waveout**实现音频播放

来源：互联网发布：易高网络招聘平台编辑：程序博客网时间：2024/05/22 14:55

最近想做一个播放，折腾了1周也没什么效果，最近在互联网上发现篇关于Waveout系

列API实现音频播放器，收获还算不少。

一、初始化设备

bool WinAudioPlay::DevOpen()

{

if (!m_bPalyStata)

{

WAVEFORMATEX wfx;

ZeroMemory(&wfx,sizeof(WAVEFORMATEX));

wfx.wFormatTag = WAVE_FORMAT_PCM;

wfx.nChannels = 2;

wfx.nSamplesPerSec = 44100L;

wfx.wBitsPerSample = 16;

wfx.cbSize = 0;

wfx.nBlockAlign = wfx.wBitsPerSample * wfx.nChannels / 8;

wfx.nAvgBytesPerSec = wfx.nChannels * wfx.nSamplesPerSec * wfx.wBitsPerSample / 8;

if(::waveOutOpen (0,0,&wfx,0,0,WAVE_FORMAT_QUERY))

{

Plug::PlugMessageBox(L"wave设备初始化失败～");

return false;

}

if (::waveOutOpen(&m_hWaveOut, WAVE_MAPPER, &wfx, (DWORD)&WinAudioPlay::waveOutProc, (DWORD)this, CALLBACK_FUNCTION))

{

Plug::PlugMessageBox(L"wave设备初始化失败～");

return false;

}

m_iBlockNum = 0;

m_bPalyStata = true;

m_spbrTgthr.reset(new boost::barrier(2));

m_sptrdWaveOutTgthr.reset(new boost::thread(boost::bind(&WinAudioPlay::ThrdWaveOutTogether,this)));

}

return true;

}

二、接收pcm格式数据，并加载到声卡缓冲区

bool __stdcall WinAudioPlay::play_audio( const void* buffer, int len )

{

if (!m_bPalyStata)

return false;

if (BLOCK_MAX <= m_iBlockNum || len <= 0)

{

return true; //超过缓冲最大包，不继续播放

}

LPWAVEHDR pWaveHeader = new WAVEHDR;

memset(pWaveHeader, 0, sizeof(WAVEHDR));

pWaveHeader->dwLoops = 1;

pWaveHeader->dwBufferLength = len;

pWaveHeader->lpData = new char[len];

if (!pWaveHeader->lpData)

{

delete pWaveHeader;

return false;

}

memcpy(pWaveHeader->lpData, buffer, len);

if (::waveOutPrepareHeader(m_hWaveOut, pWaveHeader, sizeof(WAVEHDR)))

{

delete pWaveHeader->lpData;

delete pWaveHeader;

return false;

}

if (::waveOutWrite(m_hWaveOut, pWaveHeader, sizeof(WAVEHDR)))

{

delete pWaveHeader->lpData;

delete pWaveHeader;

return false;

}

m_iBlockNum++;

return true;

}

三、回调函数

void CALLBACK WinAudioPlay::waveOutProc( HWAVEOUT hwo, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2 )

{

WinAudioPlay* pThis=(WinAudioPlay*)dwInstance;

if(WOM_DONE == uMsg) //播放完成

{

while(NULL != pThis->m_lpWaveHdrFromCallbackProc)

{

boost::this_thread::interruptible_wait(1);

}

pThis->m_lpWaveHdrFromCallbackProc = (LPWAVEHDR)dwParam1;

pThis->m_spbrTgthr->wait();

}

return ;

}

四、线程同步播放

void WinAudioPlay::ThrdWaveOutTogether()

{

while(!m_b_exit)

{

m_spbrTgthr->wait();

if (NULL != m_lpWaveHdrFromCallbackProc)

{

::waveOutUnprepareHeader(m_hWaveOut, m_lpWaveHdrFromCallbackProc, sizeof(WAVEHDR));

delete[] m_lpWaveHdrFromCallbackProc->lpData;

delete m_lpWaveHdrFromCallbackProc;

m_lpWaveHdrFromCallbackProc = NULL;

(m_iBlockNum > 0)?(m_iBlockNum--):(m_iBlockNum = 0);

}

if (m_hWaveOut != NULL)

{

::waveOutReset(m_hWaveOut);

::waveOutClose(m_hWaveOut);

}

五、关闭线程，释放资源

WinAudioPlay::~WinAudioPlay()

{

m_bPalyStata = false;

while(0 != m_iBlockNum)

{

Sleep(1);

}

m_b_exit = true;

m_spbrTgthr->wait();

m_sptrdWaveOutTgthr->join();

}

但是需要注意以下几点：

一、waveOutProc回调函数中绝对不能调用waveOut系列函数（可用线程同步实现通知在另一个线程调用）

二、调用waveOutReset函数时，函数执行完毕才返回，期间不可以调用hWaveOut

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