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Audio recorder example updated to display level using QAudioProbe.

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Change-Id: I7d5aea306aeb3cd9109615f9ed4905c53125233a
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>
This commit is contained in:
Lev Zelenskiy
2012-02-21 17:35:51 +10:00
committed by Qt by Nokia
parent 03a14a95fe
commit b37ea41ce1
6 changed files with 251 additions and 4 deletions
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93
examples/audiorecorder/audiorecorder.cpp
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@@ -43,6 +43,7 @@
#include <qaudiorecorder.h>
#include <qmediarecorder.h>
#include <qaudioprobe.h>
#include "audiorecorder.h"
@@ -61,6 +62,9 @@ AudioRecorder::AudioRecorder(QWidget *parent)
ui->setupUi(this);
audioRecorder = new QAudioRecorder(this);
probe = new QAudioProbe;
connect(probe, SIGNAL(audioBufferProbed(const QAudioBuffer&)), this, SLOT(processBuffer(QAudioBuffer)));
probe->setSource(audioRecorder);
//audio devices
ui->audioDeviceBox->addItem(tr("Default"), QVariant(QString()));
@@ -103,11 +107,12 @@ AudioRecorder::AudioRecorder(QWidget *parent)
SLOT(updateState(QMediaRecorder::State)));
connect(audioRecorder, SIGNAL(error(QMediaRecorder::Error)), this,
SLOT(displayErrorMessage()));
}
}
AudioRecorder::~AudioRecorder()
{
delete audioRecorder;
delete probe;
}
void AudioRecorder::updateProgress(qint64 duration)
@@ -221,3 +226,89 @@ QUrl AudioRecorder::generateAudioFilePath()
QUrl location(QDir::toNativeSeparators(outputDir.canonicalPath() + QString("/testclip_%1").arg(lastImage + 1, 4, 10, QLatin1Char('0'))));
return location;
}
// This function returns the maximum possible sample value for a given audio format
qreal AudioRecorder::GetPeakValue(const QAudioFormat& format)
{
// Note: Only the most common sample formats are supported
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) // other sample formats are not supported
return 0.0;
return 1.00003;
case QAudioFormat::SignedInt:
if (format.sampleSize() == 32)
return 2147483648.0;
else if (format.sampleSize() == 16)
return 32768.0;
else if (format.sampleSize() == 8)
return 128.0;
break;
case QAudioFormat::UnSignedInt:
// Unsigned formats are not supported in this example
break;
}
return 0.0;
}
qreal AudioRecorder::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;
else if (buffer.format().sampleSize() == 16)
return GetBufferLevel(buffer.constData<short int>(), buffer.sampleCount()) / peak_value;
else if (buffer.format().sampleSize() == 8)
return GetBufferLevel(buffer.constData<signed char>(), buffer.sampleCount()) / peak_value;
break;
}
return 0.0;
}
template <class T>
qreal AudioRecorder::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);
}

13
examples/audiorecorder/audiorecorder.h
View File

@@ -54,6 +54,8 @@ namespace Ui {
}
class QAudioRecorder;
class QAudioProbe;
class QAudioBuffer;
QT_END_NAMESPACE
QT_USE_NAMESPACE
@@ -65,6 +67,9 @@ public:
AudioRecorder(QWidget *parent = 0);
~AudioRecorder();
public slots:
void processBuffer(const QAudioBuffer&);
private slots:
void setOutputLocation();
void togglePause();
@@ -76,10 +81,16 @@ private slots:
QUrl generateAudioFilePath();
private:
static qreal GetPeakValue(const QAudioFormat& format);
static qreal GetBufferLevel(const QAudioBuffer& buffer);
template <class T>
static qreal GetBufferLevel(const T* buffer, int samples);
Ui::AudioRecorder *ui;
QAudioRecorder* audioRecorder;
QAudioEncoderSettings audioSettings;
QAudioProbe* probe;
bool outputLocationSet;
};

6
examples/audiorecorder/audiorecorder.pro
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@@ -4,11 +4,13 @@ TARGET = audiorecorder
QT += multimedia
HEADERS = \
audiorecorder.h
audiorecorder.h \
qaudiolevel.h
SOURCES = \
main.cpp \
audiorecorder.cpp
audiorecorder.cpp \
qaudiolevel.cpp
maemo*: {
FORMS += audiorecorder_small.ui

11
examples/audiorecorder/audiorecorder.ui
View File

@@ -155,6 +155,17 @@
</property>
</widget>
</item>
<item row="3" column="0">
<widget class="QLabel" name="levelLabel">
<property name="text">
<string>Audio Level:</string>
</property>
</widget>
</item>
<item row="3" column="1" colspan="-1">
<widget class="QAudioLevel" name="audioLevel">
</widget>
</item>
</layout>
</widget>
<widget class="QStatusBar" name="statusbar"/>

68
examples/audiorecorder/qaudiolevel.cpp Normal file
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@@ -0,0 +1,68 @@
/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qaudiolevel.h"
#include <QPainter>
QAudioLevel::QAudioLevel(QWidget *parent)
: QWidget(parent)
, m_level(0.0)
{
}
void QAudioLevel::setLevel(qreal level)
{
if (m_level != level) {
m_level = level;
update();
}
}
void QAudioLevel::paintEvent(QPaintEvent *event)
{
Q_UNUSED(event);
QPainter painter(this);
// draw level
qreal widthLevel = m_level * width();
painter.fillRect(0, 0, widthLevel, height(), Qt::red);
// clear the rest of the control
painter.fillRect(widthLevel, 0, width(), height(), Qt::black);
}

64
examples/audiorecorder/qaudiolevel.h Normal file
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@@ -0,0 +1,64 @@
/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
** the names of its contributors may be used to endorse or promote
** products derived from this software without specific prior written
** permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#ifndef QAUDIOLEVEL_H
#define QAUDIOLEVEL_H
#include <QWidget>
QT_USE_NAMESPACE
class QAudioLevel : public QWidget
{
Q_OBJECT
public:
explicit QAudioLevel(QWidget *parent = 0);
// Using [0; 1.0] range
void setLevel(qreal level);
protected:
void paintEvent(QPaintEvent *event);
private:
qreal m_level;
};
#endif // QAUDIOLEVEL_H