C++ QAudioFormat::frequency方法代码示例

void xmppClient::slotConnected()
{
    QXmppCall *call = qobject_cast<QXmppCall*>(sender());
    Q_ASSERT(call);

    qDebug() << "Call connected";
    QXmppRtpChannel *channel = call->audioChannel();

    // prepare audio format
    QAudioFormat format;
    format.setFrequency(channel->payloadType().clockrate());
    format.setChannels(channel->payloadType().channels());
    format.setSampleSize(16);
    format.setCodec("audio/pcm");
    format.setByteOrder(QAudioFormat::LittleEndian);
    format.setSampleType(QAudioFormat::SignedInt);

    // the size in bytes of the audio buffers to/from sound devices
    // 160 ms seems to be the minimum to work consistently on Linux/Mac/Windows
    const int bufferSize = (format.frequency() * format.channels() * (format.sampleSize() / 8) * 160) / 1000;

    // initialise audio output
    QAudioOutput *audioOutput = new QAudioOutput(format, this);
    audioOutput->setBufferSize(bufferSize);
    audioOutput->start(channel);

    // initialise audio input
    QAudioInput *audioInput = new QAudioInput(format, this);
    audioInput->setBufferSize(bufferSize);
    audioInput->start(channel);
}

qint64 audioLength(const QAudioFormat &format, qint64 microSeconds)
{
   qint64 result = (format.frequency() * format.channels() * (format.sampleSize() / 8))
       * microSeconds / 1000000;
   result -= result % (format.channelCount() * format.sampleSize());
   return result;
}

pa_sample_spec audioFormatToSampleSpec(const QAudioFormat &format)
{
    pa_sample_spec  spec;

    spec.rate = format.frequency();
    spec.channels = format.channels();

    if (format.sampleSize() == 8) {
        spec.format = PA_SAMPLE_U8;
    } else if (format.sampleSize() == 16) {
        switch (format.byteOrder()) {
        case QAudioFormat::BigEndian: spec.format = PA_SAMPLE_S16BE; break;
        case QAudioFormat::LittleEndian: spec.format = PA_SAMPLE_S16LE; break;
        }
    } else if (format.sampleSize() == 24) {
        switch (format.byteOrder()) {
        case QAudioFormat::BigEndian: spec.format = PA_SAMPLE_S24BE; break;
        case QAudioFormat::LittleEndian: spec.format = PA_SAMPLE_S24LE; break;
        }
    } else if (format.sampleSize() == 32) {
        switch (format.byteOrder()) {
        case QAudioFormat::BigEndian:
            format.sampleType() == QAudioFormat::Float ? spec.format = PA_SAMPLE_FLOAT32BE : spec.format = PA_SAMPLE_S32BE;
            break;
        case QAudioFormat::LittleEndian:
            format.sampleType() == QAudioFormat::Float ? spec.format = PA_SAMPLE_FLOAT32LE : spec.format = PA_SAMPLE_S32LE;
            break;
        }
    } else {
        spec.format = PA_SAMPLE_INVALID;
    }

    return spec;
}

AudioStreamBasicDescription toAudioStreamBasicDescription(QAudioFormat const& audioFormat)
{
    AudioStreamBasicDescription sf;

    sf.mFormatFlags         = kAudioFormatFlagIsPacked;
    sf.mSampleRate          = audioFormat.frequency();
    sf.mFramesPerPacket     = 1;
    sf.mChannelsPerFrame    = audioFormat.channels();
    sf.mBitsPerChannel      = audioFormat.sampleSize();
    sf.mBytesPerFrame       = sf.mChannelsPerFrame * (sf.mBitsPerChannel / 8);
    sf.mBytesPerPacket      = sf.mFramesPerPacket * sf.mBytesPerFrame;
    sf.mFormatID            = kAudioFormatLinearPCM;

    switch (audioFormat.sampleType()) {
    case QAudioFormat::SignedInt: sf.mFormatFlags |= kAudioFormatFlagIsSignedInteger; break;
    case QAudioFormat::UnSignedInt: /* default */ break;
    case QAudioFormat::Float: sf.mFormatFlags |= kAudioFormatFlagIsFloat; break;
    case QAudioFormat::Unknown:  default: break;
    }

    if (audioFormat.byteOrder() == QAudioFormat::BigEndian)
        sf.mFormatFlags |= kAudioFormatFlagIsBigEndian;

    return sf;
}

void SpectrumAnalyser::calculate(const QByteArray &buffer,
                                 const QAudioFormat &format, bool isSample,char phoneme)
{
    // QThread::currentThread is marked 'for internal use only', but
    // we're only using it for debug output here, so it's probably OK :)
    SPECTRUMANALYSER_DEBUG << "SpectrumAnalyser::calculate"
                           << QThread::currentThread()
                           << "state" << m_state;

    if (isReady()) {
        Q_ASSERT(isPCMS16LE(format));

        const int bytesPerSample = format.sampleSize() * format.channels() / 8;

#ifdef DUMP_SPECTRUMANALYSER
        m_count++;
        const QString pcmFileName = m_outputDir.filePath(QString("spectrum_%1.pcm").arg(m_count, 4, 10, QChar('0')));
        QFile pcmFile(pcmFileName);
        pcmFile.open(QIODevice::WriteOnly);
        const int bufferLength = m_numSamples * bytesPerSample;
        pcmFile.write(buffer, bufferLength);

        m_textStream << "TimeDomain " << m_count << "\n";
        const qint16* input = reinterpret_cast<const qint16*>(buffer);
        for (int i=0; i<m_numSamples; ++i) {
            m_textStream << i << "\t" << *input << "\n";
            input += format.channels();
        }
#endif

        m_state = Busy;

        // Invoke SpectrumAnalyserThread::calculateSpectrum using QMetaObject.  If
        // m_thread is in a different thread from the current thread, the
        // calculation will be done in the child thread.
        // Once the calculation is finished, a calculationChanged signal will be
        // emitted by m_thread.
        const bool b = QMetaObject::invokeMethod(m_thread, "calculateSpectrum",
                       Qt::AutoConnection,
                       Q_ARG(QByteArray, buffer),
                       Q_ARG(int, format.frequency()),
                       Q_ARG(int, bytesPerSample),
                       Q_ARG(bool,isSample),
                       Q_ARG(char,phoneme));
        Q_ASSERT(b);
        Q_UNUSED(b) // suppress warnings in release builds

#ifdef DUMP_SPECTRUMANALYSER
        m_textStream << "FrequencySpectrum " << m_count << "\n";
        FrequencySpectrum::const_iterator x = m_spectrum.begin();
        for (int i=0; i<m_numSamples; ++i, ++x)
            m_textStream << i << "\t"
                         << x->frequency << "\t"
                         << x->amplitude<< "\t"
                         << x->phase << "\n";
#endif
    }
}

 void Generator::generateData(const QAudioFormat &format, qint64 durationUs, int frequency)
 {
     const int channelBytes = format.sampleSize() / 8;
     const int sampleBytes = format.channels() * channelBytes;

     qint64 length = (format.frequency() * format.channels() * (format.sampleSize() / 8))
                         * durationUs / 100000;

     Q_ASSERT(length % sampleBytes == 0);
     Q_UNUSED(sampleBytes) // suppress warning in release builds

     m_buffer.resize(length);
     unsigned char *ptr = reinterpret_cast<unsigned char *>(m_buffer.data());
     int sampleIndex = 0;

     while (length) {
         const qreal x = qSin(2 * M_PI * frequency * qreal(sampleIndex % format.frequency()) / format.frequency());
         for (int i=0; i<format.channels(); ++i) {
             if (format.sampleSize() == 8 && format.sampleType() == QAudioFormat::UnSignedInt) {
                 const quint8 value = static_cast<quint8>((1.0 + x) / 2 * 255);
                 *reinterpret_cast<quint8*>(ptr) = value;
             } else if (format.sampleSize() == 8 && format.sampleType() == QAudioFormat::SignedInt) {
                 const qint8 value = static_cast<qint8>(x * 127);
                 *reinterpret_cast<quint8*>(ptr) = value;
             } else if (format.sampleSize() == 16 && format.sampleType() == QAudioFormat::UnSignedInt) {
                 quint16 value = static_cast<quint16>((1.0 + x) / 2 * 65535);
                 if (format.byteOrder() == QAudioFormat::LittleEndian)
                     qToLittleEndian<quint16>(value, ptr);
                 else
                     qToBigEndian<quint16>(value, ptr);
             } else if (format.sampleSize() == 16 && format.sampleType() == QAudioFormat::SignedInt) {
                 qint16 value = static_cast<qint16>(x * 32767);
                 if (format.byteOrder() == QAudioFormat::LittleEndian)
                     qToLittleEndian<qint16>(value, ptr);
                 else
                     qToBigEndian<qint16>(value, ptr);
             }

             ptr += channelBytes;
             length -= channelBytes;
         }
         ++sampleIndex;
     }
 }

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;
}

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

            result = QString("%1 Hz %2 bit %3 %4 %5")
                .arg(format.frequency())
                .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;
}

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"));
}

qint64 audioLength(const QAudioFormat &format, qint64 microSeconds)
{
   return (format.frequency() * format.channels() * (format.sampleSize() / 8))
       * microSeconds / 1000000;
}

qint64 audioDuration(const QAudioFormat &format, qint64 bytes)
{
    return (bytes * 1000000) /
        (format.frequency() * format.channels() * (format.sampleSize() / 8));
}

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).
    int err = 0;
    snd_pcm_t* handle;
    snd_pcm_hw_params_t *params;
    QString dev = device;

    // open()
    if(!dev.contains(QLatin1String("default"))) {
        int idx = snd_card_get_index(dev.toLocal8Bit().constData());
        dev = QString(QLatin1String("hw:%1,0")).arg(idx);
    }
    if(mode == QAudio::AudioOutput) {
        err=snd_pcm_open( &handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_PLAYBACK,0);
    } else {
        err=snd_pcm_open( &handle,dev.toLocal8Bit().constData(),SND_PCM_STREAM_CAPTURE,0);
    }
    if(err < 0) {
        handle = 0;
        return false;
    }

    bool testChannel = false;
    bool testCodec = false;
    bool testFreq = false;
    bool testType = false;
    bool testSize = false;

    int  dir = 0;

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

    // set the values!
    snd_pcm_hw_params_set_channels(handle,params,format.channels());
    snd_pcm_hw_params_set_rate(handle,params,format.frequency(),dir);
    switch(format.sampleSize()) {
        case 8:
            if(format.sampleType() == QAudioFormat::SignedInt)
                snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_S8);
            else if(format.sampleType() == QAudioFormat::UnSignedInt)
                snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_U8);
            break;
        case 16:
            if(format.sampleType() == QAudioFormat::SignedInt) {
                if(format.byteOrder() == QAudioFormat::LittleEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_S16_LE);
                else if(format.byteOrder() == QAudioFormat::BigEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_S16_BE);
            } else if(format.sampleType() == QAudioFormat::UnSignedInt) {
                if(format.byteOrder() == QAudioFormat::LittleEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_U16_LE);
                else if(format.byteOrder() == QAudioFormat::BigEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_U16_BE);
            }
            break;
        case 32:
            if(format.sampleType() == QAudioFormat::SignedInt) {
                if(format.byteOrder() == QAudioFormat::LittleEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_S32_LE);
                else if(format.byteOrder() == QAudioFormat::BigEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_S32_BE);
            } else if(format.sampleType() == QAudioFormat::UnSignedInt) {
                if(format.byteOrder() == QAudioFormat::LittleEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_U32_LE);
                else if(format.byteOrder() == QAudioFormat::BigEndian)
                    snd_pcm_hw_params_set_format(handle,params,SND_PCM_FORMAT_U32_BE);
            }
    }

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

    if(err>=0 && format.channels() != -1) {
        err = snd_pcm_hw_params_test_channels(handle,params,format.channels());
        if(err>=0)
            err = snd_pcm_hw_params_set_channels(handle,params,format.channels());
        if(err>=0)
            testChannel = true;
    }

    if(err>=0 && format.frequency() != -1) {
        err = snd_pcm_hw_params_test_rate(handle,params,format.frequency(),0);
        if(err>=0)
            err = snd_pcm_hw_params_set_rate(handle,params,format.frequency(),dir);
        if(err>=0)
            testFreq = true;
    }

    if((err>=0 && format.sampleSize() != -1) &&
            (format.sampleType() != QAudioFormat::Unknown)) {
        switch(format.sampleSize()) {
            case 8:
                if(format.sampleType() == QAudioFormat::SignedInt)
//.........这里部分代码省略.........

qreal nyquistFrequency(const QAudioFormat &format)
{
    return format.frequency() / 2;
}