Commit ba11fc84 authored by Sandeep Kumar's avatar Sandeep Kumar

keep alaw lut and remove other code

parent 9c1a6fc1
......@@ -40,7 +40,7 @@
#include "PHY/defs.h"
#include "PHY/LTE_TRANSPORT/if4_tools.h"
#include "PHY/TOOLS/ALAW/alaw_lut.h"
#include "PHY/TOOLS/alaw_lut.h"
#include "targets/ARCH/ETHERNET/USERSPACE/LIB/if_defs.h"
......
/**
* @companders.c - implementation
*
* @copy Copyright (C) <2012> <M. A. Chatterjee>
* @author M A Chatterjee <deftio [at] deftio [dot] com>
* @version 1.01 M. A. Chatterjee, cleaned up naming
*
* This file contains integer math compander functions for analog/audio representations on
* embedded systems. Linear2Alaw derived from Mark Spencer, Sun Microsystem and from
* the A Law specification
*
* @license:
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*
*/
#include "companders.h"
DIO_s8 DIO_LinearToALaw(DIO_s16 sample)
{
const DIO_s16 cClip = 32635;
const static DIO_s8 LogTable[128] =
{
1,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
};
DIO_s32 sign, exponent, mantissa;
DIO_s8 compandedValue;
sample = (sample ==-32768) ? -32767 : sample;
sign = ((~sample) >> 8) & 0x80;
if (!sign)
sample = (short)-sample;
if (sample > cClip)
sample = cClip;
if (sample >= 256)
{
exponent = (int)LogTable[(sample >> 8) & 0x7F];
mantissa = (sample >> (exponent + 3) ) & 0x0F;
compandedValue = ((exponent << 4) | mantissa);
}
else
{
compandedValue = (unsigned char)(sample >> 4);
}
compandedValue ^= (sign ^ 0x55);
return compandedValue;
}
DIO_s16 DIO_ALawToLinear(DIO_s8 aLawByte)
{
const static DIO_s16 ALawDecompTable[256]={
5504, 5248, 6016, 5760, 4480, 4224, 4992, 4736,
7552, 7296, 8064, 7808, 6528, 6272, 7040, 6784,
2752, 2624, 3008, 2880, 2240, 2112, 2496, 2368,
3776, 3648, 4032, 3904, 3264, 3136, 3520, 3392,
22016, 20992, 24064, 23040, 17920, 16896, 19968, 18944,
30208, 29184, 32256, 31232, 26112, 25088, 28160, 27136,
11008, 10496, 12032, 11520, 8960, 8448, 9984, 9472,
15104, 14592, 16128, 15616, 13056, 12544, 14080, 13568,
344, 328, 376, 360, 280, 264, 312, 296,
472, 456, 504, 488, 408, 392, 440, 424,
88, 72, 120, 104, 24, 8, 56, 40,
216, 200, 248, 232, 152, 136, 184, 168,
1376, 1312, 1504, 1440, 1120, 1056, 1248, 1184,
1888, 1824, 2016, 1952, 1632, 1568, 1760, 1696,
688, 656, 752, 720, 560, 528, 624, 592,
944, 912, 1008, 976, 816, 784, 880, 848,
-5504, -5248, -6016, -5760, -4480, -4224, -4992, -4736,
-7552, -7296, -8064, -7808, -6528, -6272, -7040, -6784,
-2752, -2624, -3008, -2880, -2240, -2112, -2496, -2368,
-3776, -3648, -4032, -3904, -3264, -3136, -3520, -3392,
-22016,-20992,-24064,-23040,-17920,-16896,-19968,-18944,
-30208,-29184,-32256,-31232,-26112,-25088,-28160,-27136,
-11008,-10496,-12032,-11520, -8960, -8448, -9984, -9472,
-15104,-14592,-16128,-15616,-13056,-12544,-14080,-13568,
-344, -328, -376, -360, -280, -264, -312, -296,
-472, -456, -504, -488, -408, -392, -440, -424,
-88, -72, -120, -104, -24, -8, -56, -40,
-216, -200, -248, -232, -152, -136, -184, -168,
-1376, -1312, -1504, -1440, -1120, -1056, -1248, -1184,
-1888, -1824, -2016, -1952, -1632, -1568, -1760, -1696,
-688, -656, -752, -720, -560, -528, -624, -592,
-944, -912, -1008, -976, -816, -784, -880, -848};
DIO_s16 addr = ((DIO_s16)aLawByte)+128; // done for compilers with poor expr type enforcement
return ALawDecompTable[addr];
}
// see companders.h
// fixed-radix IIR averager implementation supporting arbitrarily chosen windows
DIO_s32 DIO_IIRavgFR (DIO_s32 prevAvg, DIO_u16 windowLen, DIO_s16 newSample, DIO_u8 radix)
{
DIO_s32 iirAvg=0;
iirAvg = ((prevAvg * (windowLen-1)) + (DIO_I2FR(newSample,radix)))/windowLen;
return iirAvg;
}
// see companders.h
// fixed-radix IIR averager implementation using power-of-2 sized windows
// and only shift operations for cpu efficiency
DIO_s32 DIO_IIRavgPower2FR (DIO_s32 prevAvg, DIO_u8 windowLenInBits, DIO_s16 newSample, DIO_u8 radix)
{
DIO_s32 iirAvg=0;
iirAvg = (((prevAvg<<windowLenInBits)-prevAvg) + (DIO_I2FR(newSample,radix)))>>windowLenInBits;
return iirAvg;
}
#ifdef MAIN
int main(int argc, char* argv[])
{
return 0;
}
#endif
/**
* @companders.h - header definition file for embedded companding routines
*
* @copy Copyright (C) <2001-2012> <M. A. Chatterjee>
* @author M A Chatterjee <deftio [at] deftio [dot] com>
* @version 1.01 M. A. Chatterjee, cleaned up naming
*
* This file contains integer math settable fixed point radix math routines for
* use on systems in which floating point is not desired or unavailable.
*
* @license:
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*
*/
#ifndef __DIO_Compand_h__
#define __DIO_Compand_h__
#ifdef __cplusplus
extern "C"
{
#endif
//"DIO" prefixes are to assist in prevent name collisions if global namespace is used.
//typedefs ... change for platform dependant register size
// u/s = unsigned/signed 8/16/32 = num of bits
// keywords "int" and "long" in C/C++ are platform dependant
typedef unsigned char DIO_u8 ;
typedef signed char DIO_s8 ;
typedef unsigned short DIO_u16 ;
typedef signed short DIO_s16 ;
typedef unsigned long DIO_u32 ;
typedef signed long DIO_s32 ;
// macros for converting from Fixed-Radix to integer, vice-versa
// r represents radix precision in bits, converts to/from integer w truncation
#define DIO_I2FR(x,r) ((x)<<(r))
#define DIO_FR2I(x,r) ((x)>>(r))
// convert FR to double, this is for debug only and WILL NOT compile under many embedded systems.
// use this in test harnesses. Since this is a macro if its not used it won't expand / link
#define DIO_FR2D(x,r) ((double)(((double)(x))/((double)(1<<(r)))))
//convert signed linear 16 bit sample to an 8 bit A-Law companded sample
DIO_s8 DIO_LinearToALaw(DIO_s16 sample);
//convert 8bit Alaw companded representation back to linear 16 bit
DIO_s16 DIO_ALawToLinear(DIO_s8 aLawByte);
//DC Offset correction for integer companders
//IIR: y_0=(y_1*(w-1)+x_0)/(w)
//where w is the window length
//below are fixed radix precision IIR averagers which allow runtime tradeoffs for windowLen & precision
//Note that (windowLen)*(1<<radix) must < 32767
//DIO_IIRavgPower2FR() allows any window length but uses a divide instruction.
//output is in radix number of bits
DIO_s32 DIO_IIRavgFR (DIO_s32 prevAvg, DIO_u16 windowLen, DIO_s16 newSample, DIO_u8 radix);
//DIO_IIRavgPower2FR() similar to above, but window length is specified as a number of bits
//which removes the need for a divide in the implementation
//outpit is in radix number of bits
DIO_s32 DIO_IIRavgPower2FR (DIO_s32 prevAvg, DIO_u8 windowLenInBits, DIO_s16 newSample, DIO_u8 radix);
#ifdef __cplusplus
}
#endif
#endif /* __DIO_Compand_h__ */
/**
* @file compandit.c - implementation test file for integer companding with
* compand/uncompand support & IIR correction
*
* @copy Copyright (C) <2012> <M. A. Chatterjee>
* @author M A Chatterjee <deftio [at] deftio [dot] com>
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*
*/
#include <stdio.h>
#include <string.h>
#include "companders.h"
//===============================================
//main program for testing the functions
int main (int argc, char *argv[])
{
int ret_val = 0;
int i=0,j=0;
printf("\n============================================================\n");
printf("compandit library quikie program\n");
printf("M. A. Chatterjee (c) 2012\n\n");
printf("These routines were developed for use on embedded projects\n");
printf("for more info see the accompanying compand.txt\n");
printf("\n");
//uncomment to
//show how linear-->alaw-->linear-->alaw progression / quantization error works
/*
{
char alaw=0,alaw2;
short rev=0;
for (i= -32768; i <= 32767; i++)
{
alaw = DIO_LinearToALaw((short)i);
rev = DIO_ALawToLinear(alaw);
alaw2 =DIO_LinearToALaw(rev);
if (alaw != alaw2)
printf("***********");
printf("%7d %7d %7d %7d\n",i,(int)alaw,(int)rev,(int)alaw2);
}
}
// IIR averager examples
//IIR window length of 8 samples, using fractional precision of 4 bits
{
int a3=0, a4=0;
unsigned char rad=4; //4 bits fixed-radix fractional precision
printf(" index wave IIRav(i) IIRav(f) IIRavP2(i) IIRavP2(f)\n");
for (i=0; i < 300; i++)
{
j=(i&0x3f)-20; // triangle wave with range -20 to + 43
a3= DIO_IIRavgFR(a3,8,j,rad);
a4= DIO_IIRavgPower2FR(a4,3,j,rad);
printf("%6d %6d %6d %9.4f %6d %9.4f \n",i,j,
DIO_FR2I(a3,rad),DIO_FR2D(a3,rad) ,DIO_FR2I(a4,rad),DIO_FR2D(a4,rad));
}
}
//IIR window length of 64 samples
{
int a3=0, a4=0;
unsigned char rad=6; //rad is the number of bits of precision
printf(" index wave IIRav(i) IIRav(f) IIRavP2(i) IIRavP2(f)\n");
for (i=0; i < 300; i++)
{
j=(i&0x3f)-20; // triangle wave with range -20 to + 43
a3= DIO_IIRavgFR(a3,64,j,rad);
a4= DIO_IIRavgPower2FR(a4,6,j,rad);
printf("%6d %6d %6d %9.4f %6d %9.4f \n",i,j,
DIO_FR2I(a3,rad),DIO_FR2D(a3,rad) ,DIO_FR2I(a4,rad),DIO_FR2D(a4,rad));
}
}
// */
//Typical microcontroller application. See readme-companders.txt
// the input here simulates an A/D which has a range 0..3.3V mapped as 12 bits (0..4095)
// with a DC bias of 1.55V ==> (1.55/3.3)*4095 counts = 1923 counts
//now window length of 256 is used for rejecting the resistor bias. at 8KHz this window
// would be approx 8000/256 ~= 31 Hz (not quite but explaining Z xforms is beyond what
// can be explained in this small space.)
//we seed the DC average at 3.3/2 = 1.65V (we guess its in the middle) and let the long window
//length hone in on the correct value. (1.65V/3.3V) *4095 = 2048 counts
{
int actualDCbias =1923;
int calculatedDCbias =2048; //2048 is our initial estimate as outlined above
unsigned char windowLenPow2InBits = 8; // 8 bit long window = 256 sample long window
unsigned char rad=6; //rad is the number of bits of precision
calculatedDCbias = DIO_I2FR(calculatedDCbias,rad);
printf(" index wave actDCbias calcDCbias calcDCbias(f) alaw\n");
for (i=0; i < 1000; i++) // if 8000 hz sample rate this represents the number of samples captured
{
j=(((i&0x3f)<<1)-63)+1923; // triangle wave w range 0..127 with a bias set at actualDCbias
calculatedDCbias = DIO_IIRavgPower2FR(calculatedDCbias,windowLenPow2InBits,j,rad);
printf("%6d %6d %6d %6d %9.4f %3d\n",i,j,actualDCbias,
DIO_FR2I(calculatedDCbias,rad),DIO_FR2D(calculatedDCbias,rad),
(int)(DIO_LinearToALaw(j-DIO_FR2I(calculatedDCbias,rad)) ));
}
}
printf("\n");
return ret_val;
}
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