static int save_audio(int seq, char *audio_buff, int len) 
{
  char file_name[64] = {0};
  int ret = 0;
  snprintf(file_name, sizeof(file_name), "/tmp/audio_file_%d", seq);

  FILE *fp = fopen(file_name, "w+");
  if (!fp) {
    return -1;
  }

  ret = fwrite((void*)audio_buff, sizeof(char), len, fp);
  if(ret != len) {
    printf("write audio_buff len=%d,ret=%d failed\n",len,ret);
    fclose(fp);
    return -1;
  }

  fclose(fp);
  return 0;
}