/*************************************************************************//*                                                                       *//*                  Language Technologies Institute                      *//*                     Carnegie Mellon University                        *//*                        Copyright (c) 2000                             *//*                        All Rights Reserved.                           *//*                                                                       *//*  Permission is hereby granted, free of charge, to use and distribute  *//*  this software and its documentation without restriction, including   *//*  without limitation the rights to use, copy, modify, merge, publish,  *//*  distribute, sublicense, and/or sell copies of this work, and to      *//*  permit persons to whom this work is furnished to do so, subject to   *//*  the following conditions:                                            *//*   1. The code must retain the above copyright notice, this list of    *//*      conditions and the following disclaimer.                         *//*   2. Any modifications must be clearly marked as such.                *//*   3. Original authors' names are not deleted.                         *//*   4. The authors' names are not used to endorse or promote products   *//*      derived from this software without specific prior written        *//*      permission.                                                      *//*                                                                       *//*  CARNEGIE MELLON UNIVERSITY AND THE CONTRIBUTORS TO THIS WORK         *//*  DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING      *//*  ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT   *//*  SHALL CARNEGIE MELLON UNIVERSITY NOR THE CONTRIBUTORS BE LIABLE      *//*  FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES    *//*  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN   *//*  AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,          *//*  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF       *//*  THIS SOFTWARE.                                                       *//*                                                                       *//*************************************************************************//*             Author:  Alan W Black (awb@cs.cmu.edu)                    *//*               Date:  October 2000                                     *//*************************************************************************//*                                                                       *//*  Convertion routines for various waveform encodings                   *//*                                                                       *//*  This contains software written external to Flite                     *//*       ulaw code came via the Edinburgh Speech Tools                   *//*  g72x codec came from Sun Microsystems                                *//*                                                                       *//*************************************************************************/ #include "g72x.h" /*** This routine converts from linear to ulaw.**** Craig Reese: IDA/Supercomputing Research Center** Joe Campbell: Department of Defense** 29 September 1989**** References:** 1) CCITT Recommendation G.711  (very difficult to follow)** 2) "A New Digital Technique for Implementation of Any**     Continuous PCM Companding Law," Villeret, Michel,**     et al. 1973 IEEE Int. Conf. on Communications, Vol 1,**     1973, pg. 11.12-11.17** 3) MIL-STD-188-113,"Interoperability and Performance Standards**     for Analog-to_Digital Conversion Techniques,"**     17 February 1987**** Input: Signed 16 bit linear sample** Output: 8 bit ulaw sample*/ #define ZEROTRAP    /* turn on the trap as per the MIL-STD */#define BIAS 0x84   /* define the add-in bias for 16 bit samples */#define CLIP 32635 unsigned char cst_short_to_ulaw(short sample){    static const int exp_lut[256] = {0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,				   4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,				   5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,				   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,				   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,				   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};    int sign, exponent, mantissa;    unsigned char ulawbyte;     /* Get the sample into sign-magnitude. */    sign = (sample >> 8) & 0x80; /* set aside the sign */    if ( sign != 0 ) sample = -sample; /* get magnitude */    if ( sample > CLIP ) sample = CLIP; /* clip the magnitude */     /* Convert from 16 bit linear to ulaw. */    sample = sample + BIAS;    exponent = exp_lut[( sample >> 7 ) & 0xFF];    mantissa = ( sample >> ( exponent + 3 ) ) & 0x0F;    ulawbyte = ~ ( sign | ( exponent << 4 ) | mantissa );#ifdef ZEROTRAP    if ( ulawbyte == 0 ) ulawbyte = 0x02; /* optional CCITT trap */#endif     return ulawbyte;} /*** This routine converts from ulaw to 16 bit linear.**** Craig Reese: IDA/Supercomputing Research Center** 29 September 1989**** References:** 1) CCITT Recommendation G.711  (very difficult to follow)** 2) MIL-STD-188-113,"Interoperability and Performance Standards**     for Analog-to_Digital Conversion Techniques,"**     17 February 1987**** Input: 8 bit ulaw sample** Output: signed 16 bit linear sample*/ short cst_ulaw_to_short( unsigned char ulawbyte ){    static const int exp_lut[8] = { 0, 132, 396, 924, 1980, 4092, 8316, 16764 };    int sign, exponent, mantissa;    short sample;     ulawbyte = ~ ulawbyte;    sign = ( ulawbyte & 0x80 );    exponent = ( ulawbyte >> 4 ) & 0x07;    mantissa = ulawbyte & 0x0F;    sample = exp_lut[exponent] + ( mantissa << ( exponent + 3 ) );    if ( sign != 0 ) sample = -sample;     return sample;}  unsigned char *cst_g721_decode(int *actual_size,int size,                        const unsigned char *packed_residual                       ){    struct g72x_state state;    short sample_short;    unsigned char *unpacked_residual;    unsigned char code, xcode;    int ur=0;    int dec_bits;     *actual_size = size*2;    unpacked_residual = cst_alloc(unsigned char, *actual_size);    g72x_init_state(&state);    dec_bits = 4; /* g721 4-bit encoding */     for (ur=0; ur <*actual_size; ur++)    {        xcode = packed_residual[ur/2];        if (ur % 2 == 0)            code = (xcode & 0xF0) >> dec_bits;        else            code = (xcode & 0x0F);        sample_short = g721_decoder(code,AUDIO_ENCODING_LINEAR,&state);        unpacked_residual[ur] = cst_short_to_ulaw(sample_short);    }     return unpacked_residual;} unsigned char *cst_g721_encode(int *packed_size,int actual_size,                                const unsigned char *unpacked_residual                               ){    struct g72x_state state;    unsigned char *packed_residual;    unsigned char code, xcode=0;    int ur=0;    int dec_bits;     *packed_size = (actual_size+1)/2; /* will round down to even number */    packed_residual = cst_alloc(unsigned char, *packed_size);     g72x_init_state(&state);    dec_bits = 4; /* g721 4-bit encoding */     for (ur=0; ur < actual_size; ur++)    {        code = g721_encoder((int)cst_ulaw_to_short(unpacked_residual[ur]),                            AUDIO_ENCODING_LINEAR,&state);        if (ur % 2 == 0)        {            xcode = 0;            xcode = code << dec_bits;        }        else        {            xcode += code;            packed_residual[ur/2] = xcode;        }    }     return packed_residual; }