xref: /third_party/ffmpeg/libavcodec/amrwbdec.c (revision cabdff1a)
1/*
2 * AMR wideband decoder
3 * Copyright (c) 2010 Marcelo Galvao Povoa
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A particular PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * AMR wideband decoder
25 */
26
27#include "libavutil/channel_layout.h"
28#include "libavutil/common.h"
29#include "libavutil/float_dsp.h"
30#include "libavutil/lfg.h"
31
32#include "avcodec.h"
33#include "lsp.h"
34#include "celp_filters.h"
35#include "celp_math.h"
36#include "acelp_filters.h"
37#include "acelp_vectors.h"
38#include "acelp_pitch_delay.h"
39#include "codec_internal.h"
40#include "internal.h"
41
42#define AMR_USE_16BIT_TABLES
43#include "amr.h"
44
45#include "amrwbdata.h"
46#include "mips/amrwbdec_mips.h"
47
48typedef struct AMRWBContext {
49    AMRWBFrame                             frame; ///< AMRWB parameters decoded from bitstream
50    enum Mode                        fr_cur_mode; ///< mode index of current frame
51    uint8_t                           fr_quality; ///< frame quality index (FQI)
52    float                      isf_cur[LP_ORDER]; ///< working ISF vector from current frame
53    float                   isf_q_past[LP_ORDER]; ///< quantized ISF vector of the previous frame
54    float               isf_past_final[LP_ORDER]; ///< final processed ISF vector of the previous frame
55    double                      isp[4][LP_ORDER]; ///< ISP vectors from current frame
56    double               isp_sub4_past[LP_ORDER]; ///< ISP vector for the 4th subframe of the previous frame
57
58    float                   lp_coef[4][LP_ORDER]; ///< Linear Prediction Coefficients from ISP vector
59
60    uint8_t                       base_pitch_lag; ///< integer part of pitch lag for the next relative subframe
61    uint8_t                        pitch_lag_int; ///< integer part of pitch lag of the previous subframe
62
63    float excitation_buf[AMRWB_P_DELAY_MAX + LP_ORDER + 2 + AMRWB_SFR_SIZE]; ///< current excitation and all necessary excitation history
64    float                            *excitation; ///< points to current excitation in excitation_buf[]
65
66    float           pitch_vector[AMRWB_SFR_SIZE]; ///< adaptive codebook (pitch) vector for current subframe
67    float           fixed_vector[AMRWB_SFR_SIZE]; ///< algebraic codebook (fixed) vector for current subframe
68
69    float                    prediction_error[4]; ///< quantified prediction errors {20log10(^gamma_gc)} for previous four subframes
70    float                          pitch_gain[6]; ///< quantified pitch gains for the current and previous five subframes
71    float                          fixed_gain[2]; ///< quantified fixed gains for the current and previous subframes
72
73    float                              tilt_coef; ///< {beta_1} related to the voicing of the previous subframe
74
75    float                 prev_sparse_fixed_gain; ///< previous fixed gain; used by anti-sparseness to determine "onset"
76    uint8_t                    prev_ir_filter_nr; ///< previous impulse response filter "impNr": 0 - strong, 1 - medium, 2 - none
77    float                           prev_tr_gain; ///< previous initial gain used by noise enhancer for threshold
78
79    float samples_az[LP_ORDER + AMRWB_SFR_SIZE];         ///< low-band samples and memory from synthesis at 12.8kHz
80    float samples_up[UPS_MEM_SIZE + AMRWB_SFR_SIZE];     ///< low-band samples and memory processed for upsampling
81    float samples_hb[LP_ORDER_16k + AMRWB_SFR_SIZE_16k]; ///< high-band samples and memory from synthesis at 16kHz
82
83    float          hpf_31_mem[2], hpf_400_mem[2]; ///< previous values in the high pass filters
84    float                           demph_mem[1]; ///< previous value in the de-emphasis filter
85    float               bpf_6_7_mem[HB_FIR_SIZE]; ///< previous values in the high-band band pass filter
86    float                 lpf_7_mem[HB_FIR_SIZE]; ///< previous values in the high-band low pass filter
87
88    AVLFG                                   prng; ///< random number generator for white noise excitation
89    uint8_t                          first_frame; ///< flag active during decoding of the first frame
90    ACELPFContext                     acelpf_ctx; ///< context for filters for ACELP-based codecs
91    ACELPVContext                     acelpv_ctx; ///< context for vector operations for ACELP-based codecs
92    CELPFContext                       celpf_ctx; ///< context for filters for CELP-based codecs
93    CELPMContext                       celpm_ctx; ///< context for fixed point math operations
94
95} AMRWBContext;
96
97typedef struct AMRWBChannelsContext {
98    AMRWBContext ch[2];
99} AMRWBChannelsContext;
100
101static av_cold int amrwb_decode_init(AVCodecContext *avctx)
102{
103    AMRWBChannelsContext *s = avctx->priv_data;
104    int i;
105
106    if (avctx->ch_layout.nb_channels > 2) {
107        avpriv_report_missing_feature(avctx, ">2 channel AMR");
108        return AVERROR_PATCHWELCOME;
109    }
110
111    if (!avctx->ch_layout.nb_channels) {
112        av_channel_layout_uninit(&avctx->ch_layout);
113        avctx->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
114    }
115    if (!avctx->sample_rate)
116        avctx->sample_rate = 16000;
117    avctx->sample_fmt     = AV_SAMPLE_FMT_FLTP;
118
119    for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
120        AMRWBContext *ctx = &s->ch[ch];
121
122        av_lfg_init(&ctx->prng, 1);
123
124        ctx->excitation  = &ctx->excitation_buf[AMRWB_P_DELAY_MAX + LP_ORDER + 1];
125        ctx->first_frame = 1;
126
127        for (i = 0; i < LP_ORDER; i++)
128            ctx->isf_past_final[i] = isf_init[i] * (1.0f / (1 << 15));
129
130        for (i = 0; i < 4; i++)
131            ctx->prediction_error[i] = MIN_ENERGY;
132
133        ff_acelp_filter_init(&ctx->acelpf_ctx);
134        ff_acelp_vectors_init(&ctx->acelpv_ctx);
135        ff_celp_filter_init(&ctx->celpf_ctx);
136        ff_celp_math_init(&ctx->celpm_ctx);
137    }
138
139    return 0;
140}
141
142/**
143 * Decode the frame header in the "MIME/storage" format. This format
144 * is simpler and does not carry the auxiliary frame information.
145 *
146 * @param[in] ctx                  The Context
147 * @param[in] buf                  Pointer to the input buffer
148 *
149 * @return The decoded header length in bytes
150 */
151static int decode_mime_header(AMRWBContext *ctx, const uint8_t *buf)
152{
153    /* Decode frame header (1st octet) */
154    ctx->fr_cur_mode  = buf[0] >> 3 & 0x0F;
155    ctx->fr_quality   = (buf[0] & 0x4) == 0x4;
156
157    return 1;
158}
159
160/**
161 * Decode quantized ISF vectors using 36-bit indexes (6K60 mode only).
162 *
163 * @param[in]  ind                 Array of 5 indexes
164 * @param[out] isf_q               Buffer for isf_q[LP_ORDER]
165 */
166static void decode_isf_indices_36b(uint16_t *ind, float *isf_q)
167{
168    int i;
169
170    for (i = 0; i < 9; i++)
171        isf_q[i]      = dico1_isf[ind[0]][i]      * (1.0f / (1 << 15));
172
173    for (i = 0; i < 7; i++)
174        isf_q[i + 9]  = dico2_isf[ind[1]][i]      * (1.0f / (1 << 15));
175
176    for (i = 0; i < 5; i++)
177        isf_q[i]     += dico21_isf_36b[ind[2]][i] * (1.0f / (1 << 15));
178
179    for (i = 0; i < 4; i++)
180        isf_q[i + 5] += dico22_isf_36b[ind[3]][i] * (1.0f / (1 << 15));
181
182    for (i = 0; i < 7; i++)
183        isf_q[i + 9] += dico23_isf_36b[ind[4]][i] * (1.0f / (1 << 15));
184}
185
186/**
187 * Decode quantized ISF vectors using 46-bit indexes (except 6K60 mode).
188 *
189 * @param[in]  ind                 Array of 7 indexes
190 * @param[out] isf_q               Buffer for isf_q[LP_ORDER]
191 */
192static void decode_isf_indices_46b(uint16_t *ind, float *isf_q)
193{
194    int i;
195
196    for (i = 0; i < 9; i++)
197        isf_q[i]       = dico1_isf[ind[0]][i]  * (1.0f / (1 << 15));
198
199    for (i = 0; i < 7; i++)
200        isf_q[i + 9]   = dico2_isf[ind[1]][i]  * (1.0f / (1 << 15));
201
202    for (i = 0; i < 3; i++)
203        isf_q[i]      += dico21_isf[ind[2]][i] * (1.0f / (1 << 15));
204
205    for (i = 0; i < 3; i++)
206        isf_q[i + 3]  += dico22_isf[ind[3]][i] * (1.0f / (1 << 15));
207
208    for (i = 0; i < 3; i++)
209        isf_q[i + 6]  += dico23_isf[ind[4]][i] * (1.0f / (1 << 15));
210
211    for (i = 0; i < 3; i++)
212        isf_q[i + 9]  += dico24_isf[ind[5]][i] * (1.0f / (1 << 15));
213
214    for (i = 0; i < 4; i++)
215        isf_q[i + 12] += dico25_isf[ind[6]][i] * (1.0f / (1 << 15));
216}
217
218/**
219 * Apply mean and past ISF values using the prediction factor.
220 * Updates past ISF vector.
221 *
222 * @param[in,out] isf_q            Current quantized ISF
223 * @param[in,out] isf_past         Past quantized ISF
224 */
225static void isf_add_mean_and_past(float *isf_q, float *isf_past)
226{
227    int i;
228    float tmp;
229
230    for (i = 0; i < LP_ORDER; i++) {
231        tmp = isf_q[i];
232        isf_q[i] += isf_mean[i] * (1.0f / (1 << 15));
233        isf_q[i] += PRED_FACTOR * isf_past[i];
234        isf_past[i] = tmp;
235    }
236}
237
238/**
239 * Interpolate the fourth ISP vector from current and past frames
240 * to obtain an ISP vector for each subframe.
241 *
242 * @param[in,out] isp_q            ISPs for each subframe
243 * @param[in]     isp4_past        Past ISP for subframe 4
244 */
245static void interpolate_isp(double isp_q[4][LP_ORDER], const double *isp4_past)
246{
247    int i, k;
248
249    for (k = 0; k < 3; k++) {
250        float c = isfp_inter[k];
251        for (i = 0; i < LP_ORDER; i++)
252            isp_q[k][i] = (1.0 - c) * isp4_past[i] + c * isp_q[3][i];
253    }
254}
255
256/**
257 * Decode an adaptive codebook index into pitch lag (except 6k60, 8k85 modes).
258 * Calculate integer lag and fractional lag always using 1/4 resolution.
259 * In 1st and 3rd subframes the index is relative to last subframe integer lag.
260 *
261 * @param[out]    lag_int          Decoded integer pitch lag
262 * @param[out]    lag_frac         Decoded fractional pitch lag
263 * @param[in]     pitch_index      Adaptive codebook pitch index
264 * @param[in,out] base_lag_int     Base integer lag used in relative subframes
265 * @param[in]     subframe         Current subframe index (0 to 3)
266 */
267static void decode_pitch_lag_high(int *lag_int, int *lag_frac, int pitch_index,
268                                  uint8_t *base_lag_int, int subframe)
269{
270    if (subframe == 0 || subframe == 2) {
271        if (pitch_index < 376) {
272            *lag_int  = (pitch_index + 137) >> 2;
273            *lag_frac = pitch_index - (*lag_int << 2) + 136;
274        } else if (pitch_index < 440) {
275            *lag_int  = (pitch_index + 257 - 376) >> 1;
276            *lag_frac = (pitch_index - (*lag_int << 1) + 256 - 376) * 2;
277            /* the actual resolution is 1/2 but expressed as 1/4 */
278        } else {
279            *lag_int  = pitch_index - 280;
280            *lag_frac = 0;
281        }
282        /* minimum lag for next subframe */
283        *base_lag_int = av_clip(*lag_int - 8 - (*lag_frac < 0),
284                                AMRWB_P_DELAY_MIN, AMRWB_P_DELAY_MAX - 15);
285        // XXX: the spec states clearly that *base_lag_int should be
286        // the nearest integer to *lag_int (minus 8), but the ref code
287        // actually always uses its floor, I'm following the latter
288    } else {
289        *lag_int  = (pitch_index + 1) >> 2;
290        *lag_frac = pitch_index - (*lag_int << 2);
291        *lag_int += *base_lag_int;
292    }
293}
294
295/**
296 * Decode an adaptive codebook index into pitch lag for 8k85 and 6k60 modes.
297 * The description is analogous to decode_pitch_lag_high, but in 6k60 the
298 * relative index is used for all subframes except the first.
299 */
300static void decode_pitch_lag_low(int *lag_int, int *lag_frac, int pitch_index,
301                                 uint8_t *base_lag_int, int subframe, enum Mode mode)
302{
303    if (subframe == 0 || (subframe == 2 && mode != MODE_6k60)) {
304        if (pitch_index < 116) {
305            *lag_int  = (pitch_index + 69) >> 1;
306            *lag_frac = (pitch_index - (*lag_int << 1) + 68) * 2;
307        } else {
308            *lag_int  = pitch_index - 24;
309            *lag_frac = 0;
310        }
311        // XXX: same problem as before
312        *base_lag_int = av_clip(*lag_int - 8 - (*lag_frac < 0),
313                                AMRWB_P_DELAY_MIN, AMRWB_P_DELAY_MAX - 15);
314    } else {
315        *lag_int  = (pitch_index + 1) >> 1;
316        *lag_frac = (pitch_index - (*lag_int << 1)) * 2;
317        *lag_int += *base_lag_int;
318    }
319}
320
321/**
322 * Find the pitch vector by interpolating the past excitation at the
323 * pitch delay, which is obtained in this function.
324 *
325 * @param[in,out] ctx              The context
326 * @param[in]     amr_subframe     Current subframe data
327 * @param[in]     subframe         Current subframe index (0 to 3)
328 */
329static void decode_pitch_vector(AMRWBContext *ctx,
330                                const AMRWBSubFrame *amr_subframe,
331                                const int subframe)
332{
333    int pitch_lag_int, pitch_lag_frac;
334    int i;
335    float *exc     = ctx->excitation;
336    enum Mode mode = ctx->fr_cur_mode;
337
338    if (mode <= MODE_8k85) {
339        decode_pitch_lag_low(&pitch_lag_int, &pitch_lag_frac, amr_subframe->adap,
340                              &ctx->base_pitch_lag, subframe, mode);
341    } else
342        decode_pitch_lag_high(&pitch_lag_int, &pitch_lag_frac, amr_subframe->adap,
343                              &ctx->base_pitch_lag, subframe);
344
345    ctx->pitch_lag_int = pitch_lag_int;
346    pitch_lag_int += pitch_lag_frac > 0;
347
348    /* Calculate the pitch vector by interpolating the past excitation at the
349       pitch lag using a hamming windowed sinc function */
350    ctx->acelpf_ctx.acelp_interpolatef(exc,
351                          exc + 1 - pitch_lag_int,
352                          ac_inter, 4,
353                          pitch_lag_frac + (pitch_lag_frac > 0 ? 0 : 4),
354                          LP_ORDER, AMRWB_SFR_SIZE + 1);
355
356    /* Check which pitch signal path should be used
357     * 6k60 and 8k85 modes have the ltp flag set to 0 */
358    if (amr_subframe->ltp) {
359        memcpy(ctx->pitch_vector, exc, AMRWB_SFR_SIZE * sizeof(float));
360    } else {
361        for (i = 0; i < AMRWB_SFR_SIZE; i++)
362            ctx->pitch_vector[i] = 0.18 * exc[i - 1] + 0.64 * exc[i] +
363                                   0.18 * exc[i + 1];
364        memcpy(exc, ctx->pitch_vector, AMRWB_SFR_SIZE * sizeof(float));
365    }
366}
367
368/** Get x bits in the index interval [lsb,lsb+len-1] inclusive */
369#define BIT_STR(x,lsb,len) av_mod_uintp2((x) >> (lsb), (len))
370
371/** Get the bit at specified position */
372#define BIT_POS(x, p) (((x) >> (p)) & 1)
373
374/**
375 * The next six functions decode_[i]p_track decode exactly i pulses
376 * positions and amplitudes (-1 or 1) in a subframe track using
377 * an encoded pulse indexing (TS 26.190 section 5.8.2).
378 *
379 * The results are given in out[], in which a negative number means
380 * amplitude -1 and vice versa (i.e., ampl(x) = x / abs(x) ).
381 *
382 * @param[out] out                 Output buffer (writes i elements)
383 * @param[in]  code                Pulse index (no. of bits varies, see below)
384 * @param[in]  m                   (log2) Number of potential positions
385 * @param[in]  off                 Offset for decoded positions
386 */
387static inline void decode_1p_track(int *out, int code, int m, int off)
388{
389    int pos = BIT_STR(code, 0, m) + off; ///code: m+1 bits
390
391    out[0] = BIT_POS(code, m) ? -pos : pos;
392}
393
394static inline void decode_2p_track(int *out, int code, int m, int off) ///code: 2m+1 bits
395{
396    int pos0 = BIT_STR(code, m, m) + off;
397    int pos1 = BIT_STR(code, 0, m) + off;
398
399    out[0] = BIT_POS(code, 2*m) ? -pos0 : pos0;
400    out[1] = BIT_POS(code, 2*m) ? -pos1 : pos1;
401    out[1] = pos0 > pos1 ? -out[1] : out[1];
402}
403
404static void decode_3p_track(int *out, int code, int m, int off) ///code: 3m+1 bits
405{
406    int half_2p = BIT_POS(code, 2*m - 1) << (m - 1);
407
408    decode_2p_track(out, BIT_STR(code, 0, 2*m - 1),
409                    m - 1, off + half_2p);
410    decode_1p_track(out + 2, BIT_STR(code, 2*m, m + 1), m, off);
411}
412
413static void decode_4p_track(int *out, int code, int m, int off) ///code: 4m bits
414{
415    int half_4p, subhalf_2p;
416    int b_offset = 1 << (m - 1);
417
418    switch (BIT_STR(code, 4*m - 2, 2)) { /* case ID (2 bits) */
419    case 0: /* 0 pulses in A, 4 pulses in B or vice versa */
420        half_4p = BIT_POS(code, 4*m - 3) << (m - 1); // which has 4 pulses
421        subhalf_2p = BIT_POS(code, 2*m - 3) << (m - 2);
422
423        decode_2p_track(out, BIT_STR(code, 0, 2*m - 3),
424                        m - 2, off + half_4p + subhalf_2p);
425        decode_2p_track(out + 2, BIT_STR(code, 2*m - 2, 2*m - 1),
426                        m - 1, off + half_4p);
427        break;
428    case 1: /* 1 pulse in A, 3 pulses in B */
429        decode_1p_track(out, BIT_STR(code,  3*m - 2, m),
430                        m - 1, off);
431        decode_3p_track(out + 1, BIT_STR(code, 0, 3*m - 2),
432                        m - 1, off + b_offset);
433        break;
434    case 2: /* 2 pulses in each half */
435        decode_2p_track(out, BIT_STR(code, 2*m - 1, 2*m - 1),
436                        m - 1, off);
437        decode_2p_track(out + 2, BIT_STR(code, 0, 2*m - 1),
438                        m - 1, off + b_offset);
439        break;
440    case 3: /* 3 pulses in A, 1 pulse in B */
441        decode_3p_track(out, BIT_STR(code, m, 3*m - 2),
442                        m - 1, off);
443        decode_1p_track(out + 3, BIT_STR(code, 0, m),
444                        m - 1, off + b_offset);
445        break;
446    }
447}
448
449static void decode_5p_track(int *out, int code, int m, int off) ///code: 5m bits
450{
451    int half_3p = BIT_POS(code, 5*m - 1) << (m - 1);
452
453    decode_3p_track(out, BIT_STR(code, 2*m + 1, 3*m - 2),
454                    m - 1, off + half_3p);
455
456    decode_2p_track(out + 3, BIT_STR(code, 0, 2*m + 1), m, off);
457}
458
459static void decode_6p_track(int *out, int code, int m, int off) ///code: 6m-2 bits
460{
461    int b_offset = 1 << (m - 1);
462    /* which half has more pulses in cases 0 to 2 */
463    int half_more  = BIT_POS(code, 6*m - 5) << (m - 1);
464    int half_other = b_offset - half_more;
465
466    switch (BIT_STR(code, 6*m - 4, 2)) { /* case ID (2 bits) */
467    case 0: /* 0 pulses in A, 6 pulses in B or vice versa */
468        decode_1p_track(out, BIT_STR(code, 0, m),
469                        m - 1, off + half_more);
470        decode_5p_track(out + 1, BIT_STR(code, m, 5*m - 5),
471                        m - 1, off + half_more);
472        break;
473    case 1: /* 1 pulse in A, 5 pulses in B or vice versa */
474        decode_1p_track(out, BIT_STR(code, 0, m),
475                        m - 1, off + half_other);
476        decode_5p_track(out + 1, BIT_STR(code, m, 5*m - 5),
477                        m - 1, off + half_more);
478        break;
479    case 2: /* 2 pulses in A, 4 pulses in B or vice versa */
480        decode_2p_track(out, BIT_STR(code, 0, 2*m - 1),
481                        m - 1, off + half_other);
482        decode_4p_track(out + 2, BIT_STR(code, 2*m - 1, 4*m - 4),
483                        m - 1, off + half_more);
484        break;
485    case 3: /* 3 pulses in A, 3 pulses in B */
486        decode_3p_track(out, BIT_STR(code, 3*m - 2, 3*m - 2),
487                        m - 1, off);
488        decode_3p_track(out + 3, BIT_STR(code, 0, 3*m - 2),
489                        m - 1, off + b_offset);
490        break;
491    }
492}
493
494/**
495 * Decode the algebraic codebook index to pulse positions and signs,
496 * then construct the algebraic codebook vector.
497 *
498 * @param[out] fixed_vector        Buffer for the fixed codebook excitation
499 * @param[in]  pulse_hi            MSBs part of the pulse index array (higher modes only)
500 * @param[in]  pulse_lo            LSBs part of the pulse index array
501 * @param[in]  mode                Mode of the current frame
502 */
503static void decode_fixed_vector(float *fixed_vector, const uint16_t *pulse_hi,
504                                const uint16_t *pulse_lo, const enum Mode mode)
505{
506    /* sig_pos stores for each track the decoded pulse position indexes
507     * (1-based) multiplied by its corresponding amplitude (+1 or -1) */
508    int sig_pos[4][6];
509    int spacing = (mode == MODE_6k60) ? 2 : 4;
510    int i, j;
511
512    switch (mode) {
513    case MODE_6k60:
514        for (i = 0; i < 2; i++)
515            decode_1p_track(sig_pos[i], pulse_lo[i], 5, 1);
516        break;
517    case MODE_8k85:
518        for (i = 0; i < 4; i++)
519            decode_1p_track(sig_pos[i], pulse_lo[i], 4, 1);
520        break;
521    case MODE_12k65:
522        for (i = 0; i < 4; i++)
523            decode_2p_track(sig_pos[i], pulse_lo[i], 4, 1);
524        break;
525    case MODE_14k25:
526        for (i = 0; i < 2; i++)
527            decode_3p_track(sig_pos[i], pulse_lo[i], 4, 1);
528        for (i = 2; i < 4; i++)
529            decode_2p_track(sig_pos[i], pulse_lo[i], 4, 1);
530        break;
531    case MODE_15k85:
532        for (i = 0; i < 4; i++)
533            decode_3p_track(sig_pos[i], pulse_lo[i], 4, 1);
534        break;
535    case MODE_18k25:
536        for (i = 0; i < 4; i++)
537            decode_4p_track(sig_pos[i], (int) pulse_lo[i] +
538                           ((int) pulse_hi[i] << 14), 4, 1);
539        break;
540    case MODE_19k85:
541        for (i = 0; i < 2; i++)
542            decode_5p_track(sig_pos[i], (int) pulse_lo[i] +
543                           ((int) pulse_hi[i] << 10), 4, 1);
544        for (i = 2; i < 4; i++)
545            decode_4p_track(sig_pos[i], (int) pulse_lo[i] +
546                           ((int) pulse_hi[i] << 14), 4, 1);
547        break;
548    case MODE_23k05:
549    case MODE_23k85:
550        for (i = 0; i < 4; i++)
551            decode_6p_track(sig_pos[i], (int) pulse_lo[i] +
552                           ((int) pulse_hi[i] << 11), 4, 1);
553        break;
554    }
555
556    memset(fixed_vector, 0, sizeof(float) * AMRWB_SFR_SIZE);
557
558    for (i = 0; i < 4; i++)
559        for (j = 0; j < pulses_nb_per_mode_tr[mode][i]; j++) {
560            int pos = (FFABS(sig_pos[i][j]) - 1) * spacing + i;
561
562            fixed_vector[pos] += sig_pos[i][j] < 0 ? -1.0 : 1.0;
563        }
564}
565
566/**
567 * Decode pitch gain and fixed gain correction factor.
568 *
569 * @param[in]  vq_gain             Vector-quantized index for gains
570 * @param[in]  mode                Mode of the current frame
571 * @param[out] fixed_gain_factor   Decoded fixed gain correction factor
572 * @param[out] pitch_gain          Decoded pitch gain
573 */
574static void decode_gains(const uint8_t vq_gain, const enum Mode mode,
575                         float *fixed_gain_factor, float *pitch_gain)
576{
577    const int16_t *gains = (mode <= MODE_8k85 ? qua_gain_6b[vq_gain] :
578                                                qua_gain_7b[vq_gain]);
579
580    *pitch_gain        = gains[0] * (1.0f / (1 << 14));
581    *fixed_gain_factor = gains[1] * (1.0f / (1 << 11));
582}
583
584/**
585 * Apply pitch sharpening filters to the fixed codebook vector.
586 *
587 * @param[in]     ctx              The context
588 * @param[in,out] fixed_vector     Fixed codebook excitation
589 */
590// XXX: Spec states this procedure should be applied when the pitch
591// lag is less than 64, but this checking seems absent in reference and AMR-NB
592static void pitch_sharpening(AMRWBContext *ctx, float *fixed_vector)
593{
594    int i;
595
596    /* Tilt part */
597    for (i = AMRWB_SFR_SIZE - 1; i != 0; i--)
598        fixed_vector[i] -= fixed_vector[i - 1] * ctx->tilt_coef;
599
600    /* Periodicity enhancement part */
601    for (i = ctx->pitch_lag_int; i < AMRWB_SFR_SIZE; i++)
602        fixed_vector[i] += fixed_vector[i - ctx->pitch_lag_int] * 0.85;
603}
604
605/**
606 * Calculate the voicing factor (-1.0 = unvoiced to 1.0 = voiced).
607 *
608 * @param[in] p_vector, f_vector   Pitch and fixed excitation vectors
609 * @param[in] p_gain, f_gain       Pitch and fixed gains
610 * @param[in] ctx                  The context
611 */
612// XXX: There is something wrong with the precision here! The magnitudes
613// of the energies are not correct. Please check the reference code carefully
614static float voice_factor(float *p_vector, float p_gain,
615                          float *f_vector, float f_gain,
616                          CELPMContext *ctx)
617{
618    double p_ener = (double) ctx->dot_productf(p_vector, p_vector,
619                                                          AMRWB_SFR_SIZE) *
620                    p_gain * p_gain;
621    double f_ener = (double) ctx->dot_productf(f_vector, f_vector,
622                                                          AMRWB_SFR_SIZE) *
623                    f_gain * f_gain;
624
625    return (p_ener - f_ener) / (p_ener + f_ener + 0.01);
626}
627
628/**
629 * Reduce fixed vector sparseness by smoothing with one of three IR filters,
630 * also known as "adaptive phase dispersion".
631 *
632 * @param[in]     ctx              The context
633 * @param[in,out] fixed_vector     Unfiltered fixed vector
634 * @param[out]    buf              Space for modified vector if necessary
635 *
636 * @return The potentially overwritten filtered fixed vector address
637 */
638static float *anti_sparseness(AMRWBContext *ctx,
639                              float *fixed_vector, float *buf)
640{
641    int ir_filter_nr;
642
643    if (ctx->fr_cur_mode > MODE_8k85) // no filtering in higher modes
644        return fixed_vector;
645
646    if (ctx->pitch_gain[0] < 0.6) {
647        ir_filter_nr = 0;      // strong filtering
648    } else if (ctx->pitch_gain[0] < 0.9) {
649        ir_filter_nr = 1;      // medium filtering
650    } else
651        ir_filter_nr = 2;      // no filtering
652
653    /* detect 'onset' */
654    if (ctx->fixed_gain[0] > 3.0 * ctx->fixed_gain[1]) {
655        if (ir_filter_nr < 2)
656            ir_filter_nr++;
657    } else {
658        int i, count = 0;
659
660        for (i = 0; i < 6; i++)
661            if (ctx->pitch_gain[i] < 0.6)
662                count++;
663
664        if (count > 2)
665            ir_filter_nr = 0;
666
667        if (ir_filter_nr > ctx->prev_ir_filter_nr + 1)
668            ir_filter_nr--;
669    }
670
671    /* update ir filter strength history */
672    ctx->prev_ir_filter_nr = ir_filter_nr;
673
674    ir_filter_nr += (ctx->fr_cur_mode == MODE_8k85);
675
676    if (ir_filter_nr < 2) {
677        int i;
678        const float *coef = ir_filters_lookup[ir_filter_nr];
679
680        /* Circular convolution code in the reference
681         * decoder was modified to avoid using one
682         * extra array. The filtered vector is given by:
683         *
684         * c2(n) = sum(i,0,len-1){ c(i) * coef( (n - i + len) % len ) }
685         */
686
687        memset(buf, 0, sizeof(float) * AMRWB_SFR_SIZE);
688        for (i = 0; i < AMRWB_SFR_SIZE; i++)
689            if (fixed_vector[i])
690                ff_celp_circ_addf(buf, buf, coef, i, fixed_vector[i],
691                                  AMRWB_SFR_SIZE);
692        fixed_vector = buf;
693    }
694
695    return fixed_vector;
696}
697
698/**
699 * Calculate a stability factor {teta} based on distance between
700 * current and past isf. A value of 1 shows maximum signal stability.
701 */
702static float stability_factor(const float *isf, const float *isf_past)
703{
704    int i;
705    float acc = 0.0;
706
707    for (i = 0; i < LP_ORDER - 1; i++)
708        acc += (isf[i] - isf_past[i]) * (isf[i] - isf_past[i]);
709
710    // XXX: This part is not so clear from the reference code
711    // the result is more accurate changing the "/ 256" to "* 512"
712    return FFMAX(0.0, 1.25 - acc * 0.8 * 512);
713}
714
715/**
716 * Apply a non-linear fixed gain smoothing in order to reduce
717 * fluctuation in the energy of excitation.
718 *
719 * @param[in]     fixed_gain       Unsmoothed fixed gain
720 * @param[in,out] prev_tr_gain     Previous threshold gain (updated)
721 * @param[in]     voice_fac        Frame voicing factor
722 * @param[in]     stab_fac         Frame stability factor
723 *
724 * @return The smoothed gain
725 */
726static float noise_enhancer(float fixed_gain, float *prev_tr_gain,
727                            float voice_fac,  float stab_fac)
728{
729    float sm_fac = 0.5 * (1 - voice_fac) * stab_fac;
730    float g0;
731
732    // XXX: the following fixed-point constants used to in(de)crement
733    // gain by 1.5dB were taken from the reference code, maybe it could
734    // be simpler
735    if (fixed_gain < *prev_tr_gain) {
736        g0 = FFMIN(*prev_tr_gain, fixed_gain + fixed_gain *
737                     (6226 * (1.0f / (1 << 15)))); // +1.5 dB
738    } else
739        g0 = FFMAX(*prev_tr_gain, fixed_gain *
740                    (27536 * (1.0f / (1 << 15)))); // -1.5 dB
741
742    *prev_tr_gain = g0; // update next frame threshold
743
744    return sm_fac * g0 + (1 - sm_fac) * fixed_gain;
745}
746
747/**
748 * Filter the fixed_vector to emphasize the higher frequencies.
749 *
750 * @param[in,out] fixed_vector     Fixed codebook vector
751 * @param[in]     voice_fac        Frame voicing factor
752 */
753static void pitch_enhancer(float *fixed_vector, float voice_fac)
754{
755    int i;
756    float cpe  = 0.125 * (1 + voice_fac);
757    float last = fixed_vector[0]; // holds c(i - 1)
758
759    fixed_vector[0] -= cpe * fixed_vector[1];
760
761    for (i = 1; i < AMRWB_SFR_SIZE - 1; i++) {
762        float cur = fixed_vector[i];
763
764        fixed_vector[i] -= cpe * (last + fixed_vector[i + 1]);
765        last = cur;
766    }
767
768    fixed_vector[AMRWB_SFR_SIZE - 1] -= cpe * last;
769}
770
771/**
772 * Conduct 16th order linear predictive coding synthesis from excitation.
773 *
774 * @param[in]     ctx              Pointer to the AMRWBContext
775 * @param[in]     lpc              Pointer to the LPC coefficients
776 * @param[out]    excitation       Buffer for synthesis final excitation
777 * @param[in]     fixed_gain       Fixed codebook gain for synthesis
778 * @param[in]     fixed_vector     Algebraic codebook vector
779 * @param[in,out] samples          Pointer to the output samples and memory
780 */
781static void synthesis(AMRWBContext *ctx, float *lpc, float *excitation,
782                      float fixed_gain, const float *fixed_vector,
783                      float *samples)
784{
785    ctx->acelpv_ctx.weighted_vector_sumf(excitation, ctx->pitch_vector, fixed_vector,
786                            ctx->pitch_gain[0], fixed_gain, AMRWB_SFR_SIZE);
787
788    /* emphasize pitch vector contribution in low bitrate modes */
789    if (ctx->pitch_gain[0] > 0.5 && ctx->fr_cur_mode <= MODE_8k85) {
790        int i;
791        float energy = ctx->celpm_ctx.dot_productf(excitation, excitation,
792                                                    AMRWB_SFR_SIZE);
793
794        // XXX: Weird part in both ref code and spec. A unknown parameter
795        // {beta} seems to be identical to the current pitch gain
796        float pitch_factor = 0.25 * ctx->pitch_gain[0] * ctx->pitch_gain[0];
797
798        for (i = 0; i < AMRWB_SFR_SIZE; i++)
799            excitation[i] += pitch_factor * ctx->pitch_vector[i];
800
801        ff_scale_vector_to_given_sum_of_squares(excitation, excitation,
802                                                energy, AMRWB_SFR_SIZE);
803    }
804
805    ctx->celpf_ctx.celp_lp_synthesis_filterf(samples, lpc, excitation,
806                                 AMRWB_SFR_SIZE, LP_ORDER);
807}
808
809/**
810 * Apply to synthesis a de-emphasis filter of the form:
811 * H(z) = 1 / (1 - m * z^-1)
812 *
813 * @param[out]    out              Output buffer
814 * @param[in]     in               Input samples array with in[-1]
815 * @param[in]     m                Filter coefficient
816 * @param[in,out] mem              State from last filtering
817 */
818static void de_emphasis(float *out, float *in, float m, float mem[1])
819{
820    int i;
821
822    out[0] = in[0] + m * mem[0];
823
824    for (i = 1; i < AMRWB_SFR_SIZE; i++)
825         out[i] = in[i] + out[i - 1] * m;
826
827    mem[0] = out[AMRWB_SFR_SIZE - 1];
828}
829
830/**
831 * Upsample a signal by 5/4 ratio (from 12.8kHz to 16kHz) using
832 * a FIR interpolation filter. Uses past data from before *in address.
833 *
834 * @param[out] out                 Buffer for interpolated signal
835 * @param[in]  in                  Current signal data (length 0.8*o_size)
836 * @param[in]  o_size              Output signal length
837 * @param[in] ctx                  The context
838 */
839static void upsample_5_4(float *out, const float *in, int o_size, CELPMContext *ctx)
840{
841    const float *in0 = in - UPS_FIR_SIZE + 1;
842    int i, j, k;
843    int int_part = 0, frac_part;
844
845    i = 0;
846    for (j = 0; j < o_size / 5; j++) {
847        out[i] = in[int_part];
848        frac_part = 4;
849        i++;
850
851        for (k = 1; k < 5; k++) {
852            out[i] = ctx->dot_productf(in0 + int_part,
853                                                  upsample_fir[4 - frac_part],
854                                                  UPS_MEM_SIZE);
855            int_part++;
856            frac_part--;
857            i++;
858        }
859    }
860}
861
862/**
863 * Calculate the high-band gain based on encoded index (23k85 mode) or
864 * on the low-band speech signal and the Voice Activity Detection flag.
865 *
866 * @param[in] ctx                  The context
867 * @param[in] synth                LB speech synthesis at 12.8k
868 * @param[in] hb_idx               Gain index for mode 23k85 only
869 * @param[in] vad                  VAD flag for the frame
870 */
871static float find_hb_gain(AMRWBContext *ctx, const float *synth,
872                          uint16_t hb_idx, uint8_t vad)
873{
874    int wsp = (vad > 0);
875    float tilt;
876    float tmp;
877
878    if (ctx->fr_cur_mode == MODE_23k85)
879        return qua_hb_gain[hb_idx] * (1.0f / (1 << 14));
880
881    tmp = ctx->celpm_ctx.dot_productf(synth, synth + 1, AMRWB_SFR_SIZE - 1);
882
883    if (tmp > 0) {
884        tilt = tmp / ctx->celpm_ctx.dot_productf(synth, synth, AMRWB_SFR_SIZE);
885    } else
886        tilt = 0;
887
888    /* return gain bounded by [0.1, 1.0] */
889    return av_clipf((1.0 - tilt) * (1.25 - 0.25 * wsp), 0.1, 1.0);
890}
891
892/**
893 * Generate the high-band excitation with the same energy from the lower
894 * one and scaled by the given gain.
895 *
896 * @param[in]  ctx                 The context
897 * @param[out] hb_exc              Buffer for the excitation
898 * @param[in]  synth_exc           Low-band excitation used for synthesis
899 * @param[in]  hb_gain             Wanted excitation gain
900 */
901static void scaled_hb_excitation(AMRWBContext *ctx, float *hb_exc,
902                                 const float *synth_exc, float hb_gain)
903{
904    int i;
905    float energy = ctx->celpm_ctx.dot_productf(synth_exc, synth_exc,
906                                                AMRWB_SFR_SIZE);
907
908    /* Generate a white-noise excitation */
909    for (i = 0; i < AMRWB_SFR_SIZE_16k; i++)
910        hb_exc[i] = 32768.0 - (uint16_t) av_lfg_get(&ctx->prng);
911
912    ff_scale_vector_to_given_sum_of_squares(hb_exc, hb_exc,
913                                            energy * hb_gain * hb_gain,
914                                            AMRWB_SFR_SIZE_16k);
915}
916
917/**
918 * Calculate the auto-correlation for the ISF difference vector.
919 */
920static float auto_correlation(float *diff_isf, float mean, int lag)
921{
922    int i;
923    float sum = 0.0;
924
925    for (i = 7; i < LP_ORDER - 2; i++) {
926        float prod = (diff_isf[i] - mean) * (diff_isf[i - lag] - mean);
927        sum += prod * prod;
928    }
929    return sum;
930}
931
932/**
933 * Extrapolate a ISF vector to the 16kHz range (20th order LP)
934 * used at mode 6k60 LP filter for the high frequency band.
935 *
936 * @param[out] isf Buffer for extrapolated isf; contains LP_ORDER
937 *                 values on input
938 */
939static void extrapolate_isf(float isf[LP_ORDER_16k])
940{
941    float diff_isf[LP_ORDER - 2], diff_mean;
942    float corr_lag[3];
943    float est, scale;
944    int i, j, i_max_corr;
945
946    isf[LP_ORDER_16k - 1] = isf[LP_ORDER - 1];
947
948    /* Calculate the difference vector */
949    for (i = 0; i < LP_ORDER - 2; i++)
950        diff_isf[i] = isf[i + 1] - isf[i];
951
952    diff_mean = 0.0;
953    for (i = 2; i < LP_ORDER - 2; i++)
954        diff_mean += diff_isf[i] * (1.0f / (LP_ORDER - 4));
955
956    /* Find which is the maximum autocorrelation */
957    i_max_corr = 0;
958    for (i = 0; i < 3; i++) {
959        corr_lag[i] = auto_correlation(diff_isf, diff_mean, i + 2);
960
961        if (corr_lag[i] > corr_lag[i_max_corr])
962            i_max_corr = i;
963    }
964    i_max_corr++;
965
966    for (i = LP_ORDER - 1; i < LP_ORDER_16k - 1; i++)
967        isf[i] = isf[i - 1] + isf[i - 1 - i_max_corr]
968                            - isf[i - 2 - i_max_corr];
969
970    /* Calculate an estimate for ISF(18) and scale ISF based on the error */
971    est   = 7965 + (isf[2] - isf[3] - isf[4]) / 6.0;
972    scale = 0.5 * (FFMIN(est, 7600) - isf[LP_ORDER - 2]) /
973            (isf[LP_ORDER_16k - 2] - isf[LP_ORDER - 2]);
974
975    for (i = LP_ORDER - 1, j = 0; i < LP_ORDER_16k - 1; i++, j++)
976        diff_isf[j] = scale * (isf[i] - isf[i - 1]);
977
978    /* Stability insurance */
979    for (i = 1; i < LP_ORDER_16k - LP_ORDER; i++)
980        if (diff_isf[i] + diff_isf[i - 1] < 5.0) {
981            if (diff_isf[i] > diff_isf[i - 1]) {
982                diff_isf[i - 1] = 5.0 - diff_isf[i];
983            } else
984                diff_isf[i] = 5.0 - diff_isf[i - 1];
985        }
986
987    for (i = LP_ORDER - 1, j = 0; i < LP_ORDER_16k - 1; i++, j++)
988        isf[i] = isf[i - 1] + diff_isf[j] * (1.0f / (1 << 15));
989
990    /* Scale the ISF vector for 16000 Hz */
991    for (i = 0; i < LP_ORDER_16k - 1; i++)
992        isf[i] *= 0.8;
993}
994
995/**
996 * Spectral expand the LP coefficients using the equation:
997 *   y[i] = x[i] * (gamma ** i)
998 *
999 * @param[out] out                 Output buffer (may use input array)
1000 * @param[in]  lpc                 LP coefficients array
1001 * @param[in]  gamma               Weighting factor
1002 * @param[in]  size                LP array size
1003 */
1004static void lpc_weighting(float *out, const float *lpc, float gamma, int size)
1005{
1006    int i;
1007    float fac = gamma;
1008
1009    for (i = 0; i < size; i++) {
1010        out[i] = lpc[i] * fac;
1011        fac   *= gamma;
1012    }
1013}
1014
1015/**
1016 * Conduct 20th order linear predictive coding synthesis for the high
1017 * frequency band excitation at 16kHz.
1018 *
1019 * @param[in]     ctx              The context
1020 * @param[in]     subframe         Current subframe index (0 to 3)
1021 * @param[in,out] samples          Pointer to the output speech samples
1022 * @param[in]     exc              Generated white-noise scaled excitation
1023 * @param[in]     isf              Current frame isf vector
1024 * @param[in]     isf_past         Past frame final isf vector
1025 */
1026static void hb_synthesis(AMRWBContext *ctx, int subframe, float *samples,
1027                         const float *exc, const float *isf, const float *isf_past)
1028{
1029    float hb_lpc[LP_ORDER_16k];
1030    enum Mode mode = ctx->fr_cur_mode;
1031
1032    if (mode == MODE_6k60) {
1033        float e_isf[LP_ORDER_16k]; // ISF vector for extrapolation
1034        double e_isp[LP_ORDER_16k];
1035
1036        ctx->acelpv_ctx.weighted_vector_sumf(e_isf, isf_past, isf, isfp_inter[subframe],
1037                                1.0 - isfp_inter[subframe], LP_ORDER);
1038
1039        extrapolate_isf(e_isf);
1040
1041        e_isf[LP_ORDER_16k - 1] *= 2.0;
1042        ff_acelp_lsf2lspd(e_isp, e_isf, LP_ORDER_16k);
1043        ff_amrwb_lsp2lpc(e_isp, hb_lpc, LP_ORDER_16k);
1044
1045        lpc_weighting(hb_lpc, hb_lpc, 0.9, LP_ORDER_16k);
1046    } else {
1047        lpc_weighting(hb_lpc, ctx->lp_coef[subframe], 0.6, LP_ORDER);
1048    }
1049
1050    ctx->celpf_ctx.celp_lp_synthesis_filterf(samples, hb_lpc, exc, AMRWB_SFR_SIZE_16k,
1051                                 (mode == MODE_6k60) ? LP_ORDER_16k : LP_ORDER);
1052}
1053
1054/**
1055 * Apply a 15th order filter to high-band samples.
1056 * The filter characteristic depends on the given coefficients.
1057 *
1058 * @param[out]    out              Buffer for filtered output
1059 * @param[in]     fir_coef         Filter coefficients
1060 * @param[in,out] mem              State from last filtering (updated)
1061 * @param[in]     in               Input speech data (high-band)
1062 *
1063 * @remark It is safe to pass the same array in in and out parameters
1064 */
1065
1066#ifndef hb_fir_filter
1067static void hb_fir_filter(float *out, const float fir_coef[HB_FIR_SIZE + 1],
1068                          float mem[HB_FIR_SIZE], const float *in)
1069{
1070    int i, j;
1071    float data[AMRWB_SFR_SIZE_16k + HB_FIR_SIZE]; // past and current samples
1072
1073    memcpy(data, mem, HB_FIR_SIZE * sizeof(float));
1074    memcpy(data + HB_FIR_SIZE, in, AMRWB_SFR_SIZE_16k * sizeof(float));
1075
1076    for (i = 0; i < AMRWB_SFR_SIZE_16k; i++) {
1077        out[i] = 0.0;
1078        for (j = 0; j <= HB_FIR_SIZE; j++)
1079            out[i] += data[i + j] * fir_coef[j];
1080    }
1081
1082    memcpy(mem, data + AMRWB_SFR_SIZE_16k, HB_FIR_SIZE * sizeof(float));
1083}
1084#endif /* hb_fir_filter */
1085
1086/**
1087 * Update context state before the next subframe.
1088 */
1089static void update_sub_state(AMRWBContext *ctx)
1090{
1091    memmove(&ctx->excitation_buf[0], &ctx->excitation_buf[AMRWB_SFR_SIZE],
1092            (AMRWB_P_DELAY_MAX + LP_ORDER + 1) * sizeof(float));
1093
1094    memmove(&ctx->pitch_gain[1], &ctx->pitch_gain[0], 5 * sizeof(float));
1095    memmove(&ctx->fixed_gain[1], &ctx->fixed_gain[0], 1 * sizeof(float));
1096
1097    memmove(&ctx->samples_az[0], &ctx->samples_az[AMRWB_SFR_SIZE],
1098            LP_ORDER * sizeof(float));
1099    memmove(&ctx->samples_up[0], &ctx->samples_up[AMRWB_SFR_SIZE],
1100            UPS_MEM_SIZE * sizeof(float));
1101    memmove(&ctx->samples_hb[0], &ctx->samples_hb[AMRWB_SFR_SIZE_16k],
1102            LP_ORDER_16k * sizeof(float));
1103}
1104
1105static int amrwb_decode_frame(AVCodecContext *avctx, AVFrame *frame,
1106                              int *got_frame_ptr, AVPacket *avpkt)
1107{
1108    AMRWBChannelsContext *s  = avctx->priv_data;
1109    const uint8_t *buf = avpkt->data;
1110    int buf_size       = avpkt->size;
1111    int sub, i, ret;
1112
1113    /* get output buffer */
1114    frame->nb_samples = 4 * AMRWB_SFR_SIZE_16k;
1115    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
1116        return ret;
1117
1118    for (int ch = 0; ch < avctx->ch_layout.nb_channels; ch++) {
1119        AMRWBContext *ctx  = &s->ch[ch];
1120        AMRWBFrame   *cf   = &ctx->frame;
1121        int expected_fr_size, header_size;
1122        float spare_vector[AMRWB_SFR_SIZE];      // extra stack space to hold result from anti-sparseness processing
1123        float fixed_gain_factor;                 // fixed gain correction factor (gamma)
1124        float *synth_fixed_vector;               // pointer to the fixed vector that synthesis should use
1125        float synth_fixed_gain;                  // the fixed gain that synthesis should use
1126        float voice_fac, stab_fac;               // parameters used for gain smoothing
1127        float synth_exc[AMRWB_SFR_SIZE];         // post-processed excitation for synthesis
1128        float hb_exc[AMRWB_SFR_SIZE_16k];        // excitation for the high frequency band
1129        float hb_samples[AMRWB_SFR_SIZE_16k];    // filtered high-band samples from synthesis
1130        float hb_gain;
1131        float *buf_out = (float *)frame->extended_data[ch];
1132
1133        header_size      = decode_mime_header(ctx, buf);
1134        expected_fr_size = ((cf_sizes_wb[ctx->fr_cur_mode] + 7) >> 3) + 1;
1135
1136        if (!ctx->fr_quality)
1137            av_log(avctx, AV_LOG_ERROR, "Encountered a bad or corrupted frame\n");
1138
1139        if (ctx->fr_cur_mode == NO_DATA || !ctx->fr_quality) {
1140            /* The specification suggests a "random signal" and
1141               "a muting technique" to "gradually decrease the output level". */
1142            av_samples_set_silence(&frame->extended_data[ch], 0, frame->nb_samples, 1, AV_SAMPLE_FMT_FLT);
1143            buf += expected_fr_size;
1144            buf_size -= expected_fr_size;
1145            continue;
1146        }
1147        if (ctx->fr_cur_mode > MODE_SID) {
1148            av_log(avctx, AV_LOG_ERROR,
1149                   "Invalid mode %d\n", ctx->fr_cur_mode);
1150            return AVERROR_INVALIDDATA;
1151        }
1152
1153        if (buf_size < expected_fr_size) {
1154            av_log(avctx, AV_LOG_ERROR,
1155                   "Frame too small (%d bytes). Truncated file?\n", buf_size);
1156            *got_frame_ptr = 0;
1157            return AVERROR_INVALIDDATA;
1158        }
1159
1160        if (ctx->fr_cur_mode == MODE_SID) { /* Comfort noise frame */
1161            avpriv_request_sample(avctx, "SID mode");
1162            return AVERROR_PATCHWELCOME;
1163        }
1164
1165        ff_amr_bit_reorder((uint16_t *) &ctx->frame, sizeof(AMRWBFrame),
1166                           buf + header_size, amr_bit_orderings_by_mode[ctx->fr_cur_mode]);
1167
1168        /* Decode the quantized ISF vector */
1169        if (ctx->fr_cur_mode == MODE_6k60) {
1170            decode_isf_indices_36b(cf->isp_id, ctx->isf_cur);
1171        } else {
1172            decode_isf_indices_46b(cf->isp_id, ctx->isf_cur);
1173        }
1174
1175        isf_add_mean_and_past(ctx->isf_cur, ctx->isf_q_past);
1176        ff_set_min_dist_lsf(ctx->isf_cur, MIN_ISF_SPACING, LP_ORDER - 1);
1177
1178        stab_fac = stability_factor(ctx->isf_cur, ctx->isf_past_final);
1179
1180        ctx->isf_cur[LP_ORDER - 1] *= 2.0;
1181        ff_acelp_lsf2lspd(ctx->isp[3], ctx->isf_cur, LP_ORDER);
1182
1183        /* Generate a ISP vector for each subframe */
1184        if (ctx->first_frame) {
1185            ctx->first_frame = 0;
1186            memcpy(ctx->isp_sub4_past, ctx->isp[3], LP_ORDER * sizeof(double));
1187        }
1188        interpolate_isp(ctx->isp, ctx->isp_sub4_past);
1189
1190        for (sub = 0; sub < 4; sub++)
1191            ff_amrwb_lsp2lpc(ctx->isp[sub], ctx->lp_coef[sub], LP_ORDER);
1192
1193        for (sub = 0; sub < 4; sub++) {
1194            const AMRWBSubFrame *cur_subframe = &cf->subframe[sub];
1195            float *sub_buf = buf_out + sub * AMRWB_SFR_SIZE_16k;
1196
1197            /* Decode adaptive codebook (pitch vector) */
1198            decode_pitch_vector(ctx, cur_subframe, sub);
1199            /* Decode innovative codebook (fixed vector) */
1200            decode_fixed_vector(ctx->fixed_vector, cur_subframe->pul_ih,
1201                                cur_subframe->pul_il, ctx->fr_cur_mode);
1202
1203            pitch_sharpening(ctx, ctx->fixed_vector);
1204
1205            decode_gains(cur_subframe->vq_gain, ctx->fr_cur_mode,
1206                         &fixed_gain_factor, &ctx->pitch_gain[0]);
1207
1208            ctx->fixed_gain[0] =
1209                ff_amr_set_fixed_gain(fixed_gain_factor,
1210                                      ctx->celpm_ctx.dot_productf(ctx->fixed_vector,
1211                                                                  ctx->fixed_vector,
1212                                                                  AMRWB_SFR_SIZE) /
1213                                      AMRWB_SFR_SIZE,
1214                                      ctx->prediction_error,
1215                                      ENERGY_MEAN, energy_pred_fac);
1216
1217            /* Calculate voice factor and store tilt for next subframe */
1218            voice_fac      = voice_factor(ctx->pitch_vector, ctx->pitch_gain[0],
1219                                          ctx->fixed_vector, ctx->fixed_gain[0],
1220                                          &ctx->celpm_ctx);
1221            ctx->tilt_coef = voice_fac * 0.25 + 0.25;
1222
1223            /* Construct current excitation */
1224            for (i = 0; i < AMRWB_SFR_SIZE; i++) {
1225                ctx->excitation[i] *= ctx->pitch_gain[0];
1226                ctx->excitation[i] += ctx->fixed_gain[0] * ctx->fixed_vector[i];
1227                ctx->excitation[i] = truncf(ctx->excitation[i]);
1228            }
1229
1230            /* Post-processing of excitation elements */
1231            synth_fixed_gain = noise_enhancer(ctx->fixed_gain[0], &ctx->prev_tr_gain,
1232                                              voice_fac, stab_fac);
1233
1234            synth_fixed_vector = anti_sparseness(ctx, ctx->fixed_vector,
1235                                                 spare_vector);
1236
1237            pitch_enhancer(synth_fixed_vector, voice_fac);
1238
1239            synthesis(ctx, ctx->lp_coef[sub], synth_exc, synth_fixed_gain,
1240                      synth_fixed_vector, &ctx->samples_az[LP_ORDER]);
1241
1242            /* Synthesis speech post-processing */
1243            de_emphasis(&ctx->samples_up[UPS_MEM_SIZE],
1244                        &ctx->samples_az[LP_ORDER], PREEMPH_FAC, ctx->demph_mem);
1245
1246            ctx->acelpf_ctx.acelp_apply_order_2_transfer_function(&ctx->samples_up[UPS_MEM_SIZE],
1247                                                                  &ctx->samples_up[UPS_MEM_SIZE], hpf_zeros, hpf_31_poles,
1248                                                                  hpf_31_gain, ctx->hpf_31_mem, AMRWB_SFR_SIZE);
1249
1250            upsample_5_4(sub_buf, &ctx->samples_up[UPS_FIR_SIZE],
1251                         AMRWB_SFR_SIZE_16k, &ctx->celpm_ctx);
1252
1253            /* High frequency band (6.4 - 7.0 kHz) generation part */
1254            ctx->acelpf_ctx.acelp_apply_order_2_transfer_function(hb_samples,
1255                                                                  &ctx->samples_up[UPS_MEM_SIZE], hpf_zeros, hpf_400_poles,
1256                                                                  hpf_400_gain, ctx->hpf_400_mem, AMRWB_SFR_SIZE);
1257
1258            hb_gain = find_hb_gain(ctx, hb_samples,
1259                                   cur_subframe->hb_gain, cf->vad);
1260
1261            scaled_hb_excitation(ctx, hb_exc, synth_exc, hb_gain);
1262
1263            hb_synthesis(ctx, sub, &ctx->samples_hb[LP_ORDER_16k],
1264                         hb_exc, ctx->isf_cur, ctx->isf_past_final);
1265
1266            /* High-band post-processing filters */
1267            hb_fir_filter(hb_samples, bpf_6_7_coef, ctx->bpf_6_7_mem,
1268                          &ctx->samples_hb[LP_ORDER_16k]);
1269
1270            if (ctx->fr_cur_mode == MODE_23k85)
1271                hb_fir_filter(hb_samples, lpf_7_coef, ctx->lpf_7_mem,
1272                              hb_samples);
1273
1274            /* Add the low and high frequency bands */
1275            for (i = 0; i < AMRWB_SFR_SIZE_16k; i++)
1276                sub_buf[i] = (sub_buf[i] + hb_samples[i]) * (1.0f / (1 << 15));
1277
1278            /* Update buffers and history */
1279            update_sub_state(ctx);
1280        }
1281
1282        /* update state for next frame */
1283        memcpy(ctx->isp_sub4_past, ctx->isp[3], LP_ORDER * sizeof(ctx->isp[3][0]));
1284        memcpy(ctx->isf_past_final, ctx->isf_cur, LP_ORDER * sizeof(float));
1285
1286        buf += expected_fr_size;
1287        buf_size -= expected_fr_size;
1288    }
1289
1290    *got_frame_ptr = 1;
1291
1292    return avpkt->size;
1293}
1294
1295const FFCodec ff_amrwb_decoder = {
1296    .p.name         = "amrwb",
1297    .p.long_name    = NULL_IF_CONFIG_SMALL("AMR-WB (Adaptive Multi-Rate WideBand)"),
1298    .p.type         = AVMEDIA_TYPE_AUDIO,
1299    .p.id           = AV_CODEC_ID_AMR_WB,
1300    .priv_data_size = sizeof(AMRWBChannelsContext),
1301    .init           = amrwb_decode_init,
1302    FF_CODEC_DECODE_CB(amrwb_decode_frame),
1303    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
1304    .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLT,
1305                                                     AV_SAMPLE_FMT_NONE },
1306    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
1307};
1308