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 #include #include  #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");}

关键函数在Mix函数里面实现，实现上来看就是加在一起，然后做一个归一化处理，就是为了防止达到上限设置了一下归一化。

测试上可以用两个dtmf的声音来测试，结果如下