GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/qcelpdec.c Lines: 269 354 76.0 %
Date: 2019-11-18 18:00:01 Branches: 164 232 70.7 %

Line Branch Exec Source
1
/*
2
 * QCELP decoder
3
 * Copyright (c) 2007 Reynaldo H. Verdejo Pinochet
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
 * QCELP decoder
25
 * @author Reynaldo H. Verdejo Pinochet
26
 * @remark FFmpeg merging spearheaded by Kenan Gillet
27
 * @remark Development mentored by Benjamin Larson
28
 */
29
30
#include <stddef.h>
31
32
#include "libavutil/avassert.h"
33
#include "libavutil/channel_layout.h"
34
#include "libavutil/float_dsp.h"
35
#include "avcodec.h"
36
#include "internal.h"
37
#include "get_bits.h"
38
#include "qcelpdata.h"
39
#include "celp_filters.h"
40
#include "acelp_filters.h"
41
#include "acelp_vectors.h"
42
#include "lsp.h"
43
44
typedef enum {
45
    I_F_Q = -1,    /**< insufficient frame quality */
46
    SILENCE,
47
    RATE_OCTAVE,
48
    RATE_QUARTER,
49
    RATE_HALF,
50
    RATE_FULL
51
} qcelp_packet_rate;
52
53
typedef struct QCELPContext {
54
    GetBitContext     gb;
55
    qcelp_packet_rate bitrate;
56
    QCELPFrame        frame;    /**< unpacked data frame */
57
58
    uint8_t  erasure_count;
59
    uint8_t  octave_count;      /**< count the consecutive RATE_OCTAVE frames */
60
    float    prev_lspf[10];
61
    float    predictor_lspf[10];/**< LSP predictor for RATE_OCTAVE and I_F_Q */
62
    float    pitch_synthesis_filter_mem[303];
63
    float    pitch_pre_filter_mem[303];
64
    float    rnd_fir_filter_mem[180];
65
    float    formant_mem[170];
66
    float    last_codebook_gain;
67
    int      prev_g1[2];
68
    int      prev_bitrate;
69
    float    pitch_gain[4];
70
    uint8_t  pitch_lag[4];
71
    uint16_t first16bits;
72
    uint8_t  warned_buf_mismatch_bitrate;
73
74
    /* postfilter */
75
    float    postfilter_synth_mem[10];
76
    float    postfilter_agc_mem;
77
    float    postfilter_tilt_mem;
78
} QCELPContext;
79
80
/**
81
 * Initialize the speech codec according to the specification.
82
 *
83
 * TIA/EIA/IS-733 2.4.9
84
 */
85
3
static av_cold int qcelp_decode_init(AVCodecContext *avctx)
86
{
87
3
    QCELPContext *q = avctx->priv_data;
88
    int i;
89
90
3
    avctx->channels       = 1;
91
3
    avctx->channel_layout = AV_CH_LAYOUT_MONO;
92
3
    avctx->sample_fmt     = AV_SAMPLE_FMT_FLT;
93
94
33
    for (i = 0; i < 10; i++)
95
30
        q->prev_lspf[i] = (i + 1) / 11.0;
96
97
3
    return 0;
98
}
99
100
/**
101
 * Decode the 10 quantized LSP frequencies from the LSPV/LSP
102
 * transmission codes of any bitrate and check for badly received packets.
103
 *
104
 * @param q the context
105
 * @param lspf line spectral pair frequencies
106
 *
107
 * @return 0 on success, -1 if the packet is badly received
108
 *
109
 * TIA/EIA/IS-733 2.4.3.2.6.2-2, 2.4.8.7.3
110
 */
111
495
static int decode_lspf(QCELPContext *q, float *lspf)
112
{
113
    int i;
114
    float tmp_lspf, smooth, erasure_coeff;
115
    const float *predictors;
116
117

495
    if (q->bitrate == RATE_OCTAVE || q->bitrate == I_F_Q) {
118
193
        predictors = q->prev_bitrate != RATE_OCTAVE &&
119
27
                     q->prev_bitrate != I_F_Q ? q->prev_lspf
120
                                              : q->predictor_lspf;
121
122
166
        if (q->bitrate == RATE_OCTAVE) {
123
151
            q->octave_count++;
124
125
1661
            for (i = 0; i < 10; i++) {
126
1510
                q->predictor_lspf[i] =
127
3020
                             lspf[i] = (q->frame.lspv[i] ?  QCELP_LSP_SPREAD_FACTOR
128
1510
                                                         : -QCELP_LSP_SPREAD_FACTOR) +
129
1510
                                        predictors[i] * QCELP_LSP_OCTAVE_PREDICTOR   +
130
1510
                                        (i + 1) * ((1 - QCELP_LSP_OCTAVE_PREDICTOR) / 11);
131
            }
132
151
            smooth = q->octave_count < 10 ? .875 : 0.1;
133
        } else {
134
15
            erasure_coeff = QCELP_LSP_OCTAVE_PREDICTOR;
135
136
            av_assert2(q->bitrate == I_F_Q);
137
138
15
            if (q->erasure_count > 1)
139
14
                erasure_coeff *= q->erasure_count < 4 ? 0.9 : 0.7;
140
141
165
            for (i = 0; i < 10; i++) {
142
150
                q->predictor_lspf[i] =
143
150
                             lspf[i] = (i + 1) * (1 - erasure_coeff) / 11 +
144
150
                                       erasure_coeff * predictors[i];
145
            }
146
15
            smooth = 0.125;
147
        }
148
149
        // Check the stability of the LSP frequencies.
150
166
        lspf[0] = FFMAX(lspf[0], QCELP_LSP_SPREAD_FACTOR);
151
1660
        for (i = 1; i < 10; i++)
152
1494
            lspf[i] = FFMAX(lspf[i], lspf[i - 1] + QCELP_LSP_SPREAD_FACTOR);
153
154
166
        lspf[9] = FFMIN(lspf[9], 1.0 - QCELP_LSP_SPREAD_FACTOR);
155
1660
        for (i = 9; i > 0; i--)
156
1494
            lspf[i - 1] = FFMIN(lspf[i - 1], lspf[i] - QCELP_LSP_SPREAD_FACTOR);
157
158
        // Low-pass filter the LSP frequencies.
159
166
        ff_weighted_vector_sumf(lspf, lspf, q->prev_lspf, smooth, 1.0 - smooth, 10);
160
    } else {
161
329
        q->octave_count = 0;
162
163
329
        tmp_lspf = 0.0;
164
1974
        for (i = 0; i < 5; i++) {
165
1645
            lspf[2 * i + 0] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][0] * 0.0001;
166
1645
            lspf[2 * i + 1] = tmp_lspf += qcelp_lspvq[i][q->frame.lspv[i]][1] * 0.0001;
167
        }
168
169
        // Check for badly received packets.
170
329
        if (q->bitrate == RATE_QUARTER) {
171
            if (lspf[9] <= .70 || lspf[9] >= .97)
172
                return -1;
173
            for (i = 3; i < 10; i++)
174
                if (fabs(lspf[i] - lspf[i - 2]) < .08)
175
                    return -1;
176
        } else {
177

329
            if (lspf[9] <= .66 || lspf[9] >= .985)
178
                return -1;
179
2303
            for (i = 4; i < 10; i++)
180
1974
                if (fabs(lspf[i] - lspf[i - 4]) < .0931)
181
                    return -1;
182
        }
183
    }
184
495
    return 0;
185
}
186
187
/**
188
 * Convert codebook transmission codes to GAIN and INDEX.
189
 *
190
 * @param q the context
191
 * @param gain array holding the decoded gain
192
 *
193
 * TIA/EIA/IS-733 2.4.6.2
194
 */
195
495
static void decode_gain_and_index(QCELPContext *q, float *gain)
196
{
197
    int i, subframes_count, g1[16];
198
    float slope;
199
200
495
    if (q->bitrate >= RATE_QUARTER) {
201
329
        switch (q->bitrate) {
202
282
        case RATE_FULL: subframes_count = 16; break;
203
47
        case RATE_HALF: subframes_count =  4; break;
204
        default:        subframes_count =  5;
205
        }
206
5029
        for (i = 0; i < subframes_count; i++) {
207
4700
            g1[i] = 4 * q->frame.cbgain[i];
208

4700
            if (q->bitrate == RATE_FULL && !((i + 1) & 3)) {
209
1128
                g1[i] += av_clip((g1[i - 1] + g1[i - 2] + g1[i - 3]) / 3 - 6, 0, 32);
210
            }
211
212
4700
            gain[i] = qcelp_g12ga[g1[i]];
213
214
4700
            if (q->frame.cbsign[i]) {
215
2227
                gain[i] = -gain[i];
216
2227
                q->frame.cindex[i] = (q->frame.cindex[i] - 89) & 127;
217
            }
218
        }
219
220
329
        q->prev_g1[0]         = g1[i - 2];
221
329
        q->prev_g1[1]         = g1[i - 1];
222
329
        q->last_codebook_gain = qcelp_g12ga[g1[i - 1]];
223
224
329
        if (q->bitrate == RATE_QUARTER) {
225
            // Provide smoothing of the unvoiced excitation energy.
226
            gain[7] =       gain[4];
227
            gain[6] = 0.4 * gain[3] + 0.6 * gain[4];
228
            gain[5] =       gain[3];
229
            gain[4] = 0.8 * gain[2] + 0.2 * gain[3];
230
            gain[3] = 0.2 * gain[1] + 0.8 * gain[2];
231
            gain[2] =       gain[1];
232
            gain[1] = 0.6 * gain[0] + 0.4 * gain[1];
233
        }
234
166
    } else if (q->bitrate != SILENCE) {
235
166
        if (q->bitrate == RATE_OCTAVE) {
236
151
            g1[0] = 2 * q->frame.cbgain[0] +
237
151
                    av_clip((q->prev_g1[0] + q->prev_g1[1]) / 2 - 5, 0, 54);
238
151
            subframes_count = 8;
239
        } else {
240
            av_assert2(q->bitrate == I_F_Q);
241
242
15
            g1[0] = q->prev_g1[1];
243

15
            switch (q->erasure_count) {
244
1
            case 1 : break;
245
1
            case 2 : g1[0] -= 1; break;
246
1
            case 3 : g1[0] -= 2; break;
247
12
            default: g1[0] -= 6;
248
            }
249
15
            if (g1[0] < 0)
250
14
                g1[0] = 0;
251
15
            subframes_count = 4;
252
        }
253
        // This interpolation is done to produce smoother background noise.
254
166
        slope = 0.5 * (qcelp_g12ga[g1[0]] - q->last_codebook_gain) / subframes_count;
255
1434
        for (i = 1; i <= subframes_count; i++)
256
1268
                gain[i - 1] = q->last_codebook_gain + slope * i;
257
258
166
        q->last_codebook_gain = gain[i - 2];
259
166
        q->prev_g1[0]         = q->prev_g1[1];
260
166
        q->prev_g1[1]         = g1[0];
261
    }
262
495
}
263
264
/**
265
 * If the received packet is Rate 1/4 a further sanity check is made of the
266
 * codebook gain.
267
 *
268
 * @param cbgain the unpacked cbgain array
269
 * @return -1 if the sanity check fails, 0 otherwise
270
 *
271
 * TIA/EIA/IS-733 2.4.8.7.3
272
 */
273
static int codebook_sanity_check_for_rate_quarter(const uint8_t *cbgain)
274
{
275
    int i, diff, prev_diff = 0;
276
277
    for (i = 1; i < 5; i++) {
278
        diff = cbgain[i] - cbgain[i-1];
279
        if (FFABS(diff) > 10)
280
            return -1;
281
        else if (FFABS(diff - prev_diff) > 12)
282
            return -1;
283
        prev_diff = diff;
284
    }
285
    return 0;
286
}
287
288
/**
289
 * Compute the scaled codebook vector Cdn From INDEX and GAIN
290
 * for all rates.
291
 *
292
 * The specification lacks some information here.
293
 *
294
 * TIA/EIA/IS-733 has an omission on the codebook index determination
295
 * formula for RATE_FULL and RATE_HALF frames at section 2.4.8.1.1. It says
296
 * you have to subtract the decoded index parameter from the given scaled
297
 * codebook vector index 'n' to get the desired circular codebook index, but
298
 * it does not mention that you have to clamp 'n' to [0-9] in order to get
299
 * RI-compliant results.
300
 *
301
 * The reason for this mistake seems to be the fact they forgot to mention you
302
 * have to do these calculations per codebook subframe and adjust given
303
 * equation values accordingly.
304
 *
305
 * @param q the context
306
 * @param gain array holding the 4 pitch subframe gain values
307
 * @param cdn_vector array for the generated scaled codebook vector
308
 */
309
495
static void compute_svector(QCELPContext *q, const float *gain,
310
                            float *cdn_vector)
311
{
312
    int i, j, k;
313
    uint16_t cbseed, cindex;
314
    float *rnd, tmp_gain, fir_filter_value;
315
316

495
    switch (q->bitrate) {
317
282
    case RATE_FULL:
318
4794
        for (i = 0; i < 16; i++) {
319
4512
            tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO;
320
4512
            cindex   = -q->frame.cindex[i];
321
49632
            for (j = 0; j < 10; j++)
322
45120
                *cdn_vector++ = tmp_gain *
323
45120
                                qcelp_rate_full_codebook[cindex++ & 127];
324
        }
325
282
        break;
326
47
    case RATE_HALF:
327
235
        for (i = 0; i < 4; i++) {
328
188
            tmp_gain = gain[i] * QCELP_RATE_HALF_CODEBOOK_RATIO;
329
188
            cindex   = -q->frame.cindex[i];
330
7708
            for (j = 0; j < 40; j++)
331
7520
                *cdn_vector++ = tmp_gain *
332
7520
                                qcelp_rate_half_codebook[cindex++ & 127];
333
        }
334
47
        break;
335
    case RATE_QUARTER:
336
        cbseed = (0x0003 & q->frame.lspv[4]) << 14 |
337
                 (0x003F & q->frame.lspv[3]) <<  8 |
338
                 (0x0060 & q->frame.lspv[2]) <<  1 |
339
                 (0x0007 & q->frame.lspv[1]) <<  3 |
340
                 (0x0038 & q->frame.lspv[0]) >>  3;
341
        rnd    = q->rnd_fir_filter_mem + 20;
342
        for (i = 0; i < 8; i++) {
343
            tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0);
344
            for (k = 0; k < 20; k++) {
345
                cbseed = 521 * cbseed + 259;
346
                *rnd   = (int16_t) cbseed;
347
348
                    // FIR filter
349
                fir_filter_value = 0.0;
350
                for (j = 0; j < 10; j++)
351
                    fir_filter_value += qcelp_rnd_fir_coefs[j] *
352
                                        (rnd[-j] + rnd[-20+j]);
353
354
                fir_filter_value += qcelp_rnd_fir_coefs[10] * rnd[-10];
355
                *cdn_vector++     = tmp_gain * fir_filter_value;
356
                rnd++;
357
            }
358
        }
359
        memcpy(q->rnd_fir_filter_mem, q->rnd_fir_filter_mem + 160,
360
               20 * sizeof(float));
361
        break;
362
151
    case RATE_OCTAVE:
363
151
        cbseed = q->first16bits;
364
1359
        for (i = 0; i < 8; i++) {
365
1208
            tmp_gain = gain[i] * (QCELP_SQRT1887 / 32768.0);
366
25368
            for (j = 0; j < 20; j++) {
367
24160
                cbseed        = 521 * cbseed + 259;
368
24160
                *cdn_vector++ = tmp_gain * (int16_t) cbseed;
369
            }
370
        }
371
151
        break;
372
15
    case I_F_Q:
373
15
        cbseed = -44; // random codebook index
374
75
        for (i = 0; i < 4; i++) {
375
60
            tmp_gain = gain[i] * QCELP_RATE_FULL_CODEBOOK_RATIO;
376
2460
            for (j = 0; j < 40; j++)
377
2400
                *cdn_vector++ = tmp_gain *
378
2400
                                qcelp_rate_full_codebook[cbseed++ & 127];
379
        }
380
15
        break;
381
    case SILENCE:
382
        memset(cdn_vector, 0, 160 * sizeof(float));
383
        break;
384
    }
385
495
}
386
387
/**
388
 * Apply generic gain control.
389
 *
390
 * @param v_out output vector
391
 * @param v_in gain-controlled vector
392
 * @param v_ref vector to control gain of
393
 *
394
 * TIA/EIA/IS-733 2.4.8.3, 2.4.8.6
395
 */
396
329
static void apply_gain_ctrl(float *v_out, const float *v_ref, const float *v_in)
397
{
398
    int i;
399
400
1645
    for (i = 0; i < 160; i += 40) {
401
1316
        float res = avpriv_scalarproduct_float_c(v_ref + i, v_ref + i, 40);
402
1316
        ff_scale_vector_to_given_sum_of_squares(v_out + i, v_in + i, res, 40);
403
    }
404
329
}
405
406
/**
407
 * Apply filter in pitch-subframe steps.
408
 *
409
 * @param memory buffer for the previous state of the filter
410
 *        - must be able to contain 303 elements
411
 *        - the 143 first elements are from the previous state
412
 *        - the next 160 are for output
413
 * @param v_in input filter vector
414
 * @param gain per-subframe gain array, each element is between 0.0 and 2.0
415
 * @param lag per-subframe lag array, each element is
416
 *        - between 16 and 143 if its corresponding pfrac is 0,
417
 *        - between 16 and 139 otherwise
418
 * @param pfrac per-subframe boolean array, 1 if the lag is fractional, 0
419
 *        otherwise
420
 *
421
 * @return filter output vector
422
 */
423
658
static const float *do_pitchfilter(float memory[303], const float v_in[160],
424
                                   const float gain[4], const uint8_t *lag,
425
                                   const uint8_t pfrac[4])
426
{
427
    int i, j;
428
    float *v_lag, *v_out;
429
    const float *v_len;
430
431
658
    v_out = memory + 143; // Output vector starts at memory[143].
432
433
3290
    for (i = 0; i < 4; i++) {
434
2632
        if (gain[i]) {
435
2632
            v_lag = memory + 143 + 40 * i - lag[i];
436
107912
            for (v_len = v_in + 40; v_in < v_len; v_in++) {
437
105280
                if (pfrac[i]) { // If it is a fractional lag...
438
156400
                    for (j = 0, *v_out = 0.0; j < 4; j++)
439
125120
                        *v_out += qcelp_hammsinc_table[j] *
440
125120
                                  (v_lag[j - 4] + v_lag[3 - j]);
441
                } else
442
74000
                    *v_out = *v_lag;
443
444
105280
                *v_out = *v_in + gain[i] * *v_out;
445
446
105280
                v_lag++;
447
105280
                v_out++;
448
            }
449
        } else {
450
            memcpy(v_out, v_in, 40 * sizeof(float));
451
            v_in  += 40;
452
            v_out += 40;
453
        }
454
    }
455
456
658
    memmove(memory, memory + 160, 143 * sizeof(float));
457
658
    return memory + 143;
458
}
459
460
/**
461
 * Apply pitch synthesis filter and pitch prefilter to the scaled codebook vector.
462
 * TIA/EIA/IS-733 2.4.5.2, 2.4.8.7.2
463
 *
464
 * @param q the context
465
 * @param cdn_vector the scaled codebook vector
466
 */
467
495
static void apply_pitch_filters(QCELPContext *q, float *cdn_vector)
468
{
469
    int i;
470
    const float *v_synthesis_filtered, *v_pre_filtered;
471
472

495
    if (q->bitrate >= RATE_HALF || q->bitrate == SILENCE ||
473

166
        (q->bitrate == I_F_Q && (q->prev_bitrate >= RATE_HALF))) {
474
475
329
        if (q->bitrate >= RATE_HALF) {
476
            // Compute gain & lag for the whole frame.
477
1645
            for (i = 0; i < 4; i++) {
478
1316
                q->pitch_gain[i] = q->frame.plag[i] ? (q->frame.pgain[i] + 1) * 0.25 : 0.0;
479
480
1316
                q->pitch_lag[i] = q->frame.plag[i] + 16;
481
            }
482
        } else {
483
            float max_pitch_gain;
484
485
            if (q->bitrate == I_F_Q) {
486
                  if (q->erasure_count < 3)
487
                      max_pitch_gain = 0.9 - 0.3 * (q->erasure_count - 1);
488
                  else
489
                      max_pitch_gain = 0.0;
490
            } else {
491
                av_assert2(q->bitrate == SILENCE);
492
                max_pitch_gain = 1.0;
493
            }
494
            for (i = 0; i < 4; i++)
495
                q->pitch_gain[i] = FFMIN(q->pitch_gain[i], max_pitch_gain);
496
497
            memset(q->frame.pfrac, 0, sizeof(q->frame.pfrac));
498
        }
499
500
        // pitch synthesis filter
501
329
        v_synthesis_filtered = do_pitchfilter(q->pitch_synthesis_filter_mem,
502
329
                                              cdn_vector, q->pitch_gain,
503
329
                                              q->pitch_lag, q->frame.pfrac);
504
505
        // pitch prefilter update
506
1645
        for (i = 0; i < 4; i++)
507
1316
            q->pitch_gain[i] = 0.5 * FFMIN(q->pitch_gain[i], 1.0);
508
509
329
        v_pre_filtered       = do_pitchfilter(q->pitch_pre_filter_mem,
510
                                              v_synthesis_filtered,
511
329
                                              q->pitch_gain, q->pitch_lag,
512
329
                                              q->frame.pfrac);
513
514
329
        apply_gain_ctrl(cdn_vector, v_synthesis_filtered, v_pre_filtered);
515
    } else {
516
166
        memcpy(q->pitch_synthesis_filter_mem,
517
166
               cdn_vector + 17, 143 * sizeof(float));
518
166
        memcpy(q->pitch_pre_filter_mem, cdn_vector + 17, 143 * sizeof(float));
519
166
        memset(q->pitch_gain, 0, sizeof(q->pitch_gain));
520
166
        memset(q->pitch_lag,  0, sizeof(q->pitch_lag));
521
    }
522
495
}
523
524
/**
525
 * Reconstruct LPC coefficients from the line spectral pair frequencies
526
 * and perform bandwidth expansion.
527
 *
528
 * @param lspf line spectral pair frequencies
529
 * @param lpc linear predictive coding coefficients
530
 *
531
 * @note: bandwidth_expansion_coeff could be precalculated into a table
532
 *        but it seems to be slower on x86
533
 *
534
 * TIA/EIA/IS-733 2.4.3.3.5
535
 */
536
1482
static void lspf2lpc(const float *lspf, float *lpc)
537
{
538
    double lsp[10];
539
1482
    double bandwidth_expansion_coeff = QCELP_BANDWIDTH_EXPANSION_COEFF;
540
    int i;
541
542
16302
    for (i = 0; i < 10; i++)
543
14820
        lsp[i] = cos(M_PI * lspf[i]);
544
545
1482
    ff_acelp_lspd2lpc(lsp, lpc, 5);
546
547
16302
    for (i = 0; i < 10; i++) {
548
14820
        lpc[i]                    *= bandwidth_expansion_coeff;
549
14820
        bandwidth_expansion_coeff *= QCELP_BANDWIDTH_EXPANSION_COEFF;
550
    }
551
1482
}
552
553
/**
554
 * Interpolate LSP frequencies and compute LPC coefficients
555
 * for a given bitrate & pitch subframe.
556
 *
557
 * TIA/EIA/IS-733 2.4.3.3.4, 2.4.8.7.2
558
 *
559
 * @param q the context
560
 * @param curr_lspf LSP frequencies vector of the current frame
561
 * @param lpc float vector for the resulting LPC
562
 * @param subframe_num frame number in decoded stream
563
 */
564
1980
static void interpolate_lpc(QCELPContext *q, const float *curr_lspf,
565
                            float *lpc, const int subframe_num)
566
{
567
    float interpolated_lspf[10];
568
    float weight;
569
570
1980
    if (q->bitrate >= RATE_QUARTER)
571
1316
        weight = 0.25 * (subframe_num + 1);
572

664
    else if (q->bitrate == RATE_OCTAVE && !subframe_num)
573
151
        weight = 0.625;
574
    else
575
513
        weight = 1.0;
576
577
1980
    if (weight != 1.0) {
578
1138
        ff_weighted_vector_sumf(interpolated_lspf, curr_lspf, q->prev_lspf,
579
                                weight, 1.0 - weight, 10);
580
1138
        lspf2lpc(interpolated_lspf, lpc);
581
842
    } else if (q->bitrate >= RATE_QUARTER ||
582

513
               (q->bitrate == I_F_Q && !subframe_num))
583
344
        lspf2lpc(curr_lspf, lpc);
584

498
    else if (q->bitrate == SILENCE && !subframe_num)
585
        lspf2lpc(q->prev_lspf, lpc);
586
1980
}
587
588
990
static qcelp_packet_rate buf_size2bitrate(const int buf_size)
589
{
590

990
    switch (buf_size) {
591
283
    case 35: return RATE_FULL;
592
48
    case 17: return RATE_HALF;
593
    case  8: return RATE_QUARTER;
594
164
    case  4: return RATE_OCTAVE;
595
    case  1: return SILENCE;
596
    }
597
598
495
    return I_F_Q;
599
}
600
601
/**
602
 * Determine the bitrate from the frame size and/or the first byte of the frame.
603
 *
604
 * @param avctx the AV codec context
605
 * @param buf_size length of the buffer
606
 * @param buf the buffer
607
 *
608
 * @return the bitrate on success,
609
 *         I_F_Q  if the bitrate cannot be satisfactorily determined
610
 *
611
 * TIA/EIA/IS-733 2.4.8.7.1
612
 */
613
495
static qcelp_packet_rate determine_bitrate(AVCodecContext *avctx,
614
                                           const int buf_size,
615
                                           const uint8_t **buf)
616
{
617
    qcelp_packet_rate bitrate;
618
619
495
    if ((bitrate = buf_size2bitrate(buf_size)) >= 0) {
620
        if (bitrate > **buf) {
621
            QCELPContext *q = avctx->priv_data;
622
            if (!q->warned_buf_mismatch_bitrate) {
623
            av_log(avctx, AV_LOG_WARNING,
624
                   "Claimed bitrate and buffer size mismatch.\n");
625
                q->warned_buf_mismatch_bitrate = 1;
626
            }
627
            bitrate = **buf;
628
        } else if (bitrate < **buf) {
629
            av_log(avctx, AV_LOG_ERROR,
630
                   "Buffer is too small for the claimed bitrate.\n");
631
            return I_F_Q;
632
        }
633
        (*buf)++;
634
495
    } else if ((bitrate = buf_size2bitrate(buf_size + 1)) >= 0) {
635
495
        av_log(avctx, AV_LOG_WARNING,
636
               "Bitrate byte missing, guessing bitrate from packet size.\n");
637
    } else
638
        return I_F_Q;
639
640
495
    if (bitrate == SILENCE) {
641
        // FIXME: Remove this warning when tested with samples.
642
        avpriv_request_sample(avctx, "Blank frame handling");
643
    }
644
495
    return bitrate;
645
}
646
647
15
static void warn_insufficient_frame_quality(AVCodecContext *avctx,
648
                                            const char *message)
649
{
650
15
    av_log(avctx, AV_LOG_WARNING, "Frame #%d, IFQ: %s\n",
651
           avctx->frame_number, message);
652
15
}
653
654
495
static void postfilter(QCELPContext *q, float *samples, float *lpc)
655
{
656
    static const float pow_0_775[10] = {
657
        0.775000, 0.600625, 0.465484, 0.360750, 0.279582,
658
        0.216676, 0.167924, 0.130141, 0.100859, 0.078166
659
    }, pow_0_625[10] = {
660
        0.625000, 0.390625, 0.244141, 0.152588, 0.095367,
661
        0.059605, 0.037253, 0.023283, 0.014552, 0.009095
662
    };
663
    float lpc_s[10], lpc_p[10], pole_out[170], zero_out[160];
664
    int n;
665
666
5445
    for (n = 0; n < 10; n++) {
667
4950
        lpc_s[n] = lpc[n] * pow_0_625[n];
668
4950
        lpc_p[n] = lpc[n] * pow_0_775[n];
669
    }
670
671
495
    ff_celp_lp_zero_synthesis_filterf(zero_out, lpc_s,
672
495
                                      q->formant_mem + 10, 160, 10);
673
495
    memcpy(pole_out, q->postfilter_synth_mem, sizeof(float) * 10);
674
495
    ff_celp_lp_synthesis_filterf(pole_out + 10, lpc_p, zero_out, 160, 10);
675
495
    memcpy(q->postfilter_synth_mem, pole_out + 160, sizeof(float) * 10);
676
677
495
    ff_tilt_compensation(&q->postfilter_tilt_mem, 0.3, pole_out + 10, 160);
678
679
495
    ff_adaptive_gain_control(samples, pole_out + 10,
680
495
                             avpriv_scalarproduct_float_c(q->formant_mem + 10,
681
495
                                                          q->formant_mem + 10,
682
                                                          160),
683
                             160, 0.9375, &q->postfilter_agc_mem);
684
495
}
685
686
495
static int qcelp_decode_frame(AVCodecContext *avctx, void *data,
687
                              int *got_frame_ptr, AVPacket *avpkt)
688
{
689
495
    const uint8_t *buf = avpkt->data;
690
495
    int buf_size       = avpkt->size;
691
495
    QCELPContext *q    = avctx->priv_data;
692
495
    AVFrame *frame     = data;
693
    float *outbuffer;
694
    int   i, ret;
695
    float quantized_lspf[10], lpc[10];
696
    float gain[16];
697
    float *formant_mem;
698
699
    /* get output buffer */
700
495
    frame->nb_samples = 160;
701
495
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
702
        return ret;
703
495
    outbuffer = (float *)frame->data[0];
704
705
495
    if ((q->bitrate = determine_bitrate(avctx, buf_size, &buf)) == I_F_Q) {
706
        warn_insufficient_frame_quality(avctx, "Bitrate cannot be determined.");
707
        goto erasure;
708
    }
709
710
495
    if (q->bitrate == RATE_OCTAVE &&
711
164
        (q->first16bits = AV_RB16(buf)) == 0xFFFF) {
712
13
        warn_insufficient_frame_quality(avctx, "Bitrate is 1/8 and first 16 bits are on.");
713
13
        goto erasure;
714
    }
715
716
482
    if (q->bitrate > SILENCE) {
717
482
        const QCELPBitmap *bitmaps     = qcelp_unpacking_bitmaps_per_rate[q->bitrate];
718
482
        const QCELPBitmap *bitmaps_end = qcelp_unpacking_bitmaps_per_rate[q->bitrate] +
719
482
                                         qcelp_unpacking_bitmaps_lengths[q->bitrate];
720
482
        uint8_t *unpacked_data         = (uint8_t *)&q->frame;
721
722
482
        if ((ret = init_get_bits8(&q->gb, buf, buf_size)) < 0)
723
            return ret;
724
725
482
        memset(&q->frame, 0, sizeof(QCELPFrame));
726
727
26556
        for (; bitmaps < bitmaps_end; bitmaps++)
728
26074
            unpacked_data[bitmaps->index] |= get_bits(&q->gb, bitmaps->bitlen) << bitmaps->bitpos;
729
730
        // Check for erasures/blanks on rates 1, 1/4 and 1/8.
731
482
        if (q->frame.reserved) {
732
1
            warn_insufficient_frame_quality(avctx, "Wrong data in reserved frame area.");
733
1
            goto erasure;
734
        }
735

481
        if (q->bitrate == RATE_QUARTER &&
736
            codebook_sanity_check_for_rate_quarter(q->frame.cbgain)) {
737
            warn_insufficient_frame_quality(avctx, "Codebook gain sanity check failed.");
738
            goto erasure;
739
        }
740
741
481
        if (q->bitrate >= RATE_HALF) {
742
1646
            for (i = 0; i < 4; i++) {
743

1317
                if (q->frame.pfrac[i] && q->frame.plag[i] >= 124) {
744
1
                    warn_insufficient_frame_quality(avctx, "Cannot initialize pitch filter.");
745
1
                    goto erasure;
746
                }
747
            }
748
        }
749
    }
750
751
480
    decode_gain_and_index(q, gain);
752
480
    compute_svector(q, gain, outbuffer);
753
754
480
    if (decode_lspf(q, quantized_lspf) < 0) {
755
        warn_insufficient_frame_quality(avctx, "Badly received packets in frame.");
756
        goto erasure;
757
    }
758
759
480
    apply_pitch_filters(q, outbuffer);
760
761
480
    if (q->bitrate == I_F_Q) {
762
erasure:
763
15
        q->bitrate = I_F_Q;
764
15
        q->erasure_count++;
765
15
        decode_gain_and_index(q, gain);
766
15
        compute_svector(q, gain, outbuffer);
767
15
        decode_lspf(q, quantized_lspf);
768
15
        apply_pitch_filters(q, outbuffer);
769
    } else
770
480
        q->erasure_count = 0;
771
772
495
    formant_mem = q->formant_mem + 10;
773
2475
    for (i = 0; i < 4; i++) {
774
1980
        interpolate_lpc(q, quantized_lspf, lpc, i);
775
1980
        ff_celp_lp_synthesis_filterf(formant_mem, lpc,
776
1980
                                     outbuffer + i * 40, 40, 10);
777
1980
        formant_mem += 40;
778
    }
779
780
    // postfilter, as per TIA/EIA/IS-733 2.4.8.6
781
495
    postfilter(q, outbuffer, lpc);
782
783
495
    memcpy(q->formant_mem, q->formant_mem + 160, 10 * sizeof(float));
784
785
495
    memcpy(q->prev_lspf, quantized_lspf, sizeof(q->prev_lspf));
786
495
    q->prev_bitrate  = q->bitrate;
787
788
495
    *got_frame_ptr = 1;
789
790
495
    return buf_size;
791
}
792
793
AVCodec ff_qcelp_decoder = {
794
    .name           = "qcelp",
795
    .long_name      = NULL_IF_CONFIG_SMALL("QCELP / PureVoice"),
796
    .type           = AVMEDIA_TYPE_AUDIO,
797
    .id             = AV_CODEC_ID_QCELP,
798
    .init           = qcelp_decode_init,
799
    .decode         = qcelp_decode_frame,
800
    .capabilities   = AV_CODEC_CAP_DR1,
801
    .priv_data_size = sizeof(QCELPContext),
802
};