DSP-C6416-录音混音算法工程

//record.c record/play input using external memory

#include "dsk6416_aic23.h" //codec support

Uint32 fs=DSK6416_AIC23_FREQ_8KHZ; //set sampling rate

//#define DSK6416_AIC23_INPUT_MIC 0x0015

//#define DSK6416_AIC23_INPUT_LINE 0x0011

//Uint16 inputsource=DSK6416_AIC23_INPUT_MIC; // select input

#define N 2400000    //large buffer size 300 secs

#define n 32                //for 32-bit input

long i,j,buffer_size;

short buffer
;

short buffer_mix
;

short buffer_voice
;

char sourseFile[10][2];  

#pragma DATA_SECTION(buffer,".EXT_RAM0") //buffer ->external memory

#pragma DATA_SECTION(buffer_voice,".EXT_RAM1")

#pragma DATA_SECTION(buffer_mix,".EXT_RAM2")

#pragma DATA_SECTION(sourseFile,".EXT_RAM3")

short date_mix;   

void main()

{
short recording = 0;//录音状态变量
short playing = 0;//播放状态变量
for (i=0 ; i<N ; i++)//buffer[]用于存放第一段录音（伴奏），buffer_voice[]用于存放第二段录音(原唱)
{
buffer[i] = 0;
buffer_voice[i] = 0;
}
DSK6416_DIP_init();
DSK6416_LED_init();
comm_poll();                  
//init DSK, codec, McBSP
while(1)                          
//infinite loop
{

  if(DSK6416_DIP_get(3) == 0)      //if SW#3 is pressed
{
i=0;
recording = 1;
while (recording == 1)
{
DSK6416_LED_on(3);          
//turn on LED#3
buffer[i++] = input_left_sample(); //input data

        if (i>N||DSK6416_DIP_get(3) == 1)

  {

  recording = 0;

  DSK6416_LED_off(3);//LED#3 off when buffer full

  }            
} 
buffer_size=i;// 记录录音数据的大小
} 
//***************************//
//***************************//

  if(DSK6416_DIP_get(0)==0)//if SW#0 pressed
{
i=0;
playing = 1;
recording = 1;
while (playing == 1&&(recording==1))
{
DSK6416_LED_on(0);            
//turn on LED#0

        for (i=0 ; (i< buffer_size)&&(DSK6416_DIP_get(0) == 0) ; i++)//一旦按键，立即结束录音。

        {

        output_left_sample(buffer[i]); //在伴奏播放时开始录音

        buffer_voice[i] = input_right_sample();//input data

}

if (i>N||DSK6416_DIP_get(0) == 1)

  {

  playing = 0;

  recording = 0;

  DSK6416_LED_off(0);
for(j=0;j<=buffer_size;j++)//音频混音算法 1、线性叠加后求平均
{
int t=buffer_voice[j]+buffer[j];
buffer_mix[j]=(short)(t/2);
}
}
} // 2.PCM脉冲编码混音编码算法,效果不咋地
//if(buffer[j]<0&&buffer_voice[j]<0)
// buffer_mix[j]=buffer[j]+buffer_voice[j]-((buffer[j]*buffer_voice[j])/(-(2*pow(n-1)-1)));
//else
// buffer_mix[j]=buffer[j]+buffer_voice[j]-((buffer[j]*buffer_voice[j])/(2*pow(n-1)));

}  // while (playing == 1)

 
//***************************//
//***************************//
if(DSK6416_DIP_get(1)==0) //if SW#1 pressed
 {
i=0;
playing = 1;
while (playing == 1)
{
DSK6416_LED_on(1);            
//turn on LED#0
for (i=0 ; (i<buffer_size)&&(DSK6416_DIP_get(1)==0) ; i++)
{

        output_left_sample(buffer_mix[i]);
//输出混音后的音频数据，这里采用的是线性叠加算法。
// output_right_sample(buffer_voice[i]);
}

    if (i>N||DSK6416_DIP_get(1) == 1)

  {

  playing = 0;

  DSK6416_LED_off(1);//LED#1 off when buffer full

  }            
} // while (playing == 1)
 }
}

}

/***********3.自适应加权混音算法,目前正在调试。

void Mix_music(char sourseFile[10][SIZE_AUDIO_FRAME],int number,char *objectFile)  

{  

    //归一化混音  

    int const MAX=2147483647;  

    int const MIN=-2147483648;  

   

    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)64;  

        }  

        *(short*)(objectFile+i*2)=(short)output;  

    }     

}

*************/