FreeCalypso > hg > gsm-codec-lib
view libtwamr/d_gain_c.c @ 441:ebe499058c63
libtwamr: implement API functions for RFC 4867 I/O
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Thu, 09 May 2024 07:06:31 +0000 |
parents | a723d9f9f697 |
children |
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/* ******************************************************************************** * * GSM AMR-NB speech codec R98 Version 7.6.0 December 12, 2001 * R99 Version 3.3.0 * REL-4 Version 4.1.0 * ******************************************************************************** * * File : d_gain_c.c * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "d_gain_c.h" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "tw_amr.h" #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "no_count.h" #include "cnst.h" #include "log2.h" #include "pow2.h" #include "gc_pred.h" #include "gains_tab.h" /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /* ************************************************************************** * * Function : d_gain_code * Purpose : Decode the fixed codebook gain using the received index. * ************************************************************************** */ void d_gain_code ( gc_predState *pred_state, /* i/o : MA predictor state */ enum Mode mode, /* i : AMR mode (MR795 or MR122) */ Word16 index, /* i : received quantization index */ Word16 code[], /* i : innovation codevector */ Word16 *gain_code /* o : decoded innovation gain */ ) { Word16 gcode0, exp, frac; const Word16 *p; Word16 qua_ener_MR122, qua_ener; Word16 exp_inn_en; Word16 frac_inn_en; Word32 L_tmp; /*-------------- Decode codebook gain ---------------*/ /*-------------------------------------------------------------------* * predict codebook gain * * ~~~~~~~~~~~~~~~~~~~~~ * * gc0 = Pow2(int(d)+frac(d)) * * = 2^exp + 2^frac * * * *-------------------------------------------------------------------*/ gc_pred(pred_state, mode, code, &exp, &frac, &exp_inn_en, &frac_inn_en); p = &qua_gain_code[add (add (index, index), index)]; /* Different scalings between MR122 and the other modes */ test (); if (sub(mode, MR122) == 0) { gcode0 = extract_l (Pow2 (exp, frac)); /* predicted gain */ gcode0 = shl (gcode0, 4); *gain_code = shl (mult (gcode0, *p++), 1); move16 (); } else { gcode0 = extract_l (Pow2 (14, frac)); L_tmp = L_mult(*p++, gcode0); L_tmp = L_shr(L_tmp, sub(9, exp)); *gain_code = extract_h(L_tmp); /* Q1 */ } /*-------------------------------------------------------------------* * update table of past quantized energies * * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * *-------------------------------------------------------------------*/ qua_ener_MR122 = *p++; move16(); qua_ener = *p++; move16(); gc_pred_update(pred_state, qua_ener_MR122, qua_ener); return; }