problem with QSound : can't find audio device

[med01]

HI,
I cross-compiled qt5.4 to use it with my a10-olinuxino-lime board.
I'm trying to run this example that uses QAudioDeviceInfo at my a10-olinuxino-lime board :

foreach (const QAudioDeviceInfo &deviceInfo, QAudioDeviceInfo::availableDevices(QAudio::AudioOutput))
{
    qDebug() << "is null : " << deviceInfo.isNull();
    qDebug() << "device name : " << deviceInfo.deviceName();
}

But it shows nothing . it means that the the app can't recognize my sound device, although, the sound is working on the board when I use "speaker-test -t wav -c 2".

Please, can any one help me ?