参数

（1）采样位深：每个采样点的bit数

8bits: 0~255

16bits: 0~65535

（2）采样率：每秒采样次数

16KHz：每秒采16000个采样点

（3）声道数

双声道(stereo)：左-右-左-右…

（4）字节序

一般使用小端存储结构，16LE：低字节高字节-低字节高字节-低字节高字节…

处理

代码来自雷霄骅，致敬雷神，雷神千古！

分离test_stereo_s16le.pcm左右声道

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/**
 * Split Left and Right channel of 16LE PCM file.
 * @param url  Location of PCM file.
 *
 */
int simplest_pcm16le_split(char *url){
	FILE *fp=fopen(url,"rb+");
	FILE *fp1=fopen("output_l.pcm","wb+");
	FILE *fp2=fopen("output_r.pcm","wb+");
 
	unsigned char *sample=(unsigned char *)malloc(4);
 
	while(!feof(fp)){
		fread(sample,1,4,fp);
		//L
		fwrite(sample,1,2,fp1);
		//R
		fwrite(sample+2,1,2,fp2);
	}
 
	free(sample);
	fclose(fp);
	fclose(fp1);
	fclose(fp2);
	return 0;
}

PCM包装为WAVE

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/**
 * Convert PCM16LE raw data to WAVE format
 * @param pcmpath      Input PCM file.
 * @param channels     Channel number of PCM file.
 * @param sample_rate  Sample rate of PCM file.
 * @param wavepath     Output WAVE file.
 */
int simplest_pcm16le_to_wave(const char *pcmpath,int channels,int sample_rate,const char *wavepath)
{
 
	typedef struct WAVE_HEADER{  
		char         fccID[4];        
		unsigned   long    dwSize;            
		char         fccType[4];    
	}WAVE_HEADER;  
 
	typedef struct WAVE_FMT{  
		char         fccID[4];        
		unsigned   long       dwSize;            
		unsigned   short     wFormatTag;    
		unsigned   short     wChannels;  
		unsigned   long       dwSamplesPerSec;  
		unsigned   long       dwAvgBytesPerSec;  
		unsigned   short     wBlockAlign;  
		unsigned   short     uiBitsPerSample;  
	}WAVE_FMT;  
 
	typedef struct WAVE_DATA{  
		char       fccID[4];          
		unsigned long dwSize;              
	}WAVE_DATA;  
 
 
	if(channels==0||sample_rate==0){
    channels = 2;
    sample_rate = 44100;
	}
	int bits = 16;
 
    WAVE_HEADER   pcmHEADER;  
    WAVE_FMT   pcmFMT;  
    WAVE_DATA   pcmDATA;  
 
    unsigned   short   m_pcmData;
    FILE   *fp,*fpout;  
 
	fp=fopen(pcmpath, "rb");
    if(fp == NULL) {  
        printf("open pcm file error\n");
        return -1;  
    }
	fpout=fopen(wavepath,   "wb+");
    if(fpout == NULL) {    
        printf("create wav file error\n");  
        return -1; 
    }        
	//WAVE_HEADER
    memcpy(pcmHEADER.fccID,"RIFF",strlen("RIFF"));                    
    memcpy(pcmHEADER.fccType,"WAVE",strlen("WAVE"));  
    fseek(fpout,sizeof(WAVE_HEADER),1); 
	//WAVE_FMT
    pcmFMT.dwSamplesPerSec=sample_rate;  
    pcmFMT.dwAvgBytesPerSec=pcmFMT.dwSamplesPerSec*sizeof(m_pcmData);  
    pcmFMT.uiBitsPerSample=bits;
    memcpy(pcmFMT.fccID,"fmt ",strlen("fmt "));  
    pcmFMT.dwSize=16;  
    pcmFMT.wBlockAlign=2;  
    pcmFMT.wChannels=channels;  
    pcmFMT.wFormatTag=1;  
 
    fwrite(&pcmFMT,sizeof(WAVE_FMT),1,fpout); 
 
    //WAVE_DATA;
    memcpy(pcmDATA.fccID,"data",strlen("data"));  
    pcmDATA.dwSize=0;
    fseek(fpout,sizeof(WAVE_DATA),SEEK_CUR);
 
    fread(&m_pcmData,sizeof(unsigned short),1,fp);
    while(!feof(fp)){  
        pcmDATA.dwSize+=2;
        fwrite(&m_pcmData,sizeof(unsigned short),1,fpout);
        fread(&m_pcmData,sizeof(unsigned short),1,fp);
    }  
 
    pcmHEADER.dwSize=44+pcmDATA.dwSize;
 
    rewind(fpout);
    fwrite(&pcmHEADER,sizeof(WAVE_HEADER),1,fpout);
    fseek(fpout,sizeof(WAVE_FMT),SEEK_CUR);
    fwrite(&pcmDATA,sizeof(WAVE_DATA),1,fpout);
	
	fclose(fp);
    fclose(fpout);
 
    return 0;
}