]

I have successfully played sound like this...

Code: [Select]

#include

QSound soundSample(Resource::findSound("wave"));
soundSample.play();

However, I am trying to set the volume control.. I have tried everything I can find from googling, but no joy!

If anyone has any ideas, I'd be terrible grateful!

Here's what I have so far:[/code]
    Config      cfgSound("Sound");
    cfgSound.setGroup("System");
    int oldVolume = cfgSound.readNumEntry("Volume", 0);
    cfgSound.writeEntry("Volume", 66);
    int newVolume = cfgSound.readNumEntry("Volume", 0);
    QCopEnvelope( "QPE/System", "volumeChange(bool)" ) << FALSE;
[/code]

the code runs but the volume doesn't change..

reading it and calling readNumEntry then writeEntry then readNumEntry reveals the new value is accepted, but the volume level doesn't change!
[div align=\"right\"][a href=\"index.php?act=findpost&pid=154831\"][{POST_SNAPBACK}][/a][/div]

you can use tkvol to change the volume from the command line. the code for tkvol is included in the zplayer source....

[speculatrix]

thanks for that... looks like he does an IOCTL on the mixer device and then tells qtopia of the change! so, I am guessing the proper way doesn't work... using google I only found a few places where the official way was discussed, and one comment said that TrollTech changed the interface from the proprietary/closed versions and the public GPL one.

I shall copy this technique, although as a programmer I'd prefer to learn the proper method so as to achieve device independence!

Code: [Select]

~/build/zplayer-0.1.1/tkmix> more qtopia_volume.cpp
#include
#include
#include
#include
#include
#include
#include
#include
#include

#include "qtopia_volume.h"

bool QtopiaVolume::setLevel(int level)
{
        int iDevice, isetlv = (level + (level << 8));

        // Set value
        if ((iDevice = open("/dev/mixer", O_RDONLY)) == -1) {
                qDebug("Syntax error in open device\n");
                return false;
        }
        if (ioctl(iDevice, MIXER_WRITE(0), &isetlv) == -1) {
                qDebug("Syntax error in set volume\n");
                return false;
        }

        // Update applet
        QCopEnvelope("QPE/System", "volumeChange(bool)") << FALSE;

        close(iDevice);

        return true;
}

int QtopiaVolume::getCurrentLevel()
{
        Config cfg("qpe");
        cfg.setGroup("Volume");
        return cfg.readNumEntry("VolumePercent", 0);
}