参考了：http://www.codeguru.com/forum/showthread.php?t=132649

CWave CWave::Mix(LPCTSTR bkWav)

{

CWave wavBK(bkWav);

int iTrackLenth;

int iHeaderLen = 46;

iTrackLenth = data.dataSIZE;

CWave ret_val;

ret_val.fmt = fmt;

ret_val.riff = riff;

ret_val.data = data;

ret_val.data.dataSIZE= data.dataSIZE;

ret_val.riff.riffSIZE = data.dataSIZE + iHeaderLen - 8;

ret_val.extraParamLength = extraParamLength;

ret_val.extraParam = extraParam;

ret_val.wave = new BYTE[iTrackLenth];

memcpy(ret_val.wave,wave,iTrackLenth);

//Mix Audio

int nBytePerSnd = fmt.nAvgBytesPerSec;

int nDataSizeSrc = data.dataSIZE;

int nDataSizeBK = wavBK.data.dataSIZE;

BYTE *sb1=0,*sb2=0;

sb1 = new BYTE[1];

sb2 = new BYTE[1];

int nBeginPos(0),nCnt(0);

int nUnitLen;

nUnitLen = sizeof(BYTE);

int nData1,nData2;

while(1)

{

if(nCnt >= nDataSizeBK)

break;

if(nCnt >= nDataSizeSrc)

break;

memcpy(sb1,ret_val.wave + nBeginPos + nUnitLen * nCnt,nUnitLen);

memcpy(sb2,wavBK.wave + nUnitLen * nCnt,nUnitLen);

nData1 = (int)sb1[0];

nData2 = (int)sb2[0];

sb1[0] = (nData1 + nData2) / 2;

memcpy(ret_val.wave + nBeginPos + nUnitLen * nCnt,sb1,nUnitLen);

nCnt ++;

}

delete []sb1;

delete []sb2;

//Mix end

string folder = getFileFolder(fileName);

ret_val.fileName = folder;

ret_val.fileName.append("2");

ret_val.fileName.append(".wav");

return ret_val;

}