Record Audio in Qt6

QtAndrew

    // RECORD
    QMediaCaptureSession* session = new QMediaCaptureSession();
    QAudioInput* audioInput = new QAudioInput();
    QMediaRecorder* recorder = new QMediaRecorder();
    session->setAudioInput(audioInput);
    session->setRecorder(recorder);
    recorder->setMediaFormat(QMediaFormat::Wave);
    recorder->setOutputLocation(QUrl::fromLocalFile("test"));
    recorder->setAudioSampleRate(48000);
    recorder->setAudioChannelCount(1);
    recorder->record();

    connect(recorder, QOverload<QMediaRecorder::Error>::of(&QMediaRecorder::error),
        [=](QMediaRecorder::Error error){ /* ... */ });

    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), recorder, SLOT(stop()));
    timer->start(3500);

ERROR: 1.) Does not Record any audio but the file is created (macos ARM64)
ERROR: 2.)

/Users/christoph/Documents/DEVELOPMENT/Impulse-Response-Extractor/IRExtractor/irextractor.cpp:44: Fehler: no matching function for call to 'of'
../IRExtractor/irextractor.cpp:44:23: error: no matching function for call to 'of'
connect(recorder, QOverloadQMediaRecorder::Error::of(&QMediaRecorder::error),
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

/Volumes/Externe-SSD/Development/Qt/6.2.0/macos/lib/QtCore.framework/Headers/qglobal.h:1345:27: note: candidate template ignored: failed template argument deduction
static constexpr auto of(R (T::*ptr)(Args...) const) noexcept -> decltype(ptr)
^

jsulm

@QtAndrew Since you're on Qt6 you should use https://doc-snapshots.qt.io/qt6-dev/qmediarecorder.html#errorOccurred
And don't forget to print the error in the slot you connect to this signal.

QtAndrew

This post is deleted!

jsulm

@QtAndrew said in Record Audio in Qt6:

why does this code sniplet stand on 6.2 QMediaRecorder ?

It does not. This code snippet is in Qt5 documentation, not in Qt6. I noticed from your compile log that you're using Qt6.2 and provided you the link to Qt6 documentation.
Don't know what is unclear in the documentation...

Christian Ehrlicher

@QtAndrew said in Record Audio in Qt6:

I think i change the platorform.

Please do so. Maybe you find a toolkit where the version is automatically guessed by your browser when you search for help.

QtAndrew

This post is deleted!

QtAndrew

I tried:

1.) Threads
2.) Timers
3.) start the recording and connect the stop() to the player end of media slot.

no success...

void IRExtractor::on_sweepButton_clicked()
{
    // PLAY
    MyThread* t = new MyThread();
    t->start();

    // RECORD
    QMediaCaptureSession* session = new QMediaCaptureSession();
    QAudioInput* audioInput = new QAudioInput();
    QMediaRecorder* recorder = new QMediaRecorder();
    session->setAudioInput(audioInput);
    session->setRecorder(recorder);
    recorder->setMediaFormat(QMediaFormat::Wave);
    recorder->setOutputLocation(QUrl::fromLocalFile("test"));
    recorder->setAudioSampleRate(48000);
    recorder->setAudioChannelCount(1);
    recorder->record();
    QThread::msleep(3250);
    recorder->stop();
}

void MyThread::run()
{
    QMediaPlayer* player = new QMediaPlayer();
    QAudioOutput* audioOutput = new QAudioOutput;
    audioOutput->setVolume(0.1);
    player->setAudioOutput(audioOutput);
    player->setSource(QUrl("qrc:/res/sweep.wav"));
    player->play();

}

This version didn't play the audio.

The Project is now on GitHub: https://github.com/Christoph-Lauer/Impulse-Response-Extractor

QtAndrew

This post is deleted!

JonB

@QtAndrew
I do not know know anything about this, so no point asking me any further! But from your code are you supposed to some error checking as per https://forum.qt.io/topic/130588/qmediaplay-stream-does-not-wokk/2 ?

QtAndrew

changed to matlab --> https://github.com/Christoph-Lauer/Transfer-Function-Extractor-Matlab

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Record Audio in Qt6