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ffmpeg / libavcodec / sipr16k.c @ 2912e87a

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/*
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 * SIPR decoder for the 16k mode
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 *
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 * Copyright (c) 2008 Vladimir Voroshilov
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 * Copyright (c) 2009 Vitor Sessak
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include <math.h>
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#include "sipr.h"
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#include "libavutil/mathematics.h"
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#include "lsp.h"
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#include "celp_math.h"
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#include "acelp_vectors.h"
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#include "acelp_pitch_delay.h"
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#include "acelp_filters.h"
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#include "celp_filters.h"
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#include "sipr16kdata.h"
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/**
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 * Convert an lsf vector into an lsp vector.
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 *
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 * @param lsf               input lsf vector
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 * @param lsp               output lsp vector
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 */
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static void lsf2lsp(const float *lsf, double *lsp)
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{
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    int i;
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    for (i = 0; i < LP_FILTER_ORDER_16k; i++)
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        lsp[i] = cosf(lsf[i]);
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}
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static void dequant(float *out, const int *idx, const float *cbs[])
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{
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    int i;
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    for (i = 0; i < 4; i++)
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        memcpy(out + 3*i, cbs[i] + 3*idx[i], 3*sizeof(float));
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    memcpy(out + 12, cbs[4] + 4*idx[4], 4*sizeof(float));
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}
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static void lsf_decode_fp_16k(float* lsf_history, float* isp_new,
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                              const int* parm, int ma_pred)
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{
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    int i;
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    float isp_q[LP_FILTER_ORDER_16k];
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    dequant(isp_q, parm, lsf_codebooks_16k);
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    for (i = 0; i < LP_FILTER_ORDER_16k; i++) {
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        isp_new[i] = (1 - qu[ma_pred]) * isp_q[i]
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                    +     qu[ma_pred]  * lsf_history[i]
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                    + mean_lsf_16k[i];
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    }
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    memcpy(lsf_history, isp_q, LP_FILTER_ORDER_16k * sizeof(float));
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}
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static int dec_delay3_1st(int index)
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{
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    if (index < 390) {
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        return index + 88;
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    } else
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        return 3 * index - 690;
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}
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static int dec_delay3_2nd(int index, int pit_min, int pit_max,
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                          int pitch_lag_prev)
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{
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    if (index < 62) {
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        int pitch_delay_min = av_clip(pitch_lag_prev - 10,
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                                      pit_min, pit_max - 19);
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        return 3 * pitch_delay_min + index - 2;
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    } else
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        return 3 * pitch_lag_prev;
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}
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static void postfilter(float *out_data, float* synth, float* iir_mem,
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                       float* filt_mem[2], float* mem_preemph)
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{
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    float buf[30 + LP_FILTER_ORDER_16k];
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    float *tmpbuf = buf + LP_FILTER_ORDER_16k;
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    float s;
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    int i;
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    for (i = 0; i < LP_FILTER_ORDER_16k; i++)
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        filt_mem[0][i] = iir_mem[i] * ff_pow_0_5[i];
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    memcpy(tmpbuf - LP_FILTER_ORDER_16k, mem_preemph,
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           LP_FILTER_ORDER_16k*sizeof(*buf));
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    ff_celp_lp_synthesis_filterf(tmpbuf, filt_mem[1], synth, 30,
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                                 LP_FILTER_ORDER_16k);
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    memcpy(synth - LP_FILTER_ORDER_16k, mem_preemph,
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           LP_FILTER_ORDER_16k * sizeof(*synth));
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    ff_celp_lp_synthesis_filterf(synth, filt_mem[0], synth, 30,
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                                 LP_FILTER_ORDER_16k);
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    memcpy(out_data + 30 - LP_FILTER_ORDER_16k,
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           synth    + 30 - LP_FILTER_ORDER_16k,
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           LP_FILTER_ORDER_16k * sizeof(*synth));
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    ff_celp_lp_synthesis_filterf(out_data + 30, filt_mem[0],
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                                 synth + 30, 2 * L_SUBFR_16k - 30,
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                                 LP_FILTER_ORDER_16k);
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    memcpy(mem_preemph, out_data + 2*L_SUBFR_16k - LP_FILTER_ORDER_16k,
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           LP_FILTER_ORDER_16k * sizeof(*synth));
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    FFSWAP(float *, filt_mem[0], filt_mem[1]);
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    for (i = 0, s = 0; i < 30; i++, s += 1.0/30)
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        out_data[i] = tmpbuf[i] + s * (synth[i] - tmpbuf[i]);
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}
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/**
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 * Floating point version of ff_acelp_lp_decode().
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 */
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static void acelp_lp_decodef(float *lp_1st, float *lp_2nd,
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                             const double *lsp_2nd, const double *lsp_prev)
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{
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    double lsp_1st[LP_FILTER_ORDER_16k];
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    int i;
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    /* LSP values for first subframe (3.2.5 of G.729, Equation 24) */
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    for (i = 0; i < LP_FILTER_ORDER_16k; i++)
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        lsp_1st[i] = (lsp_2nd[i] + lsp_prev[i]) * 0.5;
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    ff_acelp_lspd2lpc(lsp_1st, lp_1st, LP_FILTER_ORDER_16k >> 1);
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    /* LSP values for second subframe (3.2.5 of G.729) */
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    ff_acelp_lspd2lpc(lsp_2nd, lp_2nd, LP_FILTER_ORDER_16k >> 1);
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}
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/**
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 * Floating point version of ff_acelp_decode_gain_code().
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 */
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static float acelp_decode_gain_codef(float gain_corr_factor, const float *fc_v,
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                                     float mr_energy, const float *quant_energy,
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                                     const float *ma_prediction_coeff,
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                                     int subframe_size, int ma_pred_order)
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{
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    mr_energy +=
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        ff_dot_productf(quant_energy, ma_prediction_coeff, ma_pred_order);
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    mr_energy = gain_corr_factor * exp(M_LN10 / 20. * mr_energy) /
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        sqrt((0.01 + ff_dot_productf(fc_v, fc_v, subframe_size)));
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    return mr_energy;
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}
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#define DIVIDE_BY_3(x) ((x) * 10923 >> 15)
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void ff_sipr_decode_frame_16k(SiprContext *ctx, SiprParameters *params,
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                              float *out_data)
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{
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    int frame_size = SUBFRAME_COUNT_16k * L_SUBFR_16k;
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    float *synth = ctx->synth_buf + LP_FILTER_ORDER_16k;
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    float lsf_new[LP_FILTER_ORDER_16k];
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    double lsp_new[LP_FILTER_ORDER_16k];
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    float Az[2][LP_FILTER_ORDER_16k];
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    float fixed_vector[L_SUBFR_16k];
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    float pitch_fac, gain_code;
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    int i;
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    int pitch_delay_3x;
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    float *excitation = ctx->excitation + 292;
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    lsf_decode_fp_16k(ctx->lsf_history, lsf_new, params->vq_indexes,
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                      params->ma_pred_switch);
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    ff_set_min_dist_lsf(lsf_new, LSFQ_DIFF_MIN / 2, LP_FILTER_ORDER_16k);
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    lsf2lsp(lsf_new, lsp_new);
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    acelp_lp_decodef(Az[0], Az[1], lsp_new, ctx->lsp_history_16k);
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    memcpy(ctx->lsp_history_16k, lsp_new, LP_FILTER_ORDER_16k * sizeof(double));
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    memcpy(synth - LP_FILTER_ORDER_16k, ctx->synth,
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           LP_FILTER_ORDER_16k * sizeof(*synth));
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    for (i = 0; i < SUBFRAME_COUNT_16k; i++) {
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        int i_subfr = i * L_SUBFR_16k;
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        AMRFixed f;
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        float gain_corr_factor;
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        int pitch_delay_int;
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        int pitch_delay_frac;
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        if (!i) {
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            pitch_delay_3x = dec_delay3_1st(params->pitch_delay[i]);
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        } else
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            pitch_delay_3x = dec_delay3_2nd(params->pitch_delay[i],
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                                            PITCH_MIN, PITCH_MAX,
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                                            ctx->pitch_lag_prev);
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        pitch_fac = gain_pitch_cb_16k[params->gp_index[i]];
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        f.pitch_fac = FFMIN(pitch_fac, 1.0);
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        f.pitch_lag = DIVIDE_BY_3(pitch_delay_3x+1);
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        ctx->pitch_lag_prev = f.pitch_lag;
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        pitch_delay_int  = DIVIDE_BY_3(pitch_delay_3x + 2);
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        pitch_delay_frac = pitch_delay_3x + 2 - 3*pitch_delay_int;
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        ff_acelp_interpolatef(&excitation[i_subfr],
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                              &excitation[i_subfr] - pitch_delay_int + 1,
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                              sinc_win, 3, pitch_delay_frac + 1,
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                              LP_FILTER_ORDER, L_SUBFR_16k);
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        memset(fixed_vector, 0, sizeof(fixed_vector));
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        ff_decode_10_pulses_35bits(params->fc_indexes[i], &f,
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                                   ff_fc_4pulses_8bits_tracks_13, 5, 4);
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        ff_set_fixed_vector(fixed_vector, &f, 1.0, L_SUBFR_16k);
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        gain_corr_factor = gain_cb_16k[params->gc_index[i]];
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        gain_code = gain_corr_factor *
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            acelp_decode_gain_codef(sqrt(L_SUBFR_16k), fixed_vector,
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                                    19.0 - 15.0/(0.05*M_LN10/M_LN2),
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                                    pred_16k, ctx->energy_history,
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                                    L_SUBFR_16k, 2);
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        ctx->energy_history[1] = ctx->energy_history[0];
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        ctx->energy_history[0] = 20.0 * log10f(gain_corr_factor);
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        ff_weighted_vector_sumf(&excitation[i_subfr], &excitation[i_subfr],
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                                fixed_vector, pitch_fac,
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                                gain_code, L_SUBFR_16k);
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        ff_celp_lp_synthesis_filterf(synth + i_subfr, Az[i],
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                                     &excitation[i_subfr], L_SUBFR_16k,
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                                     LP_FILTER_ORDER_16k);
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    }
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    memcpy(ctx->synth, synth + frame_size - LP_FILTER_ORDER_16k,
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           LP_FILTER_ORDER_16k * sizeof(*synth));
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    memmove(ctx->excitation, ctx->excitation + 2 * L_SUBFR_16k,
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            (L_INTERPOL+PITCH_MAX) * sizeof(float));
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    postfilter(out_data, synth, ctx->iir_mem, ctx->filt_mem, ctx->mem_preemph);
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    memcpy(ctx->iir_mem, Az[1], LP_FILTER_ORDER_16k * sizeof(float));
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}
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void ff_sipr_init_16k(SiprContext *ctx)
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{
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    int i;
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    for (i = 0; i < LP_FILTER_ORDER_16k; i++)
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        ctx->lsp_history_16k[i] = cos((i + 1) * M_PI/(LP_FILTER_ORDER_16k + 1));
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    ctx->filt_mem[0] = ctx->filt_buf[0];
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    ctx->filt_mem[1] = ctx->filt_buf[1];
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    ctx->pitch_lag_prev = 180;
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}