qt-everywhere-src-5.15.1/qtmultimedia/src/plugins/audiocapture/audioencodercontrol.cpp

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#include "audioencodercontrol.h"
#include "audiocapturesession.h"

#include <qaudioformat.h>

#include <QtCore/qdebug.h>

#include <algorithm>

QT_BEGIN_NAMESPACE

static QAudioFormat audioSettingsToAudioFormat(const QAudioEncoderSettings &settings)
{
    QAudioFormat fmt;
    fmt.setCodec(settings.codec());
    fmt.setChannelCount(settings.channelCount());
    fmt.setSampleRate(settings.sampleRate());
    int sampleSize = 16;
    if (settings.bitRate() && settings.channelCount() && settings.sampleRate())
        sampleSize = settings.bitRate() / settings.channelCount() / settings.sampleRate();
    fmt.setSampleSize(sampleSize);
    fmt.setSampleType(sampleSize == 8 ? QAudioFormat::UnSignedInt : QAudioFormat::SignedInt);

    fmt.setByteOrder(QAudioDeviceInfo::defaultInputDevice().preferredFormat().byteOrder());
    return fmt;
}

static QAudioEncoderSettings audioFormatToAudioSettings(const QAudioFormat &format)
{
    QAudioEncoderSettings settings;
    settings.setCodec(format.codec());
    settings.setChannelCount(format.channelCount());
    settings.setSampleRate(format.sampleRate());
    settings.setEncodingMode(QMultimedia::ConstantBitRateEncoding);
    settings.setBitRate(format.channelCount()
                        * format.sampleSize()
                        * format.sampleRate());
    return settings;
}

AudioEncoderControl::AudioEncoderControl(QObject *parent)
    :QAudioEncoderSettingsControl(parent)
{
    m_session = qobject_cast<AudioCaptureSession*>(parent);
    update();
}

AudioEncoderControl::~AudioEncoderControl()
{
}

QStringList AudioEncoderControl::supportedAudioCodecs() const
{
    return QStringList() << QStringLiteral("audio/pcm");
}

QString AudioEncoderControl::codecDescription(const QString &codecName) const
{
    if (QString::compare(codecName, QLatin1String("audio/pcm")) == 0)
        return tr("Linear PCM audio data");

    return QString();
}

QList<int> AudioEncoderControl::supportedSampleRates(const QAudioEncoderSettings &settings, bool *continuous) const
{
    if (continuous)
        *continuous = false;

    if (settings.codec().isEmpty() || settings.codec() == QLatin1String("audio/pcm"))
        return m_sampleRates;

    return QList<int>();
}

QAudioEncoderSettings AudioEncoderControl::audioSettings() const
{
    return audioFormatToAudioSettings(m_session->format());
}

void AudioEncoderControl::setAudioSettings(const QAudioEncoderSettings &settings)
{
    QAudioFormat fmt = audioSettingsToAudioFormat(settings);

    if (settings.encodingMode() == QMultimedia::ConstantQualityEncoding) {
        fmt.setCodec("audio/pcm");
        switch (settings.quality()) {
        case QMultimedia::VeryLowQuality:
            fmt.setSampleSize(8);
            fmt.setSampleRate(8000);
            fmt.setSampleType(QAudioFormat::UnSignedInt);
            break;
        case QMultimedia::LowQuality:
            fmt.setSampleSize(8);
            fmt.setSampleRate(22050);
            fmt.setSampleType(QAudioFormat::UnSignedInt);
            break;
        case QMultimedia::HighQuality:
            fmt.setSampleSize(16);
            fmt.setSampleRate(48000);
            fmt.setSampleType(QAudioFormat::SignedInt);
            break;
        case QMultimedia::VeryHighQuality:
            fmt.setSampleSize(16);
            fmt.setSampleRate(96000);
            fmt.setSampleType(QAudioFormat::SignedInt);
            break;
        case QMultimedia::NormalQuality:
        default:
            fmt.setSampleSize(16);
            fmt.setSampleRate(44100);
            fmt.setSampleType(QAudioFormat::SignedInt);
            break;
        }
    }

    m_session->setFormat(fmt);
}

void AudioEncoderControl::update()
{
    m_sampleRates.clear();
    QList<QAudioDeviceInfo> devices = QAudioDeviceInfo::availableDevices(QAudio::AudioInput);
    for (int i = 0; i < devices.size(); ++i) {
        QList<int> rates = devices.at(i).supportedSampleRates();
        for (int j = 0; j < rates.size(); ++j) {
            int rate = rates.at(j);
            if (!m_sampleRates.contains(rate))
                m_sampleRates.append(rate);
        }
    }
    std::sort(m_sampleRates.begin(), m_sampleRates.end());
}

QT_END_NAMESPACE