FreeCalypso > hg > gsm-codec-lib
view libtwamr/d2_9pf.c @ 375:1d2b39027b70
libtwamr: integrate qgain475.c
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Mon, 06 May 2024 04:14:52 +0000 |
parents | 2303ba1490dd |
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 : d2_9pf.c * Purpose : Algebraic codebook decoder * ***************************************************************************** */ /* ***************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ***************************************************************************** */ #include "namespace.h" #include "d2_9pf.h" /* ***************************************************************************** * INCLUDE FILES ***************************************************************************** */ #include "typedef.h" #include "basic_op.h" #include "no_count.h" #include "cnst.h" /* ******************************************************************************** * LOCAL VARIABLES AND TABLES ******************************************************************************** */ #define NB_PULSE 2 /* number of pulses */ #include "c2_9pf.tab" /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /************************************************************************* * * FUNCTION: decode_2i40_9bits (decod_ACELP()) * * PURPOSE: Algebraic codebook decoder. For details about the encoding se * c2_9pf.c * *************************************************************************/ void decode_2i40_9bits( Word16 subNr, /* i : subframe number */ Word16 sign, /* i : signs of 2 pulses. */ Word16 index, /* i : Positions of the 2 pulses. */ Word16 cod[] /* o : algebraic (fixed) codebook excitation */ ) { Word16 i, j, k; Word16 pos[NB_PULSE]; /* Decode the positions */ /* table bit is the MSB */ j = shr((index & 64),6); logic16 (); i = index & 7; logic16 (); i = add(i, shl(i, 2)); /* pos0 =i*5+startPos[j*8+subNr*2] */ k = startPos[add(shl(j, 3), shl(subNr, 1))]; pos[0] = add(i, k); move16 (); index = shr(index, 3); i = index & 7; logic16 (); i = add(i, shl(i, 2)); /* pos1 =i*5+startPos[j*8+subNr*2+1] */ k = startPos[add(add(shl(j, 3), shl(subNr, 1)), 1)]; pos[1] = add(i, k); move16 (); /* decode the signs and build the codeword */ for (i = 0; i < L_SUBFR; i++) { cod[i] = 0; move16 (); } for (j = 0; j < NB_PULSE; j++) { i = sign & 1; logic16 (); sign = shr(sign, 1); test (); if (i != 0) { cod[pos[j]] = 8191; move16 (); /* +1.0 */ } else { cod[pos[j]] = -8192; move16 (); /* -1.0 */ } } return; }