1/*
2 * AAC encoder
3 * Copyright (C) 2008 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * AAC encoder
25 */
26
27/***********************************
28 *              TODOs:
29 * add sane pulse detection
30 * add temporal noise shaping
31 ***********************************/
32
33#include "avcodec.h"
34#include "put_bits.h"
35#include "dsputil.h"
36#include "mpeg4audio.h"
37
38#include "aac.h"
39#include "aactab.h"
40#include "aacenc.h"
41
42#include "psymodel.h"
43
44static const uint8_t swb_size_1024_96[] = {
45    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8,
46    12, 12, 12, 12, 12, 16, 16, 24, 28, 36, 44,
47    64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64
48};
49
50static const uint8_t swb_size_1024_64[] = {
51    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8,
52    12, 12, 12, 16, 16, 16, 20, 24, 24, 28, 36,
53    40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40
54};
55
56static const uint8_t swb_size_1024_48[] = {
57    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8,
58    12, 12, 12, 12, 16, 16, 20, 20, 24, 24, 28, 28,
59    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32,
60    96
61};
62
63static const uint8_t swb_size_1024_32[] = {
64    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8,
65    12, 12, 12, 12, 16, 16, 20, 20, 24, 24, 28, 28,
66    32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
67};
68
69static const uint8_t swb_size_1024_24[] = {
70    4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
71    12, 12, 12, 12, 16, 16, 16, 20, 20, 24, 24, 28, 28,
72    32, 36, 36, 40, 44, 48, 52, 52, 64, 64, 64, 64, 64
73};
74
75static const uint8_t swb_size_1024_16[] = {
76    8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
77    12, 12, 12, 12, 12, 12, 12, 12, 12, 16, 16, 16, 16, 20, 20, 20, 24, 24, 28, 28,
78    32, 36, 40, 40, 44, 48, 52, 56, 60, 64, 64, 64
79};
80
81static const uint8_t swb_size_1024_8[] = {
82    12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12,
83    16, 16, 16, 16, 16, 16, 16, 20, 20, 20, 20, 24, 24, 24, 28, 28,
84    32, 36, 36, 40, 44, 48, 52, 56, 60, 64, 80
85};
86
87static const uint8_t *swb_size_1024[] = {
88    swb_size_1024_96, swb_size_1024_96, swb_size_1024_64,
89    swb_size_1024_48, swb_size_1024_48, swb_size_1024_32,
90    swb_size_1024_24, swb_size_1024_24, swb_size_1024_16,
91    swb_size_1024_16, swb_size_1024_16, swb_size_1024_8
92};
93
94static const uint8_t swb_size_128_96[] = {
95    4, 4, 4, 4, 4, 4, 8, 8, 8, 16, 28, 36
96};
97
98static const uint8_t swb_size_128_48[] = {
99    4, 4, 4, 4, 4, 8, 8, 8, 12, 12, 12, 16, 16, 16
100};
101
102static const uint8_t swb_size_128_24[] = {
103    4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 12, 12, 16, 16, 20
104};
105
106static const uint8_t swb_size_128_16[] = {
107    4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 12, 12, 16, 20, 20
108};
109
110static const uint8_t swb_size_128_8[] = {
111    4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 12, 16, 20, 20
112};
113
114static const uint8_t *swb_size_128[] = {
115    /* the last entry on the following row is swb_size_128_64 but is a
116       duplicate of swb_size_128_96 */
117    swb_size_128_96, swb_size_128_96, swb_size_128_96,
118    swb_size_128_48, swb_size_128_48, swb_size_128_48,
119    swb_size_128_24, swb_size_128_24, swb_size_128_16,
120    swb_size_128_16, swb_size_128_16, swb_size_128_8
121};
122
123/** default channel configurations */
124static const uint8_t aac_chan_configs[6][5] = {
125 {1, TYPE_SCE},                               // 1 channel  - single channel element
126 {1, TYPE_CPE},                               // 2 channels - channel pair
127 {2, TYPE_SCE, TYPE_CPE},                     // 3 channels - center + stereo
128 {3, TYPE_SCE, TYPE_CPE, TYPE_SCE},           // 4 channels - front center + stereo + back center
129 {3, TYPE_SCE, TYPE_CPE, TYPE_CPE},           // 5 channels - front center + stereo + back stereo
130 {4, TYPE_SCE, TYPE_CPE, TYPE_CPE, TYPE_LFE}, // 6 channels - front center + stereo + back stereo + LFE
131};
132
133/**
134 * Make AAC audio config object.
135 * @see 1.6.2.1 "Syntax - AudioSpecificConfig"
136 */
137static void put_audio_specific_config(AVCodecContext *avctx)
138{
139    PutBitContext pb;
140    AACEncContext *s = avctx->priv_data;
141
142    init_put_bits(&pb, avctx->extradata, avctx->extradata_size*8);
143    put_bits(&pb, 5, 2); //object type - AAC-LC
144    put_bits(&pb, 4, s->samplerate_index); //sample rate index
145    put_bits(&pb, 4, avctx->channels);
146    //GASpecificConfig
147    put_bits(&pb, 1, 0); //frame length - 1024 samples
148    put_bits(&pb, 1, 0); //does not depend on core coder
149    put_bits(&pb, 1, 0); //is not extension
150    flush_put_bits(&pb);
151}
152
153static av_cold int aac_encode_init(AVCodecContext *avctx)
154{
155    AACEncContext *s = avctx->priv_data;
156    int i;
157    const uint8_t *sizes[2];
158    int lengths[2];
159
160    avctx->frame_size = 1024;
161
162    for (i = 0; i < 16; i++)
163        if (avctx->sample_rate == ff_mpeg4audio_sample_rates[i])
164            break;
165    if (i == 16) {
166        av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate %d\n", avctx->sample_rate);
167        return -1;
168    }
169    if (avctx->channels > 6) {
170        av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %d\n", avctx->channels);
171        return -1;
172    }
173    if (avctx->profile != FF_PROFILE_UNKNOWN && avctx->profile != FF_PROFILE_AAC_LOW) {
174        av_log(avctx, AV_LOG_ERROR, "Unsupported profile %d\n", avctx->profile);
175        return -1;
176    }
177    if (1024.0 * avctx->bit_rate / avctx->sample_rate > 6144 * avctx->channels) {
178        av_log(avctx, AV_LOG_ERROR, "Too many bits per frame requested\n");
179        return -1;
180    }
181    s->samplerate_index = i;
182
183    dsputil_init(&s->dsp, avctx);
184    ff_mdct_init(&s->mdct1024, 11, 0, 1.0);
185    ff_mdct_init(&s->mdct128,   8, 0, 1.0);
186    // window init
187    ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
188    ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
189    ff_init_ff_sine_windows(10);
190    ff_init_ff_sine_windows(7);
191
192    s->samples            = av_malloc(2 * 1024 * avctx->channels * sizeof(s->samples[0]));
193    s->cpe                = av_mallocz(sizeof(ChannelElement) * aac_chan_configs[avctx->channels-1][0]);
194    avctx->extradata      = av_malloc(2);
195    avctx->extradata_size = 2;
196    put_audio_specific_config(avctx);
197
198    sizes[0]   = swb_size_1024[i];
199    sizes[1]   = swb_size_128[i];
200    lengths[0] = ff_aac_num_swb_1024[i];
201    lengths[1] = ff_aac_num_swb_128[i];
202    ff_psy_init(&s->psy, avctx, 2, sizes, lengths);
203    s->psypp = ff_psy_preprocess_init(avctx);
204    s->coder = &ff_aac_coders[0];
205
206    s->lambda = avctx->global_quality ? avctx->global_quality : 120;
207#if !CONFIG_HARDCODED_TABLES
208    for (i = 0; i < 428; i++)
209        ff_aac_pow2sf_tab[i] = pow(2, (i - 200)/4.);
210#endif /* CONFIG_HARDCODED_TABLES */
211
212    if (avctx->channels > 5)
213        av_log(avctx, AV_LOG_ERROR, "This encoder does not yet enforce the restrictions on LFEs. "
214               "The output will most likely be an illegal bitstream.\n");
215
216    return 0;
217}
218
219static void apply_window_and_mdct(AVCodecContext *avctx, AACEncContext *s,
220                                  SingleChannelElement *sce, short *audio, int channel)
221{
222    int i, j, k;
223    const float * lwindow = sce->ics.use_kb_window[0] ? ff_aac_kbd_long_1024 : ff_sine_1024;
224    const float * swindow = sce->ics.use_kb_window[0] ? ff_aac_kbd_short_128 : ff_sine_128;
225    const float * pwindow = sce->ics.use_kb_window[1] ? ff_aac_kbd_short_128 : ff_sine_128;
226
227    if (sce->ics.window_sequence[0] != EIGHT_SHORT_SEQUENCE) {
228        memcpy(s->output, sce->saved, sizeof(float)*1024);
229        if (sce->ics.window_sequence[0] == LONG_STOP_SEQUENCE) {
230            memset(s->output, 0, sizeof(s->output[0]) * 448);
231            for (i = 448; i < 576; i++)
232                s->output[i] = sce->saved[i] * pwindow[i - 448];
233            for (i = 576; i < 704; i++)
234                s->output[i] = sce->saved[i];
235        }
236        if (sce->ics.window_sequence[0] != LONG_START_SEQUENCE) {
237            j = channel;
238            for (i = 0; i < 1024; i++, j += avctx->channels) {
239                s->output[i+1024]         = audio[j] * lwindow[1024 - i - 1];
240                sce->saved[i] = audio[j] * lwindow[i];
241            }
242        } else {
243            j = channel;
244            for (i = 0; i < 448; i++, j += avctx->channels)
245                s->output[i+1024]         = audio[j];
246            for (i = 448; i < 576; i++, j += avctx->channels)
247                s->output[i+1024]         = audio[j] * swindow[576 - i - 1];
248            memset(s->output+1024+576, 0, sizeof(s->output[0]) * 448);
249            j = channel;
250            for (i = 0; i < 1024; i++, j += avctx->channels)
251                sce->saved[i] = audio[j];
252        }
253        ff_mdct_calc(&s->mdct1024, sce->coeffs, s->output);
254    } else {
255        j = channel;
256        for (k = 0; k < 1024; k += 128) {
257            for (i = 448 + k; i < 448 + k + 256; i++)
258                s->output[i - 448 - k] = (i < 1024)
259                                         ? sce->saved[i]
260                                         : audio[channel + (i-1024)*avctx->channels];
261            s->dsp.vector_fmul        (s->output,     k ?  swindow : pwindow, 128);
262            s->dsp.vector_fmul_reverse(s->output+128, s->output+128, swindow, 128);
263            ff_mdct_calc(&s->mdct128, sce->coeffs + k, s->output);
264        }
265        j = channel;
266        for (i = 0; i < 1024; i++, j += avctx->channels)
267            sce->saved[i] = audio[j];
268    }
269}
270
271/**
272 * Encode ics_info element.
273 * @see Table 4.6 (syntax of ics_info)
274 */
275static void put_ics_info(AACEncContext *s, IndividualChannelStream *info)
276{
277    int w;
278
279    put_bits(&s->pb, 1, 0);                // ics_reserved bit
280    put_bits(&s->pb, 2, info->window_sequence[0]);
281    put_bits(&s->pb, 1, info->use_kb_window[0]);
282    if (info->window_sequence[0] != EIGHT_SHORT_SEQUENCE) {
283        put_bits(&s->pb, 6, info->max_sfb);
284        put_bits(&s->pb, 1, 0);            // no prediction
285    } else {
286        put_bits(&s->pb, 4, info->max_sfb);
287        for (w = 1; w < 8; w++)
288            put_bits(&s->pb, 1, !info->group_len[w]);
289    }
290}
291
292/**
293 * Encode MS data.
294 * @see 4.6.8.1 "Joint Coding - M/S Stereo"
295 */
296static void encode_ms_info(PutBitContext *pb, ChannelElement *cpe)
297{
298    int i, w;
299
300    put_bits(pb, 2, cpe->ms_mode);
301    if (cpe->ms_mode == 1)
302        for (w = 0; w < cpe->ch[0].ics.num_windows; w += cpe->ch[0].ics.group_len[w])
303            for (i = 0; i < cpe->ch[0].ics.max_sfb; i++)
304                put_bits(pb, 1, cpe->ms_mask[w*16 + i]);
305}
306
307/**
308 * Produce integer coefficients from scalefactors provided by the model.
309 */
310static void adjust_frame_information(AACEncContext *apc, ChannelElement *cpe, int chans)
311{
312    int i, w, w2, g, ch;
313    int start, sum, maxsfb, cmaxsfb;
314
315    for (ch = 0; ch < chans; ch++) {
316        IndividualChannelStream *ics = &cpe->ch[ch].ics;
317        start = 0;
318        maxsfb = 0;
319        cpe->ch[ch].pulse.num_pulse = 0;
320        for (w = 0; w < ics->num_windows*16; w += 16) {
321            for (g = 0; g < ics->num_swb; g++) {
322                sum = 0;
323                //apply M/S
324                if (!ch && cpe->ms_mask[w + g]) {
325                    for (i = 0; i < ics->swb_sizes[g]; i++) {
326                        cpe->ch[0].coeffs[start+i] = (cpe->ch[0].coeffs[start+i] + cpe->ch[1].coeffs[start+i]) / 2.0;
327                        cpe->ch[1].coeffs[start+i] =  cpe->ch[0].coeffs[start+i] - cpe->ch[1].coeffs[start+i];
328                    }
329                }
330                start += ics->swb_sizes[g];
331            }
332            for (cmaxsfb = ics->num_swb; cmaxsfb > 0 && cpe->ch[ch].zeroes[w+cmaxsfb-1]; cmaxsfb--)
333                ;
334            maxsfb = FFMAX(maxsfb, cmaxsfb);
335        }
336        ics->max_sfb = maxsfb;
337
338        //adjust zero bands for window groups
339        for (w = 0; w < ics->num_windows; w += ics->group_len[w]) {
340            for (g = 0; g < ics->max_sfb; g++) {
341                i = 1;
342                for (w2 = w; w2 < w + ics->group_len[w]; w2++) {
343                    if (!cpe->ch[ch].zeroes[w2*16 + g]) {
344                        i = 0;
345                        break;
346                    }
347                }
348                cpe->ch[ch].zeroes[w*16 + g] = i;
349            }
350        }
351    }
352
353    if (chans > 1 && cpe->common_window) {
354        IndividualChannelStream *ics0 = &cpe->ch[0].ics;
355        IndividualChannelStream *ics1 = &cpe->ch[1].ics;
356        int msc = 0;
357        ics0->max_sfb = FFMAX(ics0->max_sfb, ics1->max_sfb);
358        ics1->max_sfb = ics0->max_sfb;
359        for (w = 0; w < ics0->num_windows*16; w += 16)
360            for (i = 0; i < ics0->max_sfb; i++)
361                if (cpe->ms_mask[w+i])
362                    msc++;
363        if (msc == 0 || ics0->max_sfb == 0)
364            cpe->ms_mode = 0;
365        else
366            cpe->ms_mode = msc < ics0->max_sfb ? 1 : 2;
367    }
368}
369
370/**
371 * Encode scalefactor band coding type.
372 */
373static void encode_band_info(AACEncContext *s, SingleChannelElement *sce)
374{
375    int w;
376
377    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
378        s->coder->encode_window_bands_info(s, sce, w, sce->ics.group_len[w], s->lambda);
379}
380
381/**
382 * Encode scalefactors.
383 */
384static void encode_scale_factors(AVCodecContext *avctx, AACEncContext *s,
385                                 SingleChannelElement *sce)
386{
387    int off = sce->sf_idx[0], diff;
388    int i, w;
389
390    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
391        for (i = 0; i < sce->ics.max_sfb; i++) {
392            if (!sce->zeroes[w*16 + i]) {
393                diff = sce->sf_idx[w*16 + i] - off + SCALE_DIFF_ZERO;
394                if (diff < 0 || diff > 120)
395                    av_log(avctx, AV_LOG_ERROR, "Scalefactor difference is too big to be coded\n");
396                off = sce->sf_idx[w*16 + i];
397                put_bits(&s->pb, ff_aac_scalefactor_bits[diff], ff_aac_scalefactor_code[diff]);
398            }
399        }
400    }
401}
402
403/**
404 * Encode pulse data.
405 */
406static void encode_pulses(AACEncContext *s, Pulse *pulse)
407{
408    int i;
409
410    put_bits(&s->pb, 1, !!pulse->num_pulse);
411    if (!pulse->num_pulse)
412        return;
413
414    put_bits(&s->pb, 2, pulse->num_pulse - 1);
415    put_bits(&s->pb, 6, pulse->start);
416    for (i = 0; i < pulse->num_pulse; i++) {
417        put_bits(&s->pb, 5, pulse->pos[i]);
418        put_bits(&s->pb, 4, pulse->amp[i]);
419    }
420}
421
422/**
423 * Encode spectral coefficients processed by psychoacoustic model.
424 */
425static void encode_spectral_coeffs(AACEncContext *s, SingleChannelElement *sce)
426{
427    int start, i, w, w2;
428
429    for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
430        start = 0;
431        for (i = 0; i < sce->ics.max_sfb; i++) {
432            if (sce->zeroes[w*16 + i]) {
433                start += sce->ics.swb_sizes[i];
434                continue;
435            }
436            for (w2 = w; w2 < w + sce->ics.group_len[w]; w2++)
437                s->coder->quantize_and_encode_band(s, &s->pb, sce->coeffs + start + w2*128,
438                                                   sce->ics.swb_sizes[i],
439                                                   sce->sf_idx[w*16 + i],
440                                                   sce->band_type[w*16 + i],
441                                                   s->lambda);
442            start += sce->ics.swb_sizes[i];
443        }
444    }
445}
446
447/**
448 * Encode one channel of audio data.
449 */
450static int encode_individual_channel(AVCodecContext *avctx, AACEncContext *s,
451                                     SingleChannelElement *sce,
452                                     int common_window)
453{
454    put_bits(&s->pb, 8, sce->sf_idx[0]);
455    if (!common_window)
456        put_ics_info(s, &sce->ics);
457    encode_band_info(s, sce);
458    encode_scale_factors(avctx, s, sce);
459    encode_pulses(s, &sce->pulse);
460    put_bits(&s->pb, 1, 0); //tns
461    put_bits(&s->pb, 1, 0); //ssr
462    encode_spectral_coeffs(s, sce);
463    return 0;
464}
465
466/**
467 * Write some auxiliary information about the created AAC file.
468 */
469static void put_bitstream_info(AVCodecContext *avctx, AACEncContext *s,
470                               const char *name)
471{
472    int i, namelen, padbits;
473
474    namelen = strlen(name) + 2;
475    put_bits(&s->pb, 3, TYPE_FIL);
476    put_bits(&s->pb, 4, FFMIN(namelen, 15));
477    if (namelen >= 15)
478        put_bits(&s->pb, 8, namelen - 16);
479    put_bits(&s->pb, 4, 0); //extension type - filler
480    padbits = 8 - (put_bits_count(&s->pb) & 7);
481    align_put_bits(&s->pb);
482    for (i = 0; i < namelen - 2; i++)
483        put_bits(&s->pb, 8, name[i]);
484    put_bits(&s->pb, 12 - padbits, 0);
485}
486
487static int aac_encode_frame(AVCodecContext *avctx,
488                            uint8_t *frame, int buf_size, void *data)
489{
490    AACEncContext *s = avctx->priv_data;
491    int16_t *samples = s->samples, *samples2, *la;
492    ChannelElement *cpe;
493    int i, j, chans, tag, start_ch;
494    const uint8_t *chan_map = aac_chan_configs[avctx->channels-1];
495    int chan_el_counter[4];
496    FFPsyWindowInfo windows[avctx->channels];
497
498    if (s->last_frame)
499        return 0;
500    if (data) {
501        if (!s->psypp) {
502            memcpy(s->samples + 1024 * avctx->channels, data,
503                   1024 * avctx->channels * sizeof(s->samples[0]));
504        } else {
505            start_ch = 0;
506            samples2 = s->samples + 1024 * avctx->channels;
507            for (i = 0; i < chan_map[0]; i++) {
508                tag = chan_map[i+1];
509                chans = tag == TYPE_CPE ? 2 : 1;
510                ff_psy_preprocess(s->psypp, (uint16_t*)data + start_ch,
511                                  samples2 + start_ch, start_ch, chans);
512                start_ch += chans;
513            }
514        }
515    }
516    if (!avctx->frame_number) {
517        memcpy(s->samples, s->samples + 1024 * avctx->channels,
518               1024 * avctx->channels * sizeof(s->samples[0]));
519        return 0;
520    }
521
522    start_ch = 0;
523    for (i = 0; i < chan_map[0]; i++) {
524        FFPsyWindowInfo* wi = windows + start_ch;
525        tag      = chan_map[i+1];
526        chans    = tag == TYPE_CPE ? 2 : 1;
527        cpe      = &s->cpe[i];
528        samples2 = samples + start_ch;
529        la       = samples2 + 1024 * avctx->channels + start_ch;
530        if (!data)
531            la = NULL;
532        for (j = 0; j < chans; j++) {
533            IndividualChannelStream *ics = &cpe->ch[j].ics;
534            int k;
535            wi[j] = ff_psy_suggest_window(&s->psy, samples2, la, start_ch + j, ics->window_sequence[0]);
536            ics->window_sequence[1] = ics->window_sequence[0];
537            ics->window_sequence[0] = wi[j].window_type[0];
538            ics->use_kb_window[1]   = ics->use_kb_window[0];
539            ics->use_kb_window[0]   = wi[j].window_shape;
540            ics->num_windows        = wi[j].num_windows;
541            ics->swb_sizes          = s->psy.bands    [ics->num_windows == 8];
542            ics->num_swb            = s->psy.num_bands[ics->num_windows == 8];
543            for (k = 0; k < ics->num_windows; k++)
544                ics->group_len[k] = wi[j].grouping[k];
545
546            s->cur_channel = start_ch + j;
547            apply_window_and_mdct(avctx, s, &cpe->ch[j], samples2, j);
548        }
549        start_ch += chans;
550    }
551    do {
552        int frame_bits;
553        init_put_bits(&s->pb, frame, buf_size*8);
554        if ((avctx->frame_number & 0xFF)==1 && !(avctx->flags & CODEC_FLAG_BITEXACT))
555            put_bitstream_info(avctx, s, LIBAVCODEC_IDENT);
556        start_ch = 0;
557        memset(chan_el_counter, 0, sizeof(chan_el_counter));
558        for (i = 0; i < chan_map[0]; i++) {
559            FFPsyWindowInfo* wi = windows + start_ch;
560            tag      = chan_map[i+1];
561            chans    = tag == TYPE_CPE ? 2 : 1;
562            cpe      = &s->cpe[i];
563            for (j = 0; j < chans; j++) {
564                s->cur_channel = start_ch + j;
565                s->coder->search_for_quantizers(avctx, s, &cpe->ch[j], s->lambda);
566            }
567            cpe->common_window = 0;
568            if (chans > 1
569                && wi[0].window_type[0] == wi[1].window_type[0]
570                && wi[0].window_shape   == wi[1].window_shape) {
571
572                cpe->common_window = 1;
573                for (j = 0; j < wi[0].num_windows; j++) {
574                    if (wi[0].grouping[j] != wi[1].grouping[j]) {
575                        cpe->common_window = 0;
576                        break;
577                    }
578                }
579            }
580            s->cur_channel = start_ch;
581            if (cpe->common_window && s->coder->search_for_ms)
582                s->coder->search_for_ms(s, cpe, s->lambda);
583            adjust_frame_information(s, cpe, chans);
584            put_bits(&s->pb, 3, tag);
585            put_bits(&s->pb, 4, chan_el_counter[tag]++);
586            if (chans == 2) {
587                put_bits(&s->pb, 1, cpe->common_window);
588                if (cpe->common_window) {
589                    put_ics_info(s, &cpe->ch[0].ics);
590                    encode_ms_info(&s->pb, cpe);
591                }
592            }
593            for (j = 0; j < chans; j++) {
594                s->cur_channel = start_ch + j;
595                ff_psy_set_band_info(&s->psy, s->cur_channel, cpe->ch[j].coeffs, &wi[j]);
596                encode_individual_channel(avctx, s, &cpe->ch[j], cpe->common_window);
597            }
598            start_ch += chans;
599        }
600
601        frame_bits = put_bits_count(&s->pb);
602        if (frame_bits <= 6144 * avctx->channels - 3)
603            break;
604
605        s->lambda *= avctx->bit_rate * 1024.0f / avctx->sample_rate / frame_bits;
606
607    } while (1);
608
609    put_bits(&s->pb, 3, TYPE_END);
610    flush_put_bits(&s->pb);
611    avctx->frame_bits = put_bits_count(&s->pb);
612
613    // rate control stuff
614    if (!(avctx->flags & CODEC_FLAG_QSCALE)) {
615        float ratio = avctx->bit_rate * 1024.0f / avctx->sample_rate / avctx->frame_bits;
616        s->lambda *= ratio;
617        s->lambda = FFMIN(s->lambda, 65536.f);
618    }
619
620    if (!data)
621        s->last_frame = 1;
622    memcpy(s->samples, s->samples + 1024 * avctx->channels,
623           1024 * avctx->channels * sizeof(s->samples[0]));
624    return put_bits_count(&s->pb)>>3;
625}
626
627static av_cold int aac_encode_end(AVCodecContext *avctx)
628{
629    AACEncContext *s = avctx->priv_data;
630
631    ff_mdct_end(&s->mdct1024);
632    ff_mdct_end(&s->mdct128);
633    ff_psy_end(&s->psy);
634    ff_psy_preprocess_end(s->psypp);
635    av_freep(&s->samples);
636    av_freep(&s->cpe);
637    return 0;
638}
639
640AVCodec aac_encoder = {
641    "aac",
642    AVMEDIA_TYPE_AUDIO,
643    CODEC_ID_AAC,
644    sizeof(AACEncContext),
645    aac_encode_init,
646    aac_encode_frame,
647    aac_encode_end,
648    .capabilities = CODEC_CAP_SMALL_LAST_FRAME | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
649    .sample_fmts = (const enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
650    .long_name = NULL_IF_CONFIG_SMALL("Advanced Audio Coding"),
651};
652