How to use different codec than audio/pcm with QAudioRecorder

How to record audio with Qt4.8 with other codec than wave (audio/pcm)? I am only able to record to a .wav-file. Here is the core of the code:

QString fileName = "C:/Audio/testRecording"; //.wav removed
audioRecorder->setOutputLocation(QUrl::fromLocalFile(fileName));
audioRecorder->setAudioInput(boxValue(ui->audioDeviceBox).toString());

QAudioEncoderSettings settings;
//settings.setCodec           ("audio/pcm");
settings.setCodec           ("audio/vorbis");
settings.setSampleRate      (44100);
settings.setBitRate         (8000);
settings.setChannelCount    (1);
settings.setQuality         (QMultimedia::EncodingQuality(2));
settings.setEncodingMode    (QMultimedia::EncodingMode(3));

//QString container = "audio/x-wav";
QString container = "audio/ogg";

audioRecorder->setEncodingSettings(settings, QVideoEncoderSettings(), container);
audioRecorder->record();

If I switch to "audio/vorbis" and "audio/ogg" it still records to a .wav-file.

How to install a codec? Where are the codecs installed on Windows? What is the application expecting when it reads "audio/pcm"?