audiorecorder.cpp Example File
audiorecorder/audiorecorder.cpp
#include <QAudioProbe>
#include <QAudioRecorder>
#include <QDir>
#include <QFileDialog>
#include <QMediaRecorder>
#include "audiorecorder.h"
#if defined(Q_WS_MAEMO_6)
#include "ui_audiorecorder_small.h"
#else
#include "ui_audiorecorder.h"
#endif
static qreal getPeakValue(const QAudioFormat &format);
static qreal getBufferLevel(const QAudioBuffer &buffer);
template <class T>
static qreal getBufferLevel(const T *buffer, int samples);
AudioRecorder::AudioRecorder(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::AudioRecorder),
outputLocationSet(false)
{
ui->setupUi(this);
audioRecorder = new QAudioRecorder(this);
probe = new QAudioProbe;
connect(probe, SIGNAL(audioBufferProbed(QAudioBuffer)), this, SLOT(processBuffer(QAudioBuffer)));
probe->setSource(audioRecorder);
ui->audioDeviceBox->addItem(tr("Default"), QVariant(QString()));
foreach (const QString &device, audioRecorder->audioInputs()) {
ui->audioDeviceBox->addItem(device, QVariant(device));
}
ui->audioCodecBox->addItem(tr("Default"), QVariant(QString()));
foreach (const QString &codecName, audioRecorder->supportedAudioCodecs()) {
ui->audioCodecBox->addItem(codecName, QVariant(codecName));
}
ui->containerBox->addItem(tr("Default"), QVariant(QString()));
foreach (const QString &containerName, audioRecorder->supportedContainers()) {
ui->containerBox->addItem(containerName, QVariant(containerName));
}
ui->sampleRateBox->addItem(tr("Default"), QVariant(0));
foreach (int sampleRate, audioRecorder->supportedAudioSampleRates()) {
ui->sampleRateBox->addItem(QString::number(sampleRate), QVariant(
sampleRate));
}
ui->qualitySlider->setRange(0, int(QMultimedia::VeryHighQuality));
ui->qualitySlider->setValue(int(QMultimedia::NormalQuality));
ui->bitrateBox->addItem(QString("Default"), QVariant(0));
ui->bitrateBox->addItem(QString("32000"), QVariant(32000));
ui->bitrateBox->addItem(QString("64000"), QVariant(64000));
ui->bitrateBox->addItem(QString("96000"), QVariant(96000));
ui->bitrateBox->addItem(QString("128000"), QVariant(128000));
connect(audioRecorder, SIGNAL(durationChanged(qint64)), this,
SLOT(updateProgress(qint64)));
connect(audioRecorder, SIGNAL(stateChanged(QMediaRecorder::State)), this,
SLOT(updateState(QMediaRecorder::State)));
connect(audioRecorder, SIGNAL(error(QMediaRecorder::Error)), this,
SLOT(displayErrorMessage()));
}
AudioRecorder::~AudioRecorder()
{
delete audioRecorder;
delete probe;
}
void AudioRecorder::updateProgress(qint64 duration)
{
if (audioRecorder->error() != QMediaRecorder::NoError || duration < 2000)
return;
ui->statusbar->showMessage(tr("Recorded %1 sec").arg(duration / 1000));
}
void AudioRecorder::updateState(QMediaRecorder::State state)
{
QString statusMessage;
switch (state) {
case QMediaRecorder::RecordingState:
ui->recordButton->setText(tr("Stop"));
ui->pauseButton->setText(tr("Pause"));
if (audioRecorder->outputLocation().isEmpty())
statusMessage = tr("Recording");
else
statusMessage = tr("Recording to %1").arg(
audioRecorder->outputLocation().toString());
break;
case QMediaRecorder::PausedState:
ui->recordButton->setText(tr("Stop"));
ui->pauseButton->setText(tr("Resume"));
statusMessage = tr("Paused");
break;
case QMediaRecorder::StoppedState:
ui->recordButton->setText(tr("Record"));
ui->pauseButton->setText(tr("Pause"));
statusMessage = tr("Stopped");
}
ui->pauseButton->setEnabled(state != QMediaRecorder::StoppedState);
if (audioRecorder->error() == QMediaRecorder::NoError)
ui->statusbar->showMessage(statusMessage);
}
static QVariant boxValue(const QComboBox *box)
{
int idx = box->currentIndex();
if (idx == -1)
return QVariant();
return box->itemData(idx);
}
void AudioRecorder::toggleRecord()
{
if (audioRecorder->state() == QMediaRecorder::StoppedState) {
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.setQuality(QMultimedia::EncodingQuality(ui->qualitySlider->value()));
settings.setEncodingMode(ui->constantQualityRadioButton->isChecked() ?
QMultimedia::ConstantQualityEncoding :
QMultimedia::ConstantBitRateEncoding);
QString container = boxValue(ui->containerBox).toString();
audioRecorder->setEncodingSettings(settings, QVideoEncoderSettings(), container);
audioRecorder->record();
}
else {
audioRecorder->stop();
}
}
void AudioRecorder::togglePause()
{
if (audioRecorder->state() != QMediaRecorder::PausedState)
audioRecorder->pause();
else
audioRecorder->record();
}
void AudioRecorder::setOutputLocation()
{
QString fileName = QFileDialog::getSaveFileName();
audioRecorder->setOutputLocation(QUrl(fileName));
outputLocationSet = true;
}
void AudioRecorder::displayErrorMessage()
{
ui->statusbar->showMessage(audioRecorder->errorString());
}
qreal getPeakValue(const QAudioFormat& format)
{
if (!format.isValid())
return 0.0;
if (format.codec() != "audio/pcm")
return 0.0;
switch (format.sampleType()) {
case QAudioFormat::Unknown:
break;
case QAudioFormat::Float:
if (format.sampleSize() != 32)
return 0.0;
return 1.00003;
case QAudioFormat::SignedInt:
if (format.sampleSize() == 32)
return 2147483648.0;
if (format.sampleSize() == 16)
return 32768.0;
if (format.sampleSize() == 8)
return 128.0;
break;
case QAudioFormat::UnSignedInt:
break;
}
return 0.0;
}
qreal getBufferLevel(const QAudioBuffer& buffer)
{
if (!buffer.format().isValid() || buffer.format().byteOrder() != QAudioFormat::LittleEndian)
return 0.0;
if (buffer.format().codec() != "audio/pcm")
return 0.0;
qreal peak_value = getPeakValue(buffer.format());
if (qFuzzyCompare(peak_value, 0.0))
return 0.0;
switch (buffer.format().sampleType()) {
case QAudioFormat::Unknown:
case QAudioFormat::UnSignedInt:
break;
case QAudioFormat::Float:
if (buffer.format().sampleSize() == 32)
return getBufferLevel(buffer.constData<float>(), buffer.sampleCount()) / peak_value;
break;
case QAudioFormat::SignedInt:
if (buffer.format().sampleSize() == 32)
return getBufferLevel(buffer.constData<long int>(), buffer.sampleCount()) / peak_value;
if (buffer.format().sampleSize() == 16)
return getBufferLevel(buffer.constData<short int>(), buffer.sampleCount()) / peak_value;
if (buffer.format().sampleSize() == 8)
return getBufferLevel(buffer.constData<signed char>(), buffer.sampleCount()) / peak_value;
break;
}
return 0.0;
}
template <class T>
qreal getBufferLevel(const T *buffer, int samples)
{
qreal max_value = 0.0;
for (int i = 0; i < samples; ++i) {
qreal value = qAbs(qreal(buffer[i]));
if (value > max_value)
max_value = value;
}
return max_value;
}
void AudioRecorder::processBuffer(const QAudioBuffer& buffer)
{
qreal level = getBufferLevel(buffer);
ui->audioLevel->setLevel(level);
}