查表法aLaw编解码算法

aLaw.h源码文件：

//==============================================================================
//  Copyright (C) 2019 王小康. All rights reserved.
//
//  作者: 王小康
//  描述: A-LAW编解码
//  日期: 2019-04-29
//
//==============================================================================

/*
0000000abcd-  000abcd
0000001abcd-  001abcd
000001abcd--  010abcd
00001abcd---  011abcd
0001abcd----  100abcd
001abcd-----  101abcd
01abcd------  110abcd
1abcd-------  111abcd
*/
#ifndef _A_LAW_H_
#define _A_LAW_H_

void aLaw_encode(unsigned char *output, signed short *input, int number);
void aLaw_decode(signed short *output, unsigned char *input, int number);

#endif

aLaw_encode()用于编码，output是输出地址，input是输入地址，number是采样点个数。
aLaw_decode()用于解码，output是输出地址，input是输入地址，number是采样点个数。

aLaw.c源码文件：

//==============================================================================
//  Copyright (C) 2019 王小康. All rights reserved.
//
//  作者: 王小康
//  描述: A-LAW编解码
//  日期: 2019-04-29
//
//==============================================================================

#include "aLaw.h"

 //PCM16 -> A-LAW 
static unsigned char table1[2048] = {
    0x55, 0x54, 0x57, 0x56, 0x51, 0x50, 0x53, 0x52,
    0x5d, 0x5c, 0x5f, 0x5e, 0x59, 0x58, 0x5b, 0x5a,
    0x45, 0x44, 0x47, 0x46, 0x41, 0x40, 0x43, 0x42,
    0x4d, 0x4c, 0x4f, 0x4e, 0x49, 0x48, 0x4b, 0x4a,
    0x75, 0x75, 0x74, 0x74, 0x77, 0x77, 0x76, 0x76,
    0x71, 0x71, 0x70, 0x70, 0x73, 0x73, 0x72, 0x72,
    0x7d, 0x7d, 0x7c, 0x7c, 0x7f, 0x7f, 0x7e, 0x7e,
    0x79, 0x79, 0x78, 0x78, 0x7b, 0x7b, 0x7a, 0x7a,
    0x65, 0x65, 0x65, 0x65, 0x64, 0x64, 0x64, 0x64,
    0x67, 0x67, 0x67, 0x67, 0x66, 0x66, 0x66, 0x66,
    0x61, 0x61, 0x61, 0x61, 0x60, 0x60, 0x60, 0x60,
    0x63, 0x63, 0x63, 0x63, 0x62, 0x62, 0x62, 0x62,
    0x6d, 0x6d, 0x6d, 0x6d, 0x6c, 0x6c, 0x6c, 0x6c,
    0x6f, 0x6f, 0x6f, 0x6f, 0x6e, 0x6e, 0x6e, 0x6e,
    0x69, 0x69, 0x69, 0x69, 0x68, 0x68, 0x68, 0x68,
    0x6b, 0x6b, 0x6b, 0x6b, 0x6a, 0x6a, 0x6a, 0x6a,
    0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15,
    0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14,
    0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17, 0x17,
    0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16,
    0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11,
    0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10,
    0x13, 0x13, 0x13, 0x13, 0x13, 0x13, 0x13, 0x13,
    0x12, 0x12, 0x12, 0x12, 0x12, 0x12, 0x12, 0x12,
    0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d, 0x1d,
    0x1c, 0x1c, 0x1c, 0x1c, 0x1c, 0x1c, 0x1c, 0x1c,
    0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f,
    0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e, 0x1e,
    0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19,
    0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18,
    0x1b, 0x1b, 0x1b, 0x1b, 0x1b, 0x1b, 0x1b, 0x1b,
    0x1a, 0x1a, 0x1a, 0x1a, 0x1a, 0x1a, 0x1a, 0x1a,
    0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
    0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05,
    0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
    0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04,
    0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
    0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07, 0x07,
    0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
    0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06, 0x06,
    0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
    0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
    0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03,
    0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
    0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02,
    0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d,
    0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d, 0x0d,
    0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
    0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c,
    0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
    0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
    0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e,
    0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e, 0x0e,
    0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
    0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09,
    0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
    0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
    0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
    0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
    0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
    0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a, 0x0a,
    0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35,
    0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35,
    0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35,
    0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35, 0x35,
    0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
    0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
    0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
    0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34, 0x34,
    0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37,
    0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37,
    0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37,
    0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37, 0x37,
    0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
    0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
    0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
    0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
    0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
    0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
    0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
    0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31,
    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
    0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30,
    0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
    0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
    0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
    0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33,
    0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32,
    0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32,
    0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32,
    0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32, 0x32,
    0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d,
    0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d,
    0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d,
    0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d, 0x3d,
    0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c,
    0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c,
    0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c,
    0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c, 0x3c,
    0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f,
    0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f,
    0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f,
    0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f, 0x3f,
    0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e,
    0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e,
    0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e,
    0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e, 0x3e,
    0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39,
    0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39,
    0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39,
    0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39, 0x39,
    0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38,
    0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38,
    0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38,
    0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38, 0x38,
    0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b,
    0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b,
    0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b,
    0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b, 0x3b,
    0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a,
    0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a,
    0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a,
    0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a, 0x3a,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25, 0x25,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24, 0x24,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27, 0x27,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26, 0x26,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21, 0x21,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23, 0x23,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22, 0x22,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d, 0x2d,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c, 0x2c,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f, 0x2f,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29, 0x29,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28, 0x28,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b, 0x2b,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a,
    0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a, 0x2a
};

 //A-LAW -> PCM16
static signed  short table2[128] = {
    0x157f, 0x147f, 0x177f, 0x167f, 0x117f, 0x107f, 0x137f, 0x127f,
    0x1d7f, 0x1c7f, 0x1f7f, 0x1e7f, 0x197f, 0x187f, 0x1b7f, 0x1a7f,
    0x0abf, 0x0a3f, 0x0bbf, 0x0b3f, 0x08bf, 0x083f, 0x09bf, 0x093f,
    0x0ebf, 0x0e3f, 0x0fbf, 0x0f3f, 0x0cbf, 0x0c3f, 0x0dbf, 0x0d3f,
    0x55ff, 0x51ff, 0x5dff, 0x59ff, 0x45ff, 0x41ff, 0x4dff, 0x49ff,
    0x75ff, 0x71ff, 0x7dff, 0x79ff, 0x65ff, 0x61ff, 0x6dff, 0x69ff,
    0x2aff, 0x28ff, 0x2eff, 0x2cff, 0x22ff, 0x20ff, 0x26ff, 0x24ff,
    0x3aff, 0x38ff, 0x3eff, 0x3cff, 0x32ff, 0x30ff, 0x36ff, 0x34ff,
    0x0157, 0x0147, 0x0177, 0x0167, 0x0117, 0x0107, 0x0137, 0x0127,
    0x01d7, 0x01c7, 0x01f7, 0x01e7, 0x0197, 0x0187, 0x01b7, 0x01a7,
    0x0057, 0x0047, 0x0077, 0x0067, 0x0017, 0x0007, 0x0037, 0x0027,
    0x00d7, 0x00c7, 0x00f7, 0x00e7, 0x0097, 0x0087, 0x00b7, 0x00a7,
    0x055f, 0x051f, 0x05df, 0x059f, 0x045f, 0x041f, 0x04df, 0x049f,
    0x075f, 0x071f, 0x07df, 0x079f, 0x065f, 0x061f, 0x06df, 0x069f,
    0x02af, 0x028f, 0x02ef, 0x02cf, 0x022f, 0x020f, 0x026f, 0x024f,
    0x03af, 0x038f, 0x03ef, 0x03cf, 0x032f, 0x030f, 0x036f, 0x034f
};

void aLaw_encode(unsigned char *output, signed short *input, int number){
    while(number-- > 0){
        if(input[0] >= 0) output[0] = table1[input[0] >> 4] | 0x80;
        else              output[0] = table1[(-input[0]) >> 4];
        output += 1;
        input += 1;
    }
}

void aLaw_decode(signed short *output, unsigned char *input, int number){
    while(number-- > 0){
        if(input[0]&0x80) output[0] = table2[input[0]&0x7f];
        else              output[0] = -table2[input[0]];
        output += 1;
        input += 1;
    }
}

最后编辑于：2021.03.05 15:43:36

人面猴
序言：七十年代末，一起剥皮案震惊了整个滨河市，随后出现的几起案子，更是在滨河造成了极大的恐慌，老刑警刘岩，带你破解...
沈念sama阅读 214,776评论 6赞 496
死咒
序言：滨河连续发生了三起死亡事件，死亡现场离奇诡异，居然都是意外死亡，警方通过查阅死者的电脑和手机，发现死者居然都...
沈念sama阅读 91,527评论 3赞 389
救了他两次的神仙让他今天三更去死
文/潘晓璐我一进店门，熙熙楼的掌柜王于贵愁眉苦脸地迎上来，“玉大人，你说我怎么就摊上这事。” “怎么了？”我有些...
开封第一讲书人阅读 160,361评论 0赞 350
道士缉凶录：失踪的卖姜人
文/不坏的土叔我叫张陵，是天一观的道长。经常有香客问我，道长，这世上最难降的妖魔是什么？我笑而不...
开封第一讲书人阅读 57,430评论 1赞 288
港岛之恋（遗憾婚礼）
正文为了忘掉前任，我火速办了婚礼，结果婚礼上，老公的妹妹穿的比我还像新娘。我一直安慰自己，他们只是感情好，可当我...
茶点故事阅读 66,511评论 6赞 386
恶毒庶女顶嫁案：这布局不是一般人想出来的
文/花漫我一把揭开白布。她就那样静静地躺着，像睡着了一般。火红的嫁衣衬着肌肤如雪。梳的纹丝不乱的头发上，一...
开封第一讲书人阅读 50,544评论 1赞 293
城市分裂传说
那天，我揣着相机与录音，去河边找鬼。笑死，一个胖子当着我的面吹牛，可吹牛的内容都是我干的。我是一名探鬼主播，决...
沈念sama阅读 39,561评论 3赞 414
双鸳鸯连环套：你想象不到人心有多黑
文/苍兰香墨我猛地睁开眼，长吁一口气：“原来是场噩梦啊……” “哼！你这毒妇竟也来了？” 一声冷哼从身侧响起，我...
开封第一讲书人阅读 38,315评论 0赞 270
万荣杀人案实录
序言：老挝万荣一对情侣失踪，失踪者是张志新（化名）和其女友刘颖，没想到半个月后，有当地人在树林里发现了一具尸体，经...
沈念sama阅读 44,763评论 1赞 307
护林员之死
正文独居荒郊野岭守林人离奇死亡，尸身上长有42处带血的脓包…… 初始之章·张勋以下内容为张勋视角年9月15日...
茶点故事阅读 37,070评论 2赞 330
白月光启示录
正文我和宋清朗相恋三年，在试婚纱的时候发现自己被绿了。大学时的朋友给我发了我未婚夫和他白月光在一起吃饭的照片。...
茶点故事阅读 39,235评论 1赞 343
活死人
序言：一个原本活蹦乱跳的男人离奇死亡，死状恐怖，灵堂内的尸体忽然破棺而出，到底是诈尸还是另有隐情，我是刑警宁泽，带...
沈念sama阅读 34,911评论 5赞 338
日本核电站爆炸内幕
正文年R本政府宣布，位于F岛的核电站，受9级特大地震影响，放射性物质发生泄漏。R本人自食恶果不足惜，却给世界环境...
茶点故事阅读 40,554评论 3赞 322
男人毒药：我在死后第九天来索命
文/蒙蒙一、第九天我趴在偏房一处隐蔽的房顶上张望。院中可真热闹，春花似锦、人声如沸。这庄子的主人今日做“春日...
开封第一讲书人阅读 31,173评论 0赞 21
一桩弑父案，背后竟有这般阴谋
文/苍兰香墨我抬头看了看天上的太阳。三九已至，却和暖如春，着一层夹袄步出监牢的瞬间，已是汗流浃背。一阵脚步声响...
开封第一讲书人阅读 32,424评论 1赞 268
情欲美人皮
我被黑心中介骗来泰国打工，没想到刚下飞机就差点儿被人妖公主榨干…… 1. 我叫王不留，地道东北人。一个月前我还...
沈念sama阅读 47,106评论 2赞 365
代替公主和亲
正文我出身青楼，却偏偏与公主长得像，于是被迫代替她去往敌国和亲。传闻我的和亲对象是个残疾皇子，可洞房花烛夜当晚...
茶点故事阅读 44,103评论 2赞 352

查表法aLaw编解码算法

推荐阅读更多精彩内容