G.729A--编码--主函数

G.729A编码器

 主要函数：

  1. 初始化预处理Init_Pre_Process();

  2. 初始化编码Init_Coder_ld8a();

  3. 清空存放编码参数区域Set_zero(prm, PRM_SIZE);

  4. 预处理（140HZ高通滤波，除2定标）    Pre_Process(new_speech, L_FRAME);

  5. 主要编码程序，返回分析参数   Coder_ld8a(prm);   

  6. 将编码器参数向量转换成串行比特的向量（实现16:1的压缩）  prm2bits_ld8k( prm, serial);

 

int main(int argc, char *argv[] )
{
  FILE *f_speech;               /* File of speech data                   */
  FILE *f_serial;               /* File of serial bits for transmission  */

  extern Word16 *new_speech;     /* Pointer to new speech data            */

  Word16 prm[PRM_SIZE];          /* Analysis parameters.                  */
  unsigned char serial[SERIAL_SIZE];    /* Output bitstream buffer               */

  Word16 frame;                  /* frame counter */
/*--------------------------------------------------------------------------*
* Open speech file and result file (output serial bit stream)              *
*--------------------------------------------------------------------------*/
  if ( (f_speech = fopen(argv[1], "rb")) == NULL) {//读二进制文件
     printf("%s - Error opening file  %s !!\n", argv[0], argv[1]);
     exit(0);
  }
  printf(" Input speech file    :  %s\n", argv[1]);

  if ( (f_serial = fopen(argv[2], "wb")) == NULL) {
     printf("%s - Error opening file  %s !!\n", argv[0], argv[2]);
     exit(0);
  }
  printf(" Output bitstream file:  %s\n", argv[2]);

/*--------------------------------------------------------------------------*
* Initialization of the coder.                                             *
*--------------------------------------------------------------------------*/
//初始化编码器
  Init_Pre_Process();
  Init_Coder_ld8a();
  Set_zero(prm, PRM_SIZE);

  /* Loop for each "L_FRAME" speech data. */

  frame =0;
  //从f_speech文件位置，读L_FRAME（80）个元素，每个元素sizeof(Word16)个字节，存于new_speech
  while( fread(new_speech, sizeof(Word16), L_FRAME, f_speech) == L_FRAME)
  {
     printf("Frame =%d\r", frame++);

     Pre_Process(new_speech, L_FRAME);//预处理（HP滤波，定标）

    Coder_ld8a(prm);//主要编码程序，返回分析参数

    prm2bits_ld8k( prm, serial);//将编码器参数向量转换成串行比特的向量

    fwrite(serial, 1, SERIAL_SIZE, f_serial);
  }

  return (0);
}