Audio I/O Implementation

// Ok, this is my implementation so far -
AudioBuffer::AudioBuffer()
{
    this->init();
}

AudioBuffer::~AudioBuffer()
{
    delete this->buffer;
}

void AudioBuffer::init()
{
    this->buffer = new char[this->MAXSIZE];
    this->writePosition = this->readPosition = this->currentBufferLength = 0;
}

// OVERRIDE
qint64 AudioBuffer::writeData(const char *data, qint64 len)
{
    if((this->writePosition + len) > this->MAXSIZE)
    {
        qint64 firstData = this->MAXSIZE - this->writePosition;
        memcpy(&this->buffer[this->writePosition], data, firstData);
        memcpy(&this->buffer[0], data+firstData, len - firstData);
    }
    else
    {
        memcpy(&this->buffer[writePosition], data, len);
    }

    this->writePosition = (this->writePosition + len) % this->MAXSIZE;
    this->currentBufferLength += len;

    return len;
}

// OVERRIDE
qint64 AudioBuffer::readData(char *data, qint64 maxlen)
{
    if(this->currentBufferLength <= 0)
        return 0;

    qint64 writeLen = qMin(maxlen, this->currentBufferLength);
    if( (writeLen + this->readPosition) > this->MAXSIZE)
    {
        qint64 firstData = this->MAXSIZE - this->readPosition;
        memcpy(data, &this->buffer[this->readPosition], firstData);
        memcpy(data+firstData, &this->buffer[0], writeLen - firstData);
    }
    else
    {
        memcpy(data, &this->buffer[this->readPosition], writeLen);
    }

    this->readPosition = (this->readPosition + writeLen) % this->MAXSIZE;
    this->currentBufferLength -= writeLen;

    return writeLen;
}





// and this is the code that's using this buffer -
void MainWindow::on_btnStart_clicked()
{
    QAudioFormat format = this->getFormat();

    this->audioInput = new QAudioInput(format, this);
    connect(this->audioInput, SIGNAL(stateChanged(QAudio::State)), SLOT(inputStateChanged(QAudio::State)));
    audioInput->start(this->buffer);

    this->audioOutput = new QAudioOutput(format, this);
    connect(this->audioOutput, SIGNAL(stateChanged(QAudio::State)), SLOT(outputStateChanged(QAudio::State)));
    audioOutput->start(this->buffer);
}

QAudioFormat MainWindow::getFormat()
{
    QAudioFormat format;
    format.setSampleRate(8000);
    format.setChannelCount(1);
    format.setSampleSize(8);
    format.setCodec("audio/pcm");
    format.setByteOrder(QAudioFormat::LittleEndian);
    format.setSampleType(QAudioFormat::UnSignedInt);

    return format;
}

void MainWindow::inputStateChanged(QAudio::State state)
{
    QString message="";

    if(state==QAudio::ActiveState)
    {
        message = "Input state has gone to ACTIVE! ";
    }
    else if(state==QAudio::SuspendedState)
    {
        message = "Input state has gone to SUSPENDED! ";
    }
    else if(state==QAudio::StoppedState)
    {
        message = "Input state has gone to STOPPED! ";
    }
    else if(state==QAudio::IdleState)
    {
        message = "Input state has gone to IDLE! ";
    }

    // Check if any error has occured
    if(this->audioInput->error() == QAudio::OpenError)
        message.append("Input: Open Error has occured!");
    else if(this->audioInput->error() == QAudio::IOError)
        message.append("Input: IO Error has occured!");
    else if(this->audioInput->error() == QAudio::UnderrunError)
        message.append("Input: Underrun Error has occured!");
    else if(this->audioInput->error() == QAudio::FatalError)
        message.append("Input: Fatal Error has occured!");
    else
        message.append("Input: No error has occured!");

    this->logger.log(message);
}

void MainWindow::outputStateChanged(QAudio::State state)
{
    QString message="";

    if(state==QAudio::ActiveState)
    {
        message = "Output state has gone to ACTIVE! ";
    }
    else if(state==QAudio::SuspendedState)
    {
        message = "Output state has gone to SUSPENDED! ";
    }
    else if(state==QAudio::StoppedState)
    {
        message = "Output state has gone to STOPPED! ";
    }
    else if(state==QAudio::IdleState)
    {
        message = "Output state has gone to IDLE! ";
        // Check if any error has occured
        if(this->audioOutput->error() == QAudio::OpenError)
            message.append("Output: Open Error has occured!");
        else if(this->audioOutput->error() == QAudio::IOError)
            message.append("Output: IO Error has occured!");
        else if(this->audioOutput->error() == QAudio::UnderrunError)
            message.append("Output: Underrun Error has occured!");
        else if(this->audioOutput->error() == QAudio::FatalError)
            message.append("Output: Fatal Error has occured!");
        else
            message.append("Output: No error has occured!");

        this->logger.log(message);

        this->audioOutput->start(this->buffer);
    }

    // Check if any error has occured
    if(this->audioOutput->error() == QAudio::OpenError)
        message.append("Output: Open Error has occured!");
    else if(this->audioOutput->error() == QAudio::IOError)
        message.append("Output: IO Error has occured!");
    else if(this->audioOutput->error() == QAudio::UnderrunError)
        message.append("Output: Underrun Error has occured!");
    else if(this->audioOutput->error() == QAudio::FatalError)
        message.append("Output: Fatal Error has occured!");
    else
        message.append("Output: No error has occured!");

    this->logger.log(message);
}