Unsolved QAudioDeviceInfo::defaultOutputDevice is not set

[th.thielemann]

On Linux Ubuntu 12.04, Qt5.3, libasound2 installed I checked my audio configuration from Qt.

• Devices are available
• wav seems to be supported
  But QAudioDeviceInfo::defaultOutputDevice().deviceName(): is empty
• can not play any sound from Qt (but from Linux)

How to I set the output device?

QAudioDeviceInfo.supportedCodecs:
QAudioDeviceInfo::availableDevices(QAudio::AudioOutput):
Device name:  "sysdefault:CARD=MID"
Device name:  "front:CARD=MID,DEV=0"
Device name:  "surround40:CARD=MID,DEV=0"
Device name:  "surround41:CARD=MID,DEV=0"
Device name:  "surround50:CARD=MID,DEV=0"
Device name:  "surround51:CARD=MID,DEV=0"
Device name:  "surround71:CARD=MID,DEV=0"
Device name:  "hdmi:CARD=MID,DEV=0"
Device name:  "hdmi:CARD=MID,DEV=1"
Device name:  "hdmi:CARD=MID,DEV=2"
Device name:  "dmix:CARD=MID,DEV=0"
Device name:  "dmix:CARD=MID,DEV=3"
Device name:  "dmix:CARD=MID,DEV=7"
Device name:  "dmix:CARD=MID,DEV=8"
Device name:  "dsnoop:CARD=MID,DEV=0"
Device name:  "dsnoop:CARD=MID,DEV=3"
Device name:  "dsnoop:CARD=MID,DEV=7"
Device name:  "dsnoop:CARD=MID,DEV=8"
Device name:  "hw:CARD=MID,DEV=0"
Device name:  "hw:CARD=MID,DEV=3"
Device name:  "hw:CARD=MID,DEV=7"
Device name:  "hw:CARD=MID,DEV=8"
Device name:  "plughw:CARD=MID,DEV=0"
Device name:  "plughw:CARD=MID,DEV=3"
Device name:  "plughw:CARD=MID,DEV=7"
Device name:  "plughw:CARD=MID,DEV=8"
Device name:  "default"
QAudioDeviceInfo::defaultOutputDevice().deviceName():  ""
QSoundEffect.supportedMimeTypes()
mimeType:  "audio/x-wav"
mimeType:  "audio/wav"
mimeType:  "audio/wave"
mimeType:  "audio/x-pn-wav"

[SGaist]

Hi,

IIRC Qt uses PulseAudio as backend on linux.

Can you print what is the current list of available devices is ?

[th.thielemann]

Hi,

the list of available devices is within my initial post.

Regards

[SGaist]

How did you get that device list ?

[th.thielemann]

QString CAudioVideoReplay::supportedAudioCodecs()
{
    QAudioDeviceInfo info;
    QStringList codecs = info.supportedCodecs();
    QString result;
    if (codecs.empty())  {
        result.append("No Audio Codecs defined\n");
    }
    for (const QString& codec : codecs)  {
        result.append(codec);
        result.append("\n");
    }
    qDebug() << "supportedAudioCodecs=" << result;
    return result;
}

QString CAudioVideoReplay::availableAudioDevices()
{
    QList<QAudioDeviceInfo> devices = QAudioDeviceInfo::availableDevices(QAudio::AudioOutput);
    QString result;
    if (devices.empty()) {
        result.append("No Audio Devices defined\n");
    }
    for (const QAudioDeviceInfo& device : devices) {
        QString row;
        row.append("Device Name: " + device.deviceName() + "\n");
        row.append("    Preferred Format: " + toString(device.preferredFormat()) + "\n");
        result.append(row);
    }
    qDebug() << "availableAudioDevices=" << result;
    return result;
}

[SGaist]

Are you asking for the supported codecs of an empty QAudioDeviceInfo ?