C++ QAudioFormat::codec方法代码示例

QString formatToString(const QAudioFormat &format)
{
    QString result;

    if (QAudioFormat() != format) {
        if (format.codec() == "audio/pcm") {
            Q_ASSERT(format.sampleType() == QAudioFormat::SignedInt);

            const QString formatEndian = (format.byteOrder() == QAudioFormat::LittleEndian)
                ?   QString("LE") : QString("BE");

            QString formatType;
            switch (format.sampleType()) {
            case QAudioFormat::SignedInt:
                formatType = "signed";
                break;
            case QAudioFormat::UnSignedInt:
                formatType = "unsigned";
                break;
            case QAudioFormat::Float:
                formatType = "float";
                break;
            case QAudioFormat::Unknown:
                formatType = "unknown";
                break;
            }

            QString formatChannels = QString("%1 channels").arg(format.channelCount());
            switch (format.channelCount()) {
            case 1:
                formatChannels = "mono";
                break;
            case 2:
                formatChannels = "stereo";
                break;
            }

            result = QString("%1 Hz %2 bit %3 %4 %5")
                .arg(format.sampleRate())
                .arg(format.sampleSize())
                .arg(formatType)
                .arg(formatEndian)
                .arg(formatChannels);
        } else {
            result = format.codec();
        }
    }

    return result;
}

bool QAudioDeviceInfoInternal::isFormatSupported(
                                 const QAudioFormat &format) const
{
    getSupportedFormats();
    bool supported = false;
    if (m_capabilities.contains(format.codec())) {
        const Capabilities &codecCaps = m_capabilities[format.codec()];
        supported = codecCaps.m_frequencies.contains(format.frequency())
                &&  codecCaps.m_channels.contains(format.channels())
                &&  codecCaps.m_sampleSizes.contains(format.sampleSize())
                &&  codecCaps.m_byteOrders.contains(format.byteOrder())
                &&  codecCaps.m_sampleTypes.contains(format.sampleType());
    }
    return supported;
}

bool QAudioDeviceInfoInternal::testSettings(const QAudioFormat& format) const
{
    // Set nearest to closest settings that do work.
    // See if what is in settings will work (return value).

    bool failed = false;

    // For now, just accept only audio/pcm codec
    if(!format.codec().startsWith(QLatin1String("audio/pcm")))
        failed = true;

    if(!failed && !(format.channels() == 1 || format.channels() == 2))
        failed = true;

    if(!failed) {
        if(!(format.frequency() == 8000 || format.frequency() == 11025 || format.frequency() == 22050 ||
	   format.frequency() == 44100 || format.frequency() == 48000 || format.frequency() == 96000))
	    failed = true;
    }

    if(!failed && !(format.sampleSize() == 8 || format.sampleSize() == 16))
        failed = true;

    if(!failed) {
        // settings work
        return true;
    }
    return false;
}

bool WaveFileWriter::open(const QString& fileName, const QAudioFormat& format)
{
    if (file.isOpen())
        return false; // file already open

    if (format.codec() != "audio/pcm" || format.sampleType() != QAudioFormat::SignedInt)
        return false; // data format is not supported

    if (fileName == "stdout")
    {
        if (!file.open(stdout, QIODevice::WriteOnly))
            return false;
    }
    else
    {
        file.setFileName(fileName);
        if (!file.open(QIODevice::WriteOnly))
            return false; // unable to open file for writing
    }

    if (!writeHeader(format))
        return false;

    m_format = format;
    return true;
}

QAudioFormat QAudioDeviceInfoInternal::preferredFormat() const
{
    QAudioFormat format;
    switch (m_mode) {
    case QAudio::AudioOutput:
        format.setFrequency(44100);
        format.setChannels(2);
        format.setSampleSize(16);
        format.setByteOrder(QAudioFormat::LittleEndian);
        format.setSampleType(QAudioFormat::SignedInt);
        format.setCodec(QLatin1String("audio/pcm"));
        break;

    case QAudio::AudioInput:
        format.setFrequency(8000);
        format.setChannels(1);
        format.setSampleSize(16);
        format.setByteOrder(QAudioFormat::LittleEndian);
        format.setSampleType(QAudioFormat::SignedInt);
        format.setCodec(QLatin1String("audio/pcm"));
        break;

    default:
        Q_ASSERT_X(false, Q_FUNC_INFO, "Invalid mode");
    }

    if (!isFormatSupported(format)) {
        format = QAudioFormat();
        format.setCodec(QLatin1String("audio/pcm"));
        if (m_capabilities.contains(format.codec())) {
            const Capabilities &codecCaps = m_capabilities[format.codec()];
            if (codecCaps.m_frequencies.size())
                format.setFrequency(codecCaps.m_frequencies[0]);
            if (codecCaps.m_channels.size())
                format.setChannels(codecCaps.m_channels[0]);
            if (codecCaps.m_sampleSizes.size())
                format.setSampleSize(codecCaps.m_sampleSizes[0]);
            if (codecCaps.m_byteOrders.size())
                format.setByteOrder(codecCaps.m_byteOrders[0]);
            if (codecCaps.m_sampleTypes.size())
                format.setSampleType(codecCaps.m_sampleTypes[0]);
        }
    }

    return format;
}

/*!
    Returns the closest QAudioFormat to the supplied \a settings that the system supports.

    These settings are provided by the platform/audio plugin being used.

    They are also dependent on the \l {QAudio}::Mode being used.
*/
QAudioFormat QAudioDeviceInfo::nearestFormat(const QAudioFormat &settings) const
{
    if (isFormatSupported(settings))
        return settings;

    QAudioFormat nearest = settings;

    QList<QString> testCodecs = supportedCodecs();
    QList<int> testChannels = supportedChannelCounts();
    QList<QAudioFormat::Endian> testByteOrders = supportedByteOrders();
    QList<QAudioFormat::SampleType> testSampleTypes;
    QList<QAudioFormat::SampleType> sampleTypesAvailable = supportedSampleTypes();
    QMap<int,int> testSampleRates;
    QList<int> sampleRatesAvailable = supportedSampleRates();
    QMap<int,int> testSampleSizes;
    QList<int> sampleSizesAvailable = supportedSampleSizes();

    // Get sorted lists for checking
    if (testCodecs.contains(settings.codec())) {
        testCodecs.removeAll(settings.codec());
        testCodecs.insert(0, settings.codec());
    }
    testChannels.removeAll(settings.channelCount());
    testChannels.insert(0, settings.channelCount());
    testByteOrders.removeAll(settings.byteOrder());
    testByteOrders.insert(0, settings.byteOrder());

    if (sampleTypesAvailable.contains(settings.sampleType()))
        testSampleTypes.append(settings.sampleType());
    if (sampleTypesAvailable.contains(QAudioFormat::SignedInt))
        testSampleTypes.append(QAudioFormat::SignedInt);
    if (sampleTypesAvailable.contains(QAudioFormat::UnSignedInt))
        testSampleTypes.append(QAudioFormat::UnSignedInt);
    if (sampleTypesAvailable.contains(QAudioFormat::Float))
        testSampleTypes.append(QAudioFormat::Float);

    if (sampleSizesAvailable.contains(settings.sampleSize()))
        testSampleSizes.insert(0,settings.sampleSize());
    sampleSizesAvailable.removeAll(settings.sampleSize());
    foreach (int size, sampleSizesAvailable) {
        int larger  = (size > settings.sampleSize()) ? size : settings.sampleSize();
        int smaller = (size > settings.sampleSize()) ? settings.sampleSize() : size;
        bool isMultiple = ( 0 == (larger % smaller));
        int diff = larger - smaller;
        testSampleSizes.insert((isMultiple ? diff : diff+100000), size);
    }

S60AudioEncoderControl::S60AudioEncoderControl(QObject *session, QObject *parent)
    :QAudioEncoderControl(parent), m_quality(QtMultimediaKit::NormalQuality)
{   
    m_session = qobject_cast<S60AudioCaptureSession*>(session);
    QAudioFormat fmt = m_session->format();
    // medium, 22050Hz mono S16
    fmt.setSampleType(QAudioFormat::SignedInt);
    if (fmt.codec().compare("PCM", Qt::CaseInsensitive) == 0) {
        fmt.setSampleSize(16);
        fmt.setFrequency(22050);
    }
    fmt.setChannels(1);
    m_session->setFormat(fmt);
    m_settings.setChannelCount(fmt.channels());
    m_settings.setCodec(fmt.codec());
    m_settings.setSampleRate(fmt.sampleRate());
}

void EQAlgorithm::gatherData()
{
    this->file = Core::autoEQCore->mainWin->fileNames;
    this->file.open(QIODevice::ReadWrite);
    this->fftInput = file.readAll();
    this->file.close();
    QAudioFormat format;
    this->fftOutput = new QAudioBuffer(fftInput, format.codec(), 0);
}

bool Lockin2::isFormatSupported(const QAudioFormat &format)
{
    if (format.codec() != "audio/pcm") {
        return false;
    }

    if (format.channelCount() != 2) {
        return false;
    }

    return true;
}

QDebug operator<<(QDebug dbg, const QAudioFormat &f)
{
    dbg.nospace() << "QAudioFormat(" << f.sampleRate();
    dbg.nospace() << "Hz, " << f.sampleSize();
    dbg.nospace() << "bit, channelCount=" << f.channelCount();
    dbg.nospace() << ", sampleType=" << f.sampleType();
    dbg.nospace() << ", byteOrder=" << f.byteOrder();
    dbg.nospace() << ", codec=" << f.codec();
    dbg.nospace() << ")";

    return dbg.space();
}

QT_BEGIN_NAMESPACE

// Debugging
QDebug operator<<(QDebug dbg, const QAudioFormat& audioFormat)
{
    dbg.nospace() << "QAudioFormat(" <<
            audioFormat.frequency() << "," <<
            audioFormat.channels() << "," <<
            audioFormat.sampleSize()<< "," <<
            audioFormat.codec() << "," <<
            audioFormat.byteOrder() << "," <<
            audioFormat.sampleType() << ")";

    return dbg.space();
}

void AudioTest::test()
{
    // tries to set all the settings picked.
    logOutput->clear();
    logOutput->append("NOTE: an invalid codec audio/test exists for testing, to get a fail condition.");

    if (!deviceInfo.isNull()) {
        if (deviceInfo.isFormatSupported(settings)) {
            logOutput->append(tr("Success"));
            nearestFreq->setText("");
            nearestChannel->setText("");
            nearestCodec->setText("");
            nearestSampleSize->setText("");
            nearestSampleType->setText("");
            nearestEndian->setText("");
        } else {
            QAudioFormat nearest = deviceInfo.nearestFormat(settings);
            logOutput->append(tr("Failed"));
            nearestFreq->setText(QString("%1").arg(nearest.frequency()));
            nearestChannel->setText(QString("%1").arg(nearest.channels()));
            nearestCodec->setText(nearest.codec());
            nearestSampleSize->setText(QString("%1").arg(nearest.sampleSize()));

            switch(nearest.sampleType()) {
                case QAudioFormat::SignedInt:
                    nearestSampleType->setText("SignedInt");
                    break;
                case QAudioFormat::UnSignedInt:
                    nearestSampleType->setText("UnSignedInt");
                    break;
                case QAudioFormat::Float:
                    nearestSampleType->setText("Float");
                    break;
                case QAudioFormat::Unknown:
                    nearestSampleType->setText("Unknown");
            }
            switch(nearest.byteOrder()) {
                case QAudioFormat::LittleEndian:
                    nearestEndian->setText("LittleEndian");
                    break;
                case QAudioFormat::BigEndian:
                    nearestEndian->setText("BigEndian");
            }
        }
    }
    else
        logOutput->append(tr("No Device"));
}

// This function returns the maximum possible sample value for a given audio format
qreal getPeakValue(const QAudioFormat& format)
{
    // Note: Only the most common sample formats are supported
    if (!format.isValid())
        return qreal(0);

    if (format.codec() != "audio/pcm")
        return qreal(0);

    switch (format.sampleType()) {
    case QAudioFormat::Unknown:
        break;
    case QAudioFormat::Float:
        if (format.sampleSize() != 32) // other sample formats are not supported
            return qreal(0);
        return qreal(1.00003);
    case QAudioFormat::SignedInt:
        if (format.sampleSize() == 32)
            return qreal(INT_MAX);
        if (format.sampleSize() == 16)
            return qreal(SHRT_MAX);
        if (format.sampleSize() == 8)
            return qreal(CHAR_MAX);
        break;
    case QAudioFormat::UnSignedInt:
        if (format.sampleSize() == 32)
            return qreal(UINT_MAX);
        if (format.sampleSize() == 16)
            return qreal(USHRT_MAX);
        if (format.sampleSize() == 8)
            return qreal(UCHAR_MAX);
        break;
    }

    return qreal(0);
}

bool QAlsaAudioDeviceInfo::testSettings(const QAudioFormat& format) const
{
    // Set nearest to closest settings that do work.
    // See if what is in settings will work (return value).
    int err = -1;
    snd_pcm_t* pcmHandle;
    snd_pcm_hw_params_t *params;
    QString dev;

#if(SND_LIB_MAJOR == 1 && SND_LIB_MINOR == 0 && SND_LIB_SUBMINOR >= 14)
    dev = device;
    if (dev.compare(QLatin1String("default")) == 0) {
        QList<QByteArray> devices = availableDevices(QAudio::AudioOutput);
        if (!devices.isEmpty())
            dev = QLatin1String(devices.first().constData());
    }
#else
    if (dev.compare(QLatin1String("default")) == 0) {
        dev = QLatin1String("hw:0,0");
    } else {
        int idx = 0;
        char *name;

        QString shortName = device.mid(device.indexOf(QLatin1String("="),0)+1);

        while(snd_card_get_name(idx,&name) == 0) {
            if(shortName.compare(QLatin1String(name)) == 0)
                break;
            idx++;
        }
        dev = QString(QLatin1String("hw:%1,0")).arg(idx);
    }
#endif

    snd_pcm_stream_t stream = mode == QAudio::AudioOutput
                            ? SND_PCM_STREAM_PLAYBACK : SND_PCM_STREAM_CAPTURE;

    if (snd_pcm_open(&pcmHandle, dev.toLocal8Bit().constData(), stream, 0) < 0)
        return false;

    snd_pcm_nonblock(pcmHandle, 0);
    snd_pcm_hw_params_alloca(&params);
    snd_pcm_hw_params_any(pcmHandle, params);

    // set the values!
    snd_pcm_hw_params_set_channels(pcmHandle, params, format.channelCount());
    snd_pcm_hw_params_set_rate(pcmHandle, params, format.sampleRate(), 0);

    snd_pcm_format_t pcmFormat = SND_PCM_FORMAT_UNKNOWN;
    switch (format.sampleSize()) {
    case 8:
        if (format.sampleType() == QAudioFormat::SignedInt)
            pcmFormat = SND_PCM_FORMAT_S8;
        else if (format.sampleType() == QAudioFormat::UnSignedInt)
            pcmFormat = SND_PCM_FORMAT_U8;
        break;
    case 16:
        if (format.sampleType() == QAudioFormat::SignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_S16_LE : SND_PCM_FORMAT_S16_BE;
        } else if (format.sampleType() == QAudioFormat::UnSignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_U16_LE : SND_PCM_FORMAT_U16_BE;
        }
        break;
    case 32:
        if (format.sampleType() == QAudioFormat::SignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_S32_LE : SND_PCM_FORMAT_S32_BE;
        } else if (format.sampleType() == QAudioFormat::UnSignedInt) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_U32_LE : SND_PCM_FORMAT_U32_BE;
        } else if (format.sampleType() == QAudioFormat::Float) {
            pcmFormat = format.byteOrder() == QAudioFormat::LittleEndian
                      ? SND_PCM_FORMAT_FLOAT_LE : SND_PCM_FORMAT_FLOAT_BE;
        }
    }

    if (pcmFormat != SND_PCM_FORMAT_UNKNOWN)
        err = snd_pcm_hw_params_set_format(pcmHandle, params, pcmFormat);

    // For now, just accept only audio/pcm codec
    if (!format.codec().startsWith(QLatin1String("audio/pcm")))
        err = -1;

    if (err >= 0 && format.channelCount() != -1) {
        err = snd_pcm_hw_params_test_channels(pcmHandle, params, format.channelCount());
        if (err >= 0)
            err = snd_pcm_hw_params_set_channels(pcmHandle, params, format.channelCount());
    }

    if (err >= 0 && format.sampleRate() != -1) {
        err = snd_pcm_hw_params_test_rate(pcmHandle, params, format.sampleRate(), 0);
        if (err >= 0)
            err = snd_pcm_hw_params_set_rate(pcmHandle, params, format.sampleRate(), 0);
    }

    if (err >= 0 && pcmFormat != SND_PCM_FORMAT_UNKNOWN)
        err = snd_pcm_hw_params_set_format(pcmHandle, params, pcmFormat);

//.........这里部分代码省略.........

bool isPCM(const QAudioFormat &format)
{
    return (format.codec() == "audio/pcm");
}