Real time audio processing

[Andrea993]

I want to do the arithmetic mean of values of a buffer which I wanna to fill with QAudioInput.

I declare these objects:

QAudioFormat audioformat;
QAudioInput *input;
QIODevice *intermediario;
QByteArray buffer;

QAudioFormat audioformat;
QAudioInput *input;
QIODevice *intermediario;
QByteArray buffer;

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I wrote this function for formatting audioformat:

void formatta_audio (QAudioFormat *formato)
{
    formato->setFrequency(1000);
    formato->setSampleSize(8);
    formato->setCodec("audio/pcm");
    formato->setByteOrder(QAudioFormat::LittleEndian);
    formato->setSampleType(QAudioFormat::UnSignedInt);
    formato->setChannels(1);
}

void formatta_audio (QAudioFormat *formato)
{
    formato->setFrequency(1000);
    formato->setSampleSize(8);
    formato->setCodec("audio/pcm");
    formato->setByteOrder(QAudioFormat::LittleEndian);
    formato->setSampleType(QAudioFormat::UnSignedInt);
    formato->setChannels(1);
}

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In the MainWindow costructor I wrote this:

QAudioDeviceInfo info =  QAudioDeviceInfo::defaultInputDevice();
 
formatta_audio(&audioformat);
 
if (!info.isFormatSupported(audioformat))
    audioformat = info.nearestFormat(audioformat);
 
input= new QAudioInput (audioformat);
 
 ui->setupUi(this);

QAudioDeviceInfo info =  QAudioDeviceInfo::defaultInputDevice();
 
formatta_audio(&audioformat);
 
if (!info.isFormatSupported(audioformat))
    audioformat = info.nearestFormat(audioformat);
 
input= new QAudioInput (audioformat);
 
 ui->setupUi(this);

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I start the QaudioInput in this way:

intermediario = input->start();
       connect (intermediario,SIGNAL(readyRead()),this,SLOT(cattura()));

intermediario = input->start();
       connect (intermediario,SIGNAL(readyRead()),this,SLOT(cattura()));

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And stop the QaudioInput in this way:

input->stop();

input->stop();

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"cattura()" function is this:

void MainWindow::cattura()
{
 
    qint64 Nbytesletti;
    qint64 i;
    qint64 media=0;
    qint64 bytescatturati;
 
 
    bytescatturati= intermediario->bytesAvailable();
 
    if (bytescatturati>0)
    {
 
        Nbytesletti= intermediario->read(buffer.data(),bytescatturati);
 
        for (i=0;i<Nbytesletti;i++)
        {
            media+=(qint64)buffer.at(i);
        }
 
        media/=Nbytesletti;
 
        ui->label->setText(QString("%1").arg(media));
    }
 
 
}

void MainWindow::cattura()
{

    qint64 Nbytesletti;
    qint64 i;
    qint64 media=0;
    qint64 bytescatturati;

  
    bytescatturati= intermediario->bytesAvailable();

    if (bytescatturati>0)
    {
      
        Nbytesletti= intermediario->read(buffer.data(),bytescatturati);

        for (i=0;i<Nbytesletti;i++)
        {
            media+=(qint64)buffer.at(i);
        }

        media/=Nbytesletti;

        ui->label->setText(QString("%1").arg(media));
    }


}

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I've tried a lot of times but "intermediario->bytesAvailable()" return ever "0"

Why? What is the problem?

[Andrea993]

nobody can hellp me?

[SeeLook]

In fact QAudioInput is little unpredictable.
bytesAvaiable() returns 0, bytesRead() will give You some "positive" value.
but only Nbytesletti returns by read() gives true bytes number, usualy much biger than byteaRead
and completely ignores buffer size and second parameter in read() method.

Don't give up :-)