FreeCalypso > hg > gsm-codec-lib
view libtwamr/ec_gains.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 | 9cbd1b5d061f |
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 : ec_gains.c * Purpose: : Error concealment for pitch and codebook gains * ******************************************************************************** */ /* ******************************************************************************** * MODULE INCLUDE FILE AND VERSION ID ******************************************************************************** */ #include "namespace.h" #include "ec_gains.h" /* ******************************************************************************** * INCLUDE FILES ******************************************************************************** */ #include "typedef.h" #include "basic_op.h" #include "oper_32b.h" #include "no_count.h" #include "cnst.h" #include "gmed_n.h" #include "gc_pred.h" #include "gains_tab.h" /* ******************************************************************************** * PUBLIC PROGRAM CODE ******************************************************************************** */ /* ************************************************************************** * * Function : ec_gain_code_reset * Purpose : Resets state memory * ************************************************************************** */ void ec_gain_code_reset (ec_gain_codeState *state) { Word16 i; for ( i = 0; i < 5; i++) state->gbuf[i] = 1; state->past_gain_code = 0; state->prev_gc = 1; } /* ************************************************************************** * * Function : ec_gain_code * Purpose : conceal the codebook gain * Call this function only in BFI (instead of normal gain * decoding function) * ************************************************************************** */ void ec_gain_code ( ec_gain_codeState *st, /* i/o : State struct */ gc_predState *pred_state, /* i/o : MA predictor state */ Word16 state, /* i : state of the state machine */ Word16 *gain_code /* o : decoded innovation gain */ ) { static const Word16 cdown[7] = { 32767, 32112, 32112, 32112, 32112, 32112, 22937 }; Word16 tmp; Word16 qua_ener_MR122; Word16 qua_ener; /* calculate median of last five gain values */ tmp = gmed_n (st->gbuf,5); move16 (); /* new gain = minimum(median, past_gain) * cdown[state] */ test (); if (sub (tmp, st->past_gain_code) > 0) { tmp = st->past_gain_code; move16 (); } tmp = mult (tmp, cdown[state]); *gain_code = tmp; move16 (); /* update table of past quantized energies with average of * current values */ gc_pred_average_limited(pred_state, &qua_ener_MR122, &qua_ener); gc_pred_update(pred_state, qua_ener_MR122, qua_ener); } /* ************************************************************************** * * Function : ec_gain_code_update * Purpose : update the codebook gain concealment state; * limit gain_code if the previous frame was bad * Call this function always after decoding (or concealing) * the gain * ************************************************************************** */ void ec_gain_code_update ( ec_gain_codeState *st, /* i/o : State struct */ Word16 bfi, /* i : flag: frame is bad */ Word16 prev_bf, /* i : flag: previous frame was bad */ Word16 *gain_code /* i/o : decoded innovation gain */ ) { Word16 i; /* limit gain_code by previous good gain if previous frame was bad */ test (); if (bfi == 0) { test (); if (prev_bf != 0) { test (); if (sub (*gain_code, st->prev_gc) > 0) { *gain_code = st->prev_gc; move16 (); } } st->prev_gc = *gain_code; move16 (); } /* update EC states: previous gain, gain buffer */ st->past_gain_code = *gain_code; move16 (); for (i = 1; i < 5; i++) { st->gbuf[i - 1] = st->gbuf[i]; move16 (); } st->gbuf[4] = *gain_code; move16 (); return; } /* ************************************************************************** * * Function: ec_gain_pitch_reset * Purpose: Resets state memory * ************************************************************************** */ void ec_gain_pitch_reset (ec_gain_pitchState *state) { Word16 i; for(i = 0; i < 5; i++) state->pbuf[i] = 1640; state->past_gain_pit = 0; state->prev_gp = 16384; } /* ************************************************************************** * * Function : ec_gain_pitch * Purpose : conceal the pitch gain * Call this function only in BFI (instead of normal gain * decoding function) * ************************************************************************** */ void ec_gain_pitch ( ec_gain_pitchState *st, /* i/o : state variables */ Word16 state, /* i : state of the state machine */ Word16 *gain_pitch /* o : pitch gain (Q14) */ ) { static const Word16 pdown[7] = { 32767, 32112, 32112, 26214, 9830, 6553, 6553 }; Word16 tmp; /* calculate median of last five gains */ tmp = gmed_n (st->pbuf, 5); move16 (); /* new gain = minimum(median, past_gain) * pdown[state] */ test (); if (sub (tmp, st->past_gain_pit) > 0) { tmp = st->past_gain_pit; move16 (); } *gain_pitch = mult (tmp, pdown[state]); } /* ************************************************************************** * * Function : ec_gain_pitch_update * Purpose : update the pitch gain concealment state; * limit gain_pitch if the previous frame was bad * Call this function always after decoding (or concealing) * the gain * ************************************************************************** */ void ec_gain_pitch_update ( ec_gain_pitchState *st, /* i/o : state variables */ Word16 bfi, /* i : flag: frame is bad */ Word16 prev_bf, /* i : flag: previous frame was bad */ Word16 *gain_pitch /* i/o : pitch gain */ ) { Word16 i; test (); if (bfi == 0) { test (); if (prev_bf != 0) { test (); if (sub (*gain_pitch, st->prev_gp) > 0) { *gain_pitch = st->prev_gp; } } st->prev_gp = *gain_pitch; move16 (); } st->past_gain_pit = *gain_pitch; move16 (); test (); if (sub (st->past_gain_pit, 16384) > 0) /* if (st->past_gain_pit > 1.0) */ { st->past_gain_pit = 16384; move16 (); } for (i = 1; i < 5; i++) { st->pbuf[i - 1] = st->pbuf[i]; move16 (); } st->pbuf[4] = st->past_gain_pit; move16 (); }