Recording Audio Using QtAudioRecorder



  • Hi everyone,

    im trying to use the QtAudioRecorder to record some simple soundfiles. But I've discovered a few problems.

    First if I'm trying to use it like in the example it keeps showing an error like:

    "Could not create a media muxer element: "" "

    It's always the same error even if i switch the codec.

    However there's a workaround for that error. It dissapears when im not using
    @audioSettings.setCodec("audio/wav");@

    If i dont use the codec im able to take up to 3 records stored correctly in a .wav file (Sometimes i can take only 1 record, then again it's 2 or 3... I can't discover any regularity in it). But then the programm freezes when I'm using:
    @audioRecorder->stop();@

    My Code:
    @
    QAudioRecorder *audioRecorder; //Class member

    audioRecorder = new QAudioRecorder(this);

    audioRecorder->setAudioInput(audioRecorder->defaultAudioInput());
    QAudioEncoderSettings audioSettings;
    audioSettings.setCodec("audio/wav");
    audioSettings.setSampleRate(16000);
    audioSettings.setBitRate(32);
    audioSettings.setQuality(QMultimedia::HighQuality);
    audioSettings.setEncodingMode(QMultimedia::ConstantQualityEncoding);
    audioRecorder->setEncodingSettings(audioSettings);
    audioRecorder->setOutputLocation(QUrl::fromLocalFile("Test.wav"));

    //start Recording
    if (audioRecorder->state() == QMediaRecorder::StoppedState)
    {
    audioRecorder->record();
    }

    //stop Recording

    if (audioRecorder->state() == QMediaRecorder::RecordingState)
    {
    audioRecorder->stop();
    }
    @

    My OS is Debian 7.

    Any help is appreciated! Thanks in advance.

    Lucas



  • This post is quite old, but I had a similar problem and solved it, so here is what I did. The problem was that I had to define both the codec and the container. The latter is necessary to create the muxer element, and the former has to be a string as defined in the Qt code (so I had to use "audio/PCM"; it did not work with "audio/wav" or "audio/pcm"):

    audioSettings.setCodec("audio/PCM");
    ...
    audioRecorder->setContainerFormat("wav");
    

    I could then record into a WAV file.



  • Absolutely!


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