pcm转wav的方法及代码示例

<pre class="cpp" name="code">pcm文件转wav文件时，主要是在pcm文件加入wav的头。wav的文件头包含wav标示及解码标示。<p>下面的一段代码为将8k,16bit,PCM(Intel（LSB,MSB）未加压缩的转wav文件。</p>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

using namespace std;
//读文件，返回内存指针，记得free
void* ReadFile(const char *path, unsigned int *len)
{
FILE *f = fopen(path, "rb");
if (f == NULL)
return NULL;
fseek(f, 0, SEEK_END);
*len = ftell(f);
fseek(f, 0, SEEK_SET);
void *buffer = malloc(*len);
*len = fread(buffer, 1, *len, f);
fclose(f);
return buffer;
}

//pcm转wav，返回wav内存指针和wav长度
void* pcmToWav(const void *pcm, unsigned int pcmlen, unsigned int *wavlen)
{
//44字节wav头
void *wav = malloc(pcmlen + 44);
//wav文件多了44个字节
*wavlen = pcmlen + 44;
//添加wav文件头
memcpy(wav, "RIFF", 4);
*(int *)((char*)wav + 4) = pcmlen + 36;
memcpy(((char*)wav + 8), "WAVEfmt ", 8);
*(int *)((char*)wav + 16) = 16;
*(short *)((char*)wav + 20) = 1;
*(short *)((char*)wav + 22) = 1;
*(int *)((char*)wav + 24) = 8000;
*(int *)((char*)wav + 28) = 16000;
*(short *)((char*)wav + 32) = 16 / 8;
*(short *)((char*)wav + 34) = 16;
strcpy((char*)((char*)wav + 36), "data");
*(int *)((char*)wav + 40) = pcmlen;

//拷贝pcm数据到wav中
memcpy((char*)wav + 44, pcm, pcmlen);
return wav;
}

//pcm文件转wav文件，pcmfilePath:pcm文件路劲，wavfilePath:生成的wav路劲
int pcmfileToWavfile(const char *pcmfilePath, const char *wavfilePath)
{
unsigned int pcmlen;
//读取文件获得pcm流，也可以从其他方式获得
void *pcm = ReadFile(pcmfilePath, &pcmlen);
if (pcm == NULL)
{
printf("not found file\n");
return 1;
}

//pcm转wav
unsigned int wavLen;
void *wav = pcmToWav(pcm, pcmlen, &wavLen);

FILE *fwav = fopen(wavfilePath, "wb");
fwrite(wav, 1, wavLen, fwav);
fclose(fwav);
free(pcm);
free(wav);
return 0;
}

int main(int argc,char *argv[])
{
if(argc<3) return 1;
if(strstr(argv[1],".pcm")==NULL) return 1;
if(strstr(argv[2],".wav")==NULL) return 1;
int ret = pcmfileToWavfile(argv[1],argv[2]);
if (ret != 0)
{
printf("error pcm to wav\n");
}
else
{
printf("succ");
}
}

比如将这段代码复制到一个文件中，该文件名字为pcm2wav.cpp。将其编译。 

g++ pcm2wav.cpp -o pcm2wav

./pcm2wav /home/20160630102824.pcm  /20160630102824.wav