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/*
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 * SIPR / ACELP.NET decoder
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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 FFmpeg.
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 *
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 * FFmpeg 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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 * FFmpeg 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 FFmpeg; 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 <stdint.h>
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#include "libavutil/mathematics.h"
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#include "avcodec.h"
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#define ALT_BITSTREAM_READER_LE
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#include "get_bits.h"
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#include "dsputil.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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#define MAX_SUBFRAME_COUNT   5
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#include "sipr.h"
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#include "siprdata.h"
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typedef struct {
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    const char *mode_name;
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    uint16_t bits_per_frame;
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    uint8_t subframe_count;
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    uint8_t frames_per_packet;
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    float pitch_sharp_factor;
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    /* bitstream parameters */
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    uint8_t number_of_fc_indexes;
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    /** size in bits of the i-th stage vector of quantizer */
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    uint8_t vq_indexes_bits[5];
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    /** size in bits of the adaptive-codebook index for every subframe */
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    uint8_t pitch_delay_bits[5];
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    uint8_t gp_index_bits;
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    uint8_t fc_index_bits[10]; ///< size in bits of the fixed codebook indexes
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    uint8_t gc_index_bits;     ///< size in bits of the gain  codebook indexes
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} SiprModeParam;
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static const SiprModeParam modes[MODE_COUNT] = {
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    [MODE_8k5] = {
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        .mode_name          = "8k5",
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        .bits_per_frame     = 152,
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        .subframe_count     = 3,
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        .frames_per_packet  = 1,
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        .pitch_sharp_factor = 0.8,
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        .number_of_fc_indexes = 3,
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        .vq_indexes_bits      = {6, 7, 7, 7, 5},
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        .pitch_delay_bits     = {8, 5, 5},
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        .gp_index_bits        = 0,
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        .fc_index_bits        = {9, 9, 9},
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        .gc_index_bits        = 7
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    },
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    [MODE_6k5] = {
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        .mode_name          = "6k5",
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        .bits_per_frame     = 232,
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        .subframe_count     = 3,
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        .frames_per_packet  = 2,
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        .pitch_sharp_factor = 0.8,
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        .number_of_fc_indexes = 3,
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        .vq_indexes_bits      = {6, 7, 7, 7, 5},
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        .pitch_delay_bits     = {8, 5, 5},
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        .gp_index_bits        = 0,
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        .fc_index_bits        = {5, 5, 5},
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        .gc_index_bits        = 7
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    },
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    [MODE_5k0] = {
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        .mode_name          = "5k0",
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        .bits_per_frame     = 296,
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        .subframe_count     = 5,
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        .frames_per_packet  = 2,
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        .pitch_sharp_factor = 0.85,
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        .number_of_fc_indexes = 1,
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        .vq_indexes_bits      = {6, 7, 7, 7, 5},
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        .pitch_delay_bits     = {8, 5, 8, 5, 5},
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        .gp_index_bits        = 0,
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        .fc_index_bits        = {10},
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        .gc_index_bits        = 7
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    }
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};
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113
static void dequant(float *out, const int *idx, const float *cbs[])
114
{
115
    int i;
116
    int stride  = 2;
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    int num_vec = 5;
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    for (i = 0; i < num_vec; i++)
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        memcpy(out + stride*i, cbs[i] + stride*idx[i], stride*sizeof(float));
121

    
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}
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static void lsf_decode_fp(float *lsfnew, float *lsf_history,
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                          const SiprParameters *parm)
126
{
127
    int i;
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    float lsf_tmp[LP_FILTER_ORDER];
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    dequant(lsf_tmp, parm->vq_indexes, lsf_codebooks);
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    for (i = 0; i < LP_FILTER_ORDER; i++)
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        lsfnew[i] = lsf_history[i] * 0.33 + lsf_tmp[i] + mean_lsf[i];
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    ff_sort_nearly_sorted_floats(lsfnew, LP_FILTER_ORDER - 1);
136

    
137
    /* Note that a minimum distance is not enforced between the last value and
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       the previous one, contrary to what is done in ff_acelp_reorder_lsf() */
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    ff_set_min_dist_lsf(lsfnew, LSFQ_DIFF_MIN, LP_FILTER_ORDER - 1);
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    lsfnew[9] = FFMIN(lsfnew[LP_FILTER_ORDER - 1], 1.3 * M_PI);
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    memcpy(lsf_history, lsf_tmp, LP_FILTER_ORDER * sizeof(*lsf_history));
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    for (i = 0; i < LP_FILTER_ORDER - 1; i++)
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        lsfnew[i] = cos(lsfnew[i]);
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    lsfnew[LP_FILTER_ORDER - 1] *= 6.153848 / M_PI;
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}
148

    
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/** Apply pitch lag to the fixed vector (AMR section 6.1.2). */
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static void pitch_sharpening(int pitch_lag_int, float beta,
151
                             float *fixed_vector)
152
{
153
    int i;
154

    
155
    for (i = pitch_lag_int; i < SUBFR_SIZE; i++)
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        fixed_vector[i] += beta * fixed_vector[i - pitch_lag_int];
157
}
158

    
159
/**
160
 * Extracts decoding parameters from the input bitstream.
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 * @param parms          parameters structure
162
 * @param pgb            pointer to initialized GetBitContext structure
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 */
164
static void decode_parameters(SiprParameters* parms, GetBitContext *pgb,
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                              const SiprModeParam *p)
166
{
167
    int i, j;
168

    
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    for (i = 0; i < 5; i++)
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        parms->vq_indexes[i]        = get_bits(pgb, p->vq_indexes_bits[i]);
171

    
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    for (i = 0; i < p->subframe_count; i++) {
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        parms->pitch_delay[i]       = get_bits(pgb, p->pitch_delay_bits[i]);
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        parms->gp_index[i]          = get_bits(pgb, p->gp_index_bits);
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        for (j = 0; j < p->number_of_fc_indexes; j++)
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            parms->fc_indexes[i][j] = get_bits(pgb, p->fc_index_bits[j]);
178

    
179
        parms->gc_index[i]          = get_bits(pgb, p->gc_index_bits);
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    }
181
}
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183
static void lsp2lpc_sipr(const double *lsp, float *Az)
184
{
185
    int lp_half_order = LP_FILTER_ORDER >> 1;
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    double buf[(LP_FILTER_ORDER >> 1) + 1];
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    double pa[(LP_FILTER_ORDER >> 1) + 1];
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    double *qa = buf + 1;
189
    int i,j;
190

    
191
    qa[-1] = 0.0;
192

    
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    ff_lsp2polyf(lsp    , pa, lp_half_order    );
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    ff_lsp2polyf(lsp + 1, qa, lp_half_order - 1);
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    for (i = 1, j = LP_FILTER_ORDER - 1; i < lp_half_order; i++, j--) {
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        double paf =  pa[i]            * (1 + lsp[LP_FILTER_ORDER - 1]);
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        double qaf = (qa[i] - qa[i-2]) * (1 - lsp[LP_FILTER_ORDER - 1]);
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        Az[i-1]  = (paf + qaf) * 0.5;
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        Az[j-1]  = (paf - qaf) * 0.5;
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    }
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    Az[lp_half_order - 1] = (1.0 + lsp[LP_FILTER_ORDER - 1]) *
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        pa[lp_half_order] * 0.5;
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    Az[LP_FILTER_ORDER - 1] = lsp[LP_FILTER_ORDER - 1];
207
}
208

    
209
static void sipr_decode_lp(float *lsfnew, const float *lsfold, float *Az,
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                           int num_subfr)
211
{
212
    double lsfint[LP_FILTER_ORDER];
213
    int i,j;
214
    float t, t0 = 1.0 / num_subfr;
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    t = t0 * 0.5;
217
    for (i = 0; i < num_subfr; i++) {
218
        for (j = 0; j < LP_FILTER_ORDER; j++)
219
            lsfint[j] = lsfold[j] * (1 - t) + t * lsfnew[j];
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221
        lsp2lpc_sipr(lsfint, Az);
222
        Az += LP_FILTER_ORDER;
223
        t += t0;
224
    }
225
}
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227
/**
228
 * Evaluates the adaptative impulse response.
229
 */
230
static void eval_ir(const float *Az, int pitch_lag, float *freq,
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                    float pitch_sharp_factor)
232
{
233
    float tmp1[SUBFR_SIZE+1], tmp2[LP_FILTER_ORDER+1];
234
    int i;
235

    
236
    tmp1[0] = 1.;
237
    for (i = 0; i < LP_FILTER_ORDER; i++) {
238
        tmp1[i+1] = Az[i] * ff_pow_0_55[i];
239
        tmp2[i  ] = Az[i] * ff_pow_0_7 [i];
240
    }
241
    memset(tmp1 + 11, 0, 37 * sizeof(float));
242

    
243
    ff_celp_lp_synthesis_filterf(freq, tmp2, tmp1, SUBFR_SIZE,
244
                                 LP_FILTER_ORDER);
245

    
246
    pitch_sharpening(pitch_lag, pitch_sharp_factor, freq);
247
}
248

    
249
/**
250
 * Evaluates the convolution of a vector with a sparse vector.
251
 */
252
static void convolute_with_sparse(float *out, const AMRFixed *pulses,
253
                                  const float *shape, int length)
254
{
255
    int i, j;
256

    
257
    memset(out, 0, length*sizeof(float));
258
    for (i = 0; i < pulses->n; i++)
259
        for (j = pulses->x[i]; j < length; j++)
260
            out[j] += pulses->y[i] * shape[j - pulses->x[i]];
261
}
262

    
263
/**
264
 * Apply postfilter, very similar to AMR one.
265
 */
266
static void postfilter_5k0(SiprContext *ctx, const float *lpc, float *samples)
267
{
268
    float buf[SUBFR_SIZE + LP_FILTER_ORDER];
269
    float *pole_out = buf + LP_FILTER_ORDER;
270
    float lpc_n[LP_FILTER_ORDER];
271
    float lpc_d[LP_FILTER_ORDER];
272
    int i;
273

    
274
    for (i = 0; i < LP_FILTER_ORDER; i++) {
275
        lpc_d[i] = lpc[i] * ff_pow_0_75[i];
276
        lpc_n[i] = lpc[i] *    pow_0_5 [i];
277
    };
278

    
279
    memcpy(pole_out - LP_FILTER_ORDER, ctx->postfilter_mem,
280
           LP_FILTER_ORDER*sizeof(float));
281

    
282
    ff_celp_lp_synthesis_filterf(pole_out, lpc_d, samples, SUBFR_SIZE,
283
                                 LP_FILTER_ORDER);
284

    
285
    memcpy(ctx->postfilter_mem, pole_out + SUBFR_SIZE - LP_FILTER_ORDER,
286
           LP_FILTER_ORDER*sizeof(float));
287

    
288
    ff_tilt_compensation(&ctx->tilt_mem, 0.4, pole_out, SUBFR_SIZE);
289

    
290
    memcpy(pole_out - LP_FILTER_ORDER, ctx->postfilter_mem5k0,
291
           LP_FILTER_ORDER*sizeof(*pole_out));
292

    
293
    memcpy(ctx->postfilter_mem5k0, pole_out + SUBFR_SIZE - LP_FILTER_ORDER,
294
           LP_FILTER_ORDER*sizeof(*pole_out));
295

    
296
    ff_celp_lp_zero_synthesis_filterf(samples, lpc_n, pole_out, SUBFR_SIZE,
297
                                      LP_FILTER_ORDER);
298

    
299
}
300

    
301
static void decode_fixed_sparse(AMRFixed *fixed_sparse, const int16_t *pulses,
302
                                SiprMode mode, int low_gain)
303
{
304
    int i;
305

    
306
    switch (mode) {
307
    case MODE_6k5:
308
        for (i = 0; i < 3; i++) {
309
            fixed_sparse->x[i] = 3 * (pulses[i] & 0xf) + i;
310
            fixed_sparse->y[i] = pulses[i] & 0x10 ? -1 : 1;
311
        }
312
        fixed_sparse->n = 3;
313
        break;
314
    case MODE_8k5:
315
        for (i = 0; i < 3; i++) {
316
            fixed_sparse->x[2*i    ] = 3 * ((pulses[i] >> 4) & 0xf) + i;
317
            fixed_sparse->x[2*i + 1] = 3 * ( pulses[i]       & 0xf) + i;
318

    
319
            fixed_sparse->y[2*i    ] = (pulses[i] & 0x100) ? -1.0: 1.0;
320

    
321
            fixed_sparse->y[2*i + 1] =
322
                (fixed_sparse->x[2*i + 1] < fixed_sparse->x[2*i]) ?
323
                -fixed_sparse->y[2*i    ] : fixed_sparse->y[2*i];
324
        }
325

    
326
        fixed_sparse->n = 6;
327
        break;
328
    case MODE_5k0:
329
    default:
330
        if (low_gain) {
331
            int offset = (pulses[0] & 0x200) ? 2 : 0;
332
            int val = pulses[0];
333

    
334
            for (i = 0; i < 3; i++) {
335
                int index = (val & 0x7) * 6 + 4 - i*2;
336

    
337
                fixed_sparse->y[i] = (offset + index) & 0x3 ? -1 : 1;
338
                fixed_sparse->x[i] = index;
339

    
340
                val >>= 3;
341
            }
342
            fixed_sparse->n = 3;
343
        } else {
344
            int pulse_subset = (pulses[0] >> 8) & 1;
345

    
346
            fixed_sparse->x[0] = ((pulses[0] >> 4) & 15) * 3 + pulse_subset;
347
            fixed_sparse->x[1] = ( pulses[0]       & 15) * 3 + pulse_subset + 1;
348

    
349
            fixed_sparse->y[0] = pulses[0] & 0x200 ? -1 : 1;
350
            fixed_sparse->y[1] = -fixed_sparse->y[0];
351
            fixed_sparse->n = 2;
352
        }
353
        break;
354
    }
355
}
356

    
357
static void decode_frame(SiprContext *ctx, SiprParameters *params,
358
                         float *out_data)
359
{
360
    int i, j;
361
    int subframe_count = modes[ctx->mode].subframe_count;
362
    int frame_size = subframe_count * SUBFR_SIZE;
363
    float Az[LP_FILTER_ORDER * MAX_SUBFRAME_COUNT];
364
    float *excitation;
365
    float ir_buf[SUBFR_SIZE + LP_FILTER_ORDER];
366
    float lsf_new[LP_FILTER_ORDER];
367
    float *impulse_response = ir_buf + LP_FILTER_ORDER;
368
    float *synth = ctx->synth_buf + 16; // 16 instead of LP_FILTER_ORDER for
369
                                        // memory alignment
370
    int t0_first = 0;
371
    AMRFixed fixed_cb;
372

    
373
    memset(ir_buf, 0, LP_FILTER_ORDER * sizeof(float));
374
    lsf_decode_fp(lsf_new, ctx->lsf_history, params);
375

    
376
    sipr_decode_lp(lsf_new, ctx->lsp_history, Az, subframe_count);
377

    
378
    memcpy(ctx->lsp_history, lsf_new, LP_FILTER_ORDER * sizeof(float));
379

    
380
    excitation = ctx->excitation + PITCH_DELAY_MAX + L_INTERPOL;
381

    
382
    for (i = 0; i < subframe_count; i++) {
383
        float *pAz = Az + i*LP_FILTER_ORDER;
384
        float fixed_vector[SUBFR_SIZE];
385
        int T0,T0_frac;
386
        float pitch_gain, gain_code, avg_energy;
387

    
388
        ff_decode_pitch_lag(&T0, &T0_frac, params->pitch_delay[i], t0_first, i,
389
                            ctx->mode == MODE_5k0, 6);
390

    
391
        if (i == 0 || (i == 2 && ctx->mode == MODE_5k0))
392
            t0_first = T0;
393

    
394
        ff_acelp_interpolatef(excitation, excitation - T0 + (T0_frac <= 0),
395
                              ff_b60_sinc, 6,
396
                              2 * ((2 + T0_frac)%3 + 1), LP_FILTER_ORDER,
397
                              SUBFR_SIZE);
398

    
399
        decode_fixed_sparse(&fixed_cb, params->fc_indexes[i], ctx->mode,
400
                            ctx->past_pitch_gain < 0.8);
401

    
402
        eval_ir(pAz, T0, impulse_response, modes[ctx->mode].pitch_sharp_factor);
403

    
404
        convolute_with_sparse(fixed_vector, &fixed_cb, impulse_response,
405
                              SUBFR_SIZE);
406

    
407
        avg_energy =
408
            (0.01 + ff_dot_productf(fixed_vector, fixed_vector, SUBFR_SIZE))/
409
                SUBFR_SIZE;
410

    
411
        ctx->past_pitch_gain = pitch_gain = gain_cb[params->gc_index[i]][0];
412

    
413
        gain_code = ff_amr_set_fixed_gain(gain_cb[params->gc_index[i]][1],
414
                                          avg_energy, ctx->energy_history,
415
                                          34 - 15.0/(0.05*M_LN10/M_LN2),
416
                                          pred);
417

    
418
        ff_weighted_vector_sumf(excitation, excitation, fixed_vector,
419
                                pitch_gain, gain_code, SUBFR_SIZE);
420

    
421
        pitch_gain *= 0.5 * pitch_gain;
422
        pitch_gain = FFMIN(pitch_gain, 0.4);
423

    
424
        ctx->gain_mem = 0.7 * ctx->gain_mem + 0.3 * pitch_gain;
425
        ctx->gain_mem = FFMIN(ctx->gain_mem, pitch_gain);
426
        gain_code *= ctx->gain_mem;
427

    
428
        for (j = 0; j < SUBFR_SIZE; j++)
429
            fixed_vector[j] = excitation[j] - gain_code * fixed_vector[j];
430

    
431
        if (ctx->mode == MODE_5k0) {
432
            postfilter_5k0(ctx, pAz, fixed_vector);
433

    
434
            ff_celp_lp_synthesis_filterf(ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i*SUBFR_SIZE,
435
                                         pAz, excitation, SUBFR_SIZE,
436
                                         LP_FILTER_ORDER);
437
        }
438

    
439
        ff_celp_lp_synthesis_filterf(synth + i*SUBFR_SIZE, pAz, fixed_vector,
440
                                     SUBFR_SIZE, LP_FILTER_ORDER);
441

    
442
        excitation += SUBFR_SIZE;
443
    }
444

    
445
    memcpy(synth - LP_FILTER_ORDER, synth + frame_size - LP_FILTER_ORDER,
446
           LP_FILTER_ORDER * sizeof(float));
447

    
448
    if (ctx->mode == MODE_5k0) {
449
        for (i = 0; i < subframe_count; i++) {
450
            float energy = ff_dot_productf(ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i*SUBFR_SIZE,
451
                                           ctx->postfilter_syn5k0 + LP_FILTER_ORDER + i*SUBFR_SIZE,
452
                                           SUBFR_SIZE);
453
            ff_adaptative_gain_control(&synth[i * SUBFR_SIZE], energy,
454
                                       SUBFR_SIZE, 0.9, &ctx->postfilter_agc);
455
        }
456

    
457
        memcpy(ctx->postfilter_syn5k0, ctx->postfilter_syn5k0 + frame_size,
458
               LP_FILTER_ORDER*sizeof(float));
459
    }
460
    memcpy(ctx->excitation, excitation - PITCH_DELAY_MAX - L_INTERPOL,
461
           (PITCH_DELAY_MAX + L_INTERPOL) * sizeof(float));
462

    
463
    ff_acelp_apply_order_2_transfer_function(synth,
464
                                             (const float[2]) {-1.99997   , 1.000000000},
465
                                             (const float[2]) {-1.93307352, 0.935891986},
466
                                             0.939805806,
467
                                             ctx->highpass_filt_mem,
468
                                             frame_size);
469

    
470
    ctx->dsp.vector_clipf(out_data, synth, -1, 32767./(1<<15), frame_size);
471

    
472
}
473

    
474
static av_cold int sipr_decoder_init(AVCodecContext * avctx)
475
{
476
    SiprContext *ctx = avctx->priv_data;
477
    int i;
478

    
479
    if      (avctx->bit_rate > 12200) ctx->mode = MODE_16k;
480
    else if (avctx->bit_rate > 7500 ) ctx->mode = MODE_8k5;
481
    else if (avctx->bit_rate > 5750 ) ctx->mode = MODE_6k5;
482
    else                              ctx->mode = MODE_5k0;
483

    
484
    av_log(avctx, AV_LOG_DEBUG, "Mode: %s\n", modes[ctx->mode].mode_name);
485

    
486
    for (i = 0; i < LP_FILTER_ORDER; i++)
487
        ctx->lsp_history[i] = cos((i+1) * M_PI / (LP_FILTER_ORDER + 1));
488

    
489
    for (i = 0; i < 4; i++)
490
        ctx->energy_history[i] = -14;
491

    
492
    avctx->sample_fmt = SAMPLE_FMT_FLT;
493

    
494
    if (ctx->mode == MODE_16k) {
495
        av_log(avctx, AV_LOG_ERROR, "decoding 16kbps SIPR files is not "
496
                                    "supported yet.\n");
497
        return -1;
498
    }
499

    
500
    dsputil_init(&ctx->dsp, avctx);
501

    
502
    return 0;
503
}
504

    
505
static int sipr_decode_frame(AVCodecContext *avctx, void *datap,
506
                             int *data_size, AVPacket *avpkt)
507
{
508
    SiprContext *ctx = avctx->priv_data;
509
    const uint8_t *buf=avpkt->data;
510
    SiprParameters parm;
511
    const SiprModeParam *mode_par = &modes[ctx->mode];
512
    GetBitContext gb;
513
    float *data = datap;
514
    int i;
515

    
516
    ctx->avctx = avctx;
517
    if (avpkt->size < (mode_par->bits_per_frame >> 3)) {
518
        av_log(avctx, AV_LOG_ERROR,
519
               "Error processing packet: packet size (%d) too small\n",
520
               avpkt->size);
521

    
522
        *data_size = 0;
523
        return -1;
524
    }
525
    if (*data_size < SUBFR_SIZE * mode_par->subframe_count * sizeof(float)) {
526
        av_log(avctx, AV_LOG_ERROR,
527
               "Error processing packet: output buffer (%d) too small\n",
528
               *data_size);
529

    
530
        *data_size = 0;
531
        return -1;
532
    }
533

    
534
    init_get_bits(&gb, buf, mode_par->bits_per_frame);
535

    
536
    for (i = 0; i < mode_par->frames_per_packet; i++) {
537
        decode_parameters(&parm, &gb, mode_par);
538
        decode_frame(ctx, &parm, data);
539

    
540
        data += SUBFR_SIZE * mode_par->subframe_count;
541
    }
542

    
543
    *data_size = mode_par->frames_per_packet * SUBFR_SIZE *
544
        mode_par->subframe_count * sizeof(float);
545

    
546
    return mode_par->bits_per_frame >> 3;
547
};
548

    
549
AVCodec sipr_decoder = {
550
    "sipr",
551
    CODEC_TYPE_AUDIO,
552
    CODEC_ID_SIPR,
553
    sizeof(SiprContext),
554
    sipr_decoder_init,
555
    NULL,
556
    NULL,
557
    sipr_decode_frame,
558
    .long_name = NULL_IF_CONFIG_SMALL("RealAudio SIPR / ACELP.NET"),
559
};