1/*
2 * The simplest AC-3 encoder
3 * Copyright (c) 2000 Fabrice Bellard
4 * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
5 * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24/**
25 * @file
26 * The simplest AC-3 encoder.
27 */
28
29#include <stdint.h>
30
31#include "libavutil/attributes.h"
32#include "libavutil/avassert.h"
33#include "libavutil/avstring.h"
34#include "libavutil/channel_layout.h"
35#include "libavutil/crc.h"
36#include "libavutil/internal.h"
37#include "libavutil/opt.h"
38#include "avcodec.h"
39#include "put_bits.h"
40#include "audiodsp.h"
41#include "ac3dsp.h"
42#include "ac3.h"
43#include "fft.h"
44#include "ac3enc.h"
45#include "eac3enc.h"
46
47typedef struct AC3Mant {
48    int16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
49    int mant1_cnt, mant2_cnt, mant4_cnt;    ///< mantissa counts for bap=1,2,4
50} AC3Mant;
51
52#define CMIXLEV_NUM_OPTIONS 3
53static const float cmixlev_options[CMIXLEV_NUM_OPTIONS] = {
54    LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB
55};
56
57#define SURMIXLEV_NUM_OPTIONS 3
58static const float surmixlev_options[SURMIXLEV_NUM_OPTIONS] = {
59    LEVEL_MINUS_3DB, LEVEL_MINUS_6DB, LEVEL_ZERO
60};
61
62#define EXTMIXLEV_NUM_OPTIONS 8
63static const float extmixlev_options[EXTMIXLEV_NUM_OPTIONS] = {
64    LEVEL_PLUS_3DB,  LEVEL_PLUS_1POINT5DB,  LEVEL_ONE,       LEVEL_MINUS_4POINT5DB,
65    LEVEL_MINUS_3DB, LEVEL_MINUS_4POINT5DB, LEVEL_MINUS_6DB, LEVEL_ZERO
66};
67
68
69/**
70 * LUT for number of exponent groups.
71 * exponent_group_tab[coupling][exponent strategy-1][number of coefficients]
72 */
73static uint8_t exponent_group_tab[2][3][256];
74
75
76/**
77 * List of supported channel layouts.
78 */
79const uint64_t ff_ac3_channel_layouts[19] = {
80     AV_CH_LAYOUT_MONO,
81     AV_CH_LAYOUT_STEREO,
82     AV_CH_LAYOUT_2_1,
83     AV_CH_LAYOUT_SURROUND,
84     AV_CH_LAYOUT_2_2,
85     AV_CH_LAYOUT_QUAD,
86     AV_CH_LAYOUT_4POINT0,
87     AV_CH_LAYOUT_5POINT0,
88     AV_CH_LAYOUT_5POINT0_BACK,
89    (AV_CH_LAYOUT_MONO     | AV_CH_LOW_FREQUENCY),
90    (AV_CH_LAYOUT_STEREO   | AV_CH_LOW_FREQUENCY),
91    (AV_CH_LAYOUT_2_1      | AV_CH_LOW_FREQUENCY),
92    (AV_CH_LAYOUT_SURROUND | AV_CH_LOW_FREQUENCY),
93    (AV_CH_LAYOUT_2_2      | AV_CH_LOW_FREQUENCY),
94    (AV_CH_LAYOUT_QUAD     | AV_CH_LOW_FREQUENCY),
95    (AV_CH_LAYOUT_4POINT0  | AV_CH_LOW_FREQUENCY),
96     AV_CH_LAYOUT_5POINT1,
97     AV_CH_LAYOUT_5POINT1_BACK,
98     0
99};
100
101
102/**
103 * LUT to select the bandwidth code based on the bit rate, sample rate, and
104 * number of full-bandwidth channels.
105 * bandwidth_tab[fbw_channels-1][sample rate code][bit rate code]
106 */
107static const uint8_t ac3_bandwidth_tab[5][3][19] = {
108//      32  40  48  56  64  80  96 112 128 160 192 224 256 320 384 448 512 576 640
109
110    { {  0,  0,  0, 12, 16, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
111      {  0,  0,  0, 16, 20, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
112      {  0,  0,  0, 32, 40, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
113
114    { {  0,  0,  0,  0,  0,  0,  0, 20, 24, 32, 48, 48, 48, 48, 48, 48, 48, 48, 48 },
115      {  0,  0,  0,  0,  0,  0,  4, 24, 28, 36, 56, 56, 56, 56, 56, 56, 56, 56, 56 },
116      {  0,  0,  0,  0,  0,  0, 20, 44, 52, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60 } },
117
118    { {  0,  0,  0,  0,  0,  0,  0,  0,  0, 16, 24, 32, 40, 48, 48, 48, 48, 48, 48 },
119      {  0,  0,  0,  0,  0,  0,  0,  0,  4, 20, 28, 36, 44, 56, 56, 56, 56, 56, 56 },
120      {  0,  0,  0,  0,  0,  0,  0,  0, 20, 40, 48, 60, 60, 60, 60, 60, 60, 60, 60 } },
121
122    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 12, 24, 32, 48, 48, 48, 48, 48, 48 },
123      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 16, 28, 36, 56, 56, 56, 56, 56, 56 },
124      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 32, 48, 60, 60, 60, 60, 60, 60, 60 } },
125
126    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  8, 20, 32, 40, 48, 48, 48, 48 },
127      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 12, 24, 36, 44, 56, 56, 56, 56 },
128      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0, 28, 44, 60, 60, 60, 60, 60, 60 } }
129};
130
131
132/**
133 * LUT to select the coupling start band based on the bit rate, sample rate, and
134 * number of full-bandwidth channels. -1 = coupling off
135 * ac3_coupling_start_tab[channel_mode-2][sample rate code][bit rate code]
136 *
137 * TODO: more testing for optimal parameters.
138 *       multi-channel tests at 44.1kHz and 32kHz.
139 */
140static const int8_t ac3_coupling_start_tab[6][3][19] = {
141//      32  40  48  56  64  80  96 112 128 160 192 224 256 320 384 448 512 576 640
142
143    // 2/0
144    { {  0,  0,  0,  0,  0,  0,  0,  1,  1,  7,  8, 11, 12, -1, -1, -1, -1, -1, -1 },
145      {  0,  0,  0,  0,  0,  0,  1,  3,  5,  7, 10, 12, 13, -1, -1, -1, -1, -1, -1 },
146      {  0,  0,  0,  0,  1,  2,  2,  9, 13, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
147
148    // 3/0
149    { {  0,  0,  0,  0,  0,  0,  0,  0,  2,  2,  6,  9, 11, 12, 13, -1, -1, -1, -1 },
150      {  0,  0,  0,  0,  0,  0,  0,  0,  2,  2,  6,  9, 11, 12, 13, -1, -1, -1, -1 },
151      { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
152
153    // 2/1 - untested
154    { {  0,  0,  0,  0,  0,  0,  0,  0,  2,  2,  6,  9, 11, 12, 13, -1, -1, -1, -1 },
155      {  0,  0,  0,  0,  0,  0,  0,  0,  2,  2,  6,  9, 11, 12, 13, -1, -1, -1, -1 },
156      { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
157
158    // 3/1
159    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  3,  2, 10, 11, 11, 12, 12, 14, -1 },
160      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  3,  2, 10, 11, 11, 12, 12, 14, -1 },
161      { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
162
163    // 2/2 - untested
164    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  3,  2, 10, 11, 11, 12, 12, 14, -1 },
165      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  3,  2, 10, 11, 11, 12, 12, 14, -1 },
166      { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
167
168    // 3/2
169    { {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  6,  8, 11, 12, 12, -1, -1 },
170      {  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  1,  6,  8, 11, 12, 12, -1, -1 },
171      { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 } },
172};
173
174
175/**
176 * Adjust the frame size to make the average bit rate match the target bit rate.
177 * This is only needed for 11025, 22050, and 44100 sample rates or any E-AC-3.
178 *
179 * @param s  AC-3 encoder private context
180 */
181void ff_ac3_adjust_frame_size(AC3EncodeContext *s)
182{
183    while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
184        s->bits_written    -= s->bit_rate;
185        s->samples_written -= s->sample_rate;
186    }
187    s->frame_size = s->frame_size_min +
188                    2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
189    s->bits_written    += s->frame_size * 8;
190    s->samples_written += AC3_BLOCK_SIZE * s->num_blocks;
191}
192
193
194/**
195 * Set the initial coupling strategy parameters prior to coupling analysis.
196 *
197 * @param s  AC-3 encoder private context
198 */
199void ff_ac3_compute_coupling_strategy(AC3EncodeContext *s)
200{
201    int blk, ch;
202    int got_cpl_snr;
203    int num_cpl_blocks;
204
205    /* set coupling use flags for each block/channel */
206    /* TODO: turn coupling on/off and adjust start band based on bit usage */
207    for (blk = 0; blk < s->num_blocks; blk++) {
208        AC3Block *block = &s->blocks[blk];
209        for (ch = 1; ch <= s->fbw_channels; ch++)
210            block->channel_in_cpl[ch] = s->cpl_on;
211    }
212
213    /* enable coupling for each block if at least 2 channels have coupling
214       enabled for that block */
215    got_cpl_snr = 0;
216    num_cpl_blocks = 0;
217    for (blk = 0; blk < s->num_blocks; blk++) {
218        AC3Block *block = &s->blocks[blk];
219        block->num_cpl_channels = 0;
220        for (ch = 1; ch <= s->fbw_channels; ch++)
221            block->num_cpl_channels += block->channel_in_cpl[ch];
222        block->cpl_in_use = block->num_cpl_channels > 1;
223        num_cpl_blocks += block->cpl_in_use;
224        if (!block->cpl_in_use) {
225            block->num_cpl_channels = 0;
226            for (ch = 1; ch <= s->fbw_channels; ch++)
227                block->channel_in_cpl[ch] = 0;
228        }
229
230        block->new_cpl_strategy = !blk;
231        if (blk) {
232            for (ch = 1; ch <= s->fbw_channels; ch++) {
233                if (block->channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
234                    block->new_cpl_strategy = 1;
235                    break;
236                }
237            }
238        }
239        block->new_cpl_leak = block->new_cpl_strategy;
240
241        if (!blk || (block->cpl_in_use && !got_cpl_snr)) {
242            block->new_snr_offsets = 1;
243            if (block->cpl_in_use)
244                got_cpl_snr = 1;
245        } else {
246            block->new_snr_offsets = 0;
247        }
248    }
249    if (!num_cpl_blocks)
250        s->cpl_on = 0;
251
252    /* set bandwidth for each channel */
253    for (blk = 0; blk < s->num_blocks; blk++) {
254        AC3Block *block = &s->blocks[blk];
255        for (ch = 1; ch <= s->fbw_channels; ch++) {
256            if (block->channel_in_cpl[ch])
257                block->end_freq[ch] = s->start_freq[CPL_CH];
258            else
259                block->end_freq[ch] = s->bandwidth_code * 3 + 73;
260        }
261    }
262}
263
264
265/**
266 * Apply stereo rematrixing to coefficients based on rematrixing flags.
267 *
268 * @param s  AC-3 encoder private context
269 */
270void ff_ac3_apply_rematrixing(AC3EncodeContext *s)
271{
272    int nb_coefs;
273    int blk, bnd, i;
274    int start, end;
275    uint8_t *flags = NULL;
276
277    if (!s->rematrixing_enabled)
278        return;
279
280    for (blk = 0; blk < s->num_blocks; blk++) {
281        AC3Block *block = &s->blocks[blk];
282        if (block->new_rematrixing_strategy)
283            flags = block->rematrixing_flags;
284        nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
285        for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
286            if (flags[bnd]) {
287                start = ff_ac3_rematrix_band_tab[bnd];
288                end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
289                for (i = start; i < end; i++) {
290                    int32_t lt = block->fixed_coef[1][i];
291                    int32_t rt = block->fixed_coef[2][i];
292                    block->fixed_coef[1][i] = (lt + rt) >> 1;
293                    block->fixed_coef[2][i] = (lt - rt) >> 1;
294                }
295            }
296        }
297    }
298}
299
300
301/*
302 * Initialize exponent tables.
303 */
304static av_cold void exponent_init(AC3EncodeContext *s)
305{
306    int expstr, i, grpsize;
307
308    for (expstr = EXP_D15-1; expstr <= EXP_D45-1; expstr++) {
309        grpsize = 3 << expstr;
310        for (i = 12; i < 256; i++) {
311            exponent_group_tab[0][expstr][i] = (i + grpsize - 4) / grpsize;
312            exponent_group_tab[1][expstr][i] = (i              ) / grpsize;
313        }
314    }
315    /* LFE */
316    exponent_group_tab[0][0][7] = 2;
317
318    if (CONFIG_EAC3_ENCODER && s->eac3)
319        ff_eac3_exponent_init();
320}
321
322
323/*
324 * Extract exponents from the MDCT coefficients.
325 */
326static void extract_exponents(AC3EncodeContext *s)
327{
328    int ch        = !s->cpl_on;
329    int chan_size = AC3_MAX_COEFS * s->num_blocks * (s->channels - ch + 1);
330    AC3Block *block = &s->blocks[0];
331
332    s->ac3dsp.extract_exponents(block->exp[ch], block->fixed_coef[ch], chan_size);
333}
334
335
336/**
337 * Exponent Difference Threshold.
338 * New exponents are sent if their SAD exceed this number.
339 */
340#define EXP_DIFF_THRESHOLD 500
341
342/**
343 * Table used to select exponent strategy based on exponent reuse block interval.
344 */
345static const uint8_t exp_strategy_reuse_tab[4][6] = {
346    { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
347    { EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
348    { EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15, EXP_D15 },
349    { EXP_D45, EXP_D25, EXP_D25, EXP_D15, EXP_D15, EXP_D15 }
350};
351
352/*
353 * Calculate exponent strategies for all channels.
354 * Array arrangement is reversed to simplify the per-channel calculation.
355 */
356static void compute_exp_strategy(AC3EncodeContext *s)
357{
358    int ch, blk, blk1;
359
360    for (ch = !s->cpl_on; ch <= s->fbw_channels; ch++) {
361        uint8_t *exp_strategy = s->exp_strategy[ch];
362        uint8_t *exp          = s->blocks[0].exp[ch];
363        int exp_diff;
364
365        /* estimate if the exponent variation & decide if they should be
366           reused in the next frame */
367        exp_strategy[0] = EXP_NEW;
368        exp += AC3_MAX_COEFS;
369        for (blk = 1; blk < s->num_blocks; blk++, exp += AC3_MAX_COEFS) {
370            if (ch == CPL_CH) {
371                if (!s->blocks[blk-1].cpl_in_use) {
372                    exp_strategy[blk] = EXP_NEW;
373                    continue;
374                } else if (!s->blocks[blk].cpl_in_use) {
375                    exp_strategy[blk] = EXP_REUSE;
376                    continue;
377                }
378            } else if (s->blocks[blk].channel_in_cpl[ch] != s->blocks[blk-1].channel_in_cpl[ch]) {
379                exp_strategy[blk] = EXP_NEW;
380                continue;
381            }
382            exp_diff = s->dsp.sad[0](NULL, exp, exp - AC3_MAX_COEFS, 16, 16);
383            exp_strategy[blk] = EXP_REUSE;
384            if (ch == CPL_CH && exp_diff > (EXP_DIFF_THRESHOLD * (s->blocks[blk].end_freq[ch] - s->start_freq[ch]) / AC3_MAX_COEFS))
385                exp_strategy[blk] = EXP_NEW;
386            else if (ch > CPL_CH && exp_diff > EXP_DIFF_THRESHOLD)
387                exp_strategy[blk] = EXP_NEW;
388        }
389
390        /* now select the encoding strategy type : if exponents are often
391           recoded, we use a coarse encoding */
392        blk = 0;
393        while (blk < s->num_blocks) {
394            blk1 = blk + 1;
395            while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE)
396                blk1++;
397            exp_strategy[blk] = exp_strategy_reuse_tab[s->num_blks_code][blk1-blk-1];
398            blk = blk1;
399        }
400    }
401    if (s->lfe_on) {
402        ch = s->lfe_channel;
403        s->exp_strategy[ch][0] = EXP_D15;
404        for (blk = 1; blk < s->num_blocks; blk++)
405            s->exp_strategy[ch][blk] = EXP_REUSE;
406    }
407
408    /* for E-AC-3, determine frame exponent strategy */
409    if (CONFIG_EAC3_ENCODER && s->eac3)
410        ff_eac3_get_frame_exp_strategy(s);
411}
412
413
414/**
415 * Update the exponents so that they are the ones the decoder will decode.
416 *
417 * @param[in,out] exp   array of exponents for 1 block in 1 channel
418 * @param nb_exps       number of exponents in active bandwidth
419 * @param exp_strategy  exponent strategy for the block
420 * @param cpl           indicates if the block is in the coupling channel
421 */
422static void encode_exponents_blk_ch(uint8_t *exp, int nb_exps, int exp_strategy,
423                                    int cpl)
424{
425    int nb_groups, i, k;
426
427    nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_exps] * 3;
428
429    /* for each group, compute the minimum exponent */
430    switch(exp_strategy) {
431    case EXP_D25:
432        for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
433            uint8_t exp_min = exp[k];
434            if (exp[k+1] < exp_min)
435                exp_min = exp[k+1];
436            exp[i-cpl] = exp_min;
437            k += 2;
438        }
439        break;
440    case EXP_D45:
441        for (i = 1, k = 1-cpl; i <= nb_groups; i++) {
442            uint8_t exp_min = exp[k];
443            if (exp[k+1] < exp_min)
444                exp_min = exp[k+1];
445            if (exp[k+2] < exp_min)
446                exp_min = exp[k+2];
447            if (exp[k+3] < exp_min)
448                exp_min = exp[k+3];
449            exp[i-cpl] = exp_min;
450            k += 4;
451        }
452        break;
453    }
454
455    /* constraint for DC exponent */
456    if (!cpl && exp[0] > 15)
457        exp[0] = 15;
458
459    /* decrease the delta between each groups to within 2 so that they can be
460       differentially encoded */
461    for (i = 1; i <= nb_groups; i++)
462        exp[i] = FFMIN(exp[i], exp[i-1] + 2);
463    i--;
464    while (--i >= 0)
465        exp[i] = FFMIN(exp[i], exp[i+1] + 2);
466
467    if (cpl)
468        exp[-1] = exp[0] & ~1;
469
470    /* now we have the exponent values the decoder will see */
471    switch (exp_strategy) {
472    case EXP_D25:
473        for (i = nb_groups, k = (nb_groups * 2)-cpl; i > 0; i--) {
474            uint8_t exp1 = exp[i-cpl];
475            exp[k--] = exp1;
476            exp[k--] = exp1;
477        }
478        break;
479    case EXP_D45:
480        for (i = nb_groups, k = (nb_groups * 4)-cpl; i > 0; i--) {
481            exp[k] = exp[k-1] = exp[k-2] = exp[k-3] = exp[i-cpl];
482            k -= 4;
483        }
484        break;
485    }
486}
487
488
489/*
490 * Encode exponents from original extracted form to what the decoder will see.
491 * This copies and groups exponents based on exponent strategy and reduces
492 * deltas between adjacent exponent groups so that they can be differentially
493 * encoded.
494 */
495static void encode_exponents(AC3EncodeContext *s)
496{
497    int blk, blk1, ch, cpl;
498    uint8_t *exp, *exp_strategy;
499    int nb_coefs, num_reuse_blocks;
500
501    for (ch = !s->cpl_on; ch <= s->channels; ch++) {
502        exp          = s->blocks[0].exp[ch] + s->start_freq[ch];
503        exp_strategy = s->exp_strategy[ch];
504
505        cpl = (ch == CPL_CH);
506        blk = 0;
507        while (blk < s->num_blocks) {
508            AC3Block *block = &s->blocks[blk];
509            if (cpl && !block->cpl_in_use) {
510                exp += AC3_MAX_COEFS;
511                blk++;
512                continue;
513            }
514            nb_coefs = block->end_freq[ch] - s->start_freq[ch];
515            blk1 = blk + 1;
516
517            /* count the number of EXP_REUSE blocks after the current block
518               and set exponent reference block numbers */
519            s->exp_ref_block[ch][blk] = blk;
520            while (blk1 < s->num_blocks && exp_strategy[blk1] == EXP_REUSE) {
521                s->exp_ref_block[ch][blk1] = blk;
522                blk1++;
523            }
524            num_reuse_blocks = blk1 - blk - 1;
525
526            /* for the EXP_REUSE case we select the min of the exponents */
527            s->ac3dsp.ac3_exponent_min(exp-s->start_freq[ch], num_reuse_blocks,
528                                       AC3_MAX_COEFS);
529
530            encode_exponents_blk_ch(exp, nb_coefs, exp_strategy[blk], cpl);
531
532            exp += AC3_MAX_COEFS * (num_reuse_blocks + 1);
533            blk = blk1;
534        }
535    }
536
537    /* reference block numbers have been changed, so reset ref_bap_set */
538    s->ref_bap_set = 0;
539}
540
541
542/*
543 * Count exponent bits based on bandwidth, coupling, and exponent strategies.
544 */
545static int count_exponent_bits(AC3EncodeContext *s)
546{
547    int blk, ch;
548    int nb_groups, bit_count;
549
550    bit_count = 0;
551    for (blk = 0; blk < s->num_blocks; blk++) {
552        AC3Block *block = &s->blocks[blk];
553        for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
554            int exp_strategy = s->exp_strategy[ch][blk];
555            int cpl          = (ch == CPL_CH);
556            int nb_coefs     = block->end_freq[ch] - s->start_freq[ch];
557
558            if (exp_strategy == EXP_REUSE)
559                continue;
560
561            nb_groups = exponent_group_tab[cpl][exp_strategy-1][nb_coefs];
562            bit_count += 4 + (nb_groups * 7);
563        }
564    }
565
566    return bit_count;
567}
568
569
570/**
571 * Group exponents.
572 * 3 delta-encoded exponents are in each 7-bit group. The number of groups
573 * varies depending on exponent strategy and bandwidth.
574 *
575 * @param s  AC-3 encoder private context
576 */
577void ff_ac3_group_exponents(AC3EncodeContext *s)
578{
579    int blk, ch, i, cpl;
580    int group_size, nb_groups;
581    uint8_t *p;
582    int delta0, delta1, delta2;
583    int exp0, exp1;
584
585    for (blk = 0; blk < s->num_blocks; blk++) {
586        AC3Block *block = &s->blocks[blk];
587        for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
588            int exp_strategy = s->exp_strategy[ch][blk];
589            if (exp_strategy == EXP_REUSE)
590                continue;
591            cpl = (ch == CPL_CH);
592            group_size = exp_strategy + (exp_strategy == EXP_D45);
593            nb_groups = exponent_group_tab[cpl][exp_strategy-1][block->end_freq[ch]-s->start_freq[ch]];
594            p = block->exp[ch] + s->start_freq[ch] - cpl;
595
596            /* DC exponent */
597            exp1 = *p++;
598            block->grouped_exp[ch][0] = exp1;
599
600            /* remaining exponents are delta encoded */
601            for (i = 1; i <= nb_groups; i++) {
602                /* merge three delta in one code */
603                exp0   = exp1;
604                exp1   = p[0];
605                p     += group_size;
606                delta0 = exp1 - exp0 + 2;
607                av_assert2(delta0 >= 0 && delta0 <= 4);
608
609                exp0   = exp1;
610                exp1   = p[0];
611                p     += group_size;
612                delta1 = exp1 - exp0 + 2;
613                av_assert2(delta1 >= 0 && delta1 <= 4);
614
615                exp0   = exp1;
616                exp1   = p[0];
617                p     += group_size;
618                delta2 = exp1 - exp0 + 2;
619                av_assert2(delta2 >= 0 && delta2 <= 4);
620
621                block->grouped_exp[ch][i] = ((delta0 * 5 + delta1) * 5) + delta2;
622            }
623        }
624    }
625}
626
627
628/**
629 * Calculate final exponents from the supplied MDCT coefficients and exponent shift.
630 * Extract exponents from MDCT coefficients, calculate exponent strategies,
631 * and encode final exponents.
632 *
633 * @param s  AC-3 encoder private context
634 */
635void ff_ac3_process_exponents(AC3EncodeContext *s)
636{
637    extract_exponents(s);
638
639    compute_exp_strategy(s);
640
641    encode_exponents(s);
642
643    emms_c();
644}
645
646
647/*
648 * Count frame bits that are based solely on fixed parameters.
649 * This only has to be run once when the encoder is initialized.
650 */
651static void count_frame_bits_fixed(AC3EncodeContext *s)
652{
653    static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 };
654    int blk;
655    int frame_bits;
656
657    /* assumptions:
658     *   no dynamic range codes
659     *   bit allocation parameters do not change between blocks
660     *   no delta bit allocation
661     *   no skipped data
662     *   no auxiliary data
663     *   no E-AC-3 metadata
664     */
665
666    /* header */
667    frame_bits = 16; /* sync info */
668    if (s->eac3) {
669        /* bitstream info header */
670        frame_bits += 35;
671        frame_bits += 1 + 1;
672        if (s->num_blocks != 0x6)
673            frame_bits++;
674        frame_bits++;
675        /* audio frame header */
676        if (s->num_blocks == 6)
677            frame_bits += 2;
678        frame_bits += 10;
679        /* exponent strategy */
680        if (s->use_frame_exp_strategy)
681            frame_bits += 5 * s->fbw_channels;
682        else
683            frame_bits += s->num_blocks * 2 * s->fbw_channels;
684        if (s->lfe_on)
685            frame_bits += s->num_blocks;
686        /* converter exponent strategy */
687        if (s->num_blks_code != 0x3)
688            frame_bits++;
689        else
690            frame_bits += s->fbw_channels * 5;
691        /* snr offsets */
692        frame_bits += 10;
693        /* block start info */
694        if (s->num_blocks != 1)
695            frame_bits++;
696    } else {
697        frame_bits += 49;
698        frame_bits += frame_bits_inc[s->channel_mode];
699    }
700
701    /* audio blocks */
702    for (blk = 0; blk < s->num_blocks; blk++) {
703        if (!s->eac3) {
704            /* block switch flags */
705            frame_bits += s->fbw_channels;
706
707            /* dither flags */
708            frame_bits += s->fbw_channels;
709        }
710
711        /* dynamic range */
712        frame_bits++;
713
714        /* spectral extension */
715        if (s->eac3)
716            frame_bits++;
717
718        if (!s->eac3) {
719            /* exponent strategy */
720            frame_bits += 2 * s->fbw_channels;
721            if (s->lfe_on)
722                frame_bits++;
723
724            /* bit allocation params */
725            frame_bits++;
726            if (!blk)
727                frame_bits += 2 + 2 + 2 + 2 + 3;
728        }
729
730        /* converter snr offset */
731        if (s->eac3)
732            frame_bits++;
733
734        if (!s->eac3) {
735            /* delta bit allocation */
736            frame_bits++;
737
738            /* skipped data */
739            frame_bits++;
740        }
741    }
742
743    /* auxiliary data */
744    frame_bits++;
745
746    /* CRC */
747    frame_bits += 1 + 16;
748
749    s->frame_bits_fixed = frame_bits;
750}
751
752
753/*
754 * Initialize bit allocation.
755 * Set default parameter codes and calculate parameter values.
756 */
757static av_cold void bit_alloc_init(AC3EncodeContext *s)
758{
759    int ch;
760
761    /* init default parameters */
762    s->slow_decay_code = 2;
763    s->fast_decay_code = 1;
764    s->slow_gain_code  = 1;
765    s->db_per_bit_code = s->eac3 ? 2 : 3;
766    s->floor_code      = 7;
767    for (ch = 0; ch <= s->channels; ch++)
768        s->fast_gain_code[ch] = 4;
769
770    /* initial snr offset */
771    s->coarse_snr_offset = 40;
772
773    /* compute real values */
774    /* currently none of these values change during encoding, so we can just
775       set them once at initialization */
776    s->bit_alloc.slow_decay = ff_ac3_slow_decay_tab[s->slow_decay_code] >> s->bit_alloc.sr_shift;
777    s->bit_alloc.fast_decay = ff_ac3_fast_decay_tab[s->fast_decay_code] >> s->bit_alloc.sr_shift;
778    s->bit_alloc.slow_gain  = ff_ac3_slow_gain_tab[s->slow_gain_code];
779    s->bit_alloc.db_per_bit = ff_ac3_db_per_bit_tab[s->db_per_bit_code];
780    s->bit_alloc.floor      = ff_ac3_floor_tab[s->floor_code];
781    s->bit_alloc.cpl_fast_leak = 0;
782    s->bit_alloc.cpl_slow_leak = 0;
783
784    count_frame_bits_fixed(s);
785}
786
787
788/*
789 * Count the bits used to encode the frame, minus exponents and mantissas.
790 * Bits based on fixed parameters have already been counted, so now we just
791 * have to add the bits based on parameters that change during encoding.
792 */
793static void count_frame_bits(AC3EncodeContext *s)
794{
795    AC3EncOptions *opt = &s->options;
796    int blk, ch;
797    int frame_bits = 0;
798
799    /* header */
800    if (s->eac3) {
801        if (opt->eac3_mixing_metadata) {
802            if (s->channel_mode > AC3_CHMODE_STEREO)
803                frame_bits += 2;
804            if (s->has_center)
805                frame_bits += 6;
806            if (s->has_surround)
807                frame_bits += 6;
808            frame_bits += s->lfe_on;
809            frame_bits += 1 + 1 + 2;
810            if (s->channel_mode < AC3_CHMODE_STEREO)
811                frame_bits++;
812            frame_bits++;
813        }
814        if (opt->eac3_info_metadata) {
815            frame_bits += 3 + 1 + 1;
816            if (s->channel_mode == AC3_CHMODE_STEREO)
817                frame_bits += 2 + 2;
818            if (s->channel_mode >= AC3_CHMODE_2F2R)
819                frame_bits += 2;
820            frame_bits++;
821            if (opt->audio_production_info)
822                frame_bits += 5 + 2 + 1;
823            frame_bits++;
824        }
825        /* coupling */
826        if (s->channel_mode > AC3_CHMODE_MONO) {
827            frame_bits++;
828            for (blk = 1; blk < s->num_blocks; blk++) {
829                AC3Block *block = &s->blocks[blk];
830                frame_bits++;
831                if (block->new_cpl_strategy)
832                    frame_bits++;
833            }
834        }
835        /* coupling exponent strategy */
836        if (s->cpl_on) {
837            if (s->use_frame_exp_strategy) {
838                frame_bits += 5 * s->cpl_on;
839            } else {
840                for (blk = 0; blk < s->num_blocks; blk++)
841                    frame_bits += 2 * s->blocks[blk].cpl_in_use;
842            }
843        }
844    } else {
845        if (opt->audio_production_info)
846            frame_bits += 7;
847        if (s->bitstream_id == 6) {
848            if (opt->extended_bsi_1)
849                frame_bits += 14;
850            if (opt->extended_bsi_2)
851                frame_bits += 14;
852        }
853    }
854
855    /* audio blocks */
856    for (blk = 0; blk < s->num_blocks; blk++) {
857        AC3Block *block = &s->blocks[blk];
858
859        /* coupling strategy */
860        if (!s->eac3)
861            frame_bits++;
862        if (block->new_cpl_strategy) {
863            if (!s->eac3)
864                frame_bits++;
865            if (block->cpl_in_use) {
866                if (s->eac3)
867                    frame_bits++;
868                if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO)
869                    frame_bits += s->fbw_channels;
870                if (s->channel_mode == AC3_CHMODE_STEREO)
871                    frame_bits++;
872                frame_bits += 4 + 4;
873                if (s->eac3)
874                    frame_bits++;
875                else
876                    frame_bits += s->num_cpl_subbands - 1;
877            }
878        }
879
880        /* coupling coordinates */
881        if (block->cpl_in_use) {
882            for (ch = 1; ch <= s->fbw_channels; ch++) {
883                if (block->channel_in_cpl[ch]) {
884                    if (!s->eac3 || block->new_cpl_coords[ch] != 2)
885                        frame_bits++;
886                    if (block->new_cpl_coords[ch]) {
887                        frame_bits += 2;
888                        frame_bits += (4 + 4) * s->num_cpl_bands;
889                    }
890                }
891            }
892        }
893
894        /* stereo rematrixing */
895        if (s->channel_mode == AC3_CHMODE_STEREO) {
896            if (!s->eac3 || blk > 0)
897                frame_bits++;
898            if (s->blocks[blk].new_rematrixing_strategy)
899                frame_bits += block->num_rematrixing_bands;
900        }
901
902        /* bandwidth codes & gain range */
903        for (ch = 1; ch <= s->fbw_channels; ch++) {
904            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
905                if (!block->channel_in_cpl[ch])
906                    frame_bits += 6;
907                frame_bits += 2;
908            }
909        }
910
911        /* coupling exponent strategy */
912        if (!s->eac3 && block->cpl_in_use)
913            frame_bits += 2;
914
915        /* snr offsets and fast gain codes */
916        if (!s->eac3) {
917            frame_bits++;
918            if (block->new_snr_offsets)
919                frame_bits += 6 + (s->channels + block->cpl_in_use) * (4 + 3);
920        }
921
922        /* coupling leak info */
923        if (block->cpl_in_use) {
924            if (!s->eac3 || block->new_cpl_leak != 2)
925                frame_bits++;
926            if (block->new_cpl_leak)
927                frame_bits += 3 + 3;
928        }
929    }
930
931    s->frame_bits = s->frame_bits_fixed + frame_bits;
932}
933
934
935/*
936 * Calculate masking curve based on the final exponents.
937 * Also calculate the power spectral densities to use in future calculations.
938 */
939static void bit_alloc_masking(AC3EncodeContext *s)
940{
941    int blk, ch;
942
943    for (blk = 0; blk < s->num_blocks; blk++) {
944        AC3Block *block = &s->blocks[blk];
945        for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
946            /* We only need psd and mask for calculating bap.
947               Since we currently do not calculate bap when exponent
948               strategy is EXP_REUSE we do not need to calculate psd or mask. */
949            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
950                ff_ac3_bit_alloc_calc_psd(block->exp[ch], s->start_freq[ch],
951                                          block->end_freq[ch], block->psd[ch],
952                                          block->band_psd[ch]);
953                ff_ac3_bit_alloc_calc_mask(&s->bit_alloc, block->band_psd[ch],
954                                           s->start_freq[ch], block->end_freq[ch],
955                                           ff_ac3_fast_gain_tab[s->fast_gain_code[ch]],
956                                           ch == s->lfe_channel,
957                                           DBA_NONE, 0, NULL, NULL, NULL,
958                                           block->mask[ch]);
959            }
960        }
961    }
962}
963
964
965/*
966 * Ensure that bap for each block and channel point to the current bap_buffer.
967 * They may have been switched during the bit allocation search.
968 */
969static void reset_block_bap(AC3EncodeContext *s)
970{
971    int blk, ch;
972    uint8_t *ref_bap;
973
974    if (s->ref_bap[0][0] == s->bap_buffer && s->ref_bap_set)
975        return;
976
977    ref_bap = s->bap_buffer;
978    for (ch = 0; ch <= s->channels; ch++) {
979        for (blk = 0; blk < s->num_blocks; blk++)
980            s->ref_bap[ch][blk] = ref_bap + AC3_MAX_COEFS * s->exp_ref_block[ch][blk];
981        ref_bap += AC3_MAX_COEFS * s->num_blocks;
982    }
983    s->ref_bap_set = 1;
984}
985
986
987/**
988 * Initialize mantissa counts.
989 * These are set so that they are padded to the next whole group size when bits
990 * are counted in compute_mantissa_size.
991 *
992 * @param[in,out] mant_cnt  running counts for each bap value for each block
993 */
994static void count_mantissa_bits_init(uint16_t mant_cnt[AC3_MAX_BLOCKS][16])
995{
996    int blk;
997
998    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
999        memset(mant_cnt[blk], 0, sizeof(mant_cnt[blk]));
1000        mant_cnt[blk][1] = mant_cnt[blk][2] = 2;
1001        mant_cnt[blk][4] = 1;
1002    }
1003}
1004
1005
1006/**
1007 * Update mantissa bit counts for all blocks in 1 channel in a given bandwidth
1008 * range.
1009 *
1010 * @param s                 AC-3 encoder private context
1011 * @param ch                channel index
1012 * @param[in,out] mant_cnt  running counts for each bap value for each block
1013 * @param start             starting coefficient bin
1014 * @param end               ending coefficient bin
1015 */
1016static void count_mantissa_bits_update_ch(AC3EncodeContext *s, int ch,
1017                                          uint16_t mant_cnt[AC3_MAX_BLOCKS][16],
1018                                          int start, int end)
1019{
1020    int blk;
1021
1022    for (blk = 0; blk < s->num_blocks; blk++) {
1023        AC3Block *block = &s->blocks[blk];
1024        if (ch == CPL_CH && !block->cpl_in_use)
1025            continue;
1026        s->ac3dsp.update_bap_counts(mant_cnt[blk],
1027                                    s->ref_bap[ch][blk] + start,
1028                                    FFMIN(end, block->end_freq[ch]) - start);
1029    }
1030}
1031
1032
1033/*
1034 * Count the number of mantissa bits in the frame based on the bap values.
1035 */
1036static int count_mantissa_bits(AC3EncodeContext *s)
1037{
1038    int ch, max_end_freq;
1039    LOCAL_ALIGNED_16(uint16_t, mant_cnt, [AC3_MAX_BLOCKS], [16]);
1040
1041    count_mantissa_bits_init(mant_cnt);
1042
1043    max_end_freq = s->bandwidth_code * 3 + 73;
1044    for (ch = !s->cpl_enabled; ch <= s->channels; ch++)
1045        count_mantissa_bits_update_ch(s, ch, mant_cnt, s->start_freq[ch],
1046                                      max_end_freq);
1047
1048    return s->ac3dsp.compute_mantissa_size(mant_cnt);
1049}
1050
1051
1052/**
1053 * Run the bit allocation with a given SNR offset.
1054 * This calculates the bit allocation pointers that will be used to determine
1055 * the quantization of each mantissa.
1056 *
1057 * @param s           AC-3 encoder private context
1058 * @param snr_offset  SNR offset, 0 to 1023
1059 * @return the number of bits needed for mantissas if the given SNR offset is
1060 *         is used.
1061 */
1062static int bit_alloc(AC3EncodeContext *s, int snr_offset)
1063{
1064    int blk, ch;
1065
1066    snr_offset = (snr_offset - 240) << 2;
1067
1068    reset_block_bap(s);
1069    for (blk = 0; blk < s->num_blocks; blk++) {
1070        AC3Block *block = &s->blocks[blk];
1071
1072        for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1073            /* Currently the only bit allocation parameters which vary across
1074               blocks within a frame are the exponent values.  We can take
1075               advantage of that by reusing the bit allocation pointers
1076               whenever we reuse exponents. */
1077            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
1078                s->ac3dsp.bit_alloc_calc_bap(block->mask[ch], block->psd[ch],
1079                                             s->start_freq[ch], block->end_freq[ch],
1080                                             snr_offset, s->bit_alloc.floor,
1081                                             ff_ac3_bap_tab, s->ref_bap[ch][blk]);
1082            }
1083        }
1084    }
1085    return count_mantissa_bits(s);
1086}
1087
1088
1089/*
1090 * Constant bitrate bit allocation search.
1091 * Find the largest SNR offset that will allow data to fit in the frame.
1092 */
1093static int cbr_bit_allocation(AC3EncodeContext *s)
1094{
1095    int ch;
1096    int bits_left;
1097    int snr_offset, snr_incr;
1098
1099    bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
1100    if (bits_left < 0)
1101        return AVERROR(EINVAL);
1102
1103    snr_offset = s->coarse_snr_offset << 4;
1104
1105    /* if previous frame SNR offset was 1023, check if current frame can also
1106       use SNR offset of 1023. if so, skip the search. */
1107    if ((snr_offset | s->fine_snr_offset[1]) == 1023) {
1108        if (bit_alloc(s, 1023) <= bits_left)
1109            return 0;
1110    }
1111
1112    while (snr_offset >= 0 &&
1113           bit_alloc(s, snr_offset) > bits_left) {
1114        snr_offset -= 64;
1115    }
1116    if (snr_offset < 0)
1117        return AVERROR(EINVAL);
1118
1119    FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1120    for (snr_incr = 64; snr_incr > 0; snr_incr >>= 2) {
1121        while (snr_offset + snr_incr <= 1023 &&
1122               bit_alloc(s, snr_offset + snr_incr) <= bits_left) {
1123            snr_offset += snr_incr;
1124            FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1125        }
1126    }
1127    FFSWAP(uint8_t *, s->bap_buffer, s->bap1_buffer);
1128    reset_block_bap(s);
1129
1130    s->coarse_snr_offset = snr_offset >> 4;
1131    for (ch = !s->cpl_on; ch <= s->channels; ch++)
1132        s->fine_snr_offset[ch] = snr_offset & 0xF;
1133
1134    return 0;
1135}
1136
1137
1138/*
1139 * Perform bit allocation search.
1140 * Finds the SNR offset value that maximizes quality and fits in the specified
1141 * frame size.  Output is the SNR offset and a set of bit allocation pointers
1142 * used to quantize the mantissas.
1143 */
1144int ff_ac3_compute_bit_allocation(AC3EncodeContext *s)
1145{
1146    count_frame_bits(s);
1147
1148    s->exponent_bits = count_exponent_bits(s);
1149
1150    bit_alloc_masking(s);
1151
1152    return cbr_bit_allocation(s);
1153}
1154
1155
1156/**
1157 * Symmetric quantization on 'levels' levels.
1158 *
1159 * @param c       unquantized coefficient
1160 * @param e       exponent
1161 * @param levels  number of quantization levels
1162 * @return        quantized coefficient
1163 */
1164static inline int sym_quant(int c, int e, int levels)
1165{
1166    int v = (((levels * c) >> (24 - e)) + levels) >> 1;
1167    av_assert2(v >= 0 && v < levels);
1168    return v;
1169}
1170
1171
1172/**
1173 * Asymmetric quantization on 2^qbits levels.
1174 *
1175 * @param c      unquantized coefficient
1176 * @param e      exponent
1177 * @param qbits  number of quantization bits
1178 * @return       quantized coefficient
1179 */
1180static inline int asym_quant(int c, int e, int qbits)
1181{
1182    int m;
1183
1184    c = (((c << e) >> (24 - qbits)) + 1) >> 1;
1185    m = (1 << (qbits-1));
1186    if (c >= m)
1187        c = m - 1;
1188    av_assert2(c >= -m);
1189    return c;
1190}
1191
1192
1193/**
1194 * Quantize a set of mantissas for a single channel in a single block.
1195 *
1196 * @param s           Mantissa count context
1197 * @param fixed_coef  unquantized fixed-point coefficients
1198 * @param exp         exponents
1199 * @param bap         bit allocation pointer indices
1200 * @param[out] qmant  quantized coefficients
1201 * @param start_freq  starting coefficient bin
1202 * @param end_freq    ending coefficient bin
1203 */
1204static void quantize_mantissas_blk_ch(AC3Mant *s, int32_t *fixed_coef,
1205                                      uint8_t *exp, uint8_t *bap,
1206                                      int16_t *qmant, int start_freq,
1207                                      int end_freq)
1208{
1209    int i;
1210
1211    for (i = start_freq; i < end_freq; i++) {
1212        int c = fixed_coef[i];
1213        int e = exp[i];
1214        int v = bap[i];
1215        if (v)
1216        switch (v) {
1217        case 1:
1218            v = sym_quant(c, e, 3);
1219            switch (s->mant1_cnt) {
1220            case 0:
1221                s->qmant1_ptr = &qmant[i];
1222                v = 9 * v;
1223                s->mant1_cnt = 1;
1224                break;
1225            case 1:
1226                *s->qmant1_ptr += 3 * v;
1227                s->mant1_cnt = 2;
1228                v = 128;
1229                break;
1230            default:
1231                *s->qmant1_ptr += v;
1232                s->mant1_cnt = 0;
1233                v = 128;
1234                break;
1235            }
1236            break;
1237        case 2:
1238            v = sym_quant(c, e, 5);
1239            switch (s->mant2_cnt) {
1240            case 0:
1241                s->qmant2_ptr = &qmant[i];
1242                v = 25 * v;
1243                s->mant2_cnt = 1;
1244                break;
1245            case 1:
1246                *s->qmant2_ptr += 5 * v;
1247                s->mant2_cnt = 2;
1248                v = 128;
1249                break;
1250            default:
1251                *s->qmant2_ptr += v;
1252                s->mant2_cnt = 0;
1253                v = 128;
1254                break;
1255            }
1256            break;
1257        case 3:
1258            v = sym_quant(c, e, 7);
1259            break;
1260        case 4:
1261            v = sym_quant(c, e, 11);
1262            switch (s->mant4_cnt) {
1263            case 0:
1264                s->qmant4_ptr = &qmant[i];
1265                v = 11 * v;
1266                s->mant4_cnt = 1;
1267                break;
1268            default:
1269                *s->qmant4_ptr += v;
1270                s->mant4_cnt = 0;
1271                v = 128;
1272                break;
1273            }
1274            break;
1275        case 5:
1276            v = sym_quant(c, e, 15);
1277            break;
1278        case 14:
1279            v = asym_quant(c, e, 14);
1280            break;
1281        case 15:
1282            v = asym_quant(c, e, 16);
1283            break;
1284        default:
1285            v = asym_quant(c, e, v - 1);
1286            break;
1287        }
1288        qmant[i] = v;
1289    }
1290}
1291
1292
1293/**
1294 * Quantize mantissas using coefficients, exponents, and bit allocation pointers.
1295 *
1296 * @param s  AC-3 encoder private context
1297 */
1298void ff_ac3_quantize_mantissas(AC3EncodeContext *s)
1299{
1300    int blk, ch, ch0=0, got_cpl;
1301
1302    for (blk = 0; blk < s->num_blocks; blk++) {
1303        AC3Block *block = &s->blocks[blk];
1304        AC3Mant m = { 0 };
1305
1306        got_cpl = !block->cpl_in_use;
1307        for (ch = 1; ch <= s->channels; ch++) {
1308            if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1309                ch0     = ch - 1;
1310                ch      = CPL_CH;
1311                got_cpl = 1;
1312            }
1313            quantize_mantissas_blk_ch(&m, block->fixed_coef[ch],
1314                                      s->blocks[s->exp_ref_block[ch][blk]].exp[ch],
1315                                      s->ref_bap[ch][blk], block->qmant[ch],
1316                                      s->start_freq[ch], block->end_freq[ch]);
1317            if (ch == CPL_CH)
1318                ch = ch0;
1319        }
1320    }
1321}
1322
1323
1324/*
1325 * Write the AC-3 frame header to the output bitstream.
1326 */
1327static void ac3_output_frame_header(AC3EncodeContext *s)
1328{
1329    AC3EncOptions *opt = &s->options;
1330
1331    put_bits(&s->pb, 16, 0x0b77);   /* frame header */
1332    put_bits(&s->pb, 16, 0);        /* crc1: will be filled later */
1333    put_bits(&s->pb, 2,  s->bit_alloc.sr_code);
1334    put_bits(&s->pb, 6,  s->frame_size_code + (s->frame_size - s->frame_size_min) / 2);
1335    put_bits(&s->pb, 5,  s->bitstream_id);
1336    put_bits(&s->pb, 3,  s->bitstream_mode);
1337    put_bits(&s->pb, 3,  s->channel_mode);
1338    if ((s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO)
1339        put_bits(&s->pb, 2, s->center_mix_level);
1340    if (s->channel_mode & 0x04)
1341        put_bits(&s->pb, 2, s->surround_mix_level);
1342    if (s->channel_mode == AC3_CHMODE_STEREO)
1343        put_bits(&s->pb, 2, opt->dolby_surround_mode);
1344    put_bits(&s->pb, 1, s->lfe_on); /* LFE */
1345    put_bits(&s->pb, 5, -opt->dialogue_level);
1346    put_bits(&s->pb, 1, 0);         /* no compression control word */
1347    put_bits(&s->pb, 1, 0);         /* no lang code */
1348    put_bits(&s->pb, 1, opt->audio_production_info);
1349    if (opt->audio_production_info) {
1350        put_bits(&s->pb, 5, opt->mixing_level - 80);
1351        put_bits(&s->pb, 2, opt->room_type);
1352    }
1353    put_bits(&s->pb, 1, opt->copyright);
1354    put_bits(&s->pb, 1, opt->original);
1355    if (s->bitstream_id == 6) {
1356        /* alternate bit stream syntax */
1357        put_bits(&s->pb, 1, opt->extended_bsi_1);
1358        if (opt->extended_bsi_1) {
1359            put_bits(&s->pb, 2, opt->preferred_stereo_downmix);
1360            put_bits(&s->pb, 3, s->ltrt_center_mix_level);
1361            put_bits(&s->pb, 3, s->ltrt_surround_mix_level);
1362            put_bits(&s->pb, 3, s->loro_center_mix_level);
1363            put_bits(&s->pb, 3, s->loro_surround_mix_level);
1364        }
1365        put_bits(&s->pb, 1, opt->extended_bsi_2);
1366        if (opt->extended_bsi_2) {
1367            put_bits(&s->pb, 2, opt->dolby_surround_ex_mode);
1368            put_bits(&s->pb, 2, opt->dolby_headphone_mode);
1369            put_bits(&s->pb, 1, opt->ad_converter_type);
1370            put_bits(&s->pb, 9, 0);     /* xbsi2 and encinfo : reserved */
1371        }
1372    } else {
1373    put_bits(&s->pb, 1, 0);         /* no time code 1 */
1374    put_bits(&s->pb, 1, 0);         /* no time code 2 */
1375    }
1376    put_bits(&s->pb, 1, 0);         /* no additional bit stream info */
1377}
1378
1379
1380/*
1381 * Write one audio block to the output bitstream.
1382 */
1383static void output_audio_block(AC3EncodeContext *s, int blk)
1384{
1385    int ch, i, baie, bnd, got_cpl, av_uninit(ch0);
1386    AC3Block *block = &s->blocks[blk];
1387
1388    /* block switching */
1389    if (!s->eac3) {
1390        for (ch = 0; ch < s->fbw_channels; ch++)
1391            put_bits(&s->pb, 1, 0);
1392    }
1393
1394    /* dither flags */
1395    if (!s->eac3) {
1396        for (ch = 0; ch < s->fbw_channels; ch++)
1397            put_bits(&s->pb, 1, 1);
1398    }
1399
1400    /* dynamic range codes */
1401    put_bits(&s->pb, 1, 0);
1402
1403    /* spectral extension */
1404    if (s->eac3)
1405        put_bits(&s->pb, 1, 0);
1406
1407    /* channel coupling */
1408    if (!s->eac3)
1409        put_bits(&s->pb, 1, block->new_cpl_strategy);
1410    if (block->new_cpl_strategy) {
1411        if (!s->eac3)
1412            put_bits(&s->pb, 1, block->cpl_in_use);
1413        if (block->cpl_in_use) {
1414            int start_sub, end_sub;
1415            if (s->eac3)
1416                put_bits(&s->pb, 1, 0); /* enhanced coupling */
1417            if (!s->eac3 || s->channel_mode != AC3_CHMODE_STEREO) {
1418                for (ch = 1; ch <= s->fbw_channels; ch++)
1419                    put_bits(&s->pb, 1, block->channel_in_cpl[ch]);
1420            }
1421            if (s->channel_mode == AC3_CHMODE_STEREO)
1422                put_bits(&s->pb, 1, 0); /* phase flags in use */
1423            start_sub = (s->start_freq[CPL_CH] - 37) / 12;
1424            end_sub   = (s->cpl_end_freq       - 37) / 12;
1425            put_bits(&s->pb, 4, start_sub);
1426            put_bits(&s->pb, 4, end_sub - 3);
1427            /* coupling band structure */
1428            if (s->eac3) {
1429                put_bits(&s->pb, 1, 0); /* use default */
1430            } else {
1431                for (bnd = start_sub+1; bnd < end_sub; bnd++)
1432                    put_bits(&s->pb, 1, ff_eac3_default_cpl_band_struct[bnd]);
1433            }
1434        }
1435    }
1436
1437    /* coupling coordinates */
1438    if (block->cpl_in_use) {
1439        for (ch = 1; ch <= s->fbw_channels; ch++) {
1440            if (block->channel_in_cpl[ch]) {
1441                if (!s->eac3 || block->new_cpl_coords[ch] != 2)
1442                    put_bits(&s->pb, 1, block->new_cpl_coords[ch]);
1443                if (block->new_cpl_coords[ch]) {
1444                    put_bits(&s->pb, 2, block->cpl_master_exp[ch]);
1445                    for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
1446                        put_bits(&s->pb, 4, block->cpl_coord_exp [ch][bnd]);
1447                        put_bits(&s->pb, 4, block->cpl_coord_mant[ch][bnd]);
1448                    }
1449                }
1450            }
1451        }
1452    }
1453
1454    /* stereo rematrixing */
1455    if (s->channel_mode == AC3_CHMODE_STEREO) {
1456        if (!s->eac3 || blk > 0)
1457            put_bits(&s->pb, 1, block->new_rematrixing_strategy);
1458        if (block->new_rematrixing_strategy) {
1459            /* rematrixing flags */
1460            for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++)
1461                put_bits(&s->pb, 1, block->rematrixing_flags[bnd]);
1462        }
1463    }
1464
1465    /* exponent strategy */
1466    if (!s->eac3) {
1467        for (ch = !block->cpl_in_use; ch <= s->fbw_channels; ch++)
1468            put_bits(&s->pb, 2, s->exp_strategy[ch][blk]);
1469        if (s->lfe_on)
1470            put_bits(&s->pb, 1, s->exp_strategy[s->lfe_channel][blk]);
1471    }
1472
1473    /* bandwidth */
1474    for (ch = 1; ch <= s->fbw_channels; ch++) {
1475        if (s->exp_strategy[ch][blk] != EXP_REUSE && !block->channel_in_cpl[ch])
1476            put_bits(&s->pb, 6, s->bandwidth_code);
1477    }
1478
1479    /* exponents */
1480    for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1481        int nb_groups;
1482        int cpl = (ch == CPL_CH);
1483
1484        if (s->exp_strategy[ch][blk] == EXP_REUSE)
1485            continue;
1486
1487        /* DC exponent */
1488        put_bits(&s->pb, 4, block->grouped_exp[ch][0] >> cpl);
1489
1490        /* exponent groups */
1491        nb_groups = exponent_group_tab[cpl][s->exp_strategy[ch][blk]-1][block->end_freq[ch]-s->start_freq[ch]];
1492        for (i = 1; i <= nb_groups; i++)
1493            put_bits(&s->pb, 7, block->grouped_exp[ch][i]);
1494
1495        /* gain range info */
1496        if (ch != s->lfe_channel && !cpl)
1497            put_bits(&s->pb, 2, 0);
1498    }
1499
1500    /* bit allocation info */
1501    if (!s->eac3) {
1502        baie = (blk == 0);
1503        put_bits(&s->pb, 1, baie);
1504        if (baie) {
1505            put_bits(&s->pb, 2, s->slow_decay_code);
1506            put_bits(&s->pb, 2, s->fast_decay_code);
1507            put_bits(&s->pb, 2, s->slow_gain_code);
1508            put_bits(&s->pb, 2, s->db_per_bit_code);
1509            put_bits(&s->pb, 3, s->floor_code);
1510        }
1511    }
1512
1513    /* snr offset */
1514    if (!s->eac3) {
1515        put_bits(&s->pb, 1, block->new_snr_offsets);
1516        if (block->new_snr_offsets) {
1517            put_bits(&s->pb, 6, s->coarse_snr_offset);
1518            for (ch = !block->cpl_in_use; ch <= s->channels; ch++) {
1519                put_bits(&s->pb, 4, s->fine_snr_offset[ch]);
1520                put_bits(&s->pb, 3, s->fast_gain_code[ch]);
1521            }
1522        }
1523    } else {
1524        put_bits(&s->pb, 1, 0); /* no converter snr offset */
1525    }
1526
1527    /* coupling leak */
1528    if (block->cpl_in_use) {
1529        if (!s->eac3 || block->new_cpl_leak != 2)
1530            put_bits(&s->pb, 1, block->new_cpl_leak);
1531        if (block->new_cpl_leak) {
1532            put_bits(&s->pb, 3, s->bit_alloc.cpl_fast_leak);
1533            put_bits(&s->pb, 3, s->bit_alloc.cpl_slow_leak);
1534        }
1535    }
1536
1537    if (!s->eac3) {
1538        put_bits(&s->pb, 1, 0); /* no delta bit allocation */
1539        put_bits(&s->pb, 1, 0); /* no data to skip */
1540    }
1541
1542    /* mantissas */
1543    got_cpl = !block->cpl_in_use;
1544    for (ch = 1; ch <= s->channels; ch++) {
1545        int b, q;
1546
1547        if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
1548            ch0     = ch - 1;
1549            ch      = CPL_CH;
1550            got_cpl = 1;
1551        }
1552        for (i = s->start_freq[ch]; i < block->end_freq[ch]; i++) {
1553            q = block->qmant[ch][i];
1554            b = s->ref_bap[ch][blk][i];
1555            switch (b) {
1556            case 0:                                          break;
1557            case 1: if (q != 128) put_bits (&s->pb,   5, q); break;
1558            case 2: if (q != 128) put_bits (&s->pb,   7, q); break;
1559            case 3:               put_sbits(&s->pb,   3, q); break;
1560            case 4: if (q != 128) put_bits (&s->pb,   7, q); break;
1561            case 14:              put_sbits(&s->pb,  14, q); break;
1562            case 15:              put_sbits(&s->pb,  16, q); break;
1563            default:              put_sbits(&s->pb, b-1, q); break;
1564            }
1565        }
1566        if (ch == CPL_CH)
1567            ch = ch0;
1568    }
1569}
1570
1571
1572/** CRC-16 Polynomial */
1573#define CRC16_POLY ((1 << 0) | (1 << 2) | (1 << 15) | (1 << 16))
1574
1575
1576static unsigned int mul_poly(unsigned int a, unsigned int b, unsigned int poly)
1577{
1578    unsigned int c;
1579
1580    c = 0;
1581    while (a) {
1582        if (a & 1)
1583            c ^= b;
1584        a = a >> 1;
1585        b = b << 1;
1586        if (b & (1 << 16))
1587            b ^= poly;
1588    }
1589    return c;
1590}
1591
1592
1593static unsigned int pow_poly(unsigned int a, unsigned int n, unsigned int poly)
1594{
1595    unsigned int r;
1596    r = 1;
1597    while (n) {
1598        if (n & 1)
1599            r = mul_poly(r, a, poly);
1600        a = mul_poly(a, a, poly);
1601        n >>= 1;
1602    }
1603    return r;
1604}
1605
1606
1607/*
1608 * Fill the end of the frame with 0's and compute the two CRCs.
1609 */
1610static void output_frame_end(AC3EncodeContext *s)
1611{
1612    const AVCRC *crc_ctx = av_crc_get_table(AV_CRC_16_ANSI);
1613    int frame_size_58, pad_bytes, crc1, crc2_partial, crc2, crc_inv;
1614    uint8_t *frame;
1615
1616    frame_size_58 = ((s->frame_size >> 2) + (s->frame_size >> 4)) << 1;
1617
1618    /* pad the remainder of the frame with zeros */
1619    av_assert2(s->frame_size * 8 - put_bits_count(&s->pb) >= 18);
1620    flush_put_bits(&s->pb);
1621    frame = s->pb.buf;
1622    pad_bytes = s->frame_size - (put_bits_ptr(&s->pb) - frame) - 2;
1623    av_assert2(pad_bytes >= 0);
1624    if (pad_bytes > 0)
1625        memset(put_bits_ptr(&s->pb), 0, pad_bytes);
1626
1627    if (s->eac3) {
1628        /* compute crc2 */
1629        crc2_partial = av_crc(crc_ctx, 0, frame + 2, s->frame_size - 5);
1630    } else {
1631    /* compute crc1 */
1632    /* this is not so easy because it is at the beginning of the data... */
1633    crc1    = av_bswap16(av_crc(crc_ctx, 0, frame + 4, frame_size_58 - 4));
1634    crc_inv = s->crc_inv[s->frame_size > s->frame_size_min];
1635    crc1    = mul_poly(crc_inv, crc1, CRC16_POLY);
1636    AV_WB16(frame + 2, crc1);
1637
1638    /* compute crc2 */
1639    crc2_partial = av_crc(crc_ctx, 0, frame + frame_size_58,
1640                          s->frame_size - frame_size_58 - 3);
1641    }
1642    crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1643    /* ensure crc2 does not match sync word by flipping crcrsv bit if needed */
1644    if (crc2 == 0x770B) {
1645        frame[s->frame_size - 3] ^= 0x1;
1646        crc2 = av_crc(crc_ctx, crc2_partial, frame + s->frame_size - 3, 1);
1647    }
1648    crc2 = av_bswap16(crc2);
1649    AV_WB16(frame + s->frame_size - 2, crc2);
1650}
1651
1652
1653/**
1654 * Write the frame to the output bitstream.
1655 *
1656 * @param s      AC-3 encoder private context
1657 * @param frame  output data buffer
1658 */
1659void ff_ac3_output_frame(AC3EncodeContext *s, unsigned char *frame)
1660{
1661    int blk;
1662
1663    init_put_bits(&s->pb, frame, AC3_MAX_CODED_FRAME_SIZE);
1664
1665    s->output_frame_header(s);
1666
1667    for (blk = 0; blk < s->num_blocks; blk++)
1668        output_audio_block(s, blk);
1669
1670    output_frame_end(s);
1671}
1672
1673
1674static void dprint_options(AC3EncodeContext *s)
1675{
1676#ifdef DEBUG
1677    AVCodecContext *avctx = s->avctx;
1678    AC3EncOptions *opt = &s->options;
1679    char strbuf[32];
1680
1681    switch (s->bitstream_id) {
1682    case  6:  av_strlcpy(strbuf, "AC-3 (alt syntax)",       32); break;
1683    case  8:  av_strlcpy(strbuf, "AC-3 (standard)",         32); break;
1684    case  9:  av_strlcpy(strbuf, "AC-3 (dnet half-rate)",   32); break;
1685    case 10:  av_strlcpy(strbuf, "AC-3 (dnet quater-rate)", 32); break;
1686    case 16:  av_strlcpy(strbuf, "E-AC-3 (enhanced)",       32); break;
1687    default: snprintf(strbuf, 32, "ERROR");
1688    }
1689    av_dlog(avctx, "bitstream_id: %s (%d)\n", strbuf, s->bitstream_id);
1690    av_dlog(avctx, "sample_fmt: %s\n", av_get_sample_fmt_name(avctx->sample_fmt));
1691    av_get_channel_layout_string(strbuf, 32, s->channels, avctx->channel_layout);
1692    av_dlog(avctx, "channel_layout: %s\n", strbuf);
1693    av_dlog(avctx, "sample_rate: %d\n", s->sample_rate);
1694    av_dlog(avctx, "bit_rate: %d\n", s->bit_rate);
1695    av_dlog(avctx, "blocks/frame: %d (code=%d)\n", s->num_blocks, s->num_blks_code);
1696    if (s->cutoff)
1697        av_dlog(avctx, "cutoff: %d\n", s->cutoff);
1698
1699    av_dlog(avctx, "per_frame_metadata: %s\n",
1700            opt->allow_per_frame_metadata?"on":"off");
1701    if (s->has_center)
1702        av_dlog(avctx, "center_mixlev: %0.3f (%d)\n", opt->center_mix_level,
1703                s->center_mix_level);
1704    else
1705        av_dlog(avctx, "center_mixlev: {not written}\n");
1706    if (s->has_surround)
1707        av_dlog(avctx, "surround_mixlev: %0.3f (%d)\n", opt->surround_mix_level,
1708                s->surround_mix_level);
1709    else
1710        av_dlog(avctx, "surround_mixlev: {not written}\n");
1711    if (opt->audio_production_info) {
1712        av_dlog(avctx, "mixing_level: %ddB\n", opt->mixing_level);
1713        switch (opt->room_type) {
1714        case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1715        case AC3ENC_OPT_LARGE_ROOM:    av_strlcpy(strbuf, "large", 32);        break;
1716        case AC3ENC_OPT_SMALL_ROOM:    av_strlcpy(strbuf, "small", 32);        break;
1717        default: snprintf(strbuf, 32, "ERROR (%d)", opt->room_type);
1718        }
1719        av_dlog(avctx, "room_type: %s\n", strbuf);
1720    } else {
1721        av_dlog(avctx, "mixing_level: {not written}\n");
1722        av_dlog(avctx, "room_type: {not written}\n");
1723    }
1724    av_dlog(avctx, "copyright: %s\n", opt->copyright?"on":"off");
1725    av_dlog(avctx, "dialnorm: %ddB\n", opt->dialogue_level);
1726    if (s->channel_mode == AC3_CHMODE_STEREO) {
1727        switch (opt->dolby_surround_mode) {
1728        case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1729        case AC3ENC_OPT_MODE_ON:       av_strlcpy(strbuf, "on", 32);           break;
1730        case AC3ENC_OPT_MODE_OFF:      av_strlcpy(strbuf, "off", 32);          break;
1731        default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_mode);
1732        }
1733        av_dlog(avctx, "dsur_mode: %s\n", strbuf);
1734    } else {
1735        av_dlog(avctx, "dsur_mode: {not written}\n");
1736    }
1737    av_dlog(avctx, "original: %s\n", opt->original?"on":"off");
1738
1739    if (s->bitstream_id == 6) {
1740        if (opt->extended_bsi_1) {
1741            switch (opt->preferred_stereo_downmix) {
1742            case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1743            case AC3ENC_OPT_DOWNMIX_LTRT:  av_strlcpy(strbuf, "ltrt", 32);         break;
1744            case AC3ENC_OPT_DOWNMIX_LORO:  av_strlcpy(strbuf, "loro", 32);         break;
1745            default: snprintf(strbuf, 32, "ERROR (%d)", opt->preferred_stereo_downmix);
1746            }
1747            av_dlog(avctx, "dmix_mode: %s\n", strbuf);
1748            av_dlog(avctx, "ltrt_cmixlev: %0.3f (%d)\n",
1749                    opt->ltrt_center_mix_level, s->ltrt_center_mix_level);
1750            av_dlog(avctx, "ltrt_surmixlev: %0.3f (%d)\n",
1751                    opt->ltrt_surround_mix_level, s->ltrt_surround_mix_level);
1752            av_dlog(avctx, "loro_cmixlev: %0.3f (%d)\n",
1753                    opt->loro_center_mix_level, s->loro_center_mix_level);
1754            av_dlog(avctx, "loro_surmixlev: %0.3f (%d)\n",
1755                    opt->loro_surround_mix_level, s->loro_surround_mix_level);
1756        } else {
1757            av_dlog(avctx, "extended bitstream info 1: {not written}\n");
1758        }
1759        if (opt->extended_bsi_2) {
1760            switch (opt->dolby_surround_ex_mode) {
1761            case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1762            case AC3ENC_OPT_MODE_ON:       av_strlcpy(strbuf, "on", 32);           break;
1763            case AC3ENC_OPT_MODE_OFF:      av_strlcpy(strbuf, "off", 32);          break;
1764            default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_surround_ex_mode);
1765            }
1766            av_dlog(avctx, "dsurex_mode: %s\n", strbuf);
1767            switch (opt->dolby_headphone_mode) {
1768            case AC3ENC_OPT_NOT_INDICATED: av_strlcpy(strbuf, "notindicated", 32); break;
1769            case AC3ENC_OPT_MODE_ON:       av_strlcpy(strbuf, "on", 32);           break;
1770            case AC3ENC_OPT_MODE_OFF:      av_strlcpy(strbuf, "off", 32);          break;
1771            default: snprintf(strbuf, 32, "ERROR (%d)", opt->dolby_headphone_mode);
1772            }
1773            av_dlog(avctx, "dheadphone_mode: %s\n", strbuf);
1774
1775            switch (opt->ad_converter_type) {
1776            case AC3ENC_OPT_ADCONV_STANDARD: av_strlcpy(strbuf, "standard", 32); break;
1777            case AC3ENC_OPT_ADCONV_HDCD:     av_strlcpy(strbuf, "hdcd", 32);     break;
1778            default: snprintf(strbuf, 32, "ERROR (%d)", opt->ad_converter_type);
1779            }
1780            av_dlog(avctx, "ad_conv_type: %s\n", strbuf);
1781        } else {
1782            av_dlog(avctx, "extended bitstream info 2: {not written}\n");
1783        }
1784    }
1785#endif
1786}
1787
1788
1789#define FLT_OPTION_THRESHOLD 0.01
1790
1791static int validate_float_option(float v, const float *v_list, int v_list_size)
1792{
1793    int i;
1794
1795    for (i = 0; i < v_list_size; i++) {
1796        if (v < (v_list[i] + FLT_OPTION_THRESHOLD) &&
1797            v > (v_list[i] - FLT_OPTION_THRESHOLD))
1798            break;
1799    }
1800    if (i == v_list_size)
1801        return -1;
1802
1803    return i;
1804}
1805
1806
1807static void validate_mix_level(void *log_ctx, const char *opt_name,
1808                               float *opt_param, const float *list,
1809                               int list_size, int default_value, int min_value,
1810                               int *ctx_param)
1811{
1812    int mixlev = validate_float_option(*opt_param, list, list_size);
1813    if (mixlev < min_value) {
1814        mixlev = default_value;
1815        if (*opt_param >= 0.0) {
1816            av_log(log_ctx, AV_LOG_WARNING, "requested %s is not valid. using "
1817                   "default value: %0.3f\n", opt_name, list[mixlev]);
1818        }
1819    }
1820    *opt_param = list[mixlev];
1821    *ctx_param = mixlev;
1822}
1823
1824
1825/**
1826 * Validate metadata options as set by AVOption system.
1827 * These values can optionally be changed per-frame.
1828 *
1829 * @param s  AC-3 encoder private context
1830 */
1831int ff_ac3_validate_metadata(AC3EncodeContext *s)
1832{
1833    AVCodecContext *avctx = s->avctx;
1834    AC3EncOptions *opt = &s->options;
1835
1836    opt->audio_production_info = 0;
1837    opt->extended_bsi_1        = 0;
1838    opt->extended_bsi_2        = 0;
1839    opt->eac3_mixing_metadata  = 0;
1840    opt->eac3_info_metadata    = 0;
1841
1842    /* determine mixing metadata / xbsi1 use */
1843    if (s->channel_mode > AC3_CHMODE_STEREO && opt->preferred_stereo_downmix != AC3ENC_OPT_NONE) {
1844        opt->extended_bsi_1       = 1;
1845        opt->eac3_mixing_metadata = 1;
1846    }
1847    if (s->has_center &&
1848        (opt->ltrt_center_mix_level >= 0 || opt->loro_center_mix_level >= 0)) {
1849        opt->extended_bsi_1       = 1;
1850        opt->eac3_mixing_metadata = 1;
1851    }
1852    if (s->has_surround &&
1853        (opt->ltrt_surround_mix_level >= 0 || opt->loro_surround_mix_level >= 0)) {
1854        opt->extended_bsi_1       = 1;
1855        opt->eac3_mixing_metadata = 1;
1856    }
1857
1858    if (s->eac3) {
1859        /* determine info metadata use */
1860        if (avctx->audio_service_type != AV_AUDIO_SERVICE_TYPE_MAIN)
1861            opt->eac3_info_metadata = 1;
1862        if (opt->copyright != AC3ENC_OPT_NONE || opt->original != AC3ENC_OPT_NONE)
1863            opt->eac3_info_metadata = 1;
1864        if (s->channel_mode == AC3_CHMODE_STEREO &&
1865            (opt->dolby_headphone_mode != AC3ENC_OPT_NONE || opt->dolby_surround_mode != AC3ENC_OPT_NONE))
1866            opt->eac3_info_metadata = 1;
1867        if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1868            opt->eac3_info_metadata = 1;
1869        if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE ||
1870            opt->ad_converter_type != AC3ENC_OPT_NONE) {
1871            opt->audio_production_info = 1;
1872            opt->eac3_info_metadata    = 1;
1873        }
1874    } else {
1875        /* determine audio production info use */
1876        if (opt->mixing_level != AC3ENC_OPT_NONE || opt->room_type != AC3ENC_OPT_NONE)
1877            opt->audio_production_info = 1;
1878
1879        /* determine xbsi2 use */
1880        if (s->channel_mode >= AC3_CHMODE_2F2R && opt->dolby_surround_ex_mode != AC3ENC_OPT_NONE)
1881            opt->extended_bsi_2 = 1;
1882        if (s->channel_mode == AC3_CHMODE_STEREO && opt->dolby_headphone_mode != AC3ENC_OPT_NONE)
1883            opt->extended_bsi_2 = 1;
1884        if (opt->ad_converter_type != AC3ENC_OPT_NONE)
1885            opt->extended_bsi_2 = 1;
1886    }
1887
1888    /* validate AC-3 mixing levels */
1889    if (!s->eac3) {
1890        if (s->has_center) {
1891            validate_mix_level(avctx, "center_mix_level", &opt->center_mix_level,
1892                            cmixlev_options, CMIXLEV_NUM_OPTIONS, 1, 0,
1893                            &s->center_mix_level);
1894        }
1895        if (s->has_surround) {
1896            validate_mix_level(avctx, "surround_mix_level", &opt->surround_mix_level,
1897                            surmixlev_options, SURMIXLEV_NUM_OPTIONS, 1, 0,
1898                            &s->surround_mix_level);
1899        }
1900    }
1901
1902    /* validate extended bsi 1 / mixing metadata */
1903    if (opt->extended_bsi_1 || opt->eac3_mixing_metadata) {
1904        /* default preferred stereo downmix */
1905        if (opt->preferred_stereo_downmix == AC3ENC_OPT_NONE)
1906            opt->preferred_stereo_downmix = AC3ENC_OPT_NOT_INDICATED;
1907        if (!s->eac3 || s->has_center) {
1908            /* validate Lt/Rt center mix level */
1909            validate_mix_level(avctx, "ltrt_center_mix_level",
1910                               &opt->ltrt_center_mix_level, extmixlev_options,
1911                               EXTMIXLEV_NUM_OPTIONS, 5, 0,
1912                               &s->ltrt_center_mix_level);
1913            /* validate Lo/Ro center mix level */
1914            validate_mix_level(avctx, "loro_center_mix_level",
1915                               &opt->loro_center_mix_level, extmixlev_options,
1916                               EXTMIXLEV_NUM_OPTIONS, 5, 0,
1917                               &s->loro_center_mix_level);
1918        }
1919        if (!s->eac3 || s->has_surround) {
1920            /* validate Lt/Rt surround mix level */
1921            validate_mix_level(avctx, "ltrt_surround_mix_level",
1922                               &opt->ltrt_surround_mix_level, extmixlev_options,
1923                               EXTMIXLEV_NUM_OPTIONS, 6, 3,
1924                               &s->ltrt_surround_mix_level);
1925            /* validate Lo/Ro surround mix level */
1926            validate_mix_level(avctx, "loro_surround_mix_level",
1927                               &opt->loro_surround_mix_level, extmixlev_options,
1928                               EXTMIXLEV_NUM_OPTIONS, 6, 3,
1929                               &s->loro_surround_mix_level);
1930        }
1931    }
1932
1933    /* validate audio service type / channels combination */
1934    if ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_KARAOKE &&
1935         avctx->channels == 1) ||
1936        ((avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_COMMENTARY ||
1937          avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_EMERGENCY  ||
1938          avctx->audio_service_type == AV_AUDIO_SERVICE_TYPE_VOICE_OVER)
1939         && avctx->channels > 1)) {
1940        av_log(avctx, AV_LOG_ERROR, "invalid audio service type for the "
1941                                    "specified number of channels\n");
1942        return AVERROR(EINVAL);
1943    }
1944
1945    /* validate extended bsi 2 / info metadata */
1946    if (opt->extended_bsi_2 || opt->eac3_info_metadata) {
1947        /* default dolby headphone mode */
1948        if (opt->dolby_headphone_mode == AC3ENC_OPT_NONE)
1949            opt->dolby_headphone_mode = AC3ENC_OPT_NOT_INDICATED;
1950        /* default dolby surround ex mode */
1951        if (opt->dolby_surround_ex_mode == AC3ENC_OPT_NONE)
1952            opt->dolby_surround_ex_mode = AC3ENC_OPT_NOT_INDICATED;
1953        /* default A/D converter type */
1954        if (opt->ad_converter_type == AC3ENC_OPT_NONE)
1955            opt->ad_converter_type = AC3ENC_OPT_ADCONV_STANDARD;
1956    }
1957
1958    /* copyright & original defaults */
1959    if (!s->eac3 || opt->eac3_info_metadata) {
1960        /* default copyright */
1961        if (opt->copyright == AC3ENC_OPT_NONE)
1962            opt->copyright = AC3ENC_OPT_OFF;
1963        /* default original */
1964        if (opt->original == AC3ENC_OPT_NONE)
1965            opt->original = AC3ENC_OPT_ON;
1966    }
1967
1968    /* dolby surround mode default */
1969    if (!s->eac3 || opt->eac3_info_metadata) {
1970        if (opt->dolby_surround_mode == AC3ENC_OPT_NONE)
1971            opt->dolby_surround_mode = AC3ENC_OPT_NOT_INDICATED;
1972    }
1973
1974    /* validate audio production info */
1975    if (opt->audio_production_info) {
1976        if (opt->mixing_level == AC3ENC_OPT_NONE) {
1977            av_log(avctx, AV_LOG_ERROR, "mixing_level must be set if "
1978                   "room_type is set\n");
1979            return AVERROR(EINVAL);
1980        }
1981        if (opt->mixing_level < 80) {
1982            av_log(avctx, AV_LOG_ERROR, "invalid mixing level. must be between "
1983                   "80dB and 111dB\n");
1984            return AVERROR(EINVAL);
1985        }
1986        /* default room type */
1987        if (opt->room_type == AC3ENC_OPT_NONE)
1988            opt->room_type = AC3ENC_OPT_NOT_INDICATED;
1989    }
1990
1991    /* set bitstream id for alternate bitstream syntax */
1992    if (!s->eac3 && (opt->extended_bsi_1 || opt->extended_bsi_2)) {
1993        if (s->bitstream_id > 8 && s->bitstream_id < 11) {
1994            static int warn_once = 1;
1995            if (warn_once) {
1996                av_log(avctx, AV_LOG_WARNING, "alternate bitstream syntax is "
1997                       "not compatible with reduced samplerates. writing of "
1998                       "extended bitstream information will be disabled.\n");
1999                warn_once = 0;
2000            }
2001        } else {
2002            s->bitstream_id = 6;
2003        }
2004    }
2005
2006    return 0;
2007}
2008
2009
2010/**
2011 * Finalize encoding and free any memory allocated by the encoder.
2012 *
2013 * @param avctx  Codec context
2014 */
2015av_cold int ff_ac3_encode_close(AVCodecContext *avctx)
2016{
2017    int blk, ch;
2018    AC3EncodeContext *s = avctx->priv_data;
2019
2020    av_freep(&s->windowed_samples);
2021    if (s->planar_samples)
2022    for (ch = 0; ch < s->channels; ch++)
2023        av_freep(&s->planar_samples[ch]);
2024    av_freep(&s->planar_samples);
2025    av_freep(&s->bap_buffer);
2026    av_freep(&s->bap1_buffer);
2027    av_freep(&s->mdct_coef_buffer);
2028    av_freep(&s->fixed_coef_buffer);
2029    av_freep(&s->exp_buffer);
2030    av_freep(&s->grouped_exp_buffer);
2031    av_freep(&s->psd_buffer);
2032    av_freep(&s->band_psd_buffer);
2033    av_freep(&s->mask_buffer);
2034    av_freep(&s->qmant_buffer);
2035    av_freep(&s->cpl_coord_exp_buffer);
2036    av_freep(&s->cpl_coord_mant_buffer);
2037    for (blk = 0; blk < s->num_blocks; blk++) {
2038        AC3Block *block = &s->blocks[blk];
2039        av_freep(&block->mdct_coef);
2040        av_freep(&block->fixed_coef);
2041        av_freep(&block->exp);
2042        av_freep(&block->grouped_exp);
2043        av_freep(&block->psd);
2044        av_freep(&block->band_psd);
2045        av_freep(&block->mask);
2046        av_freep(&block->qmant);
2047        av_freep(&block->cpl_coord_exp);
2048        av_freep(&block->cpl_coord_mant);
2049    }
2050
2051    s->mdct_end(s);
2052
2053    return 0;
2054}
2055
2056
2057/*
2058 * Set channel information during initialization.
2059 */
2060static av_cold int set_channel_info(AC3EncodeContext *s, int channels,
2061                                    uint64_t *channel_layout)
2062{
2063    int ch_layout;
2064
2065    if (channels < 1 || channels > AC3_MAX_CHANNELS)
2066        return AVERROR(EINVAL);
2067    if (*channel_layout > 0x7FF)
2068        return AVERROR(EINVAL);
2069    ch_layout = *channel_layout;
2070    if (!ch_layout)
2071        ch_layout = av_get_default_channel_layout(channels);
2072
2073    s->lfe_on       = !!(ch_layout & AV_CH_LOW_FREQUENCY);
2074    s->channels     = channels;
2075    s->fbw_channels = channels - s->lfe_on;
2076    s->lfe_channel  = s->lfe_on ? s->fbw_channels + 1 : -1;
2077    if (s->lfe_on)
2078        ch_layout -= AV_CH_LOW_FREQUENCY;
2079
2080    switch (ch_layout) {
2081    case AV_CH_LAYOUT_MONO:           s->channel_mode = AC3_CHMODE_MONO;   break;
2082    case AV_CH_LAYOUT_STEREO:         s->channel_mode = AC3_CHMODE_STEREO; break;
2083    case AV_CH_LAYOUT_SURROUND:       s->channel_mode = AC3_CHMODE_3F;     break;
2084    case AV_CH_LAYOUT_2_1:            s->channel_mode = AC3_CHMODE_2F1R;   break;
2085    case AV_CH_LAYOUT_4POINT0:        s->channel_mode = AC3_CHMODE_3F1R;   break;
2086    case AV_CH_LAYOUT_QUAD:
2087    case AV_CH_LAYOUT_2_2:            s->channel_mode = AC3_CHMODE_2F2R;   break;
2088    case AV_CH_LAYOUT_5POINT0:
2089    case AV_CH_LAYOUT_5POINT0_BACK:   s->channel_mode = AC3_CHMODE_3F2R;   break;
2090    default:
2091        return AVERROR(EINVAL);
2092    }
2093    s->has_center   = (s->channel_mode & 0x01) && s->channel_mode != AC3_CHMODE_MONO;
2094    s->has_surround =  s->channel_mode & 0x04;
2095
2096    s->channel_map  = ff_ac3_enc_channel_map[s->channel_mode][s->lfe_on];
2097    *channel_layout = ch_layout;
2098    if (s->lfe_on)
2099        *channel_layout |= AV_CH_LOW_FREQUENCY;
2100
2101    return 0;
2102}
2103
2104
2105static av_cold int validate_options(AC3EncodeContext *s)
2106{
2107    AVCodecContext *avctx = s->avctx;
2108    int i, ret, max_sr;
2109
2110    /* validate channel layout */
2111    if (!avctx->channel_layout) {
2112        av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
2113                                      "encoder will guess the layout, but it "
2114                                      "might be incorrect.\n");
2115    }
2116    ret = set_channel_info(s, avctx->channels, &avctx->channel_layout);
2117    if (ret) {
2118        av_log(avctx, AV_LOG_ERROR, "invalid channel layout\n");
2119        return ret;
2120    }
2121
2122    /* validate sample rate */
2123    /* note: max_sr could be changed from 2 to 5 for E-AC-3 once we find a
2124             decoder that supports half sample rate so we can validate that
2125             the generated files are correct. */
2126    max_sr = s->eac3 ? 2 : 8;
2127    for (i = 0; i <= max_sr; i++) {
2128        if ((ff_ac3_sample_rate_tab[i % 3] >> (i / 3)) == avctx->sample_rate)
2129            break;
2130    }
2131    if (i > max_sr) {
2132        av_log(avctx, AV_LOG_ERROR, "invalid sample rate\n");
2133        return AVERROR(EINVAL);
2134    }
2135    s->sample_rate        = avctx->sample_rate;
2136    s->bit_alloc.sr_shift = i / 3;
2137    s->bit_alloc.sr_code  = i % 3;
2138    s->bitstream_id       = s->eac3 ? 16 : 8 + s->bit_alloc.sr_shift;
2139
2140    /* select a default bit rate if not set by the user */
2141    if (!avctx->bit_rate) {
2142        switch (s->fbw_channels) {
2143        case 1: avctx->bit_rate =  96000; break;
2144        case 2: avctx->bit_rate = 192000; break;
2145        case 3: avctx->bit_rate = 320000; break;
2146        case 4: avctx->bit_rate = 384000; break;
2147        case 5: avctx->bit_rate = 448000; break;
2148        }
2149    }
2150
2151    /* validate bit rate */
2152    if (s->eac3) {
2153        int max_br, min_br, wpf, min_br_dist, min_br_code;
2154        int num_blks_code, num_blocks, frame_samples;
2155
2156        /* calculate min/max bitrate */
2157        /* TODO: More testing with 3 and 2 blocks. All E-AC-3 samples I've
2158                 found use either 6 blocks or 1 block, even though 2 or 3 blocks
2159                 would work as far as the bit rate is concerned. */
2160        for (num_blks_code = 3; num_blks_code >= 0; num_blks_code--) {
2161            num_blocks = ((int[]){ 1, 2, 3, 6 })[num_blks_code];
2162            frame_samples  = AC3_BLOCK_SIZE * num_blocks;
2163            max_br = 2048 * s->sample_rate / frame_samples * 16;
2164            min_br = ((s->sample_rate + (frame_samples-1)) / frame_samples) * 16;
2165            if (avctx->bit_rate <= max_br)
2166                break;
2167        }
2168        if (avctx->bit_rate < min_br || avctx->bit_rate > max_br) {
2169            av_log(avctx, AV_LOG_ERROR, "invalid bit rate. must be %d to %d "
2170                   "for this sample rate\n", min_br, max_br);
2171            return AVERROR(EINVAL);
2172        }
2173        s->num_blks_code = num_blks_code;
2174        s->num_blocks    = num_blocks;
2175
2176        /* calculate words-per-frame for the selected bitrate */
2177        wpf = (avctx->bit_rate / 16) * frame_samples / s->sample_rate;
2178        av_assert1(wpf > 0 && wpf <= 2048);
2179
2180        /* find the closest AC-3 bitrate code to the selected bitrate.
2181           this is needed for lookup tables for bandwidth and coupling
2182           parameter selection */
2183        min_br_code = -1;
2184        min_br_dist = INT_MAX;
2185        for (i = 0; i < 19; i++) {
2186            int br_dist = abs(ff_ac3_bitrate_tab[i] * 1000 - avctx->bit_rate);
2187            if (br_dist < min_br_dist) {
2188                min_br_dist = br_dist;
2189                min_br_code = i;
2190            }
2191        }
2192
2193        /* make sure the minimum frame size is below the average frame size */
2194        s->frame_size_code = min_br_code << 1;
2195        while (wpf > 1 && wpf * s->sample_rate / AC3_FRAME_SIZE * 16 > avctx->bit_rate)
2196            wpf--;
2197        s->frame_size_min = 2 * wpf;
2198    } else {
2199        int best_br = 0, best_code = 0, best_diff = INT_MAX;
2200        for (i = 0; i < 19; i++) {
2201            int br   = (ff_ac3_bitrate_tab[i] >> s->bit_alloc.sr_shift) * 1000;
2202            int diff = abs(br - avctx->bit_rate);
2203            if (diff < best_diff) {
2204                best_br   = br;
2205                best_code = i;
2206                best_diff = diff;
2207            }
2208            if (!best_diff)
2209                break;
2210        }
2211        avctx->bit_rate    = best_br;
2212        s->frame_size_code = best_code << 1;
2213        s->frame_size_min  = 2 * ff_ac3_frame_size_tab[s->frame_size_code][s->bit_alloc.sr_code];
2214        s->num_blks_code   = 0x3;
2215        s->num_blocks      = 6;
2216    }
2217    s->bit_rate   = avctx->bit_rate;
2218    s->frame_size = s->frame_size_min;
2219
2220    /* validate cutoff */
2221    if (avctx->cutoff < 0) {
2222        av_log(avctx, AV_LOG_ERROR, "invalid cutoff frequency\n");
2223        return AVERROR(EINVAL);
2224    }
2225    s->cutoff = avctx->cutoff;
2226    if (s->cutoff > (s->sample_rate >> 1))
2227        s->cutoff = s->sample_rate >> 1;
2228
2229    ret = ff_ac3_validate_metadata(s);
2230    if (ret)
2231        return ret;
2232
2233    s->rematrixing_enabled = s->options.stereo_rematrixing &&
2234                             (s->channel_mode == AC3_CHMODE_STEREO);
2235
2236    s->cpl_enabled = s->options.channel_coupling &&
2237                     s->channel_mode >= AC3_CHMODE_STEREO;
2238
2239    return 0;
2240}
2241
2242
2243/*
2244 * Set bandwidth for all channels.
2245 * The user can optionally supply a cutoff frequency. Otherwise an appropriate
2246 * default value will be used.
2247 */
2248static av_cold void set_bandwidth(AC3EncodeContext *s)
2249{
2250    int blk, ch, av_uninit(cpl_start);
2251
2252    if (s->cutoff) {
2253        /* calculate bandwidth based on user-specified cutoff frequency */
2254        int fbw_coeffs;
2255        fbw_coeffs     = s->cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
2256        s->bandwidth_code = av_clip((fbw_coeffs - 73) / 3, 0, 60);
2257    } else {
2258        /* use default bandwidth setting */
2259        s->bandwidth_code = ac3_bandwidth_tab[s->fbw_channels-1][s->bit_alloc.sr_code][s->frame_size_code/2];
2260    }
2261
2262    /* set number of coefficients for each channel */
2263    for (ch = 1; ch <= s->fbw_channels; ch++) {
2264        s->start_freq[ch] = 0;
2265        for (blk = 0; blk < s->num_blocks; blk++)
2266            s->blocks[blk].end_freq[ch] = s->bandwidth_code * 3 + 73;
2267    }
2268    /* LFE channel always has 7 coefs */
2269    if (s->lfe_on) {
2270        s->start_freq[s->lfe_channel] = 0;
2271        for (blk = 0; blk < s->num_blocks; blk++)
2272            s->blocks[blk].end_freq[ch] = 7;
2273    }
2274
2275    /* initialize coupling strategy */
2276    if (s->cpl_enabled) {
2277        if (s->options.cpl_start != AC3ENC_OPT_AUTO) {
2278            cpl_start = s->options.cpl_start;
2279        } else {
2280            cpl_start = ac3_coupling_start_tab[s->channel_mode-2][s->bit_alloc.sr_code][s->frame_size_code/2];
2281            if (cpl_start < 0) {
2282                if (s->options.channel_coupling == AC3ENC_OPT_AUTO)
2283                    s->cpl_enabled = 0;
2284                else
2285                    cpl_start = 15;
2286            }
2287        }
2288    }
2289    if (s->cpl_enabled) {
2290        int i, cpl_start_band, cpl_end_band;
2291        uint8_t *cpl_band_sizes = s->cpl_band_sizes;
2292
2293        cpl_end_band   = s->bandwidth_code / 4 + 3;
2294        cpl_start_band = av_clip(cpl_start, 0, FFMIN(cpl_end_band-1, 15));
2295
2296        s->num_cpl_subbands = cpl_end_band - cpl_start_band;
2297
2298        s->num_cpl_bands = 1;
2299        *cpl_band_sizes  = 12;
2300        for (i = cpl_start_band + 1; i < cpl_end_band; i++) {
2301            if (ff_eac3_default_cpl_band_struct[i]) {
2302                *cpl_band_sizes += 12;
2303            } else {
2304                s->num_cpl_bands++;
2305                cpl_band_sizes++;
2306                *cpl_band_sizes = 12;
2307            }
2308        }
2309
2310        s->start_freq[CPL_CH] = cpl_start_band * 12 + 37;
2311        s->cpl_end_freq       = cpl_end_band   * 12 + 37;
2312        for (blk = 0; blk < s->num_blocks; blk++)
2313            s->blocks[blk].end_freq[CPL_CH] = s->cpl_end_freq;
2314    }
2315}
2316
2317
2318static av_cold int allocate_buffers(AC3EncodeContext *s)
2319{
2320    AVCodecContext *avctx = s->avctx;
2321    int blk, ch;
2322    int channels = s->channels + 1; /* includes coupling channel */
2323    int channel_blocks = channels * s->num_blocks;
2324    int total_coefs    = AC3_MAX_COEFS * channel_blocks;
2325
2326    if (s->allocate_sample_buffers(s))
2327        goto alloc_fail;
2328
2329    FF_ALLOC_OR_GOTO(avctx, s->bap_buffer, total_coefs *
2330                     sizeof(*s->bap_buffer), alloc_fail);
2331    FF_ALLOC_OR_GOTO(avctx, s->bap1_buffer, total_coefs *
2332                     sizeof(*s->bap1_buffer), alloc_fail);
2333    FF_ALLOCZ_OR_GOTO(avctx, s->mdct_coef_buffer, total_coefs *
2334                      sizeof(*s->mdct_coef_buffer), alloc_fail);
2335    FF_ALLOC_OR_GOTO(avctx, s->exp_buffer, total_coefs *
2336                     sizeof(*s->exp_buffer), alloc_fail);
2337    FF_ALLOC_OR_GOTO(avctx, s->grouped_exp_buffer, channel_blocks * 128 *
2338                     sizeof(*s->grouped_exp_buffer), alloc_fail);
2339    FF_ALLOC_OR_GOTO(avctx, s->psd_buffer, total_coefs *
2340                     sizeof(*s->psd_buffer), alloc_fail);
2341    FF_ALLOC_OR_GOTO(avctx, s->band_psd_buffer, channel_blocks * 64 *
2342                     sizeof(*s->band_psd_buffer), alloc_fail);
2343    FF_ALLOC_OR_GOTO(avctx, s->mask_buffer, channel_blocks * 64 *
2344                     sizeof(*s->mask_buffer), alloc_fail);
2345    FF_ALLOC_OR_GOTO(avctx, s->qmant_buffer, total_coefs *
2346                     sizeof(*s->qmant_buffer), alloc_fail);
2347    if (s->cpl_enabled) {
2348        FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_exp_buffer, channel_blocks * 16 *
2349                         sizeof(*s->cpl_coord_exp_buffer), alloc_fail);
2350        FF_ALLOC_OR_GOTO(avctx, s->cpl_coord_mant_buffer, channel_blocks * 16 *
2351                         sizeof(*s->cpl_coord_mant_buffer), alloc_fail);
2352    }
2353    for (blk = 0; blk < s->num_blocks; blk++) {
2354        AC3Block *block = &s->blocks[blk];
2355        FF_ALLOCZ_OR_GOTO(avctx, block->mdct_coef, channels * sizeof(*block->mdct_coef),
2356                          alloc_fail);
2357        FF_ALLOCZ_OR_GOTO(avctx, block->exp, channels * sizeof(*block->exp),
2358                          alloc_fail);
2359        FF_ALLOCZ_OR_GOTO(avctx, block->grouped_exp, channels * sizeof(*block->grouped_exp),
2360                          alloc_fail);
2361        FF_ALLOCZ_OR_GOTO(avctx, block->psd, channels * sizeof(*block->psd),
2362                          alloc_fail);
2363        FF_ALLOCZ_OR_GOTO(avctx, block->band_psd, channels * sizeof(*block->band_psd),
2364                          alloc_fail);
2365        FF_ALLOCZ_OR_GOTO(avctx, block->mask, channels * sizeof(*block->mask),
2366                          alloc_fail);
2367        FF_ALLOCZ_OR_GOTO(avctx, block->qmant, channels * sizeof(*block->qmant),
2368                          alloc_fail);
2369        if (s->cpl_enabled) {
2370            FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_exp, channels * sizeof(*block->cpl_coord_exp),
2371                              alloc_fail);
2372            FF_ALLOCZ_OR_GOTO(avctx, block->cpl_coord_mant, channels * sizeof(*block->cpl_coord_mant),
2373                              alloc_fail);
2374        }
2375
2376        for (ch = 0; ch < channels; ch++) {
2377            /* arrangement: block, channel, coeff */
2378            block->grouped_exp[ch] = &s->grouped_exp_buffer[128           * (blk * channels + ch)];
2379            block->psd[ch]         = &s->psd_buffer        [AC3_MAX_COEFS * (blk * channels + ch)];
2380            block->band_psd[ch]    = &s->band_psd_buffer   [64            * (blk * channels + ch)];
2381            block->mask[ch]        = &s->mask_buffer       [64            * (blk * channels + ch)];
2382            block->qmant[ch]       = &s->qmant_buffer      [AC3_MAX_COEFS * (blk * channels + ch)];
2383            if (s->cpl_enabled) {
2384                block->cpl_coord_exp[ch]  = &s->cpl_coord_exp_buffer [16  * (blk * channels + ch)];
2385                block->cpl_coord_mant[ch] = &s->cpl_coord_mant_buffer[16  * (blk * channels + ch)];
2386            }
2387
2388            /* arrangement: channel, block, coeff */
2389            block->exp[ch]         = &s->exp_buffer        [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2390            block->mdct_coef[ch]   = &s->mdct_coef_buffer  [AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2391        }
2392    }
2393
2394    if (!s->fixed_point) {
2395        FF_ALLOCZ_OR_GOTO(avctx, s->fixed_coef_buffer, total_coefs *
2396                          sizeof(*s->fixed_coef_buffer), alloc_fail);
2397        for (blk = 0; blk < s->num_blocks; blk++) {
2398            AC3Block *block = &s->blocks[blk];
2399            FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2400                              sizeof(*block->fixed_coef), alloc_fail);
2401            for (ch = 0; ch < channels; ch++)
2402                block->fixed_coef[ch] = &s->fixed_coef_buffer[AC3_MAX_COEFS * (s->num_blocks * ch + blk)];
2403        }
2404    } else {
2405        for (blk = 0; blk < s->num_blocks; blk++) {
2406            AC3Block *block = &s->blocks[blk];
2407            FF_ALLOCZ_OR_GOTO(avctx, block->fixed_coef, channels *
2408                              sizeof(*block->fixed_coef), alloc_fail);
2409            for (ch = 0; ch < channels; ch++)
2410                block->fixed_coef[ch] = (int32_t *)block->mdct_coef[ch];
2411        }
2412    }
2413
2414    return 0;
2415alloc_fail:
2416    return AVERROR(ENOMEM);
2417}
2418
2419
2420av_cold int ff_ac3_encode_init(AVCodecContext *avctx)
2421{
2422    AC3EncodeContext *s = avctx->priv_data;
2423    int ret, frame_size_58;
2424
2425    s->avctx = avctx;
2426
2427    s->eac3 = avctx->codec_id == AV_CODEC_ID_EAC3;
2428
2429    ff_ac3_common_init();
2430
2431    ret = validate_options(s);
2432    if (ret)
2433        return ret;
2434
2435    avctx->frame_size = AC3_BLOCK_SIZE * s->num_blocks;
2436    avctx->delay      = AC3_BLOCK_SIZE;
2437
2438    s->bitstream_mode = avctx->audio_service_type;
2439    if (s->bitstream_mode == AV_AUDIO_SERVICE_TYPE_KARAOKE)
2440        s->bitstream_mode = 0x7;
2441
2442    s->bits_written    = 0;
2443    s->samples_written = 0;
2444
2445    /* calculate crc_inv for both possible frame sizes */
2446    frame_size_58 = (( s->frame_size    >> 2) + ( s->frame_size    >> 4)) << 1;
2447    s->crc_inv[0] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2448    if (s->bit_alloc.sr_code == 1) {
2449        frame_size_58 = (((s->frame_size+2) >> 2) + ((s->frame_size+2) >> 4)) << 1;
2450        s->crc_inv[1] = pow_poly((CRC16_POLY >> 1), (8 * frame_size_58) - 16, CRC16_POLY);
2451    }
2452
2453    /* set function pointers */
2454    if (CONFIG_AC3_FIXED_ENCODER && s->fixed_point) {
2455        s->mdct_end                     = ff_ac3_fixed_mdct_end;
2456        s->mdct_init                    = ff_ac3_fixed_mdct_init;
2457        s->allocate_sample_buffers      = ff_ac3_fixed_allocate_sample_buffers;
2458    } else if (CONFIG_AC3_ENCODER || CONFIG_EAC3_ENCODER) {
2459        s->mdct_end                     = ff_ac3_float_mdct_end;
2460        s->mdct_init                    = ff_ac3_float_mdct_init;
2461        s->allocate_sample_buffers      = ff_ac3_float_allocate_sample_buffers;
2462    }
2463    if (CONFIG_EAC3_ENCODER && s->eac3)
2464        s->output_frame_header = ff_eac3_output_frame_header;
2465    else
2466        s->output_frame_header = ac3_output_frame_header;
2467
2468    set_bandwidth(s);
2469
2470    exponent_init(s);
2471
2472    bit_alloc_init(s);
2473
2474    ret = s->mdct_init(s);
2475    if (ret)
2476        goto init_fail;
2477
2478    ret = allocate_buffers(s);
2479    if (ret)
2480        goto init_fail;
2481
2482    ff_audiodsp_init(&s->adsp);
2483    ff_dsputil_init(&s->dsp, avctx);
2484    ff_ac3dsp_init(&s->ac3dsp, avctx->flags & CODEC_FLAG_BITEXACT);
2485
2486    dprint_options(s);
2487
2488    return 0;
2489init_fail:
2490    ff_ac3_encode_close(avctx);
2491    return ret;
2492}
2493