1/*
2 * AAC encoder
3 * Copyright (C) 2008 Konstantin Shishkov
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * AAC encoder
25 */
26
27/***********************************
28 *              TODOs:
29 * add sane pulse detection
30 * add temporal noise shaping
31 ***********************************/
32
33#include "libavutil/opt.h"
34#include "avcodec.h"
35#include "put_bits.h"
36#include "dsputil.h"
37#include "mpeg4audio.h"
38#include "kbdwin.h"
39#include "sinewin.h"
40
41#include "aac.h"
42#include "aactab.h"
43#include "aacenc.h"
44
45#include "psymodel.h"
46
47#define AAC_MAX_CHANNELS 6
48
49static const uint8_t swb_size_1024_96[] = {
50    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8,
51    12, 12, 12, 12, 12, 16, 16, 24, 28, 36, 44,
52    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
53};
54
55static const uint8_t swb_size_1024_64[] = {
56    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8,
57    12, 12, 12, 16, 16, 16, 20, 24, 24, 28, 36,
58    40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40
59};
60
61static const uint8_t swb_size_1024_48[] = {
62    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8,
63    12, 12, 12, 12, 16, 16, 20, 20, 24, 24, 28, 28,
64    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
65    96
66};
67
68static const uint8_t swb_size_1024_32[] = {
69    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8,
70    12, 12, 12, 12, 16, 16, 20, 20, 24, 24, 28, 28,
71    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
72};
73
74static const uint8_t swb_size_1024_24[] = {
75    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
76    12, 12, 12, 12, 16, 16, 16, 20, 20, 24, 24, 28, 28,
77    32, 36, 36, 40, 44, 48, 52, 52, 64, 64, 64, 64, 64
78};
79
80static const uint8_t swb_size_1024_16[] = {
81    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
82    12, 12, 12, 12, 12, 12, 12, 12, 12, 16, 16, 16, 16, 20, 20, 20, 24, 24, 28, 28,
83    32, 36, 40, 40, 44, 48, 52, 56, 60, 64, 64, 64
84};
85
86static const uint8_t swb_size_1024_8[] = {
87    12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
88    16, 16, 16, 16, 16, 16, 16, 20, 20, 20, 20, 24, 24, 24, 28, 28,
89    32, 36, 36, 40, 44, 48, 52, 56, 60, 64, 80
90};
91
92static const uint8_t *swb_size_1024[] = {
93    swb_size_1024_96, swb_size_1024_96, swb_size_1024_64,
94    swb_size_1024_48, swb_size_1024_48, swb_size_1024_32,
95    swb_size_1024_24, swb_size_1024_24, swb_size_1024_16,
96    swb_size_1024_16, swb_size_1024_16, swb_size_1024_8
97};
98
99static const uint8_t swb_size_128_96[] = {
100    4, 4, 4, 4, 4, 4, 8, 8, 8, 16, 28, 36
101};
102
103static const uint8_t swb_size_128_48[] = {
104    4, 4, 4, 4, 4, 8, 8, 8, 12, 12, 12, 16, 16, 16
105};
106
107static const uint8_t swb_size_128_24[] = {
108    4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 12, 12, 16, 16, 20
109};
110
111static const uint8_t swb_size_128_16[] = {
112    4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 12, 12, 16, 20, 20
113};
114
115static const uint8_t swb_size_128_8[] = {
116    4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 12, 16, 20, 20
117};
118
119static const uint8_t *swb_size_128[] = {
120    /* the last entry on the following row is swb_size_128_64 but is a
121       duplicate of swb_size_128_96 */
122    swb_size_128_96, swb_size_128_96, swb_size_128_96,
123    swb_size_128_48, swb_size_128_48, swb_size_128_48,
124    swb_size_128_24, swb_size_128_24, swb_size_128_16,
125    swb_size_128_16, swb_size_128_16, swb_size_128_8
126};
127
128/** default channel configurations */
129static const uint8_t aac_chan_configs[6][5] = {
130 {1, TYPE_SCE},                               // 1 channel  - single channel element
131 {1, TYPE_CPE},                               // 2 channels - channel pair
132 {2, TYPE_SCE, TYPE_CPE},                     // 3 channels - center + stereo
133 {3, TYPE_SCE, TYPE_CPE, TYPE_SCE},           // 4 channels - front center + stereo + back center
134 {3, TYPE_SCE, TYPE_CPE, TYPE_CPE},           // 5 channels - front center + stereo + back stereo
135 {4, TYPE_SCE, TYPE_CPE, TYPE_CPE, TYPE_LFE}, // 6 channels - front center + stereo + back stereo + LFE
136};
137
138/**
139 * Make AAC audio config object.
140 * @see 1.6.2.1 "Syntax - AudioSpecificConfig"
141 */
142static void put_audio_specific_config(AVCodecContext *avctx)
143{
144    PutBitContext pb;
145    AACEncContext *s = avctx->priv_data;
146
147    init_put_bits(&pb, avctx->extradata, avctx->extradata_size*8);
148    put_bits(&pb, 5, 2); //object type - AAC-LC
149    put_bits(&pb, 4, s->samplerate_index); //sample rate index
150    put_bits(&pb, 4, avctx->channels);
151    //GASpecificConfig
152    put_bits(&pb, 1, 0); //frame length - 1024 samples
153    put_bits(&pb, 1, 0); //does not depend on core coder
154    put_bits(&pb, 1, 0); //is not extension
155
156    //Explicitly Mark SBR absent
157    put_bits(&pb, 11, 0x2b7); //sync extension
158    put_bits(&pb, 5,  AOT_SBR);
159    put_bits(&pb, 1,  0);
160    flush_put_bits(&pb);
161}
162
163static av_cold int aac_encode_init(AVCodecContext *avctx)
164{
165    AACEncContext *s = avctx->priv_data;
166    int i;
167    const uint8_t *sizes[2];
168    uint8_t grouping[AAC_MAX_CHANNELS];
169    int lengths[2];
170
171    avctx->frame_size = 1024;
172
173    for (i = 0; i < 16; i++)
174        if (avctx->sample_rate == avpriv_mpeg4audio_sample_rates[i])
175            break;
176    if (i == 16) {
177        av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate %d\n", avctx->sample_rate);
178        return -1;
179    }
180    if (avctx->channels > AAC_MAX_CHANNELS) {
181        av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %d\n", avctx->channels);
182        return -1;
183    }
184    if (avctx->profile != FF_PROFILE_UNKNOWN && avctx->profile != FF_PROFILE_AAC_LOW) {
185        av_log(avctx, AV_LOG_ERROR, "Unsupported profile %d\n", avctx->profile);
186        return -1;
187    }
188    if (1024.0 * avctx->bit_rate / avctx->sample_rate > 6144 * avctx->channels) {
189        av_log(avctx, AV_LOG_ERROR, "Too many bits per frame requested\n");
190        return -1;
191    }
192    s->samplerate_index = i;
193
194    dsputil_init(&s->dsp, avctx);
195    ff_mdct_init(&s->mdct1024, 11, 0, 1.0);
196    ff_mdct_init(&s->mdct128,   8, 0, 1.0);
197    // window init
198    ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
199    ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
200    ff_init_ff_sine_windows(10);
201    ff_init_ff_sine_windows(7);
202
203    s->chan_map           = aac_chan_configs[avctx->channels-1];
204    s->samples            = av_malloc(2 * 1024 * avctx->channels * sizeof(s->samples[0]));
205    s->cpe                = av_mallocz(sizeof(ChannelElement) * s->chan_map[0]);
206    avctx->extradata      = av_mallocz(5 + FF_INPUT_BUFFER_PADDING_SIZE);
207    avctx->extradata_size = 5;
208    put_audio_specific_config(avctx);
209
210    sizes[0]   = swb_size_1024[i];
211    sizes[1]   = swb_size_128[i];
212    lengths[0] = ff_aac_num_swb_1024[i];
213    lengths[1] = ff_aac_num_swb_128[i];
214    for (i = 0; i < s->chan_map[0]; i++)
215        grouping[i] = s->chan_map[i + 1] == TYPE_CPE;
216    ff_psy_init(&s->psy, avctx, 2, sizes, lengths, s->chan_map[0], grouping);
217    s->psypp = ff_psy_preprocess_init(avctx);
218    s->coder = &ff_aac_coders[2];
219
220    s->lambda = avctx->global_quality ? avctx->global_quality : 120;
221
222    ff_aac_tableinit();
223
224    return 0;
225}
226
227static void apply_window_and_mdct(AVCodecContext *avctx, AACEncContext *s,
228                                  SingleChannelElement *sce, short *audio)
229{
230    int i, k;
231    const int chans = avctx->channels;
232    const float * lwindow = sce->ics.use_kb_window[0] ? ff_aac_kbd_long_1024 : ff_sine_1024;
233    const float * swindow = sce->ics.use_kb_window[0] ? ff_aac_kbd_short_128 : ff_sine_128;
234    const float * pwindow = sce->ics.use_kb_window[1] ? ff_aac_kbd_short_128 : ff_sine_128;
235    float *output = sce->ret;
236
237    if (sce->ics.window_sequence[0] != EIGHT_SHORT_SEQUENCE) {
238        memcpy(output, sce->saved, sizeof(float)*1024);
239        if (sce->ics.window_sequence[0] == LONG_STOP_SEQUENCE) {
240            memset(output, 0, sizeof(output[0]) * 448);
241            for (i = 448; i < 576; i++)
242                output[i] = sce->saved[i] * pwindow[i - 448];
243            for (i = 576; i < 704; i++)
244                output[i] = sce->saved[i];
245        }
246        if (sce->ics.window_sequence[0] != LONG_START_SEQUENCE) {
247            for (i = 0; i < 1024; i++) {
248                output[i+1024]         = audio[i * chans] * lwindow[1024 - i - 1];
249                sce->saved[i] = audio[i * chans] * lwindow[i];
250            }
251        } else {
252            for (i = 0; i < 448; i++)
253                output[i+1024]         = audio[i * chans];
254            for (; i < 576; i++)
255                output[i+1024]         = audio[i * chans] * swindow[576 - i - 1];
256            memset(output+1024+576, 0, sizeof(output[0]) * 448);
257            for (i = 0; i < 1024; i++)
258                sce->saved[i] = audio[i * chans];
259        }
260        s->mdct1024.mdct_calc(&s->mdct1024, sce->coeffs, output);
261    } else {
262        for (k = 0; k < 1024; k += 128) {
263            for (i = 448 + k; i < 448 + k + 256; i++)
264                output[i - 448 - k] = (i < 1024)
265                                         ? sce->saved[i]
266                                         : audio[(i-1024)*chans];
267            s->dsp.vector_fmul        (output,     output, k ?  swindow : pwindow, 128);
268            s->dsp.vector_fmul_reverse(output+128, output+128, swindow, 128);
269            s->mdct128.mdct_calc(&s->mdct128, sce->coeffs + k, output);
270        }
271        for (i = 0; i < 1024; i++)
272            sce->saved[i] = audio[i * chans];
273    }
274}
275
276/**
277 * Encode ics_info element.
278 * @see Table 4.6 (syntax of ics_info)
279 */
280static void put_ics_info(AACEncContext *s, IndividualChannelStream *info)
281{
282    int w;
283
284    put_bits(&s->pb, 1, 0);                // ics_reserved bit
285    put_bits(&s->pb, 2, info->window_sequence[0]);
286    put_bits(&s->pb, 1, info->use_kb_window[0]);
287    if (info->window_sequence[0] != EIGHT_SHORT_SEQUENCE) {
288        put_bits(&s->pb, 6, info->max_sfb);
289        put_bits(&s->pb, 1, 0);            // no prediction
290    } else {
291        put_bits(&s->pb, 4, info->max_sfb);
292        for (w = 1; w < 8; w++)
293            put_bits(&s->pb, 1, !info->group_len[w]);
294    }
295}
296
297/**
298 * Encode MS data.
299 * @see 4.6.8.1 "Joint Coding - M/S Stereo"
300 */
301static void encode_ms_info(PutBitContext *pb, ChannelElement *cpe)
302{
303    int i, w;
304
305    put_bits(pb, 2, cpe->ms_mode);
306    if (cpe->ms_mode == 1)
307        for (w = 0; w < cpe->ch[0].ics.num_windows; w += cpe->ch[0].ics.group_len[w])
308            for (i = 0; i < cpe->ch[0].ics.max_sfb; i++)
309                put_bits(pb, 1, cpe->ms_mask[w*16 + i]);
310}
311
312/**
313 * Produce integer coefficients from scalefactors provided by the model.
314 */
315static void adjust_frame_information(AACEncContext *apc, ChannelElement *cpe, int chans)
316{
317    int i, w, w2, g, ch;
318    int start, maxsfb, cmaxsfb;
319
320    for (ch = 0; ch < chans; ch++) {
321        IndividualChannelStream *ics = &cpe->ch[ch].ics;
322        start = 0;
323        maxsfb = 0;
324        cpe->ch[ch].pulse.num_pulse = 0;
325        for (w = 0; w < ics->num_windows*16; w += 16) {
326            for (g = 0; g < ics->num_swb; g++) {
327                //apply M/S
328                if (cpe->common_window && !ch && cpe->ms_mask[w + g]) {
329                    for (i = 0; i < ics->swb_sizes[g]; i++) {
330                        cpe->ch[0].coeffs[start+i] = (cpe->ch[0].coeffs[start+i] + cpe->ch[1].coeffs[start+i]) / 2.0;
331                        cpe->ch[1].coeffs[start+i] =  cpe->ch[0].coeffs[start+i] - cpe->ch[1].coeffs[start+i];
332                    }
333                }
334                start += ics->swb_sizes[g];
335            }
336            for (cmaxsfb = ics->num_swb; cmaxsfb > 0 && cpe->ch[ch].zeroes[w+cmaxsfb-1]; cmaxsfb--)
337                ;
338            maxsfb = FFMAX(maxsfb, cmaxsfb);
339        }
340        ics->max_sfb = maxsfb;
341
342        //adjust zero bands for window groups
343        for (w = 0; w < ics->num_windows; w += ics->group_len[w]) {
344            for (g = 0; g < ics->max_sfb; g++) {
345                i = 1;
346                for (w2 = w; w2 < w + ics->group_len[w]; w2++) {
347                    if (!cpe->ch[ch].zeroes[w2*16 + g]) {
348                        i = 0;
349                        break;
350                    }
351                }
352                cpe->ch[ch].zeroes[w*16 + g] = i;
353            }
354        }
355    }
356
357    if (chans > 1 && cpe->common_window) {
358        IndividualChannelStream *ics0 = &cpe->ch[0].ics;
359        IndividualChannelStream *ics1 = &cpe->ch[1].ics;
360        int msc = 0;
361        ics0->max_sfb = FFMAX(ics0->max_sfb, ics1->max_sfb);
362        ics1->max_sfb = ics0->max_sfb;
363        for (w = 0; w < ics0->num_windows*16; w += 16)
364            for (i = 0; i < ics0->max_sfb; i++)
365                if (cpe->ms_mask[w+i])
366                    msc++;
367        if (msc == 0 || ics0->max_sfb == 0)
368            cpe->ms_mode = 0;
369        else
370            cpe->ms_mode = msc < ics0->max_sfb * ics0->num_windows ? 1 : 2;
371    }
372}
373
374/**
375 * Encode scalefactor band coding type.
376 */
377static void encode_band_info(AACEncContext *s, SingleChannelElement *sce)
378{
379    int w;
380
381    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
382        s->coder->encode_window_bands_info(s, sce, w, sce->ics.group_len[w], s->lambda);
383}
384
385/**
386 * Encode scalefactors.
387 */
388static void encode_scale_factors(AVCodecContext *avctx, AACEncContext *s,
389                                 SingleChannelElement *sce)
390{
391    int off = sce->sf_idx[0], diff;
392    int i, w;
393
394    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
395        for (i = 0; i < sce->ics.max_sfb; i++) {
396            if (!sce->zeroes[w*16 + i]) {
397                diff = sce->sf_idx[w*16 + i] - off + SCALE_DIFF_ZERO;
398                if (diff < 0 || diff > 120)
399                    av_log(avctx, AV_LOG_ERROR, "Scalefactor difference is too big to be coded\n");
400                off = sce->sf_idx[w*16 + i];
401                put_bits(&s->pb, ff_aac_scalefactor_bits[diff], ff_aac_scalefactor_code[diff]);
402            }
403        }
404    }
405}
406
407/**
408 * Encode pulse data.
409 */
410static void encode_pulses(AACEncContext *s, Pulse *pulse)
411{
412    int i;
413
414    put_bits(&s->pb, 1, !!pulse->num_pulse);
415    if (!pulse->num_pulse)
416        return;
417
418    put_bits(&s->pb, 2, pulse->num_pulse - 1);
419    put_bits(&s->pb, 6, pulse->start);
420    for (i = 0; i < pulse->num_pulse; i++) {
421        put_bits(&s->pb, 5, pulse->pos[i]);
422        put_bits(&s->pb, 4, pulse->amp[i]);
423    }
424}
425
426/**
427 * Encode spectral coefficients processed by psychoacoustic model.
428 */
429static void encode_spectral_coeffs(AACEncContext *s, SingleChannelElement *sce)
430{
431    int start, i, w, w2;
432
433    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
434        start = 0;
435        for (i = 0; i < sce->ics.max_sfb; i++) {
436            if (sce->zeroes[w*16 + i]) {
437                start += sce->ics.swb_sizes[i];
438                continue;
439            }
440            for (w2 = w; w2 < w + sce->ics.group_len[w]; w2++)
441                s->coder->quantize_and_encode_band(s, &s->pb, sce->coeffs + start + w2*128,
442                                                   sce->ics.swb_sizes[i],
443                                                   sce->sf_idx[w*16 + i],
444                                                   sce->band_type[w*16 + i],
445                                                   s->lambda);
446            start += sce->ics.swb_sizes[i];
447        }
448    }
449}
450
451/**
452 * Encode one channel of audio data.
453 */
454static int encode_individual_channel(AVCodecContext *avctx, AACEncContext *s,
455                                     SingleChannelElement *sce,
456                                     int common_window)
457{
458    put_bits(&s->pb, 8, sce->sf_idx[0]);
459    if (!common_window)
460        put_ics_info(s, &sce->ics);
461    encode_band_info(s, sce);
462    encode_scale_factors(avctx, s, sce);
463    encode_pulses(s, &sce->pulse);
464    put_bits(&s->pb, 1, 0); //tns
465    put_bits(&s->pb, 1, 0); //ssr
466    encode_spectral_coeffs(s, sce);
467    return 0;
468}
469
470/**
471 * Write some auxiliary information about the created AAC file.
472 */
473static void put_bitstream_info(AVCodecContext *avctx, AACEncContext *s,
474                               const char *name)
475{
476    int i, namelen, padbits;
477
478    namelen = strlen(name) + 2;
479    put_bits(&s->pb, 3, TYPE_FIL);
480    put_bits(&s->pb, 4, FFMIN(namelen, 15));
481    if (namelen >= 15)
482        put_bits(&s->pb, 8, namelen - 16);
483    put_bits(&s->pb, 4, 0); //extension type - filler
484    padbits = 8 - (put_bits_count(&s->pb) & 7);
485    avpriv_align_put_bits(&s->pb);
486    for (i = 0; i < namelen - 2; i++)
487        put_bits(&s->pb, 8, name[i]);
488    put_bits(&s->pb, 12 - padbits, 0);
489}
490
491static int aac_encode_frame(AVCodecContext *avctx,
492                            uint8_t *frame, int buf_size, void *data)
493{
494    AACEncContext *s = avctx->priv_data;
495    int16_t *samples = s->samples, *samples2, *la;
496    ChannelElement *cpe;
497    int i, ch, w, g, chans, tag, start_ch;
498    int chan_el_counter[4];
499    FFPsyWindowInfo windows[AAC_MAX_CHANNELS];
500
501    if (s->last_frame)
502        return 0;
503    if (data) {
504        if (!s->psypp) {
505            memcpy(s->samples + 1024 * avctx->channels, data,
506                   1024 * avctx->channels * sizeof(s->samples[0]));
507        } else {
508            start_ch = 0;
509            samples2 = s->samples + 1024 * avctx->channels;
510            for (i = 0; i < s->chan_map[0]; i++) {
511                tag = s->chan_map[i+1];
512                chans = tag == TYPE_CPE ? 2 : 1;
513                ff_psy_preprocess(s->psypp, (uint16_t*)data + start_ch,
514                                  samples2 + start_ch, start_ch, chans);
515                start_ch += chans;
516            }
517        }
518    }
519    if (!avctx->frame_number) {
520        memcpy(s->samples, s->samples + 1024 * avctx->channels,
521               1024 * avctx->channels * sizeof(s->samples[0]));
522        return 0;
523    }
524
525    start_ch = 0;
526    for (i = 0; i < s->chan_map[0]; i++) {
527        FFPsyWindowInfo* wi = windows + start_ch;
528        tag      = s->chan_map[i+1];
529        chans    = tag == TYPE_CPE ? 2 : 1;
530        cpe      = &s->cpe[i];
531        for (ch = 0; ch < chans; ch++) {
532            IndividualChannelStream *ics = &cpe->ch[ch].ics;
533            int cur_channel = start_ch + ch;
534            samples2 = samples + cur_channel;
535            la       = samples2 + (448+64) * avctx->channels;
536            if (!data)
537                la = NULL;
538            if (tag == TYPE_LFE) {
539                wi[ch].window_type[0] = ONLY_LONG_SEQUENCE;
540                wi[ch].window_shape   = 0;
541                wi[ch].num_windows    = 1;
542                wi[ch].grouping[0]    = 1;
543
544                /* Only the lowest 12 coefficients are used in a LFE channel.
545                 * The expression below results in only the bottom 8 coefficients
546                 * being used for 11.025kHz to 16kHz sample rates.
547                 */
548                ics->num_swb = s->samplerate_index >= 8 ? 1 : 3;
549            } else {
550                wi[ch] = s->psy.model->window(&s->psy, samples2, la, cur_channel,
551                                              ics->window_sequence[0]);
552            }
553            ics->window_sequence[1] = ics->window_sequence[0];
554            ics->window_sequence[0] = wi[ch].window_type[0];
555            ics->use_kb_window[1]   = ics->use_kb_window[0];
556            ics->use_kb_window[0]   = wi[ch].window_shape;
557            ics->num_windows        = wi[ch].num_windows;
558            ics->swb_sizes          = s->psy.bands    [ics->num_windows == 8];
559            ics->num_swb            = tag == TYPE_LFE ? ics->num_swb : s->psy.num_bands[ics->num_windows == 8];
560            for (w = 0; w < ics->num_windows; w++)
561                ics->group_len[w] = wi[ch].grouping[w];
562
563            apply_window_and_mdct(avctx, s, &cpe->ch[ch], samples2);
564        }
565        start_ch += chans;
566    }
567    do {
568        int frame_bits;
569        init_put_bits(&s->pb, frame, buf_size*8);
570        if ((avctx->frame_number & 0xFF)==1 && !(avctx->flags & CODEC_FLAG_BITEXACT))
571            put_bitstream_info(avctx, s, LIBAVCODEC_IDENT);
572        start_ch = 0;
573        memset(chan_el_counter, 0, sizeof(chan_el_counter));
574        for (i = 0; i < s->chan_map[0]; i++) {
575            FFPsyWindowInfo* wi = windows + start_ch;
576            const float *coeffs[2];
577            tag      = s->chan_map[i+1];
578            chans    = tag == TYPE_CPE ? 2 : 1;
579            cpe      = &s->cpe[i];
580            put_bits(&s->pb, 3, tag);
581            put_bits(&s->pb, 4, chan_el_counter[tag]++);
582            for (ch = 0; ch < chans; ch++)
583                coeffs[ch] = cpe->ch[ch].coeffs;
584            s->psy.model->analyze(&s->psy, start_ch, coeffs, wi);
585            for (ch = 0; ch < chans; ch++) {
586                s->cur_channel = start_ch * 2 + ch;
587                s->coder->search_for_quantizers(avctx, s, &cpe->ch[ch], s->lambda);
588            }
589            cpe->common_window = 0;
590            if (chans > 1
591                && wi[0].window_type[0] == wi[1].window_type[0]
592                && wi[0].window_shape   == wi[1].window_shape) {
593
594                cpe->common_window = 1;
595                for (w = 0; w < wi[0].num_windows; w++) {
596                    if (wi[0].grouping[w] != wi[1].grouping[w]) {
597                        cpe->common_window = 0;
598                        break;
599                    }
600                }
601            }
602            s->cur_channel = start_ch * 2;
603            if (s->options.stereo_mode && cpe->common_window) {
604                if (s->options.stereo_mode > 0) {
605                    IndividualChannelStream *ics = &cpe->ch[0].ics;
606                    for (w = 0; w < ics->num_windows; w += ics->group_len[w])
607                        for (g = 0;  g < ics->num_swb; g++)
608                            cpe->ms_mask[w*16+g] = 1;
609                } else if (s->coder->search_for_ms) {
610                    s->coder->search_for_ms(s, cpe, s->lambda);
611                }
612            }
613            adjust_frame_information(s, cpe, chans);
614            if (chans == 2) {
615                put_bits(&s->pb, 1, cpe->common_window);
616                if (cpe->common_window) {
617                    put_ics_info(s, &cpe->ch[0].ics);
618                    encode_ms_info(&s->pb, cpe);
619                }
620            }
621            for (ch = 0; ch < chans; ch++) {
622                s->cur_channel = start_ch + ch;
623                encode_individual_channel(avctx, s, &cpe->ch[ch], cpe->common_window);
624            }
625            start_ch += chans;
626        }
627
628        frame_bits = put_bits_count(&s->pb);
629        if (frame_bits <= 6144 * avctx->channels - 3) {
630            s->psy.bitres.bits = frame_bits / avctx->channels;
631            break;
632        }
633
634        s->lambda *= avctx->bit_rate * 1024.0f / avctx->sample_rate / frame_bits;
635
636    } while (1);
637
638    put_bits(&s->pb, 3, TYPE_END);
639    flush_put_bits(&s->pb);
640    avctx->frame_bits = put_bits_count(&s->pb);
641
642    // rate control stuff
643    if (!(avctx->flags & CODEC_FLAG_QSCALE)) {
644        float ratio = avctx->bit_rate * 1024.0f / avctx->sample_rate / avctx->frame_bits;
645        s->lambda *= ratio;
646        s->lambda = FFMIN(s->lambda, 65536.f);
647    }
648
649    if (!data)
650        s->last_frame = 1;
651    memcpy(s->samples, s->samples + 1024 * avctx->channels,
652           1024 * avctx->channels * sizeof(s->samples[0]));
653    return put_bits_count(&s->pb)>>3;
654}
655
656static av_cold int aac_encode_end(AVCodecContext *avctx)
657{
658    AACEncContext *s = avctx->priv_data;
659
660    ff_mdct_end(&s->mdct1024);
661    ff_mdct_end(&s->mdct128);
662    ff_psy_end(&s->psy);
663    ff_psy_preprocess_end(s->psypp);
664    av_freep(&s->samples);
665    av_freep(&s->cpe);
666    return 0;
667}
668
669#define AACENC_FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
670static const AVOption aacenc_options[] = {
671    {"stereo_mode", "Stereo coding method", offsetof(AACEncContext, options.stereo_mode), AV_OPT_TYPE_INT, {.dbl = 0}, -1, 1, AACENC_FLAGS, "stereo_mode"},
672        {"auto",     "Selected by the Encoder", 0, AV_OPT_TYPE_CONST, {.dbl = -1 }, INT_MIN, INT_MAX, AACENC_FLAGS, "stereo_mode"},
673        {"ms_off",   "Disable Mid/Side coding", 0, AV_OPT_TYPE_CONST, {.dbl =  0 }, INT_MIN, INT_MAX, AACENC_FLAGS, "stereo_mode"},
674        {"ms_force", "Force Mid/Side for the whole frame if possible", 0, AV_OPT_TYPE_CONST, {.dbl =  1 }, INT_MIN, INT_MAX, AACENC_FLAGS, "stereo_mode"},
675    {NULL}
676};
677
678static const AVClass aacenc_class = {
679    "AAC encoder",
680    av_default_item_name,
681    aacenc_options,
682    LIBAVUTIL_VERSION_INT,
683};
684
685AVCodec ff_aac_encoder = {
686    .name           = "aac",
687    .type           = AVMEDIA_TYPE_AUDIO,
688    .id             = CODEC_ID_AAC,
689    .priv_data_size = sizeof(AACEncContext),
690    .init           = aac_encode_init,
691    .encode         = aac_encode_frame,
692    .close          = aac_encode_end,
693    .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
694    .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
695    .long_name = NULL_IF_CONFIG_SMALL("Advanced Audio Coding"),
696    .priv_class = &aacenc_class,
697};
698