- Qt 5.5
- Qt Multimedia
- Audio Devices Example
- audiodevices.cpp Example File
- Qt 5.5.1 Reference Documentation

# audiodevices.cpp Example File

audiodevices/audiodevices.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
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    **     contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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    #include "audiodevices.h"

    // Utility functions for converting QAudioFormat fields into text

    static QString toString(QAudioFormat::SampleType sampleType)
    {
        QString result("Unknown");
        switch (sampleType) {
        case QAudioFormat::SignedInt:
            result = "SignedInt";
            break;
        case QAudioFormat::UnSignedInt:
            result = "UnSignedInt";
            break;
        case QAudioFormat::Float:
            result = "Float";
            break;
        case QAudioFormat::Unknown:
            result = "Unknown";
        }
        return result;
    }

    static QString toString(QAudioFormat::Endian endian)
    {
        QString result("Unknown");
        switch (endian) {
        case QAudioFormat::LittleEndian:
            result = "LittleEndian";
            break;
        case QAudioFormat::BigEndian:
            result = "BigEndian";
            break;
        }
        return result;
    }

    AudioDevicesBase::AudioDevicesBase(QWidget *parent)
        : QMainWindow(parent)
    {
        setupUi(this);
    }

    AudioDevicesBase::~AudioDevicesBase() {}

    AudioTest::AudioTest(QWidget *parent)
        : AudioDevicesBase(parent)
    {
        mode = QAudio::AudioOutput;

        connect(testButton, SIGNAL(clicked()), SLOT(test()));
        connect(modeBox, SIGNAL(activated(int)), SLOT(modeChanged(int)));
        connect(deviceBox, SIGNAL(activated(int)), SLOT(deviceChanged(int)));
        connect(sampleRateBox, SIGNAL(activated(int)), SLOT(sampleRateChanged(int)));
        connect(channelsBox, SIGNAL(activated(int)), SLOT(channelChanged(int)));
        connect(codecsBox, SIGNAL(activated(int)), SLOT(codecChanged(int)));
        connect(sampleSizesBox, SIGNAL(activated(int)), SLOT(sampleSizeChanged(int)));
        connect(sampleTypesBox, SIGNAL(activated(int)), SLOT(sampleTypeChanged(int)));
        connect(endianBox, SIGNAL(activated(int)), SLOT(endianChanged(int)));
        connect(populateTableButton, SIGNAL(clicked()), SLOT(populateTable()));

        modeBox->setCurrentIndex(0);
        modeChanged(0);
        deviceBox->setCurrentIndex(0);
        deviceChanged(0);
    }

    AudioTest::~AudioTest()
    {
    }

    void AudioTest::test()
    {
        // tries to set all the settings picked.
        testResult->clear();

        if (!deviceInfo.isNull()) {
            if (deviceInfo.isFormatSupported(settings)) {
                testResult->setText(tr("Success"));
                nearestSampleRate->setText("");
                nearestChannel->setText("");
                nearestCodec->setText("");
                nearestSampleSize->setText("");
                nearestSampleType->setText("");
                nearestEndian->setText("");
            } else {
                QAudioFormat nearest = deviceInfo.nearestFormat(settings);
                testResult->setText(tr("Failed"));
                nearestSampleRate->setText(QString("%1").arg(nearest.sampleRate()));
                nearestChannel->setText(QString("%1").arg(nearest.channelCount()));
                nearestCodec->setText(nearest.codec());
                nearestSampleSize->setText(QString("%1").arg(nearest.sampleSize()));
                nearestSampleType->setText(toString(nearest.sampleType()));
                nearestEndian->setText(toString(nearest.byteOrder()));
            }
        }
        else
            testResult->setText(tr("No Device"));
    }

    void AudioTest::modeChanged(int idx)
    {
        testResult->clear();

        // mode has changed
        if (idx == 0)
            mode = QAudio::AudioInput;
        else
            mode = QAudio::AudioOutput;

        deviceBox->clear();
        foreach (const QAudioDeviceInfo &deviceInfo, QAudioDeviceInfo::availableDevices(mode))
            deviceBox->addItem(deviceInfo.deviceName(), qVariantFromValue(deviceInfo));

        deviceBox->setCurrentIndex(0);
        deviceChanged(0);
    }

    void AudioTest::deviceChanged(int idx)
    {
        testResult->clear();

        if (deviceBox->count() == 0)
            return;

        // device has changed
        deviceInfo = deviceBox->itemData(idx).value<QAudioDeviceInfo>();

        sampleRateBox->clear();
        QList<int> sampleRatez = deviceInfo.supportedSampleRates();
        for (int i = 0; i < sampleRatez.size(); ++i)
            sampleRateBox->addItem(QString("%1").arg(sampleRatez.at(i)));
        if (sampleRatez.size())
            settings.setSampleRate(sampleRatez.at(0));

        channelsBox->clear();
        QList<int> chz = deviceInfo.supportedChannelCounts();
        for (int i = 0; i < chz.size(); ++i)
            channelsBox->addItem(QString("%1").arg(chz.at(i)));
        if (chz.size())
            settings.setChannelCount(chz.at(0));

        codecsBox->clear();
        QStringList codecs = deviceInfo.supportedCodecs();
        for (int i = 0; i < codecs.size(); ++i)
            codecsBox->addItem(QString("%1").arg(codecs.at(i)));
        if (codecs.size())
            settings.setCodec(codecs.at(0));
        // Add false to create failed condition!
        codecsBox->addItem("audio/test");

        sampleSizesBox->clear();
        QList<int> sampleSizez = deviceInfo.supportedSampleSizes();
        for (int i = 0; i < sampleSizez.size(); ++i)
            sampleSizesBox->addItem(QString("%1").arg(sampleSizez.at(i)));
        if (sampleSizez.size())
            settings.setSampleSize(sampleSizez.at(0));

        sampleTypesBox->clear();
        QList<QAudioFormat::SampleType> sampleTypez = deviceInfo.supportedSampleTypes();

        for (int i = 0; i < sampleTypez.size(); ++i)
            sampleTypesBox->addItem(toString(sampleTypez.at(i)));
        if (sampleTypez.size())
            settings.setSampleType(sampleTypez.at(0));

        endianBox->clear();
        QList<QAudioFormat::Endian> endianz = deviceInfo.supportedByteOrders();
        for (int i = 0; i < endianz.size(); ++i)
            endianBox->addItem(toString(endianz.at(i)));
        if (endianz.size())
            settings.setByteOrder(endianz.at(0));

        allFormatsTable->clearContents();
    }

    void AudioTest::populateTable()
    {
        int row = 0;

        QAudioFormat format;
        foreach (QString codec, deviceInfo.supportedCodecs()) {
            format.setCodec(codec);
            foreach (int sampleRate, deviceInfo.supportedSampleRates()) {
                format.setSampleRate(sampleRate);
                foreach (int channels, deviceInfo.supportedChannelCounts()) {
                    format.setChannelCount(channels);
                    foreach (QAudioFormat::SampleType sampleType, deviceInfo.supportedSampleTypes()) {
                        format.setSampleType(sampleType);
                        foreach (int sampleSize, deviceInfo.supportedSampleSizes()) {
                            format.setSampleSize(sampleSize);
                            foreach (QAudioFormat::Endian endian, deviceInfo.supportedByteOrders()) {
                                format.setByteOrder(endian);
                                if (deviceInfo.isFormatSupported(format)) {
                                    allFormatsTable->setRowCount(row + 1);

                                    QTableWidgetItem *codecItem = new QTableWidgetItem(format.codec());
                                    allFormatsTable->setItem(row, 0, codecItem);

                                    QTableWidgetItem *sampleRateItem = new QTableWidgetItem(QString("%1").arg(format.sampleRate()));
                                    allFormatsTable->setItem(row, 1, sampleRateItem);

                                    QTableWidgetItem *channelsItem = new QTableWidgetItem(QString("%1").arg(format.channelCount()));
                                    allFormatsTable->setItem(row, 2, channelsItem);

                                    QTableWidgetItem *sampleTypeItem = new QTableWidgetItem(toString(format.sampleType()));
                                    allFormatsTable->setItem(row, 3, sampleTypeItem);

                                    QTableWidgetItem *sampleSizeItem = new QTableWidgetItem(QString("%1").arg(format.sampleSize()));
                                    allFormatsTable->setItem(row, 4, sampleSizeItem);

                                    QTableWidgetItem *byteOrderItem = new QTableWidgetItem(toString(format.byteOrder()));
                                    allFormatsTable->setItem(row, 5, byteOrderItem);

                                    ++row;
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    void AudioTest::sampleRateChanged(int idx)
    {
        // sample rate has changed
        settings.setSampleRate(sampleRateBox->itemText(idx).toInt());
    }

    void AudioTest::channelChanged(int idx)
    {
        settings.setChannelCount(channelsBox->itemText(idx).toInt());
    }

    void AudioTest::codecChanged(int idx)
    {
        settings.setCodec(codecsBox->itemText(idx));
    }

    void AudioTest::sampleSizeChanged(int idx)
    {
        settings.setSampleSize(sampleSizesBox->itemText(idx).toInt());
    }

    void AudioTest::sampleTypeChanged(int idx)
    {
        switch (sampleTypesBox->itemText(idx).toInt()) {
            case QAudioFormat::SignedInt:
                settings.setSampleType(QAudioFormat::SignedInt);
                break;
            case QAudioFormat::UnSignedInt:
                settings.setSampleType(QAudioFormat::UnSignedInt);
                break;
            case QAudioFormat::Float:
                settings.setSampleType(QAudioFormat::Float);
        }
    }

    void AudioTest::endianChanged(int idx)
    {
        switch (endianBox->itemText(idx).toInt()) {
            case QAudioFormat::LittleEndian:
                settings.setByteOrder(QAudioFormat::LittleEndian);
                break;
            case QAudioFormat::BigEndian:
                settings.setByteOrder(QAudioFormat::BigEndian);
        }
    }