Windows WaveIn 录音

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;
   }