xref: /third_party/ffmpeg/libavcodec/opus_pvq.c (revision cabdff1a)
1/*
2 * Copyright (c) 2007-2008 CSIRO
3 * Copyright (c) 2007-2009 Xiph.Org Foundation
4 * Copyright (c) 2008-2009 Gregory Maxwell
5 * Copyright (c) 2012 Andrew D'Addesio
6 * Copyright (c) 2013-2014 Mozilla Corporation
7 * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
8 *
9 * This file is part of FFmpeg.
10 *
11 * FFmpeg is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
15 *
16 * FFmpeg is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with FFmpeg; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26#include "config_components.h"
27
28#include "opustab.h"
29#include "opus_pvq.h"
30
31#define CELT_PVQ_U(n, k) (ff_celt_pvq_u_row[FFMIN(n, k)][FFMAX(n, k)])
32#define CELT_PVQ_V(n, k) (CELT_PVQ_U(n, k) + CELT_PVQ_U(n, (k) + 1))
33
34static inline int16_t celt_cos(int16_t x)
35{
36    x = (MUL16(x, x) + 4096) >> 13;
37    x = (32767-x) + ROUND_MUL16(x, (-7651 + ROUND_MUL16(x, (8277 + ROUND_MUL16(-626, x)))));
38    return x + 1;
39}
40
41static inline int celt_log2tan(int isin, int icos)
42{
43    int lc, ls;
44    lc = opus_ilog(icos);
45    ls = opus_ilog(isin);
46    icos <<= 15 - lc;
47    isin <<= 15 - ls;
48    return (ls << 11) - (lc << 11) +
49           ROUND_MUL16(isin, ROUND_MUL16(isin, -2597) + 7932) -
50           ROUND_MUL16(icos, ROUND_MUL16(icos, -2597) + 7932);
51}
52
53static inline int celt_bits2pulses(const uint8_t *cache, int bits)
54{
55    // TODO: Find the size of cache and make it into an array in the parameters list
56    int i, low = 0, high;
57
58    high = cache[0];
59    bits--;
60
61    for (i = 0; i < 6; i++) {
62        int center = (low + high + 1) >> 1;
63        if (cache[center] >= bits)
64            high = center;
65        else
66            low = center;
67    }
68
69    return (bits - (low == 0 ? -1 : cache[low]) <= cache[high] - bits) ? low : high;
70}
71
72static inline int celt_pulses2bits(const uint8_t *cache, int pulses)
73{
74    // TODO: Find the size of cache and make it into an array in the parameters list
75   return (pulses == 0) ? 0 : cache[pulses] + 1;
76}
77
78static inline void celt_normalize_residual(const int * av_restrict iy, float * av_restrict X,
79                                           int N, float g)
80{
81    int i;
82    for (i = 0; i < N; i++)
83        X[i] = g * iy[i];
84}
85
86static void celt_exp_rotation_impl(float *X, uint32_t len, uint32_t stride,
87                                   float c, float s)
88{
89    float *Xptr;
90    int i;
91
92    Xptr = X;
93    for (i = 0; i < len - stride; i++) {
94        float x1     = Xptr[0];
95        float x2     = Xptr[stride];
96        Xptr[stride] = c * x2 + s * x1;
97        *Xptr++      = c * x1 - s * x2;
98    }
99
100    Xptr = &X[len - 2 * stride - 1];
101    for (i = len - 2 * stride - 1; i >= 0; i--) {
102        float x1     = Xptr[0];
103        float x2     = Xptr[stride];
104        Xptr[stride] = c * x2 + s * x1;
105        *Xptr--      = c * x1 - s * x2;
106    }
107}
108
109static inline void celt_exp_rotation(float *X, uint32_t len,
110                                     uint32_t stride, uint32_t K,
111                                     enum CeltSpread spread, const int encode)
112{
113    uint32_t stride2 = 0;
114    float c, s;
115    float gain, theta;
116    int i;
117
118    if (2*K >= len || spread == CELT_SPREAD_NONE)
119        return;
120
121    gain = (float)len / (len + (20 - 5*spread) * K);
122    theta = M_PI * gain * gain / 4;
123
124    c = cosf(theta);
125    s = sinf(theta);
126
127    if (len >= stride << 3) {
128        stride2 = 1;
129        /* This is just a simple (equivalent) way of computing sqrt(len/stride) with rounding.
130        It's basically incrementing long as (stride2+0.5)^2 < len/stride. */
131        while ((stride2 * stride2 + stride2) * stride + (stride >> 2) < len)
132            stride2++;
133    }
134
135    len /= stride;
136    for (i = 0; i < stride; i++) {
137        if (encode) {
138            celt_exp_rotation_impl(X + i * len, len, 1, c, -s);
139            if (stride2)
140                celt_exp_rotation_impl(X + i * len, len, stride2, s, -c);
141        } else {
142            if (stride2)
143                celt_exp_rotation_impl(X + i * len, len, stride2, s, c);
144            celt_exp_rotation_impl(X + i * len, len, 1, c, s);
145        }
146    }
147}
148
149static inline uint32_t celt_extract_collapse_mask(const int *iy, uint32_t N, uint32_t B)
150{
151    int i, j, N0 = N / B;
152    uint32_t collapse_mask = 0;
153
154    if (B <= 1)
155        return 1;
156
157    for (i = 0; i < B; i++)
158        for (j = 0; j < N0; j++)
159            collapse_mask |= (!!iy[i*N0+j]) << i;
160    return collapse_mask;
161}
162
163static inline void celt_stereo_merge(float *X, float *Y, float mid, int N)
164{
165    int i;
166    float xp = 0, side = 0;
167    float E[2];
168    float mid2;
169    float gain[2];
170
171    /* Compute the norm of X+Y and X-Y as |X|^2 + |Y|^2 +/- sum(xy) */
172    for (i = 0; i < N; i++) {
173        xp   += X[i] * Y[i];
174        side += Y[i] * Y[i];
175    }
176
177    /* Compensating for the mid normalization */
178    xp *= mid;
179    mid2 = mid;
180    E[0] = mid2 * mid2 + side - 2 * xp;
181    E[1] = mid2 * mid2 + side + 2 * xp;
182    if (E[0] < 6e-4f || E[1] < 6e-4f) {
183        for (i = 0; i < N; i++)
184            Y[i] = X[i];
185        return;
186    }
187
188    gain[0] = 1.0f / sqrtf(E[0]);
189    gain[1] = 1.0f / sqrtf(E[1]);
190
191    for (i = 0; i < N; i++) {
192        float value[2];
193        /* Apply mid scaling (side is already scaled) */
194        value[0] = mid * X[i];
195        value[1] = Y[i];
196        X[i] = gain[0] * (value[0] - value[1]);
197        Y[i] = gain[1] * (value[0] + value[1]);
198    }
199}
200
201static void celt_interleave_hadamard(float *tmp, float *X, int N0,
202                                     int stride, int hadamard)
203{
204    int i, j, N = N0*stride;
205    const uint8_t *order = &ff_celt_hadamard_order[hadamard ? stride - 2 : 30];
206
207    for (i = 0; i < stride; i++)
208        for (j = 0; j < N0; j++)
209            tmp[j*stride+i] = X[order[i]*N0+j];
210
211    memcpy(X, tmp, N*sizeof(float));
212}
213
214static void celt_deinterleave_hadamard(float *tmp, float *X, int N0,
215                                       int stride, int hadamard)
216{
217    int i, j, N = N0*stride;
218    const uint8_t *order = &ff_celt_hadamard_order[hadamard ? stride - 2 : 30];
219
220    for (i = 0; i < stride; i++)
221        for (j = 0; j < N0; j++)
222            tmp[order[i]*N0+j] = X[j*stride+i];
223
224    memcpy(X, tmp, N*sizeof(float));
225}
226
227static void celt_haar1(float *X, int N0, int stride)
228{
229    int i, j;
230    N0 >>= 1;
231    for (i = 0; i < stride; i++) {
232        for (j = 0; j < N0; j++) {
233            float x0 = X[stride * (2 * j + 0) + i];
234            float x1 = X[stride * (2 * j + 1) + i];
235            X[stride * (2 * j + 0) + i] = (x0 + x1) * M_SQRT1_2;
236            X[stride * (2 * j + 1) + i] = (x0 - x1) * M_SQRT1_2;
237        }
238    }
239}
240
241static inline int celt_compute_qn(int N, int b, int offset, int pulse_cap,
242                                  int stereo)
243{
244    int qn, qb;
245    int N2 = 2 * N - 1;
246    if (stereo && N == 2)
247        N2--;
248
249    /* The upper limit ensures that in a stereo split with itheta==16384, we'll
250     * always have enough bits left over to code at least one pulse in the
251     * side; otherwise it would collapse, since it doesn't get folded. */
252    qb = FFMIN3(b - pulse_cap - (4 << 3), (b + N2 * offset) / N2, 8 << 3);
253    qn = (qb < (1 << 3 >> 1)) ? 1 : ((ff_celt_qn_exp2[qb & 0x7] >> (14 - (qb >> 3))) + 1) >> 1 << 1;
254    return qn;
255}
256
257/* Convert the quantized vector to an index */
258static inline uint32_t celt_icwrsi(uint32_t N, uint32_t K, const int *y)
259{
260    int i, idx = 0, sum = 0;
261    for (i = N - 1; i >= 0; i--) {
262        const uint32_t i_s = CELT_PVQ_U(N - i, sum + FFABS(y[i]) + 1);
263        idx += CELT_PVQ_U(N - i, sum) + (y[i] < 0)*i_s;
264        sum += FFABS(y[i]);
265    }
266    return idx;
267}
268
269// this code was adapted from libopus
270static inline uint64_t celt_cwrsi(uint32_t N, uint32_t K, uint32_t i, int *y)
271{
272    uint64_t norm = 0;
273    uint32_t q, p;
274    int s, val;
275    int k0;
276
277    while (N > 2) {
278        /*Lots of pulses case:*/
279        if (K >= N) {
280            const uint32_t *row = ff_celt_pvq_u_row[N];
281
282            /* Are the pulses in this dimension negative? */
283            p  = row[K + 1];
284            s  = -(i >= p);
285            i -= p & s;
286
287            /*Count how many pulses were placed in this dimension.*/
288            k0 = K;
289            q = row[N];
290            if (q > i) {
291                K = N;
292                do {
293                    p = ff_celt_pvq_u_row[--K][N];
294                } while (p > i);
295            } else
296                for (p = row[K]; p > i; p = row[K])
297                    K--;
298
299            i    -= p;
300            val   = (k0 - K + s) ^ s;
301            norm += val * val;
302            *y++  = val;
303        } else { /*Lots of dimensions case:*/
304            /*Are there any pulses in this dimension at all?*/
305            p = ff_celt_pvq_u_row[K    ][N];
306            q = ff_celt_pvq_u_row[K + 1][N];
307
308            if (p <= i && i < q) {
309                i -= p;
310                *y++ = 0;
311            } else {
312                /*Are the pulses in this dimension negative?*/
313                s  = -(i >= q);
314                i -= q & s;
315
316                /*Count how many pulses were placed in this dimension.*/
317                k0 = K;
318                do p = ff_celt_pvq_u_row[--K][N];
319                while (p > i);
320
321                i    -= p;
322                val   = (k0 - K + s) ^ s;
323                norm += val * val;
324                *y++  = val;
325            }
326        }
327        N--;
328    }
329
330    /* N == 2 */
331    p  = 2 * K + 1;
332    s  = -(i >= p);
333    i -= p & s;
334    k0 = K;
335    K  = (i + 1) / 2;
336
337    if (K)
338        i -= 2 * K - 1;
339
340    val   = (k0 - K + s) ^ s;
341    norm += val * val;
342    *y++  = val;
343
344    /* N==1 */
345    s     = -i;
346    val   = (K + s) ^ s;
347    norm += val * val;
348    *y    = val;
349
350    return norm;
351}
352
353static inline void celt_encode_pulses(OpusRangeCoder *rc, int *y, uint32_t N, uint32_t K)
354{
355    ff_opus_rc_enc_uint(rc, celt_icwrsi(N, K, y), CELT_PVQ_V(N, K));
356}
357
358static inline float celt_decode_pulses(OpusRangeCoder *rc, int *y, uint32_t N, uint32_t K)
359{
360    const uint32_t idx = ff_opus_rc_dec_uint(rc, CELT_PVQ_V(N, K));
361    return celt_cwrsi(N, K, idx, y);
362}
363
364/*
365 * Faster than libopus's search, operates entirely in the signed domain.
366 * Slightly worse/better depending on N, K and the input vector.
367 */
368static float ppp_pvq_search_c(float *X, int *y, int K, int N)
369{
370    int i, y_norm = 0;
371    float res = 0.0f, xy_norm = 0.0f;
372
373    for (i = 0; i < N; i++)
374        res += FFABS(X[i]);
375
376    res = K/(res + FLT_EPSILON);
377
378    for (i = 0; i < N; i++) {
379        y[i] = lrintf(res*X[i]);
380        y_norm  += y[i]*y[i];
381        xy_norm += y[i]*X[i];
382        K -= FFABS(y[i]);
383    }
384
385    while (K) {
386        int max_idx = 0, phase = FFSIGN(K);
387        float max_num = 0.0f;
388        float max_den = 1.0f;
389        y_norm += 1.0f;
390
391        for (i = 0; i < N; i++) {
392            /* If the sum has been overshot and the best place has 0 pulses allocated
393             * to it, attempting to decrease it further will actually increase the
394             * sum. Prevent this by disregarding any 0 positions when decrementing. */
395            const int ca = 1 ^ ((y[i] == 0) & (phase < 0));
396            const int y_new = y_norm  + 2*phase*FFABS(y[i]);
397            float xy_new = xy_norm + 1*phase*FFABS(X[i]);
398            xy_new = xy_new * xy_new;
399            if (ca && (max_den*xy_new) > (y_new*max_num)) {
400                max_den = y_new;
401                max_num = xy_new;
402                max_idx = i;
403            }
404        }
405
406        K -= phase;
407
408        phase *= FFSIGN(X[max_idx]);
409        xy_norm += 1*phase*X[max_idx];
410        y_norm  += 2*phase*y[max_idx];
411        y[max_idx] += phase;
412    }
413
414    return (float)y_norm;
415}
416
417static uint32_t celt_alg_quant(OpusRangeCoder *rc, float *X, uint32_t N, uint32_t K,
418                               enum CeltSpread spread, uint32_t blocks, float gain,
419                               CeltPVQ *pvq)
420{
421    int *y = pvq->qcoeff;
422
423    celt_exp_rotation(X, N, blocks, K, spread, 1);
424    gain /= sqrtf(pvq->pvq_search(X, y, K, N));
425    celt_encode_pulses(rc, y,  N, K);
426    celt_normalize_residual(y, X, N, gain);
427    celt_exp_rotation(X, N, blocks, K, spread, 0);
428    return celt_extract_collapse_mask(y, N, blocks);
429}
430
431/** Decode pulse vector and combine the result with the pitch vector to produce
432    the final normalised signal in the current band. */
433static uint32_t celt_alg_unquant(OpusRangeCoder *rc, float *X, uint32_t N, uint32_t K,
434                                 enum CeltSpread spread, uint32_t blocks, float gain,
435                                 CeltPVQ *pvq)
436{
437    int *y = pvq->qcoeff;
438
439    gain /= sqrtf(celt_decode_pulses(rc, y, N, K));
440    celt_normalize_residual(y, X, N, gain);
441    celt_exp_rotation(X, N, blocks, K, spread, 0);
442    return celt_extract_collapse_mask(y, N, blocks);
443}
444
445static int celt_calc_theta(const float *X, const float *Y, int coupling, int N)
446{
447    int i;
448    float e[2] = { 0.0f, 0.0f };
449    if (coupling) { /* Coupling case */
450        for (i = 0; i < N; i++) {
451            e[0] += (X[i] + Y[i])*(X[i] + Y[i]);
452            e[1] += (X[i] - Y[i])*(X[i] - Y[i]);
453        }
454    } else {
455        for (i = 0; i < N; i++) {
456            e[0] += X[i]*X[i];
457            e[1] += Y[i]*Y[i];
458        }
459    }
460    return lrintf(32768.0f*atan2f(sqrtf(e[1]), sqrtf(e[0]))/M_PI);
461}
462
463static void celt_stereo_is_decouple(float *X, float *Y, float e_l, float e_r, int N)
464{
465    int i;
466    const float energy_n = 1.0f/(sqrtf(e_l*e_l + e_r*e_r) + FLT_EPSILON);
467    e_l *= energy_n;
468    e_r *= energy_n;
469    for (i = 0; i < N; i++)
470        X[i] = e_l*X[i] + e_r*Y[i];
471}
472
473static void celt_stereo_ms_decouple(float *X, float *Y, int N)
474{
475    int i;
476    for (i = 0; i < N; i++) {
477        const float Xret = X[i];
478        X[i] = (X[i] + Y[i])*M_SQRT1_2;
479        Y[i] = (Y[i] - Xret)*M_SQRT1_2;
480    }
481}
482
483static av_always_inline uint32_t quant_band_template(CeltPVQ *pvq, CeltFrame *f,
484                                                     OpusRangeCoder *rc,
485                                                     const int band, float *X,
486                                                     float *Y, int N, int b,
487                                                     uint32_t blocks, float *lowband,
488                                                     int duration, float *lowband_out,
489                                                     int level, float gain,
490                                                     float *lowband_scratch,
491                                                     int fill, int quant)
492{
493    int i;
494    const uint8_t *cache;
495    int stereo = !!Y, split = stereo;
496    int imid = 0, iside = 0;
497    uint32_t N0 = N;
498    int N_B = N / blocks;
499    int N_B0 = N_B;
500    int B0 = blocks;
501    int time_divide = 0;
502    int recombine = 0;
503    int inv = 0;
504    float mid = 0, side = 0;
505    int longblocks = (B0 == 1);
506    uint32_t cm = 0;
507
508    if (N == 1) {
509        float *x = X;
510        for (i = 0; i <= stereo; i++) {
511            int sign = 0;
512            if (f->remaining2 >= 1 << 3) {
513                if (quant) {
514                    sign = x[0] < 0;
515                    ff_opus_rc_put_raw(rc, sign, 1);
516                } else {
517                    sign = ff_opus_rc_get_raw(rc, 1);
518                }
519                f->remaining2 -= 1 << 3;
520            }
521            x[0] = 1.0f - 2.0f*sign;
522            x = Y;
523        }
524        if (lowband_out)
525            lowband_out[0] = X[0];
526        return 1;
527    }
528
529    if (!stereo && level == 0) {
530        int tf_change = f->tf_change[band];
531        int k;
532        if (tf_change > 0)
533            recombine = tf_change;
534        /* Band recombining to increase frequency resolution */
535
536        if (lowband &&
537            (recombine || ((N_B & 1) == 0 && tf_change < 0) || B0 > 1)) {
538            for (i = 0; i < N; i++)
539                lowband_scratch[i] = lowband[i];
540            lowband = lowband_scratch;
541        }
542
543        for (k = 0; k < recombine; k++) {
544            if (quant || lowband)
545                celt_haar1(quant ? X : lowband, N >> k, 1 << k);
546            fill = ff_celt_bit_interleave[fill & 0xF] | ff_celt_bit_interleave[fill >> 4] << 2;
547        }
548        blocks >>= recombine;
549        N_B <<= recombine;
550
551        /* Increasing the time resolution */
552        while ((N_B & 1) == 0 && tf_change < 0) {
553            if (quant || lowband)
554                celt_haar1(quant ? X : lowband, N_B, blocks);
555            fill |= fill << blocks;
556            blocks <<= 1;
557            N_B >>= 1;
558            time_divide++;
559            tf_change++;
560        }
561        B0 = blocks;
562        N_B0 = N_B;
563
564        /* Reorganize the samples in time order instead of frequency order */
565        if (B0 > 1 && (quant || lowband))
566            celt_deinterleave_hadamard(pvq->hadamard_tmp, quant ? X : lowband,
567                                       N_B >> recombine, B0 << recombine,
568                                       longblocks);
569    }
570
571    /* If we need 1.5 more bit than we can produce, split the band in two. */
572    cache = ff_celt_cache_bits +
573            ff_celt_cache_index[(duration + 1) * CELT_MAX_BANDS + band];
574    if (!stereo && duration >= 0 && b > cache[cache[0]] + 12 && N > 2) {
575        N >>= 1;
576        Y = X + N;
577        split = 1;
578        duration -= 1;
579        if (blocks == 1)
580            fill = (fill & 1) | (fill << 1);
581        blocks = (blocks + 1) >> 1;
582    }
583
584    if (split) {
585        int qn;
586        int itheta = quant ? celt_calc_theta(X, Y, stereo, N) : 0;
587        int mbits, sbits, delta;
588        int qalloc;
589        int pulse_cap;
590        int offset;
591        int orig_fill;
592        int tell;
593
594        /* Decide on the resolution to give to the split parameter theta */
595        pulse_cap = ff_celt_log_freq_range[band] + duration * 8;
596        offset = (pulse_cap >> 1) - (stereo && N == 2 ? CELT_QTHETA_OFFSET_TWOPHASE :
597                                                          CELT_QTHETA_OFFSET);
598        qn = (stereo && band >= f->intensity_stereo) ? 1 :
599             celt_compute_qn(N, b, offset, pulse_cap, stereo);
600        tell = opus_rc_tell_frac(rc);
601        if (qn != 1) {
602            if (quant)
603                itheta = (itheta*qn + 8192) >> 14;
604            /* Entropy coding of the angle. We use a uniform pdf for the
605             * time split, a step for stereo, and a triangular one for the rest. */
606            if (quant) {
607                if (stereo && N > 2)
608                    ff_opus_rc_enc_uint_step(rc, itheta, qn / 2);
609                else if (stereo || B0 > 1)
610                    ff_opus_rc_enc_uint(rc, itheta, qn + 1);
611                else
612                    ff_opus_rc_enc_uint_tri(rc, itheta, qn);
613                itheta = itheta * 16384 / qn;
614                if (stereo) {
615                    if (itheta == 0)
616                        celt_stereo_is_decouple(X, Y, f->block[0].lin_energy[band],
617                                                f->block[1].lin_energy[band], N);
618                    else
619                        celt_stereo_ms_decouple(X, Y, N);
620                }
621            } else {
622                if (stereo && N > 2)
623                    itheta = ff_opus_rc_dec_uint_step(rc, qn / 2);
624                else if (stereo || B0 > 1)
625                    itheta = ff_opus_rc_dec_uint(rc, qn+1);
626                else
627                    itheta = ff_opus_rc_dec_uint_tri(rc, qn);
628                itheta = itheta * 16384 / qn;
629            }
630        } else if (stereo) {
631            if (quant) {
632                inv = f->apply_phase_inv ? itheta > 8192 : 0;
633                 if (inv) {
634                    for (i = 0; i < N; i++)
635                       Y[i] *= -1;
636                 }
637                 celt_stereo_is_decouple(X, Y, f->block[0].lin_energy[band],
638                                         f->block[1].lin_energy[band], N);
639
640                if (b > 2 << 3 && f->remaining2 > 2 << 3) {
641                    ff_opus_rc_enc_log(rc, inv, 2);
642                } else {
643                    inv = 0;
644                }
645            } else {
646                inv = (b > 2 << 3 && f->remaining2 > 2 << 3) ? ff_opus_rc_dec_log(rc, 2) : 0;
647                inv = f->apply_phase_inv ? inv : 0;
648            }
649            itheta = 0;
650        }
651        qalloc = opus_rc_tell_frac(rc) - tell;
652        b -= qalloc;
653
654        orig_fill = fill;
655        if (itheta == 0) {
656            imid = 32767;
657            iside = 0;
658            fill = av_mod_uintp2(fill, blocks);
659            delta = -16384;
660        } else if (itheta == 16384) {
661            imid = 0;
662            iside = 32767;
663            fill &= ((1 << blocks) - 1) << blocks;
664            delta = 16384;
665        } else {
666            imid = celt_cos(itheta);
667            iside = celt_cos(16384-itheta);
668            /* This is the mid vs side allocation that minimizes squared error
669            in that band. */
670            delta = ROUND_MUL16((N - 1) << 7, celt_log2tan(iside, imid));
671        }
672
673        mid  = imid  / 32768.0f;
674        side = iside / 32768.0f;
675
676        /* This is a special case for N=2 that only works for stereo and takes
677        advantage of the fact that mid and side are orthogonal to encode
678        the side with just one bit. */
679        if (N == 2 && stereo) {
680            int c;
681            int sign = 0;
682            float tmp;
683            float *x2, *y2;
684            mbits = b;
685            /* Only need one bit for the side */
686            sbits = (itheta != 0 && itheta != 16384) ? 1 << 3 : 0;
687            mbits -= sbits;
688            c = (itheta > 8192);
689            f->remaining2 -= qalloc+sbits;
690
691            x2 = c ? Y : X;
692            y2 = c ? X : Y;
693            if (sbits) {
694                if (quant) {
695                    sign = x2[0]*y2[1] - x2[1]*y2[0] < 0;
696                    ff_opus_rc_put_raw(rc, sign, 1);
697                } else {
698                    sign = ff_opus_rc_get_raw(rc, 1);
699                }
700            }
701            sign = 1 - 2 * sign;
702            /* We use orig_fill here because we want to fold the side, but if
703            itheta==16384, we'll have cleared the low bits of fill. */
704            cm = pvq->quant_band(pvq, f, rc, band, x2, NULL, N, mbits, blocks, lowband, duration,
705                                 lowband_out, level, gain, lowband_scratch, orig_fill);
706            /* We don't split N=2 bands, so cm is either 1 or 0 (for a fold-collapse),
707            and there's no need to worry about mixing with the other channel. */
708            y2[0] = -sign * x2[1];
709            y2[1] =  sign * x2[0];
710            X[0] *= mid;
711            X[1] *= mid;
712            Y[0] *= side;
713            Y[1] *= side;
714            tmp = X[0];
715            X[0] = tmp - Y[0];
716            Y[0] = tmp + Y[0];
717            tmp = X[1];
718            X[1] = tmp - Y[1];
719            Y[1] = tmp + Y[1];
720        } else {
721            /* "Normal" split code */
722            float *next_lowband2     = NULL;
723            float *next_lowband_out1 = NULL;
724            int next_level = 0;
725            int rebalance;
726            uint32_t cmt;
727
728            /* Give more bits to low-energy MDCTs than they would
729             * otherwise deserve */
730            if (B0 > 1 && !stereo && (itheta & 0x3fff)) {
731                if (itheta > 8192)
732                    /* Rough approximation for pre-echo masking */
733                    delta -= delta >> (4 - duration);
734                else
735                    /* Corresponds to a forward-masking slope of
736                     * 1.5 dB per 10 ms */
737                    delta = FFMIN(0, delta + (N << 3 >> (5 - duration)));
738            }
739            mbits = av_clip((b - delta) / 2, 0, b);
740            sbits = b - mbits;
741            f->remaining2 -= qalloc;
742
743            if (lowband && !stereo)
744                next_lowband2 = lowband + N; /* >32-bit split case */
745
746            /* Only stereo needs to pass on lowband_out.
747             * Otherwise, it's handled at the end */
748            if (stereo)
749                next_lowband_out1 = lowband_out;
750            else
751                next_level = level + 1;
752
753            rebalance = f->remaining2;
754            if (mbits >= sbits) {
755                /* In stereo mode, we do not apply a scaling to the mid
756                 * because we need the normalized mid for folding later */
757                cm = pvq->quant_band(pvq, f, rc, band, X, NULL, N, mbits, blocks,
758                                     lowband, duration, next_lowband_out1, next_level,
759                                     stereo ? 1.0f : (gain * mid), lowband_scratch, fill);
760                rebalance = mbits - (rebalance - f->remaining2);
761                if (rebalance > 3 << 3 && itheta != 0)
762                    sbits += rebalance - (3 << 3);
763
764                /* For a stereo split, the high bits of fill are always zero,
765                 * so no folding will be done to the side. */
766                cmt = pvq->quant_band(pvq, f, rc, band, Y, NULL, N, sbits, blocks,
767                                      next_lowband2, duration, NULL, next_level,
768                                      gain * side, NULL, fill >> blocks);
769                cm |= cmt << ((B0 >> 1) & (stereo - 1));
770            } else {
771                /* For a stereo split, the high bits of fill are always zero,
772                 * so no folding will be done to the side. */
773                cm = pvq->quant_band(pvq, f, rc, band, Y, NULL, N, sbits, blocks,
774                                     next_lowband2, duration, NULL, next_level,
775                                     gain * side, NULL, fill >> blocks);
776                cm <<= ((B0 >> 1) & (stereo - 1));
777                rebalance = sbits - (rebalance - f->remaining2);
778                if (rebalance > 3 << 3 && itheta != 16384)
779                    mbits += rebalance - (3 << 3);
780
781                /* In stereo mode, we do not apply a scaling to the mid because
782                 * we need the normalized mid for folding later */
783                cm |= pvq->quant_band(pvq, f, rc, band, X, NULL, N, mbits, blocks,
784                                      lowband, duration, next_lowband_out1, next_level,
785                                      stereo ? 1.0f : (gain * mid), lowband_scratch, fill);
786            }
787        }
788    } else {
789        /* This is the basic no-split case */
790        uint32_t q         = celt_bits2pulses(cache, b);
791        uint32_t curr_bits = celt_pulses2bits(cache, q);
792        f->remaining2 -= curr_bits;
793
794        /* Ensures we can never bust the budget */
795        while (f->remaining2 < 0 && q > 0) {
796            f->remaining2 += curr_bits;
797            curr_bits      = celt_pulses2bits(cache, --q);
798            f->remaining2 -= curr_bits;
799        }
800
801        if (q != 0) {
802            /* Finally do the actual (de)quantization */
803            if (quant) {
804                cm = celt_alg_quant(rc, X, N, (q < 8) ? q : (8 + (q & 7)) << ((q >> 3) - 1),
805                                    f->spread, blocks, gain, pvq);
806            } else {
807                cm = celt_alg_unquant(rc, X, N, (q < 8) ? q : (8 + (q & 7)) << ((q >> 3) - 1),
808                                      f->spread, blocks, gain, pvq);
809            }
810        } else {
811            /* If there's no pulse, fill the band anyway */
812            uint32_t cm_mask = (1 << blocks) - 1;
813            fill &= cm_mask;
814            if (fill) {
815                if (!lowband) {
816                    /* Noise */
817                    for (i = 0; i < N; i++)
818                        X[i] = (((int32_t)celt_rng(f)) >> 20);
819                    cm = cm_mask;
820                } else {
821                    /* Folded spectrum */
822                    for (i = 0; i < N; i++) {
823                        /* About 48 dB below the "normal" folding level */
824                        X[i] = lowband[i] + (((celt_rng(f)) & 0x8000) ? 1.0f / 256 : -1.0f / 256);
825                    }
826                    cm = fill;
827                }
828                celt_renormalize_vector(X, N, gain);
829            } else {
830                memset(X, 0, N*sizeof(float));
831            }
832        }
833    }
834
835    /* This code is used by the decoder and by the resynthesis-enabled encoder */
836    if (stereo) {
837        if (N > 2)
838            celt_stereo_merge(X, Y, mid, N);
839        if (inv) {
840            for (i = 0; i < N; i++)
841                Y[i] *= -1;
842        }
843    } else if (level == 0) {
844        int k;
845
846        /* Undo the sample reorganization going from time order to frequency order */
847        if (B0 > 1)
848            celt_interleave_hadamard(pvq->hadamard_tmp, X, N_B >> recombine,
849                                     B0 << recombine, longblocks);
850
851        /* Undo time-freq changes that we did earlier */
852        N_B = N_B0;
853        blocks = B0;
854        for (k = 0; k < time_divide; k++) {
855            blocks >>= 1;
856            N_B <<= 1;
857            cm |= cm >> blocks;
858            celt_haar1(X, N_B, blocks);
859        }
860
861        for (k = 0; k < recombine; k++) {
862            cm = ff_celt_bit_deinterleave[cm];
863            celt_haar1(X, N0>>k, 1<<k);
864        }
865        blocks <<= recombine;
866
867        /* Scale output for later folding */
868        if (lowband_out) {
869            float n = sqrtf(N0);
870            for (i = 0; i < N0; i++)
871                lowband_out[i] = n * X[i];
872        }
873        cm = av_mod_uintp2(cm, blocks);
874    }
875
876    return cm;
877}
878
879static QUANT_FN(pvq_decode_band)
880{
881#if CONFIG_OPUS_DECODER
882    return quant_band_template(pvq, f, rc, band, X, Y, N, b, blocks, lowband, duration,
883                               lowband_out, level, gain, lowband_scratch, fill, 0);
884#else
885    return 0;
886#endif
887}
888
889static QUANT_FN(pvq_encode_band)
890{
891#if CONFIG_OPUS_ENCODER
892    return quant_band_template(pvq, f, rc, band, X, Y, N, b, blocks, lowband, duration,
893                               lowband_out, level, gain, lowband_scratch, fill, 1);
894#else
895    return 0;
896#endif
897}
898
899int av_cold ff_celt_pvq_init(CeltPVQ **pvq, int encode)
900{
901    CeltPVQ *s = av_malloc(sizeof(CeltPVQ));
902    if (!s)
903        return AVERROR(ENOMEM);
904
905    s->pvq_search = ppp_pvq_search_c;
906    s->quant_band = encode ? pvq_encode_band : pvq_decode_band;
907
908#if CONFIG_OPUS_ENCODER && ARCH_X86
909    ff_celt_pvq_init_x86(s);
910#endif
911
912    *pvq = s;
913
914    return 0;
915}
916
917void av_cold ff_celt_pvq_uninit(CeltPVQ **pvq)
918{
919    av_freep(pvq);
920}
921