widget.cpp Example File

audio/widget.cpp
 /****************************************************************************
 **
 ** Copyright (C) 2016 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the Qt Charts module of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:GPL$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and The Qt Company. For licensing terms
 ** and conditions see https://www.qt.io/terms-conditions. For further
 ** information use the contact form at https://www.qt.io/contact-us.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3 or (at your option) any later version
 ** approved by the KDE Free Qt Foundation. The licenses are as published by
 ** the Free Software Foundation and appearing in the file LICENSE.GPL3
 ** included in the packaging of this file. Please review the following
 ** information to ensure the GNU General Public License requirements will
 ** be met: https://www.gnu.org/licenses/gpl-3.0.html.
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "widget.h"
 #include "xyseriesiodevice.h"

 #include <QtMultimedia/QAudioDeviceInfo>
 #include <QtMultimedia/QAudioInput>

 #include <QtCharts/QChartView>
 #include <QtCharts/QLineSeries>
 #include <QtCharts/QChart>
 #include <QtCharts/QValueAxis>

 #include <QtWidgets/QVBoxLayout>

 QT_CHARTS_USE_NAMESPACE

 Widget::Widget(const QAudioDeviceInfo &deviceInfo, QWidget *parent) :
     QWidget(parent),
     m_chart(new QChart),
     m_series(new QLineSeries)
 {
     QChartView *chartView = new QChartView(m_chart);
     chartView->setMinimumSize(800, 600);
     m_chart->addSeries(m_series);
     QValueAxis *axisX = new QValueAxis;
     axisX->setRange(0, XYSeriesIODevice::sampleCount);
     axisX->setLabelFormat("%g");
     axisX->setTitleText("Samples");
     QValueAxis *axisY = new QValueAxis;
     axisY->setRange(-1, 1);
     axisY->setTitleText("Audio level");
     m_chart->addAxis(axisX, Qt::AlignBottom);
     m_series->attachAxis(axisX);
     m_chart->addAxis(axisY, Qt::AlignLeft);
     m_series->attachAxis(axisY);
     m_chart->legend()->hide();
     m_chart->setTitle("Data from the microphone (" + deviceInfo.deviceName() + ')');

     QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->addWidget(chartView);

     QAudioFormat formatAudio;
     formatAudio.setSampleRate(8000);
     formatAudio.setChannelCount(1);
     formatAudio.setSampleSize(8);
     formatAudio.setCodec("audio/pcm");
     formatAudio.setByteOrder(QAudioFormat::LittleEndian);
     formatAudio.setSampleType(QAudioFormat::UnSignedInt);

     m_audioInput = new QAudioInput(deviceInfo, formatAudio, this);

     m_device = new XYSeriesIODevice(m_series, this);
     m_device->open(QIODevice::WriteOnly);

     m_audioInput->start(m_device);
 }

 Widget::~Widget()
 {
     m_audioInput->stop();
     m_device->close();
 }