一.QT6音频调用及与QT5的区别
1.音频输入
QAudioSource代替QAudioInput类
QAudioSource类提供了一个接口，用于从音频输入设备接收音频数据。
Header: #include <QAudioSource>
qmake: QT += multimedia
2.音频输出
QAudioSink代替QAudioOutput类
QAudioSink类提供了一个接口，用于将音频数据发送到音频输出设备。
Header: #include <QAudioSink>
qmake: QT += multimedia
二.代码示例
其功能为本地产生一些声音数据，然后输出到扬声器或者耳机。
可以应用在通过网络接收的声音数据，然后输出到音频播放设备；
代码为纯qt实现，可以应用在windows、linux和android上，无需修改。
1.audiooutput.h
#ifndef AUDIOOUTPUT_H
#define AUDIOOUTPUT_H
#include <QAudioSink>
#include <QByteArray>
#include <QComboBox>
#include <QIODevice>
#include <QLabel>
#include <QMainWindow>
#include <QMediaDevices>
#include <QObject>
#include <QPushButton>
#include <QScopedPointer>
#include <QSlider>
#include <QTimer>
#include <math.h>
class Generator : public QIODevice
{
Q_OBJECT
public:
Generator(const QAudioFormat &format, qint64 durationUs, int sampleRate);
void start();
void stop();
qint64 readData(char *data, qint64 maxlen) override;
qint64 writeData(const char *data, qint64 len) override;
qint64 bytesAvailable() const override;
qint64 size() const override { return m_buffer.size(); }
private:
void generateData(const QAudioFormat &format, qint64 durationUs, int sampleRate);
private:
qint64 m_pos = 0;
QByteArray m_buffer;
};
class AudioTest : public QMainWindow
{
Q_OBJECT
public:
AudioTest();
~AudioTest();
private:
void initializeWindow();
void initializeAudio(const QAudioDevice &deviceInfo);
private:
QMediaDevices *m_devices = nullptr;
QTimer *m_pushTimer = nullptr;
// Owned by layout
QPushButton *m_modeButton = nullptr;
QPushButton *m_suspendResumeButton = nullptr;
QComboBox *m_deviceBox = nullptr;
QLabel *m_volumeLabel = nullptr;
QSlider *m_volumeSlider = nullptr;
QScopedPointer<Generator> m_generator;
QScopedPointer<QAudioSink> m_audioOutput;
bool m_pullMode = true;
private slots:
void toggleMode();
void toggleSuspendResume();
void deviceChanged(int index);
void volumeChanged(int);
void updateAudioDevices();
};
#endif // AUDIOOUTPUT_H
2.audiooutput.cpp
#include "audiooutput.h"
#include <QAudioDevice>
#include <QAudioSink>
#include <QDebug>
#include <QVBoxLayout>
#include <QtEndian>
#include <QtMath>
Generator::Generator(const QAudioFormat &format, qint64 durationUs, int sampleRate)
{
if (format.isValid())
generateData(format, durationUs, sampleRate);
}
void Generator::start()
{
open(QIODevice::ReadOnly);
}
void Generator::stop()
{
m_pos = 0;
close();
}
void Generator::generateData(const QAudioFormat &format, qint64 durationUs, int sampleRate)
{
const int channelBytes = format.bytesPerSample();
const int sampleBytes = format.channelCount() * channelBytes;
qint64 length = format.bytesForDuration(durationUs);
Q_ASSERT(length % sampleBytes == 0);
Q_UNUSED(sampleBytes); // suppress warning in release builds
m_buffer.resize(length);
unsigned char *ptr = reinterpret_cast<unsigned char *>(m_buffer.data());
int sampleIndex = 0;
while (length) {
// Produces value (-1..1)
const qreal x = qSin(2 * M_PI * sampleRate * qreal(sampleIndex++ % format.sampleRate())
/ format.sampleRate());
for (int i = 0; i < format.channelCount(); ++i) {
switch (format.sampleFormat()) {
case QAudioFormat::UInt8:
*reinterpret_cast<quint8 *>(ptr) = static_cast<quint8>((1.0 + x) / 2 * 255);
break;
case QAudioFormat::Int16:
*reinterpret_cast<qint16 *>(ptr) = static_cast<qint16>(x * 32767);
break;
case QAudioFormat::Int32:
*reinterpret_cast<qint32 *>(ptr) =
static_cast<qint32>(x * std::numeric_limits<qint32>::max());
break;
case QAudioFormat::Float:
*reinterpret_cast<float *>(ptr) = x;
break;
default:
break;
}
ptr += channelBytes;
length -= channelBytes;
}
}
}
qint64 Generator::readData(char *data, qint64 len)
{
qint64 total = 0;
if (!m_buffer.isEmpty()) {
while (len - total > 0) {
const qint64 chunk = qMin((m_buffer.size() - m_pos), len - total);
memcpy(data + total, m_buffer.constData() + m_pos, chunk);
m_pos = (m_pos + chunk) % m_buffer.size();
total += chunk;
}
}
return total;
}
qint64 Generator::writeData(const char *data, qint64 len)
{
Q_UNUSED(data);
Q_UNUSED(len);
return 0;
}
qint64 Generator::bytesAvailable() const
{
return m_buffer.size() + QIODevice::bytesAvailable();
}
AudioTest::AudioTest() : m_devices(new QMediaDevices(this)), m_pushTimer(new QTimer(this))
{
initializeWindow();
initializeAudio(m_devices->defaultAudioOutput());
qDebug()<<"11111111111111111111";
}
AudioTest::~AudioTest()
{
m_pushTimer->stop();
}
void AudioTest::initializeWindow()
{
QWidget *window = new QWidget;
QVBoxLayout *layout = new QVBoxLayout;
m_deviceBox = new QComboBox(this);
const QAudioDevice &defaultDeviceInfo = m_devices->defaultAudioOutput();
m_deviceBox->addItem(defaultDeviceInfo.description(), QVariant::fromValue(defaultDeviceInfo));
for (auto &deviceInfo : m_devices->audioOutputs()) {
if (deviceInfo != defaultDeviceInfo)
m_deviceBox->addItem(deviceInfo.description(), QVariant::fromValue(deviceInfo));
}
connect(m_deviceBox, QOverload<int>::of(&QComboBox::activated), this,
&AudioTest::deviceChanged);
connect(m_devices, &QMediaDevices::audioOutputsChanged, this, &AudioTest::updateAudioDevices);
layout->addWidget(m_deviceBox);
m_modeButton = new QPushButton(this);
connect(m_modeButton, &QPushButton::clicked, this, &AudioTest::toggleMode);
layout->addWidget(m_modeButton);
m_suspendResumeButton = new QPushButton(this);
connect(m_suspendResumeButton, &QPushButton::clicked, this, &AudioTest::toggleSuspendResume);
layout->addWidget(m_suspendResumeButton);
QHBoxLayout *volumeBox = new QHBoxLayout;
m_volumeLabel = new QLabel;
m_volumeLabel->setText(tr("Volume:"));
m_volumeSlider = new QSlider(Qt::Horizontal);
m_volumeSlider->setMinimum(0);
m_volumeSlider->setMaximum(100);
m_volumeSlider->setSingleStep(10);
connect(m_volumeSlider, &QSlider::valueChanged, this, &AudioTest::volumeChanged);
volumeBox->addWidget(m_volumeLabel);
volumeBox->addWidget(m_volumeSlider);
layout->addLayout(volumeBox);
window->setLayout(layout);
setCentralWidget(window);
window->show();
}
void AudioTest::initializeAudio(const QAudioDevice &deviceInfo)
{
QAudioFormat format = deviceInfo.preferredFormat();
const int durationSeconds = 1;
const int toneSampleRateHz = 600;
m_generator.reset(new Generator(format, durationSeconds * 1000000, toneSampleRateHz));
m_audioOutput.reset(new QAudioSink(deviceInfo, format));
m_generator->start();
qreal initialVolume = QAudio::convertVolume(m_audioOutput->volume(), QAudio::LinearVolumeScale,
QAudio::LogarithmicVolumeScale);
m_volumeSlider->setValue(qRound(initialVolume * 100));
toggleMode();
}
void AudioTest::deviceChanged(int index)
{
m_generator->stop();
m_audioOutput->stop();
m_audioOutput->disconnect(this);
initializeAudio(m_deviceBox->itemData(index).value<QAudioDevice>());
}
void AudioTest::volumeChanged(int value)
{
qreal linearVolume = QAudio::convertVolume(value / qreal(100), QAudio::LogarithmicVolumeScale,
QAudio::LinearVolumeScale);
m_audioOutput->setVolume(linearVolume);
}
void AudioTest::updateAudioDevices()
{
m_deviceBox->clear();
const QList<QAudioDevice> devices = m_devices->audioOutputs();
for (const QAudioDevice &deviceInfo : devices)
m_deviceBox->addItem(deviceInfo.description(), QVariant::fromValue(deviceInfo));
}
void AudioTest::toggleMode()
{
m_pushTimer->stop();
m_audioOutput->stop();
toggleSuspendResume();
if (m_pullMode) {
// switch to pull mode (QAudioSink pulls from Generator as needed)
m_modeButton->setText(tr("Enable push mode"));
m_audioOutput->start(m_generator.data());
} else {
// switch to push mode (periodically push to QAudioSink using a timer)
m_modeButton->setText(tr("Enable pull mode"));
auto io = m_audioOutput->start();
m_pushTimer->disconnect();
connect(m_pushTimer, &QTimer::timeout, [this, io]() {
if (m_audioOutput->state() == QAudio::StoppedState)
return;
int len = m_audioOutput->bytesFree();
QByteArray buffer(len, 0);
len = m_generator->read(buffer.data(), len);
if (len)
io->write(buffer.data(), len);
});
m_pushTimer->start(10);
}
m_pullMode = !m_pullMode;
}
void AudioTest::toggleSuspendResume()
{
if (m_audioOutput->state() == QAudio::SuspendedState
|| m_audioOutput->state() == QAudio::StoppedState) {
m_audioOutput->resume();
m_suspendResumeButton->setText(tr("Suspend playback"));
} else if (m_audioOutput->state() == QAudio::ActiveState) {
m_audioOutput->suspend();
m_suspendResumeButton->setText(tr("Resume playback"));
} else if (m_audioOutput->state() == QAudio::IdleState) {
// no-op
}
}
3.测试页面
可以选择输出设备，音量调节，停止和继续。
**代码下载地址：**https://download.csdn.net/download/xieliru/89050304
