Qt 5.9 | Qt Charts | Audio Example | widget.cpp Example File

Qt 5.9.3 Reference Documentation

# widget.cpp Example File

audio/widget.cpp

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      ** Contact: https://www.qt.io/licensing/
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      ** This file is part of the Qt Charts module of the Qt Toolkit.
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      #include "widget.h"
      #include <QtMultimedia/QAudioDeviceInfo>
      #include <QtMultimedia/QAudioInput>
      #include <QtCharts/QChartView>
      #include <QtCharts/QLineSeries>
      #include <QtCharts/QChart>
      #include <QtWidgets/QVBoxLayout>
      #include <QtCharts/QValueAxis>
      #include "xyseriesiodevice.h"

      QT_CHARTS_USE_NAMESPACE

      Widget::Widget(QWidget *parent)
          : QWidget(parent),
            m_device(0),
            m_chart(0),
            m_series(0),
            m_audioInput(0)
      {
          m_chart = new QChart;
          QChartView *chartView = new QChartView(m_chart);
          chartView->setMinimumSize(800, 600);
          m_series = new QLineSeries;
          m_chart->addSeries(m_series);
          QValueAxis *axisX = new QValueAxis;
          axisX->setRange(0, 2000);
          axisX->setLabelFormat("%g");
          axisX->setTitleText("Samples");
          QValueAxis *axisY = new QValueAxis;
          axisY->setRange(-1, 1);
          axisY->setTitleText("Audio level");
          m_chart->setAxisX(axisX, m_series);
          m_chart->setAxisY(axisY, m_series);
          m_chart->legend()->hide();
          m_chart->setTitle("Data from the microphone");

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

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

          QAudioDeviceInfo inputDevices = QAudioDeviceInfo::defaultInputDevice();
          m_audioInput = new QAudioInput(inputDevices,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();
      }