AVSamplePlayer/TEST.m
//
//  TEST.m
//  demoCommandLineTool
//
//  Created by xyl-MacbookPro on 16/8/8.
//  Copyright © 2016年 xyl-MacbookPro. All rights reserved.
//

#import "TEST.h"

@implementation TEST
#pragma mark - G711 解析
#pragma mark
/*
 * This source code is a product of Sun Microsystems, Inc. and is provided
 * for unrestricted use.  Users may copy or modify this source code without
 * charge.
 *
 * SUN SOURCE CODE IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING
 * THE WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun source code is provided with no support and without any obligation on
 * the part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY THIS SOFTWARE
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * g711.c
 *
 * u-law, A-law and linear PCM conversions.
 */
#define	SIGN_BIT	(0x80)		/* Sign bit for a A-law byte. */
#define	QUANT_MASK	(0xf)		/* Quantization field mask. */
#define	NSEGS		(8)		/* Number of A-law segments. */
#define	SEG_SHIFT	(4)		/* Left shift for segment number. */
#define	SEG_MASK	(0x70)		/* Segment field mask. */

static short seg_end[8] = {0xFF, 0x1FF, 0x3FF, 0x7FF,
    0xFFF, 0x1FFF, 0x3FFF, 0x7FFF};

/* copy from CCITT G.711 specifications */
unsigned char _u2a[128] = {			/* u- to A-law conversions */
    1,	1,	2,	2,	3,	3,	4,	4,
    5,	5,	6,	6,	7,	7,	8,	8,
    9,	10,	11,	12,	13,	14,	15,	16,
    17,	18,	19,	20,	21,	22,	23,	24,
    25,	27,	29,	31,	33,	34,	35,	36,
    37,	38,	39,	40,	41,	42,	43,	44,
    46,	48,	49,	50,	51,	52,	53,	54,
    55,	56,	57,	58,	59,	60,	61,	62,
    64,	65,	66,	67,	68,	69,	70,	71,
    72,	73,	74,	75,	76,	77,	78,	79,
    81,	82,	83,	84,	85,	86,	87,	88,
    89,	90,	91,	92,	93,	94,	95,	96,
    97,	98,	99,	100,	101,	102,	103,	104,
    105,	106,	107,	108,	109,	110,	111,	112,
    113,	114,	115,	116,	117,	118,	119,	120,
    121,	122,	123,	124,	125,	126,	127,	128};

unsigned char _a2u[128] = {			/* A- to u-law conversions */
    1,	3,	5,	7,	9,	11,	13,	15,
    16,	17,	18,	19,	20,	21,	22,	23,
    24,	25,	26,	27,	28,	29,	30,	31,
    32,	32,	33,	33,	34,	34,	35,	35,
    36,	37,	38,	39,	40,	41,	42,	43,
    44,	45,	46,	47,	48,	48,	49,	49,
    50,	51,	52,	53,	54,	55,	56,	57,
    58,	59,	60,	61,	62,	63,	64,	64,
    65,	66,	67,	68,	69,	70,	71,	72,
    73,	74,	75,	76,	77,	78,	79,	79,
    80,	81,	82,	83,	84,	85,	86,	87,
    88,	89,	90,	91,	92,	93,	94,	95,
    96,	97,	98,	99,	100,	101,	102,	103,
    104,	105,	106,	107,	108,	109,	110,	111,
    112,	113,	114,	115,	116,	117,	118,	119,
    120,	121,	122,	123,	124,	125,	126,	127};

static int search(int val,short *table,int size)
{
    int	i;
    
    for (i = 0; i < size; i++) {
        if (val <= *table++)
            return (i);
    }
    return (size);
}

/*
 * linear2alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
 *
 * linear2alaw() accepts an 16-bit integer and encodes it as A-law data.
 *
 *		Linear Input Code	Compressed Code
 *	------------------------	---------------
 *	0000000wxyza			000wxyz
 *	0000001wxyza			001wxyz
 *	000001wxyzab			010wxyz
 *	00001wxyzabc			011wxyz
 *	0001wxyzabcd			100wxyz
 *	001wxyzabcde			101wxyz
 *	01wxyzabcdef			110wxyz
 *	1wxyzabcdefg			111wxyz
 *
 * For further information see John C. Bellamy's Digital Telephony, 1982,
 * John Wiley & Sons, pps 98-111 and 472-476.
 */
unsigned char linear2alaw(int pcm_val)	/* 2's complement (16-bit range) */
{
    int mask;
    int seg;
    unsigned char aval;
    
    if (pcm_val >= 0) {
        mask = 0xD5;		/* sign (7th) bit = 1 */
    } else {
        mask = 0x55;		/* sign bit = 0 */
        pcm_val = -pcm_val - 8;
    }
    
    /* Convert the scaled magnitude to segment number. */
    seg = search(pcm_val, seg_end, 8);
    
    /* Combine the sign, segment, and quantization bits. */
    
    if (seg >= 8)		/* out of range, return maximum value. */
        return (0x7F ^ mask);
    else {
        aval = seg << SEG_SHIFT;
        if (seg < 2)
            aval |= (pcm_val >> 4) & QUANT_MASK;
        else
            aval |= (pcm_val >> (seg + 3)) & QUANT_MASK;
        return (aval ^ mask);
    }
}

/*
 * alaw2linear() - Convert an A-law value to 16-bit linear PCM
 *
 */
int alaw2linear(unsigned char a_val)
{
    int	t;
    int	seg;
    a_val ^= 0x55;
    t = (a_val & QUANT_MASK) << 4;
    seg = ((unsigned)a_val & SEG_MASK) >> SEG_SHIFT;
    switch (seg) {
        case 0:
            t += 8;
            break;
        case 1:
            t += 0x108;
            break;
        default:
            t += 0x108;
            t <<= seg - 1;
    }
    return ((a_val & SIGN_BIT) ? t : -t);
}

#define	BIAS		(0x84)		/* Bias for linear code. */

/*
 * linear2ulaw() - Convert a linear PCM value to u-law
 *
 * In order to simplify the encoding process, the original linear magnitude
 * is biased by adding 33 which shifts the encoding range from (0 - 8158) to
 * (33 - 8191). The result can be seen in the following encoding table:
 *
 *	Biased Linear Input Code	Compressed Code
 *	------------------------	---------------
 *	00000001wxyza			000wxyz
 *	0000001wxyzab			001wxyz
 *	000001wxyzabc			010wxyz
 *	00001wxyzabcd			011wxyz
 *	0001wxyzabcde			100wxyz
 *	001wxyzabcdef			101wxyz
 *	01wxyzabcdefg			110wxyz
 *	1wxyzabcdefgh			111wxyz
 *
 * Each biased linear code has a leading 1 which identifies the segment
 * number. The value of the segment number is equal to 7 minus the number
 * of leading 0's. The quantization interval is directly available as the
 * four bits wxyz.  * The trailing bits (a - h) are ignored.
 *
 * Ordinarily the complement of the resulting code word is used for
 * transmission, and so the code word is complemented before it is returned.
 *
 * For further information see John C. Bellamy's Digital Telephony, 1982,
 * John Wiley & Sons, pps 98-111 and 472-476.
 */
unsigned char linear2ulaw(int pcm_val)	/* 2's complement (16-bit range) */
{
    int		mask;
    int		seg;
    unsigned char	uval;
    
    /* Get the sign and the magnitude of the value. */
    if (pcm_val < 0) {
        pcm_val = BIAS - pcm_val;
        mask = 0x7F;
    } else {
        pcm_val += BIAS;
        mask = 0xFF;
    }
    
    /* Convert the scaled magnitude to segment number. */
    seg = search(pcm_val, seg_end, 8);
    
    /*
     * Combine the sign, segment, quantization bits;
     * and complement the code word.
     */
    if (seg >= 8)		/* out of range, return maximum value. */
        return (0x7F ^ mask);
    else {
        uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0xF);
        return (uval ^ mask);
    }
    
}

/*
 * ulaw2linear() - Convert a u-law value to 16-bit linear PCM
 *
 * First, a biased linear code is derived from the code word. An unbiased
 * output can then be obtained by subtracting 33 from the biased code.
 *
 * Note that this function expects to be passed the complement of the
 * original code word. This is in keeping with ISDN conventions.
 */
int ulaw2linear(unsigned char u_val)
{
    int		t;
    
    /* Complement to obtain normal u-law value. */
    u_val = ~u_val;
    
    /*
     * Extract and bias the quantization bits. Then
     * shift up by the segment number and subtract out the bias.
     */
    t = ((u_val & QUANT_MASK) << 3) + BIAS;
    t <<= ((unsigned)u_val & SEG_MASK) >> SEG_SHIFT;
    
    return ((u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS));
}

/* A-law to u-law conversion */
unsigned char
alaw2ulaw(
          unsigned char	aval)
{
    aval &= 0xff;
    return ((aval & 0x80) ? (0xFF ^ _a2u[aval ^ 0xD5]) :
            (0x7F ^ _a2u[aval ^ 0x55]));
}

/* u-law to A-law conversion */
unsigned char
ulaw2alaw(
          unsigned char	uval)
{
    uval &= 0xff;
    return ((uval & 0x80) ? (0xD5 ^ (_u2a[0xFF ^ uval] - 1)) :
            (0x55 ^ (_u2a[0x7F ^ uval] - 1)));
}

int g711u_decode(short amp[], const unsigned char g711u_data[], int g711u_bytes)
{
    int i;
    int samples;
    unsigned char code;
    int sl;
    
    for (samples = i = 0;;)
    {
        if (i >= g711u_bytes)
            break;
        code = g711u_data[i++];
        
        sl = ulaw2linear(code);
        
        amp[samples++] = (short) sl;
    }
    return samples*2;
}

int G711Decode(char* pRawData,const unsigned char* pBuffer, int nBufferSize)
{
    short *out_data = (short*)pRawData;
    int i = 0;
    for(; i<nBufferSize; i++)
    {
//        参考文档：http://bbs.csdn.net/topics/360024000
//          out_data[i] = (short)ulaw2linear((unsigned char)pBuffer[i]);

        int v = ulaw2linear((unsigned char)pBuffer[i]);
        out_data[i] = v < -32768 ? -32768 : v > 32767 ? 32767 : v;
    }
    
    return nBufferSize * 2;
}


void G711Encoder(void *pcm,unsigned char *code,int size,int lawflag)

{
    short *input_data = (short *)pcm;
    int i;
    if(lawflag==0){
        
        for(i=0;i<size;i++){
            
            code[i]=linear2alaw(input_data[i]);
        }
    }
    else{
        
        for(i=0;i<size;i++){
            code[i]=linear2ulaw(input_data[i]);
        }
        
    }
    
}


@end
