音频混音算法的实现

最近项目有用到混音算法，这里用比较常见的一种，就是简单的加和之后做一下归一化。

是参考这个博主实现的：
音频混音的算法实现

下面直接贴代码：

#include <stdio.h>  
#include <stdlib.h>  
#include <math.h>  #define IN_FILE1 "mic.wav"  
#define IN_FILE2 "spk.wav"  
#define OUT_FILE "remix.pcm"  #define SIZE_AUDIO_FRAME (2)  void Mix(char sourseFile[10][SIZE_AUDIO_FRAME],int number,char *objectFile)  
{  //归一化混音  int const MAX=32767;  int const MIN=-32768;  double f=1;  int output;  int i = 0,j = 0;  for (i=0;i<SIZE_AUDIO_FRAME/2;i++)  {  int temp=0;  for (j=0;j<number;j++)  {  temp+=*(short*)(sourseFile[j]+i*2);  }                  output=(int)(temp*f);  if (output>MAX)  {  f=(double)MAX/(double)(output);  output=MAX;  }  if (output<MIN)  {  f=(double)MIN/(double)(output);  output=MIN;  }  if (f<1)  {  f+=((double)1-f)/(double)32;  }  *(short*)(objectFile+i*2)=(short)output;  }  
}  int main()  
{  FILE * fp1,*fp2,*fpm;  fp1 = fopen(IN_FILE1,"rb");  fp2 = fopen(IN_FILE2,"rb");  fpm = fopen(OUT_FILE,"wb");  short data1,data2,date_mix;  int ret1,ret2;  char sourseFile[10][2];  while(1)  {  ret1 = fread(&data1,2,1,fp1);  ret2 = fread(&data2,2,1,fp2);  *(short*) sourseFile[0] = data1;  *(short*) sourseFile[1] = data2;  if(ret1>0 && ret2>0)  {  Mix(sourseFile,2,(char *)&date_mix);  if(date_mix > pow(2,16-1) || date_mix < -pow(2,16-1))  printf("mix error\n");  }  else if( (ret1 > 0) && (ret2==0))  {  date_mix = data1;  }  else if( (ret2 > 0) && (ret1==0))  {  date_mix = data2;  }  else if( (ret1 == 0) && (ret2 == 0))  {  break;  }  fwrite(&date_mix,2,1,fpm);  }  fclose(fp1);  fclose(fp2);  fclose(fpm);  printf("Done!\n");  
}