我正在尝试每 20 毫秒写入一次 QAudioOutput 的缓冲区。当我尝试执行此代码时,我可以看到进程的大小每秒增加约 4-8 kB。我试图找到一些函数来清除 QIODevice 或 DAudioOuptut 的内部缓冲区,但没有运气。
我正在使用 Qt 5.2.1
在下面的示例中,仅写入了静音(零),但具有相同的效果:
#include <QLibraryInfo>
#include <QtCore/QCoreApplication>
#include <windows.h> // for Sleep
#include <QAudioOutput>
#include <QAudioDeviceInfo>
#include <QAudioFormat>
#include <array>
class QAudioOutput;
int main(int argc, char *argv[])
{
// Create QApplication
QCoreApplication app(argc, argv);
app.setApplicationName("Audiotest");
//Initialize device
QIODevice * _output;
QAudioDeviceInfo _device = QAudioDeviceInfo::defaultOutputDevice();
QAudioFormat _format;
_format.setSampleRate(44100);
_format.setChannelCount(2);
_format.setSampleSize(16);
_format.setCodec("audio/pcm"); // This codec should be supported on all platforms and plugin implementation
_format.setByteOrder(QAudioFormat::LittleEndian);
_format.setSampleType(QAudioFormat::SignedInt);
if (!_device.isFormatSupported(_format)) {
printf("Default format not supported - trying to use nearest.\n");
_format = _device.nearestFormat(_format);
}
QAudioOutput * _audioOutput = new QAudioOutput(_device, _format);
_output = _audioOutput->start();
std::array<char, 32768> _buffer;
_buffer.fill(0);
for (;;) {
const int periodSize = _audioOutput->periodSize();
const int chunks = _audioOutput->bytesFree() / periodSize;
for (int i = 0; i < chunks; ++i) {
const qint64 len = periodSize;
if (len && _output) {
_output->write(_buffer.data(), len);
}
if (len != periodSize) {
break;
}
}
Sleep(20);
}
return 0;
}