audiorecorder.cpp Example File

multimedia/audiorecorder/audiorecorder.cpp
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#include "audiorecorder.h" #include "audiolevel.h" #include "ui_audiorecorder.h" #include <QAudioProbe> #include <QAudioRecorder> #include <QDir> #include <QFileDialog> #include <QMediaRecorder> #include <QStandardPaths> static qreal getPeakValue(const QAudioFormat &format); static QVector<qreal> getBufferLevels(const QAudioBuffer &buffer); template <class T> static QVector<qreal> getBufferLevels(const T *buffer, int frames, int channels); AudioRecorder::AudioRecorder() : ui(new Ui::AudioRecorder) { ui->setupUi(this); m_audioRecorder = new QAudioRecorder(this); m_probe = new QAudioProbe(this); connect(m_probe, &QAudioProbe::audioBufferProbed, this, &AudioRecorder::processBuffer); m_probe->setSource(m_audioRecorder); //audio devices ui->audioDeviceBox->addItem(tr("Default"), QVariant(QString())); for (auto &device: m_audioRecorder->audioInputs()) { ui->audioDeviceBox->addItem(device, QVariant(device)); } //audio codecs ui->audioCodecBox->addItem(tr("Default"), QVariant(QString())); for (auto &codecName: m_audioRecorder->supportedAudioCodecs()) { ui->audioCodecBox->addItem(codecName, QVariant(codecName)); } //containers ui->containerBox->addItem(tr("Default"), QVariant(QString())); for (auto &containerName: m_audioRecorder->supportedContainers()) { ui->containerBox->addItem(containerName, QVariant(containerName)); } //sample rate ui->sampleRateBox->addItem(tr("Default"), QVariant(0)); for (int sampleRate: m_audioRecorder->supportedAudioSampleRates()) { ui->sampleRateBox->addItem(QString::number(sampleRate), QVariant( sampleRate)); } //channels ui->channelsBox->addItem(tr("Default"), QVariant(-1)); ui->channelsBox->addItem(QStringLiteral("1"), QVariant(1)); ui->channelsBox->addItem(QStringLiteral("2"), QVariant(2)); ui->channelsBox->addItem(QStringLiteral("4"), QVariant(4)); //quality ui->qualitySlider->setRange(0, int(QMultimedia::VeryHighQuality)); ui->qualitySlider->setValue(int(QMultimedia::NormalQuality)); //bitrates: ui->bitrateBox->addItem(tr("Default"), QVariant(0)); ui->bitrateBox->addItem(QStringLiteral("32000"), QVariant(32000)); ui->bitrateBox->addItem(QStringLiteral("64000"), QVariant(64000)); ui->bitrateBox->addItem(QStringLiteral("96000"), QVariant(96000)); ui->bitrateBox->addItem(QStringLiteral("128000"), QVariant(128000)); connect(m_audioRecorder, &QAudioRecorder::durationChanged, this, &AudioRecorder::updateProgress); connect(m_audioRecorder, &QAudioRecorder::statusChanged, this, &AudioRecorder::updateStatus); connect(m_audioRecorder, &QAudioRecorder::stateChanged, this, &AudioRecorder::onStateChanged); connect(m_audioRecorder, QOverload<QMediaRecorder::Error>::of(&QAudioRecorder::error), this, &AudioRecorder::displayErrorMessage); } void AudioRecorder::updateProgress(qint64 duration) { if (m_audioRecorder->error() != QMediaRecorder::NoError || duration < 2000) return; ui->statusbar->showMessage(tr("Recorded %1 sec").arg(duration / 1000)); } void AudioRecorder::updateStatus(QMediaRecorder::Status status) { QString statusMessage; switch (status) { case QMediaRecorder::RecordingStatus: statusMessage = tr("Recording to %1").arg(m_audioRecorder->actualLocation().toString()); break; case QMediaRecorder::PausedStatus: clearAudioLevels(); statusMessage = tr("Paused"); break; case QMediaRecorder::UnloadedStatus: case QMediaRecorder::LoadedStatus: clearAudioLevels(); statusMessage = tr("Stopped"); default: break; } if (m_audioRecorder->error() == QMediaRecorder::NoError) ui->statusbar->showMessage(statusMessage); } void AudioRecorder::onStateChanged(QMediaRecorder::State state) { switch (state) { case QMediaRecorder::RecordingState: ui->recordButton->setText(tr("Stop")); ui->pauseButton->setText(tr("Pause")); break; case QMediaRecorder::PausedState: ui->recordButton->setText(tr("Stop")); ui->pauseButton->setText(tr("Resume")); break; case QMediaRecorder::StoppedState: ui->recordButton->setText(tr("Record")); ui->pauseButton->setText(tr("Pause")); break; } ui->pauseButton->setEnabled(m_audioRecorder->state() != QMediaRecorder::StoppedState); } static QVariant boxValue(const QComboBox *box) { int idx = box->currentIndex(); if (idx == -1) return QVariant(); return box->itemData(idx); } void AudioRecorder::toggleRecord() { if (m_audioRecorder->state() == QMediaRecorder::StoppedState) { m_audioRecorder->setAudioInput(boxValue(ui->audioDeviceBox).toString()); QAudioEncoderSettings settings; settings.setCodec(boxValue(ui->audioCodecBox).toString()); settings.setSampleRate(boxValue(ui->sampleRateBox).toInt()); settings.setBitRate(boxValue(ui->bitrateBox).toInt()); settings.setChannelCount(boxValue(ui->channelsBox).toInt()); settings.setQuality(QMultimedia::EncodingQuality(ui->qualitySlider->value())); settings.setEncodingMode(ui->constantQualityRadioButton->isChecked() ? QMultimedia::ConstantQualityEncoding : QMultimedia::ConstantBitRateEncoding); QString container = boxValue(ui->containerBox).toString(); m_audioRecorder->setEncodingSettings(settings, QVideoEncoderSettings(), container); m_audioRecorder->record(); } else { m_audioRecorder->stop(); } } void AudioRecorder::togglePause() { if (m_audioRecorder->state() != QMediaRecorder::PausedState) m_audioRecorder->pause(); else m_audioRecorder->record(); } void AudioRecorder::setOutputLocation() { #ifdef Q_OS_WINRT // UWP does not allow to store outside the sandbox const QString cacheDir = QStandardPaths::writableLocation(QStandardPaths::CacheLocation); if (!QDir().mkpath(cacheDir)) { qWarning() << "Failed to create cache directory"; return; } QString fileName = cacheDir + QLatin1String("/output.wav"); #else QString fileName = QFileDialog::getSaveFileName(); #endif m_audioRecorder->setOutputLocation(QUrl::fromLocalFile(fileName)); m_outputLocationSet = true; } void AudioRecorder::displayErrorMessage() { ui->statusbar->showMessage(m_audioRecorder->errorString()); } void AudioRecorder::clearAudioLevels() { for (int i = 0; i < m_audioLevels.size(); ++i) m_audioLevels.at(i)->setLevel(0); } // 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); } // returns the audio level for each channel QVector<qreal> getBufferLevels(const QAudioBuffer& buffer) { QVector<qreal> values; if (!buffer.format().isValid() || buffer.format().byteOrder() != QAudioFormat::LittleEndian) return values; if (buffer.format().codec() != "audio/pcm") return values; int channelCount = buffer.format().channelCount(); values.fill(0, channelCount); qreal peak_value = getPeakValue(buffer.format()); if (qFuzzyCompare(peak_value, qreal(0))) return values; switch (buffer.format().sampleType()) { case QAudioFormat::Unknown: case QAudioFormat::UnSignedInt: if (buffer.format().sampleSize() == 32) values = getBufferLevels(buffer.constData<quint32>(), buffer.frameCount(), channelCount); if (buffer.format().sampleSize() == 16) values = getBufferLevels(buffer.constData<quint16>(), buffer.frameCount(), channelCount); if (buffer.format().sampleSize() == 8) values = getBufferLevels(buffer.constData<quint8>(), buffer.frameCount(), channelCount); for (int i = 0; i < values.size(); ++i) values[i] = qAbs(values.at(i) - peak_value / 2) / (peak_value / 2); break; case QAudioFormat::Float: if (buffer.format().sampleSize() == 32) { values = getBufferLevels(buffer.constData<float>(), buffer.frameCount(), channelCount); for (int i = 0; i < values.size(); ++i) values[i] /= peak_value; } break; case QAudioFormat::SignedInt: if (buffer.format().sampleSize() == 32) values = getBufferLevels(buffer.constData<qint32>(), buffer.frameCount(), channelCount); if (buffer.format().sampleSize() == 16) values = getBufferLevels(buffer.constData<qint16>(), buffer.frameCount(), channelCount); if (buffer.format().sampleSize() == 8) values = getBufferLevels(buffer.constData<qint8>(), buffer.frameCount(), channelCount); for (int i = 0; i < values.size(); ++i) values[i] /= peak_value; break; } return values; } template <class T> QVector<qreal> getBufferLevels(const T *buffer, int frames, int channels) { QVector<qreal> max_values; max_values.fill(0, channels); for (int i = 0; i < frames; ++i) { for (int j = 0; j < channels; ++j) { qreal value = qAbs(qreal(buffer[i * channels + j])); if (value > max_values.at(j)) max_values.replace(j, value); } } return max_values; } void AudioRecorder::processBuffer(const QAudioBuffer& buffer) { if (m_audioLevels.count() != buffer.format().channelCount()) { qDeleteAll(m_audioLevels); m_audioLevels.clear(); for (int i = 0; i < buffer.format().channelCount(); ++i) { AudioLevel *level = new AudioLevel(ui->centralwidget); m_audioLevels.append(level); ui->levelsLayout->addWidget(level); } } QVector<qreal> levels = getBufferLevels(buffer); for (int i = 0; i < levels.count(); ++i) m_audioLevels.at(i)->setLevel(levels.at(i)); }

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