FreeCalypso > hg > gsm-codec-lib
view libtwamr/q_gain_p.c @ 480:332397bc80aa
doc/AMR-library-API: document public const data items
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Sun, 19 May 2024 23:18:17 +0000 |
parents | a01de4e40540 |
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 : q_gain_p.c * Purpose : Scalar quantization of the pitch gain * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "q_gain_p.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 "gains_tab.h" /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ Word16 q_gain_pitch ( /* Return index of quantization */ enum Mode mode, /* i : AMR mode */ Word16 gp_limit, /* i : pitch gain limit */ Word16 *gain, /* i/o: Pitch gain (unquant/quant), Q14 */ Word16 gain_cand[], /* o : pitch gain candidates (3), MR795 only, Q14 */ Word16 gain_cind[] /* o : pitch gain cand. indices (3),MR795 only, Q0 */ ) { Word16 i, index, err, err_min; err_min = abs_s (sub (*gain, qua_gain_pitch[0])); index = 0; move16 (); for (i = 1; i < NB_QUA_PITCH; i++) { test (); if (sub (qua_gain_pitch[i], gp_limit) <= 0) { err = abs_s (sub (*gain, qua_gain_pitch[i])); test (); if (sub (err, err_min) < 0) { err_min = err; move16 (); index = i; move16 (); } } } test (); if (sub (mode, MR795) == 0) { /* in MR795 mode, compute three gain_pit candidates around the index * found in the quantization loop: the index found and the two direct * neighbours, except for the extreme cases (i=0 or i=NB_QUA_PITCH-1), * where the direct neighbour and the neighbour to that is used. */ Word16 ii; test (); if (index == 0) { ii = index; move16 (); } else { test (); test (); if ( sub (index, NB_QUA_PITCH-1) == 0 || sub (qua_gain_pitch[index+1], gp_limit) > 0) { ii = sub (index, 2); } else { ii = sub (index, 1); } } /* store candidate indices and values */ for (i = 0; i < 3; i++) { gain_cind[i] = ii; move16 (); gain_cand[i] = qua_gain_pitch[ii]; move16 (); ii = add (ii, 1); } *gain = qua_gain_pitch[index]; move16 (); } else { /* in MR122 mode, just return the index and gain pitch found. * If bitexactness is required, mask away the two LSBs (because * in the original EFR, gain_pit was scaled Q12) */ test (); if (sub(mode, MR122) == 0) { /* clear 2 LSBits */ *gain = qua_gain_pitch[index] & 0xFFFC; logic16 (); move16 (); } else { *gain = qua_gain_pitch[index]; move16 (); } } return index; }