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;
}