source: trunk/examples/multimedia/audioinput/audioinput.cpp@ 846

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#include <stdlib.h>
#include <math.h>

#include <QDebug>
#include <QPainter>
#include <QVBoxLayout>

#include <QAudioDeviceInfo>
#include <QAudioInput>

#include <QtCore/qendian.h>

#include "audioinput.h"

const QString InputTest::PushModeLabel(tr("Enable push mode"));
const QString InputTest::PullModeLabel(tr("Enable pull mode"));
const QString InputTest::SuspendLabel(tr("Suspend recording"));
const QString InputTest::ResumeLabel(tr("Resume recording"));

const int BufferSize = 4096;

AudioInfo::AudioInfo(const QAudioFormat &format, QObject *parent)
    :   QIODevice(parent)
    ,   m_format(format)
    ,   m_maxAmplitude(0)
    ,   m_level(0.0)

{
    switch (m_format.sampleSize()) {
    case 8:
        switch (m_format.sampleType()) {
        case QAudioFormat::UnSignedInt:
            m_maxAmplitude = 255;
            break;
        case QAudioFormat::SignedInt:
            m_maxAmplitude = 127;
            break;
        default:
            break;
        }
        break;
    case 16:
        switch (m_format.sampleType()) {
        case QAudioFormat::UnSignedInt:
            m_maxAmplitude = 65535;
            break;
        case QAudioFormat::SignedInt:
            m_maxAmplitude = 32767;
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }
}

AudioInfo::~AudioInfo()
{
}

void AudioInfo::start()
{
    open(QIODevice::WriteOnly);
}

void AudioInfo::stop()
{
    close();
}

qint64 AudioInfo::readData(char *data, qint64 maxlen)
{
    Q_UNUSED(data)
    Q_UNUSED(maxlen)

    return 0;
}

qint64 AudioInfo::writeData(const char *data, qint64 len)
{
    if (m_maxAmplitude) {
        Q_ASSERT(m_format.sampleSize() % 8 == 0);
        const int channelBytes = m_format.sampleSize() / 8;
        const int sampleBytes = m_format.channels() * channelBytes;
        Q_ASSERT(len % sampleBytes == 0);
        const int numSamples = len / sampleBytes;

        quint16 maxValue = 0;
        const unsigned char *ptr = reinterpret_cast<const unsigned char *>(data);

        for (int i = 0; i < numSamples; ++i) {
            for(int j = 0; j < m_format.channels(); ++j) {
                quint16 value = 0;

                if (m_format.sampleSize() == 8 && m_format.sampleType() == QAudioFormat::UnSignedInt) {
                    value = *reinterpret_cast<const quint8*>(ptr);
                } else if (m_format.sampleSize() == 8 && m_format.sampleType() == QAudioFormat::SignedInt) {
                    value = qAbs(*reinterpret_cast<const qint8*>(ptr));
                } else if (m_format.sampleSize() == 16 && m_format.sampleType() == QAudioFormat::UnSignedInt) {
                    if (m_format.byteOrder() == QAudioFormat::LittleEndian)
                        value = qFromLittleEndian<quint16>(ptr);
                    else
                        value = qFromBigEndian<quint16>(ptr);
                } else if (m_format.sampleSize() == 16 && m_format.sampleType() == QAudioFormat::SignedInt) {
                    if (m_format.byteOrder() == QAudioFormat::LittleEndian)
                        value = qAbs(qFromLittleEndian<qint16>(ptr));
                    else
                        value = qAbs(qFromBigEndian<qint16>(ptr));
                }

                maxValue = qMax(value, maxValue);
                ptr += channelBytes;
            }
        }

        maxValue = qMin(maxValue, m_maxAmplitude);
        m_level = qreal(maxValue) / m_maxAmplitude;
    }

    emit update();