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");
  }
}

g++ pcm2wav.cpp -o pcm2wav
./pcm2wav /home/20160630102824.pcm  /20160630102824.wav