这里完全是照搬帮助文档中的代码生成的程序
上预览图
工程文件代码
#-------------------------------------------------
#
# Project created by QtCreator 2017-02-06T13:52:31
#
#-------------------------------------------------
QT += core gui
QT += charts multimedia
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
TARGET = qchart_Audio_Project
TEMPLATE = app
DEFINES += QT_DEPRECATED_WARNINGS
SOURCES += main.cpp\
widget.cpp \
xyseriesiodevice.cpp
HEADERS += widget.h \
xyseriesiodevice.h
FORMS += widget.ui
target.path = $$[QT_INSTALL_EXAMPLES]/charts/audio
INSTALLS += target
widget.h文件代码
#ifndef WIDGET_H
#define WIDGET_H
#include <QWidget>
#include <QtCharts/QChartGlobal>
namespace Ui {
class Widget;
}
QT_CHARTS_BEGIN_NAMESPACE
class QLineSeries;
class QChart;
QT_CHARTS_END_NAMESPACE
QT_CHARTS_USE_NAMESPACE
class XYSeriesIODevice;
class QAudioInput;
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
private:
Ui::Widget *ui;
XYSeriesIODevice *m_device;
QChart *m_chart;
QLineSeries *m_series;
QAudioInput *m_audioInput;
};
#endif // WIDGET_H
widget.cpp代码
#include "widget.h"
#include <QtMultimedia/QAudioDeviceInfo>
#include <QtMultimedia/QAudioInput>
#include <QtMultimedia/QAudioFormat>
#include <QtCharts/QChartView>
#include <QtCharts/QLineSeries>
#include <QtCharts/QChart>
#include <QtWidgets/QVBoxLayout>
#include <QtCharts/QValueAxis>
#include "xyseriesiodevice.h"
#include "ui_widget.h"
QT_CHARTS_USE_NAMESPACE
Widget::Widget(QWidget *parent) :
QWidget(parent),m_device(0),
m_chart(0),
m_series(0),
m_audioInput(0),
ui(new Ui::Widget)
{
ui->setupUi(this);
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();
delete ui;
}
xyseriesiodevice.h代码
#ifndef XYSERIESIODEVICE_H
#define XYSERIESIODEVICE_H
#include <QtCore/QIODevice>
#include <QtCharts/QChartGlobal>
QT_CHARTS_BEGIN_NAMESPACE
class QXYSeries;
QT_CHARTS_END_NAMESPACE
QT_CHARTS_USE_NAMESPACE
class XYSeriesIODevice : public QIODevice
{
Q_OBJECT
public:
explicit XYSeriesIODevice(QXYSeries * series, QObject *parent = 0);
protected:
qint64 readData(char * data, qint64 maxSize);
qint64 writeData(const char * data, qint64 maxSize);
private:
QXYSeries *m_series;
};
#endif // XYSERIESIODEVICE_H
xyseriesiodevice.cpp代码
#include "xyseriesiodevice.h"
#include <QtCharts/QXYSeries>
XYSeriesIODevice::XYSeriesIODevice(QXYSeries * series, QObject *parent) :
QIODevice(parent),
m_series(series)
{
}
qint64 XYSeriesIODevice::readData(char * data, qint64 maxSize)
{
Q_UNUSED(data)
Q_UNUSED(maxSize)
return -1;
}
qint64 XYSeriesIODevice::writeData(const char * data, qint64 maxSize)
{
qint64 range = 2000;
QVector<QPointF> oldPoints = m_series->pointsVector();
QVector<QPointF> points;
int resolution = 4;
if (oldPoints.count() < range) {
points = m_series->pointsVector();
} else {
for (int i = maxSize/resolution; i < oldPoints.count(); i++)
points.append(QPointF(i - maxSize/resolution, oldPoints.at(i).y()));
}
qint64 size = points.count();
for (int k = 0; k < maxSize/resolution; k++)
points.append(QPointF(k + size, ((quint8)data[resolution * k] - 128)/128.0));
m_series->replace(points);
return maxSize;
}