利用waveIn完成简单录音（录成wav）

1. 设置采集音频格式

   WAVEFORMATEX waveform; //采集音频的格式，结构体
   waveform.wFormatTag = WAVE_FORMAT_PCM;//声音格式为PCM
   waveform.nSamplesPerSec = 8000;//采样率，16000次/秒
   waveform.wBitsPerSample = 16;//采样比特，16bits/次
   waveform.nChannels = 1;//采样声道数，2声道
   waveform.nAvgBytesPerSec = 16000;//每秒的数据率，就是每秒能采集多少字节的数据
   waveform.nBlockAlign = 2;//一个块的大小，采样bit的字节数乘以声道数
   waveform.cbSize = 0;//一般为0

   
   
2. 提前准备好的录音数据缓存

   m_pRecoderBuf = new unsigned char[20 * 1024];
   m_recoderNum = 20;
   m_recoderBufLen = 20 * 1024;
   m_pWaveHdr	= new WAVEHDR[20];
   memset(m_pRecoderBuf, 0, 20 * 1024);
   memset(m_pWaveHdr, 0, sizeof(WAVEHDR) * 20);

   
   
3. 打开录音设备

   MMRESULT mmres = waveInOpen(&m_hWaveIn, WAVE_MAPPER, &waveform, (DWORD_PTR)WaveInProc, (DWORD_PTR)this, CALLBACK_FUNCTION );
   	
   if(mmres != MMSYSERR_NOERROR)
   {
   	// failed, try again.
   	return;
   }

   WAVE_MAPPER表示系统会自己寻找合适的录音设备。
4. 准备数据空间

   for (int i = 0; i < m_recoderNum; ++i)
   {
   	m_pWaveHdr[i].lpData = (char*)m_pRecoderBuf + i * 1024;
   	m_pWaveHdr[i].dwBufferLength = 1024;
   	mmres = waveInPrepareHeader(m_hWaveIn, &m_pWaveHdr[i], sizeof(WAVEHDR));
   	mmres = waveInAddBuffer(m_hWaveIn, &m_pWaveHdr[i], sizeof(WAVEHDR));
   }

   
   
   
5. 开始录音并打开写文件

   mmres = waveInStart(m_hWaveIn);
   
   SYSTEMTIME systemtime;
   GetLocalTime(&systemtime);
   char filename[256];
   sprintf_s(filename, 256, "%d-%d-%d_%d_%d_%d.wav", systemtime.wYear, systemtime.wMonth, systemtime.wDay, systemtime.wHour, systemtime.wMinute, systemtime.wSecond);
   m_pWavFile = wav_write_open(filename, 8000, 16, 1);

   
   
6. 要提前定义好数据接收回调函数，因为我们用的是CALLBACK_FUNCTION

   static BOOL CALLBACK WaveInProc(HWAVEOUT hwo, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2);
   BOOL   WaveInProcImpl(HWAVEOUT hwo, UINT uMsg, DWORD dwParam1, DWORD dwParam2);

   函数里的处理是：

   BOOL CAudioFileConvertDlg::WaveInProc(HWAVEOUT hwo, UINT uMsg, DWORD dwInstance, DWORD dwParam1, DWORD dwParam2)
   {
   	CAudioFileConvertDlg* pPlayer = (CAudioFileConvertDlg*)dwInstance;
   
   	return pPlayer->WaveInProcImpl(hwo, uMsg, dwParam1, dwParam2);
   }
   
   BOOL CAudioFileConvertDlg::WaveInProcImpl(HWAVEOUT hwo, UINT uMsg, DWORD dwParam1, DWORD dwParam2)
   {
   	// 忽略打开和关闭设备时的处理
   	if(uMsg == WIM_DATA)
   	{
   		LPWAVEHDR pHdr = (LPWAVEHDR) dwParam1;
   
   		MMRESULT mmres = waveInUnprepareHeader (m_hWaveIn, pHdr, sizeof(WAVEHDR));
   		//处理数据 
   		if (NULL != m_pWavFile)
   		{
   			wav_write_data(m_pWavFile, (unsigned char *)(pHdr->lpData), pHdr->dwBytesRecorded);
   		}
   		//重新准备数据
   		mmres = waveInPrepareHeader(m_hWaveIn, pHdr, sizeof(WAVEHDR));
   		mmres = waveInAddBuffer(m_hWaveIn, pHdr, sizeof(WAVEHDR));
   	}
   
   	return TRUE;
   }

   
   
7. 关闭录音并关闭wav写文件

   MMRESULT mmres = waveInStop(m_hWaveIn);
   mmres = waveInClose(m_hWaveIn);
   wav_write_close(m_pWavFile);
   if (NULL != m_pRecoderBuf)
   {
   	delete []m_pRecoderBuf;
   	m_pRecoderBuf = NULL;
   }
   
   if (NULL != m_pWaveHdr)
   {
   	delete []m_pWaveHdr;
   	m_pWaveHdr = NULL;
   }

   简单在此记录下备忘