1 /*
2  * DCA encoder
3  * Copyright (C) 2008-2012 Alexander E. Patrakov
4  *               2010 Benjamin Larsson
5  *               2011 Xiang Wang
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 #define FFT_FLOAT 0
25 
26 #include "libavutil/avassert.h"
27 #include "libavutil/channel_layout.h"
28 #include "libavutil/common.h"
29 #include "libavutil/ffmath.h"
30 #include "libavutil/mem_internal.h"
31 #include "libavutil/opt.h"
32 #include "avcodec.h"
33 #include "codec_internal.h"
34 #include "dca.h"
35 #include "dcaadpcm.h"
36 #include "dcamath.h"
37 #include "dca_core.h"
38 #include "dcadata.h"
39 #include "dcaenc.h"
40 #include "encode.h"
41 #include "fft.h"
42 #include "internal.h"
43 #include "mathops.h"
44 #include "put_bits.h"
45 
46 #define MAX_CHANNELS 6
47 #define DCA_MAX_FRAME_SIZE 16384
48 #define DCA_HEADER_SIZE 13
49 #define DCA_LFE_SAMPLES 8
50 
51 #define DCAENC_SUBBANDS 32
52 #define SUBFRAMES 1
53 #define SUBSUBFRAMES 2
54 #define SUBBAND_SAMPLES (SUBFRAMES * SUBSUBFRAMES * 8)
55 #define AUBANDS 25
56 
57 #define COS_T(x) (c->cos_table[(x) & 2047])
58 
59 typedef struct CompressionOptions {
60     int adpcm_mode;
61 } CompressionOptions;
62 
63 typedef struct DCAEncContext {
64     AVClass *class;
65     PutBitContext pb;
66     DCAADPCMEncContext adpcm_ctx;
67     FFTContext mdct;
68     CompressionOptions options;
69     int frame_size;
70     int frame_bits;
71     int fullband_channels;
72     int channels;
73     int lfe_channel;
74     int samplerate_index;
75     int bitrate_index;
76     int channel_config;
77     const int32_t *band_interpolation;
78     const int32_t *band_spectrum;
79     int lfe_scale_factor;
80     softfloat lfe_quant;
81     int32_t lfe_peak_cb;
82     const int8_t *channel_order_tab;  ///< channel reordering table, lfe and non lfe
83 
84     int32_t prediction_mode[MAX_CHANNELS][DCAENC_SUBBANDS];
85     int32_t adpcm_history[MAX_CHANNELS][DCAENC_SUBBANDS][DCA_ADPCM_COEFFS * 2];
86     int32_t history[MAX_CHANNELS][512]; /* This is a circular buffer */
87     int32_t *subband[MAX_CHANNELS][DCAENC_SUBBANDS];
88     int32_t quantized[MAX_CHANNELS][DCAENC_SUBBANDS][SUBBAND_SAMPLES];
89     int32_t peak_cb[MAX_CHANNELS][DCAENC_SUBBANDS];
90     int32_t diff_peak_cb[MAX_CHANNELS][DCAENC_SUBBANDS]; ///< expected peak of residual signal
91     int32_t downsampled_lfe[DCA_LFE_SAMPLES];
92     int32_t masking_curve_cb[SUBSUBFRAMES][256];
93     int32_t bit_allocation_sel[MAX_CHANNELS];
94     int abits[MAX_CHANNELS][DCAENC_SUBBANDS];
95     int scale_factor[MAX_CHANNELS][DCAENC_SUBBANDS];
96     softfloat quant[MAX_CHANNELS][DCAENC_SUBBANDS];
97     int32_t quant_index_sel[MAX_CHANNELS][DCA_CODE_BOOKS];
98     int32_t eff_masking_curve_cb[256];
99     int32_t band_masking_cb[32];
100     int32_t worst_quantization_noise;
101     int32_t worst_noise_ever;
102     int consumed_bits;
103     int consumed_adpcm_bits; ///< Number of bits to transmit ADPCM related info
104 
105     int32_t cos_table[2048];
106     int32_t band_interpolation_tab[2][512];
107     int32_t band_spectrum_tab[2][8];
108     int32_t auf[9][AUBANDS][256];
109     int32_t cb_to_add[256];
110     int32_t cb_to_level[2048];
111     int32_t lfe_fir_64i[512];
112 } DCAEncContext;
113 
114 /* Transfer function of outer and middle ear, Hz -> dB */
hom(double f)115 static double hom(double f)
116 {
117     double f1 = f / 1000;
118 
119     return -3.64 * pow(f1, -0.8)
120            + 6.8 * exp(-0.6 * (f1 - 3.4) * (f1 - 3.4))
121            - 6.0 * exp(-0.15 * (f1 - 8.7) * (f1 - 8.7))
122            - 0.0006 * (f1 * f1) * (f1 * f1);
123 }
124 
gammafilter(int i, double f)125 static double gammafilter(int i, double f)
126 {
127     double h = (f - fc[i]) / erb[i];
128 
129     h = 1 + h * h;
130     h = 1 / (h * h);
131     return 20 * log10(h);
132 }
133 
subband_bufer_alloc(DCAEncContext *c)134 static int subband_bufer_alloc(DCAEncContext *c)
135 {
136     int ch, band;
137     int32_t *bufer = av_calloc(MAX_CHANNELS * DCAENC_SUBBANDS *
138                                (SUBBAND_SAMPLES + DCA_ADPCM_COEFFS),
139                                sizeof(int32_t));
140     if (!bufer)
141         return AVERROR(ENOMEM);
142 
143     /* we need a place for DCA_ADPCM_COEFF samples from previous frame
144      * to calc prediction coefficients for each subband */
145     for (ch = 0; ch < MAX_CHANNELS; ch++) {
146         for (band = 0; band < DCAENC_SUBBANDS; band++) {
147             c->subband[ch][band] = bufer +
148                                    ch * DCAENC_SUBBANDS * (SUBBAND_SAMPLES + DCA_ADPCM_COEFFS) +
149                                    band * (SUBBAND_SAMPLES + DCA_ADPCM_COEFFS) + DCA_ADPCM_COEFFS;
150         }
151     }
152     return 0;
153 }
154 
subband_bufer_free(DCAEncContext *c)155 static void subband_bufer_free(DCAEncContext *c)
156 {
157     if (c->subband[0][0]) {
158         int32_t *bufer = c->subband[0][0] - DCA_ADPCM_COEFFS;
159         av_free(bufer);
160         c->subband[0][0] = NULL;
161     }
162 }
163 
encode_init(AVCodecContext *avctx)164 static int encode_init(AVCodecContext *avctx)
165 {
166     DCAEncContext *c = avctx->priv_data;
167     AVChannelLayout layout = avctx->ch_layout;
168     int i, j, k, min_frame_bits;
169     int ret;
170 
171     if ((ret = subband_bufer_alloc(c)) < 0)
172         return ret;
173 
174     c->fullband_channels = c->channels = layout.nb_channels;
175     c->lfe_channel = (c->channels == 3 || c->channels == 6);
176     c->band_interpolation = c->band_interpolation_tab[1];
177     c->band_spectrum = c->band_spectrum_tab[1];
178     c->worst_quantization_noise = -2047;
179     c->worst_noise_ever = -2047;
180     c->consumed_adpcm_bits = 0;
181 
182     if (ff_dcaadpcm_init(&c->adpcm_ctx))
183         return AVERROR(ENOMEM);
184 
185     if (layout.order == AV_CHANNEL_ORDER_UNSPEC) {
186         av_log(avctx, AV_LOG_WARNING, "No channel layout specified. The "
187                                       "encoder will guess the layout, but it "
188                                       "might be incorrect.\n");
189         av_channel_layout_default(&layout, layout.nb_channels);
190     }
191 
192     if (!av_channel_layout_compare(&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_MONO))
193         c->channel_config = 0;
194     else if (!av_channel_layout_compare(&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO))
195         c->channel_config = 2;
196     else if (!av_channel_layout_compare(&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_2_2))
197         c->channel_config = 8;
198     else if (!av_channel_layout_compare(&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT0))
199         c->channel_config = 9;
200     else if (!av_channel_layout_compare(&layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_5POINT1))
201         c->channel_config = 9;
202     else {
203         av_log(avctx, AV_LOG_ERROR, "Unsupported channel layout!\n");
204         return AVERROR_PATCHWELCOME;
205     }
206 
207     if (c->lfe_channel) {
208         c->fullband_channels--;
209         c->channel_order_tab = channel_reorder_lfe[c->channel_config];
210     } else {
211         c->channel_order_tab = channel_reorder_nolfe[c->channel_config];
212     }
213 
214     for (i = 0; i < MAX_CHANNELS; i++) {
215         for (j = 0; j < DCA_CODE_BOOKS; j++) {
216             c->quant_index_sel[i][j] = ff_dca_quant_index_group_size[j];
217         }
218         /* 6 - no Huffman */
219         c->bit_allocation_sel[i] = 6;
220 
221         for (j = 0; j < DCAENC_SUBBANDS; j++) {
222             /* -1 - no ADPCM */
223             c->prediction_mode[i][j] = -1;
224             memset(c->adpcm_history[i][j], 0, sizeof(int32_t)*DCA_ADPCM_COEFFS);
225         }
226     }
227 
228     for (i = 0; i < 9; i++) {
229         if (sample_rates[i] == avctx->sample_rate)
230             break;
231     }
232     if (i == 9)
233         return AVERROR(EINVAL);
234     c->samplerate_index = i;
235 
236     if (avctx->bit_rate < 32000 || avctx->bit_rate > 3840000) {
237         av_log(avctx, AV_LOG_ERROR, "Bit rate %"PRId64" not supported.", avctx->bit_rate);
238         return AVERROR(EINVAL);
239     }
240     for (i = 0; ff_dca_bit_rates[i] < avctx->bit_rate; i++)
241         ;
242     c->bitrate_index = i;
243     c->frame_bits = FFALIGN((avctx->bit_rate * 512 + avctx->sample_rate - 1) / avctx->sample_rate, 32);
244     min_frame_bits = 132 + (493 + 28 * 32) * c->fullband_channels + c->lfe_channel * 72;
245     if (c->frame_bits < min_frame_bits || c->frame_bits > (DCA_MAX_FRAME_SIZE << 3))
246         return AVERROR(EINVAL);
247 
248     c->frame_size = (c->frame_bits + 7) / 8;
249 
250     avctx->frame_size = 32 * SUBBAND_SAMPLES;
251 
252     if ((ret = ff_mdct_init(&c->mdct, 9, 0, 1.0)) < 0)
253         return ret;
254 
255     /* Init all tables */
256     c->cos_table[0] = 0x7fffffff;
257     c->cos_table[512] = 0;
258     c->cos_table[1024] = -c->cos_table[0];
259     for (i = 1; i < 512; i++) {
260         c->cos_table[i]   = (int32_t)(0x7fffffff * cos(M_PI * i / 1024));
261         c->cos_table[1024-i] = -c->cos_table[i];
262         c->cos_table[1024+i] = -c->cos_table[i];
263         c->cos_table[2048-i] = +c->cos_table[i];
264     }
265 
266     for (i = 0; i < 2048; i++)
267         c->cb_to_level[i] = (int32_t)(0x7fffffff * ff_exp10(-0.005 * i));
268 
269     for (k = 0; k < 32; k++) {
270         for (j = 0; j < 8; j++) {
271             c->lfe_fir_64i[64 * j + k] = (int32_t)(0xffffff800000ULL * ff_dca_lfe_fir_64[8 * k + j]);
272             c->lfe_fir_64i[64 * (7-j) + (63 - k)] = (int32_t)(0xffffff800000ULL * ff_dca_lfe_fir_64[8 * k + j]);
273         }
274     }
275 
276     for (i = 0; i < 512; i++) {
277         c->band_interpolation_tab[0][i] = (int32_t)(0x1000000000ULL * ff_dca_fir_32bands_perfect[i]);
278         c->band_interpolation_tab[1][i] = (int32_t)(0x1000000000ULL * ff_dca_fir_32bands_nonperfect[i]);
279     }
280 
281     for (i = 0; i < 9; i++) {
282         for (j = 0; j < AUBANDS; j++) {
283             for (k = 0; k < 256; k++) {
284                 double freq = sample_rates[i] * (k + 0.5) / 512;
285 
286                 c->auf[i][j][k] = (int32_t)(10 * (hom(freq) + gammafilter(j, freq)));
287             }
288         }
289     }
290 
291     for (i = 0; i < 256; i++) {
292         double add = 1 + ff_exp10(-0.01 * i);
293         c->cb_to_add[i] = (int32_t)(100 * log10(add));
294     }
295     for (j = 0; j < 8; j++) {
296         double accum = 0;
297         for (i = 0; i < 512; i++) {
298             double reconst = ff_dca_fir_32bands_perfect[i] * ((i & 64) ? (-1) : 1);
299             accum += reconst * cos(2 * M_PI * (i + 0.5 - 256) * (j + 0.5) / 512);
300         }
301         c->band_spectrum_tab[0][j] = (int32_t)(200 * log10(accum));
302     }
303     for (j = 0; j < 8; j++) {
304         double accum = 0;
305         for (i = 0; i < 512; i++) {
306             double reconst = ff_dca_fir_32bands_nonperfect[i] * ((i & 64) ? (-1) : 1);
307             accum += reconst * cos(2 * M_PI * (i + 0.5 - 256) * (j + 0.5) / 512);
308         }
309         c->band_spectrum_tab[1][j] = (int32_t)(200 * log10(accum));
310     }
311 
312     return 0;
313 }
314 
encode_close(AVCodecContext *avctx)315 static av_cold int encode_close(AVCodecContext *avctx)
316 {
317     DCAEncContext *c = avctx->priv_data;
318     ff_mdct_end(&c->mdct);
319     subband_bufer_free(c);
320     ff_dcaadpcm_free(&c->adpcm_ctx);
321 
322     return 0;
323 }
324 
subband_transform(DCAEncContext *c, const int32_t *input)325 static void subband_transform(DCAEncContext *c, const int32_t *input)
326 {
327     int ch, subs, i, k, j;
328 
329     for (ch = 0; ch < c->fullband_channels; ch++) {
330         /* History is copied because it is also needed for PSY */
331         int32_t hist[512];
332         int hist_start = 0;
333         const int chi = c->channel_order_tab[ch];
334 
335         memcpy(hist, &c->history[ch][0], 512 * sizeof(int32_t));
336 
337         for (subs = 0; subs < SUBBAND_SAMPLES; subs++) {
338             int32_t accum[64];
339             int32_t resp;
340             int band;
341 
342             /* Calculate the convolutions at once */
343             memset(accum, 0, 64 * sizeof(int32_t));
344 
345             for (k = 0, i = hist_start, j = 0;
346                     i < 512; k = (k + 1) & 63, i++, j++)
347                 accum[k] += mul32(hist[i], c->band_interpolation[j]);
348             for (i = 0; i < hist_start; k = (k + 1) & 63, i++, j++)
349                 accum[k] += mul32(hist[i], c->band_interpolation[j]);
350 
351             for (k = 16; k < 32; k++)
352                 accum[k] = accum[k] - accum[31 - k];
353             for (k = 32; k < 48; k++)
354                 accum[k] = accum[k] + accum[95 - k];
355 
356             for (band = 0; band < 32; band++) {
357                 resp = 0;
358                 for (i = 16; i < 48; i++) {
359                     int s = (2 * band + 1) * (2 * (i + 16) + 1);
360                     resp += mul32(accum[i], COS_T(s << 3)) >> 3;
361                 }
362 
363                 c->subband[ch][band][subs] = ((band + 1) & 2) ? -resp : resp;
364             }
365 
366             /* Copy in 32 new samples from input */
367             for (i = 0; i < 32; i++)
368                 hist[i + hist_start] = input[(subs * 32 + i) * c->channels + chi];
369 
370             hist_start = (hist_start + 32) & 511;
371         }
372     }
373 }
374 
lfe_downsample(DCAEncContext *c, const int32_t *input)375 static void lfe_downsample(DCAEncContext *c, const int32_t *input)
376 {
377     /* FIXME: make 128x LFE downsampling possible */
378     const int lfech = lfe_index[c->channel_config];
379     int i, j, lfes;
380     int32_t hist[512];
381     int32_t accum;
382     int hist_start = 0;
383 
384     memcpy(hist, &c->history[c->channels - 1][0], 512 * sizeof(int32_t));
385 
386     for (lfes = 0; lfes < DCA_LFE_SAMPLES; lfes++) {
387         /* Calculate the convolution */
388         accum = 0;
389 
390         for (i = hist_start, j = 0; i < 512; i++, j++)
391             accum += mul32(hist[i], c->lfe_fir_64i[j]);
392         for (i = 0; i < hist_start; i++, j++)
393             accum += mul32(hist[i], c->lfe_fir_64i[j]);
394 
395         c->downsampled_lfe[lfes] = accum;
396 
397         /* Copy in 64 new samples from input */
398         for (i = 0; i < 64; i++)
399             hist[i + hist_start] = input[(lfes * 64 + i) * c->channels + lfech];
400 
401         hist_start = (hist_start + 64) & 511;
402     }
403 }
404 
get_cb(DCAEncContext *c, int32_t in)405 static int32_t get_cb(DCAEncContext *c, int32_t in)
406 {
407     int i, res = 0;
408     in = FFABS(in);
409 
410     for (i = 1024; i > 0; i >>= 1) {
411         if (c->cb_to_level[i + res] >= in)
412             res += i;
413     }
414     return -res;
415 }
416 
add_cb(DCAEncContext *c, int32_t a, int32_t b)417 static int32_t add_cb(DCAEncContext *c, int32_t a, int32_t b)
418 {
419     if (a < b)
420         FFSWAP(int32_t, a, b);
421 
422     if (a - b >= 256)
423         return a;
424     return a + c->cb_to_add[a - b];
425 }
426 
calc_power(DCAEncContext *c, const int32_t in[2 * 256], int32_t power[256])427 static void calc_power(DCAEncContext *c,
428                        const int32_t in[2 * 256], int32_t power[256])
429 {
430     int i;
431     LOCAL_ALIGNED_32(int32_t, data,  [512]);
432     LOCAL_ALIGNED_32(int32_t, coeff, [256]);
433 
434     for (i = 0; i < 512; i++)
435         data[i] = norm__(mul32(in[i], 0x3fffffff - (COS_T(4 * i + 2) >> 1)), 4);
436 
437     c->mdct.mdct_calc(&c->mdct, coeff, data);
438     for (i = 0; i < 256; i++) {
439         const int32_t cb = get_cb(c, coeff[i]);
440         power[i] = add_cb(c, cb, cb);
441     }
442 }
443 
adjust_jnd(DCAEncContext *c, const int32_t in[512], int32_t out_cb[256])444 static void adjust_jnd(DCAEncContext *c,
445                        const int32_t in[512], int32_t out_cb[256])
446 {
447     int32_t power[256];
448     int32_t out_cb_unnorm[256];
449     int32_t denom;
450     const int32_t ca_cb = -1114;
451     const int32_t cs_cb = 928;
452     const int samplerate_index = c->samplerate_index;
453     int i, j;
454 
455     calc_power(c, in, power);
456 
457     for (j = 0; j < 256; j++)
458         out_cb_unnorm[j] = -2047; /* and can only grow */
459 
460     for (i = 0; i < AUBANDS; i++) {
461         denom = ca_cb; /* and can only grow */
462         for (j = 0; j < 256; j++)
463             denom = add_cb(c, denom, power[j] + c->auf[samplerate_index][i][j]);
464         for (j = 0; j < 256; j++)
465             out_cb_unnorm[j] = add_cb(c, out_cb_unnorm[j],
466                                       -denom + c->auf[samplerate_index][i][j]);
467     }
468 
469     for (j = 0; j < 256; j++)
470         out_cb[j] = add_cb(c, out_cb[j], -out_cb_unnorm[j] - ca_cb - cs_cb);
471 }
472 
473 typedef void (*walk_band_t)(DCAEncContext *c, int band1, int band2, int f,
474                             int32_t spectrum1, int32_t spectrum2, int channel,
475                             int32_t * arg);
476 
walk_band_low(DCAEncContext *c, int band, int channel, walk_band_t walk, int32_t *arg)477 static void walk_band_low(DCAEncContext *c, int band, int channel,
478                           walk_band_t walk, int32_t *arg)
479 {
480     int f;
481 
482     if (band == 0) {
483         for (f = 0; f < 4; f++)
484             walk(c, 0, 0, f, 0, -2047, channel, arg);
485     } else {
486         for (f = 0; f < 8; f++)
487             walk(c, band, band - 1, 8 * band - 4 + f,
488                     c->band_spectrum[7 - f], c->band_spectrum[f], channel, arg);
489     }
490 }
491 
walk_band_high(DCAEncContext *c, int band, int channel, walk_band_t walk, int32_t *arg)492 static void walk_band_high(DCAEncContext *c, int band, int channel,
493                            walk_band_t walk, int32_t *arg)
494 {
495     int f;
496 
497     if (band == 31) {
498         for (f = 0; f < 4; f++)
499             walk(c, 31, 31, 256 - 4 + f, 0, -2047, channel, arg);
500     } else {
501         for (f = 0; f < 8; f++)
502             walk(c, band, band + 1, 8 * band + 4 + f,
503                     c->band_spectrum[f], c->band_spectrum[7 - f], channel, arg);
504     }
505 }
506 
update_band_masking(DCAEncContext *c, int band1, int band2, int f, int32_t spectrum1, int32_t spectrum2, int channel, int32_t * arg)507 static void update_band_masking(DCAEncContext *c, int band1, int band2,
508                                 int f, int32_t spectrum1, int32_t spectrum2,
509                                 int channel, int32_t * arg)
510 {
511     int32_t value = c->eff_masking_curve_cb[f] - spectrum1;
512 
513     if (value < c->band_masking_cb[band1])
514         c->band_masking_cb[band1] = value;
515 }
516 
calc_masking(DCAEncContext *c, const int32_t *input)517 static void calc_masking(DCAEncContext *c, const int32_t *input)
518 {
519     int i, k, band, ch, ssf;
520     int32_t data[512];
521 
522     for (i = 0; i < 256; i++)
523         for (ssf = 0; ssf < SUBSUBFRAMES; ssf++)
524             c->masking_curve_cb[ssf][i] = -2047;
525 
526     for (ssf = 0; ssf < SUBSUBFRAMES; ssf++)
527         for (ch = 0; ch < c->fullband_channels; ch++) {
528             const int chi = c->channel_order_tab[ch];
529 
530             for (i = 0, k = 128 + 256 * ssf; k < 512; i++, k++)
531                 data[i] = c->history[ch][k];
532             for (k -= 512; i < 512; i++, k++)
533                 data[i] = input[k * c->channels + chi];
534             adjust_jnd(c, data, c->masking_curve_cb[ssf]);
535         }
536     for (i = 0; i < 256; i++) {
537         int32_t m = 2048;
538 
539         for (ssf = 0; ssf < SUBSUBFRAMES; ssf++)
540             if (c->masking_curve_cb[ssf][i] < m)
541                 m = c->masking_curve_cb[ssf][i];
542         c->eff_masking_curve_cb[i] = m;
543     }
544 
545     for (band = 0; band < 32; band++) {
546         c->band_masking_cb[band] = 2048;
547         walk_band_low(c, band, 0, update_band_masking, NULL);
548         walk_band_high(c, band, 0, update_band_masking, NULL);
549     }
550 }
551 
find_peak(DCAEncContext *c, const int32_t *in, int len)552 static inline int32_t find_peak(DCAEncContext *c, const int32_t *in, int len)
553 {
554     int sample;
555     int32_t m = 0;
556     for (sample = 0; sample < len; sample++) {
557         int32_t s = abs(in[sample]);
558         if (m < s)
559             m = s;
560     }
561     return get_cb(c, m);
562 }
563 
find_peaks(DCAEncContext *c)564 static void find_peaks(DCAEncContext *c)
565 {
566     int band, ch;
567 
568     for (ch = 0; ch < c->fullband_channels; ch++) {
569         for (band = 0; band < 32; band++)
570             c->peak_cb[ch][band] = find_peak(c, c->subband[ch][band],
571                                              SUBBAND_SAMPLES);
572     }
573 
574     if (c->lfe_channel)
575         c->lfe_peak_cb = find_peak(c, c->downsampled_lfe, DCA_LFE_SAMPLES);
576 }
577 
adpcm_analysis(DCAEncContext *c)578 static void adpcm_analysis(DCAEncContext *c)
579 {
580     int ch, band;
581     int pred_vq_id;
582     int32_t *samples;
583     int32_t estimated_diff[SUBBAND_SAMPLES];
584 
585     c->consumed_adpcm_bits = 0;
586     for (ch = 0; ch < c->fullband_channels; ch++) {
587         for (band = 0; band < 32; band++) {
588             samples = c->subband[ch][band] - DCA_ADPCM_COEFFS;
589             pred_vq_id = ff_dcaadpcm_subband_analysis(&c->adpcm_ctx, samples,
590                                                       SUBBAND_SAMPLES, estimated_diff);
591             if (pred_vq_id >= 0) {
592                 c->prediction_mode[ch][band] = pred_vq_id;
593                 c->consumed_adpcm_bits += 12; //12 bits to transmit prediction vq index
594                 c->diff_peak_cb[ch][band] = find_peak(c, estimated_diff, 16);
595             } else {
596                 c->prediction_mode[ch][band] = -1;
597             }
598         }
599     }
600 }
601 
602 static const int snr_fudge = 128;
603 #define USED_1ABITS 1
604 #define USED_26ABITS 4
605 
get_step_size(DCAEncContext *c, int ch, int band)606 static inline int32_t get_step_size(DCAEncContext *c, int ch, int band)
607 {
608     int32_t step_size;
609 
610     if (c->bitrate_index == 3)
611         step_size = ff_dca_lossless_quant[c->abits[ch][band]];
612     else
613         step_size = ff_dca_lossy_quant[c->abits[ch][band]];
614 
615     return step_size;
616 }
617 
calc_one_scale(DCAEncContext *c, int32_t peak_cb, int abits, softfloat *quant)618 static int calc_one_scale(DCAEncContext *c, int32_t peak_cb, int abits,
619                           softfloat *quant)
620 {
621     int32_t peak;
622     int our_nscale, try_remove;
623     softfloat our_quant;
624 
625     av_assert0(peak_cb <= 0);
626     av_assert0(peak_cb >= -2047);
627 
628     our_nscale = 127;
629     peak = c->cb_to_level[-peak_cb];
630 
631     for (try_remove = 64; try_remove > 0; try_remove >>= 1) {
632         if (scalefactor_inv[our_nscale - try_remove].e + stepsize_inv[abits].e <= 17)
633             continue;
634         our_quant.m = mul32(scalefactor_inv[our_nscale - try_remove].m, stepsize_inv[abits].m);
635         our_quant.e = scalefactor_inv[our_nscale - try_remove].e + stepsize_inv[abits].e - 17;
636         if ((ff_dca_quant_levels[abits] - 1) / 2 < quantize_value(peak, our_quant))
637             continue;
638         our_nscale -= try_remove;
639     }
640 
641     if (our_nscale >= 125)
642         our_nscale = 124;
643 
644     quant->m = mul32(scalefactor_inv[our_nscale].m, stepsize_inv[abits].m);
645     quant->e = scalefactor_inv[our_nscale].e + stepsize_inv[abits].e - 17;
646     av_assert0((ff_dca_quant_levels[abits] - 1) / 2 >= quantize_value(peak, *quant));
647 
648     return our_nscale;
649 }
650 
quantize_adpcm_subband(DCAEncContext *c, int ch, int band)651 static inline void quantize_adpcm_subband(DCAEncContext *c, int ch, int band)
652 {
653     int32_t step_size;
654     int32_t diff_peak_cb = c->diff_peak_cb[ch][band];
655     c->scale_factor[ch][band] = calc_one_scale(c, diff_peak_cb,
656                                                c->abits[ch][band],
657                                                &c->quant[ch][band]);
658 
659     step_size = get_step_size(c, ch, band);
660     ff_dcaadpcm_do_real(c->prediction_mode[ch][band],
661                         c->quant[ch][band],
662                         ff_dca_scale_factor_quant7[c->scale_factor[ch][band]],
663                         step_size, c->adpcm_history[ch][band], c->subband[ch][band],
664                         c->adpcm_history[ch][band] + 4, c->quantized[ch][band],
665                         SUBBAND_SAMPLES, c->cb_to_level[-diff_peak_cb]);
666 }
667 
quantize_adpcm(DCAEncContext *c)668 static void quantize_adpcm(DCAEncContext *c)
669 {
670     int band, ch;
671 
672     for (ch = 0; ch < c->fullband_channels; ch++)
673         for (band = 0; band < 32; band++)
674             if (c->prediction_mode[ch][band] >= 0)
675                 quantize_adpcm_subband(c, ch, band);
676 }
677 
quantize_pcm(DCAEncContext *c)678 static void quantize_pcm(DCAEncContext *c)
679 {
680     int sample, band, ch;
681 
682     for (ch = 0; ch < c->fullband_channels; ch++) {
683         for (band = 0; band < 32; band++) {
684             if (c->prediction_mode[ch][band] == -1) {
685                 for (sample = 0; sample < SUBBAND_SAMPLES; sample++) {
686                     int32_t val = quantize_value(c->subband[ch][band][sample],
687                                                  c->quant[ch][band]);
688                     c->quantized[ch][band][sample] = val;
689                 }
690             }
691         }
692     }
693 }
694 
accumulate_huff_bit_consumption(int abits, int32_t *quantized, uint32_t *result)695 static void accumulate_huff_bit_consumption(int abits, int32_t *quantized,
696                                             uint32_t *result)
697 {
698     uint8_t sel, id = abits - 1;
699     for (sel = 0; sel < ff_dca_quant_index_group_size[id]; sel++)
700         result[sel] += ff_dca_vlc_calc_quant_bits(quantized, SUBBAND_SAMPLES,
701                                                   sel, id);
702 }
703 
set_best_code(uint32_t vlc_bits[DCA_CODE_BOOKS][7], uint32_t clc_bits[DCA_CODE_BOOKS], int32_t res[DCA_CODE_BOOKS])704 static uint32_t set_best_code(uint32_t vlc_bits[DCA_CODE_BOOKS][7],
705                               uint32_t clc_bits[DCA_CODE_BOOKS],
706                               int32_t res[DCA_CODE_BOOKS])
707 {
708     uint8_t i, sel;
709     uint32_t best_sel_bits[DCA_CODE_BOOKS];
710     int32_t best_sel_id[DCA_CODE_BOOKS];
711     uint32_t t, bits = 0;
712 
713     for (i = 0; i < DCA_CODE_BOOKS; i++) {
714 
715         av_assert0(!((!!vlc_bits[i][0]) ^ (!!clc_bits[i])));
716         if (vlc_bits[i][0] == 0) {
717             /* do not transmit adjustment index for empty codebooks */
718             res[i] = ff_dca_quant_index_group_size[i];
719             /* and skip it */
720             continue;
721         }
722 
723         best_sel_bits[i] = vlc_bits[i][0];
724         best_sel_id[i] = 0;
725         for (sel = 0; sel < ff_dca_quant_index_group_size[i]; sel++) {
726             if (best_sel_bits[i] > vlc_bits[i][sel] && vlc_bits[i][sel]) {
727                 best_sel_bits[i] = vlc_bits[i][sel];
728                 best_sel_id[i] = sel;
729             }
730         }
731 
732         /* 2 bits to transmit scale factor adjustment index */
733         t = best_sel_bits[i] + 2;
734         if (t < clc_bits[i]) {
735             res[i] = best_sel_id[i];
736             bits += t;
737         } else {
738             res[i] = ff_dca_quant_index_group_size[i];
739             bits += clc_bits[i];
740         }
741     }
742     return bits;
743 }
744 
set_best_abits_code(int abits[DCAENC_SUBBANDS], int bands, int32_t *res)745 static uint32_t set_best_abits_code(int abits[DCAENC_SUBBANDS], int bands,
746                                     int32_t *res)
747 {
748     uint8_t i;
749     uint32_t t;
750     int32_t best_sel = 6;
751     int32_t best_bits = bands * 5;
752 
753     /* Check do we have subband which cannot be encoded by Huffman tables */
754     for (i = 0; i < bands; i++) {
755         if (abits[i] > 12 || abits[i] == 0) {
756             *res = best_sel;
757             return best_bits;
758         }
759     }
760 
761     for (i = 0; i < DCA_BITALLOC_12_COUNT; i++) {
762         t = ff_dca_vlc_calc_alloc_bits(abits, bands, i);
763         if (t < best_bits) {
764             best_bits = t;
765             best_sel = i;
766         }
767     }
768 
769     *res = best_sel;
770     return best_bits;
771 }
772 
init_quantization_noise(DCAEncContext *c, int noise, int forbid_zero)773 static int init_quantization_noise(DCAEncContext *c, int noise, int forbid_zero)
774 {
775     int ch, band, ret = USED_26ABITS | USED_1ABITS;
776     uint32_t huff_bit_count_accum[MAX_CHANNELS][DCA_CODE_BOOKS][7];
777     uint32_t clc_bit_count_accum[MAX_CHANNELS][DCA_CODE_BOOKS];
778     uint32_t bits_counter = 0;
779 
780     c->consumed_bits = 132 + 333 * c->fullband_channels;
781     c->consumed_bits += c->consumed_adpcm_bits;
782     if (c->lfe_channel)
783         c->consumed_bits += 72;
784 
785     /* attempt to guess the bit distribution based on the prevoius frame */
786     for (ch = 0; ch < c->fullband_channels; ch++) {
787         for (band = 0; band < 32; band++) {
788             int snr_cb = c->peak_cb[ch][band] - c->band_masking_cb[band] - noise;
789 
790             if (snr_cb >= 1312) {
791                 c->abits[ch][band] = 26;
792                 ret &= ~USED_1ABITS;
793             } else if (snr_cb >= 222) {
794                 c->abits[ch][band] = 8 + mul32(snr_cb - 222, 69000000);
795                 ret &= ~(USED_26ABITS | USED_1ABITS);
796             } else if (snr_cb >= 0) {
797                 c->abits[ch][band] = 2 + mul32(snr_cb, 106000000);
798                 ret &= ~(USED_26ABITS | USED_1ABITS);
799             } else if (forbid_zero || snr_cb >= -140) {
800                 c->abits[ch][band] = 1;
801                 ret &= ~USED_26ABITS;
802             } else {
803                 c->abits[ch][band] = 0;
804                 ret &= ~(USED_26ABITS | USED_1ABITS);
805             }
806         }
807         c->consumed_bits += set_best_abits_code(c->abits[ch], 32,
808                                                 &c->bit_allocation_sel[ch]);
809     }
810 
811     /* Recalc scale_factor each time to get bits consumption in case of Huffman coding.
812        It is suboptimal solution */
813     /* TODO: May be cache scaled values */
814     for (ch = 0; ch < c->fullband_channels; ch++) {
815         for (band = 0; band < 32; band++) {
816             if (c->prediction_mode[ch][band] == -1) {
817                 c->scale_factor[ch][band] = calc_one_scale(c, c->peak_cb[ch][band],
818                                                            c->abits[ch][band],
819                                                            &c->quant[ch][band]);
820             }
821         }
822     }
823     quantize_adpcm(c);
824     quantize_pcm(c);
825 
826     memset(huff_bit_count_accum, 0, MAX_CHANNELS * DCA_CODE_BOOKS * 7 * sizeof(uint32_t));
827     memset(clc_bit_count_accum, 0, MAX_CHANNELS * DCA_CODE_BOOKS * sizeof(uint32_t));
828     for (ch = 0; ch < c->fullband_channels; ch++) {
829         for (band = 0; band < 32; band++) {
830             if (c->abits[ch][band] && c->abits[ch][band] <= DCA_CODE_BOOKS) {
831                 accumulate_huff_bit_consumption(c->abits[ch][band],
832                                                 c->quantized[ch][band],
833                                                 huff_bit_count_accum[ch][c->abits[ch][band] - 1]);
834                 clc_bit_count_accum[ch][c->abits[ch][band] - 1] += bit_consumption[c->abits[ch][band]];
835             } else {
836                 bits_counter += bit_consumption[c->abits[ch][band]];
837             }
838         }
839     }
840 
841     for (ch = 0; ch < c->fullband_channels; ch++) {
842         bits_counter += set_best_code(huff_bit_count_accum[ch],
843                                       clc_bit_count_accum[ch],
844                                       c->quant_index_sel[ch]);
845     }
846 
847     c->consumed_bits += bits_counter;
848 
849     return ret;
850 }
851 
assign_bits(DCAEncContext *c)852 static void assign_bits(DCAEncContext *c)
853 {
854     /* Find the bounds where the binary search should work */
855     int low, high, down;
856     int used_abits = 0;
857     int forbid_zero = 1;
858 restart:
859     init_quantization_noise(c, c->worst_quantization_noise, forbid_zero);
860     low = high = c->worst_quantization_noise;
861     if (c->consumed_bits > c->frame_bits) {
862         while (c->consumed_bits > c->frame_bits) {
863             if (used_abits == USED_1ABITS && forbid_zero) {
864                 forbid_zero = 0;
865                 goto restart;
866             }
867             low = high;
868             high += snr_fudge;
869             used_abits = init_quantization_noise(c, high, forbid_zero);
870         }
871     } else {
872         while (c->consumed_bits <= c->frame_bits) {
873             high = low;
874             if (used_abits == USED_26ABITS)
875                 goto out; /* The requested bitrate is too high, pad with zeros */
876             low -= snr_fudge;
877             used_abits = init_quantization_noise(c, low, forbid_zero);
878         }
879     }
880 
881     /* Now do a binary search between low and high to see what fits */
882     for (down = snr_fudge >> 1; down; down >>= 1) {
883         init_quantization_noise(c, high - down, forbid_zero);
884         if (c->consumed_bits <= c->frame_bits)
885             high -= down;
886     }
887     init_quantization_noise(c, high, forbid_zero);
888 out:
889     c->worst_quantization_noise = high;
890     if (high > c->worst_noise_ever)
891         c->worst_noise_ever = high;
892 }
893 
shift_history(DCAEncContext *c, const int32_t *input)894 static void shift_history(DCAEncContext *c, const int32_t *input)
895 {
896     int k, ch;
897 
898     for (k = 0; k < 512; k++)
899         for (ch = 0; ch < c->channels; ch++) {
900             const int chi = c->channel_order_tab[ch];
901 
902             c->history[ch][k] = input[k * c->channels + chi];
903         }
904 }
905 
fill_in_adpcm_bufer(DCAEncContext *c)906 static void fill_in_adpcm_bufer(DCAEncContext *c)
907 {
908      int ch, band;
909      int32_t step_size;
910      /* We fill in ADPCM work buffer for subbands which hasn't been ADPCM coded
911       * in current frame - we need this data if subband of next frame is
912       * ADPCM
913       */
914      for (ch = 0; ch < c->channels; ch++) {
915         for (band = 0; band < 32; band++) {
916             int32_t *samples = c->subband[ch][band] - DCA_ADPCM_COEFFS;
917             if (c->prediction_mode[ch][band] == -1) {
918                 step_size = get_step_size(c, ch, band);
919 
920                 ff_dca_core_dequantize(c->adpcm_history[ch][band],
921                                        c->quantized[ch][band]+12, step_size,
922                                        ff_dca_scale_factor_quant7[c->scale_factor[ch][band]], 0, 4);
923             } else {
924                 AV_COPY128U(c->adpcm_history[ch][band], c->adpcm_history[ch][band]+4);
925             }
926             /* Copy dequantized values for LPC analysis.
927              * It reduces artifacts in case of extreme quantization,
928              * example: in current frame abits is 1 and has no prediction flag,
929              * but end of this frame is sine like signal. In this case, if LPC analysis uses
930              * original values, likely LPC analysis returns good prediction gain, and sets prediction flag.
931              * But there are no proper value in decoder history, so likely result will be no good.
932              * Bitstream has "Predictor history flag switch", but this flag disables history for all subbands
933              */
934             samples[0] = c->adpcm_history[ch][band][0] * (1 << 7);
935             samples[1] = c->adpcm_history[ch][band][1] * (1 << 7);
936             samples[2] = c->adpcm_history[ch][band][2] * (1 << 7);
937             samples[3] = c->adpcm_history[ch][band][3] * (1 << 7);
938         }
939      }
940 }
941 
calc_lfe_scales(DCAEncContext *c)942 static void calc_lfe_scales(DCAEncContext *c)
943 {
944     if (c->lfe_channel)
945         c->lfe_scale_factor = calc_one_scale(c, c->lfe_peak_cb, 11, &c->lfe_quant);
946 }
947 
put_frame_header(DCAEncContext *c)948 static void put_frame_header(DCAEncContext *c)
949 {
950     /* SYNC */
951     put_bits(&c->pb, 16, 0x7ffe);
952     put_bits(&c->pb, 16, 0x8001);
953 
954     /* Frame type: normal */
955     put_bits(&c->pb, 1, 1);
956 
957     /* Deficit sample count: none */
958     put_bits(&c->pb, 5, 31);
959 
960     /* CRC is not present */
961     put_bits(&c->pb, 1, 0);
962 
963     /* Number of PCM sample blocks */
964     put_bits(&c->pb, 7, SUBBAND_SAMPLES - 1);
965 
966     /* Primary frame byte size */
967     put_bits(&c->pb, 14, c->frame_size - 1);
968 
969     /* Audio channel arrangement */
970     put_bits(&c->pb, 6, c->channel_config);
971 
972     /* Core audio sampling frequency */
973     put_bits(&c->pb, 4, bitstream_sfreq[c->samplerate_index]);
974 
975     /* Transmission bit rate */
976     put_bits(&c->pb, 5, c->bitrate_index);
977 
978     /* Embedded down mix: disabled */
979     put_bits(&c->pb, 1, 0);
980 
981     /* Embedded dynamic range flag: not present */
982     put_bits(&c->pb, 1, 0);
983 
984     /* Embedded time stamp flag: not present */
985     put_bits(&c->pb, 1, 0);
986 
987     /* Auxiliary data flag: not present */
988     put_bits(&c->pb, 1, 0);
989 
990     /* HDCD source: no */
991     put_bits(&c->pb, 1, 0);
992 
993     /* Extension audio ID: N/A */
994     put_bits(&c->pb, 3, 0);
995 
996     /* Extended audio data: not present */
997     put_bits(&c->pb, 1, 0);
998 
999     /* Audio sync word insertion flag: after each sub-frame */
1000     put_bits(&c->pb, 1, 0);
1001 
1002     /* Low frequency effects flag: not present or 64x subsampling */
1003     put_bits(&c->pb, 2, c->lfe_channel ? 2 : 0);
1004 
1005     /* Predictor history switch flag: on */
1006     put_bits(&c->pb, 1, 1);
1007 
1008     /* No CRC */
1009     /* Multirate interpolator switch: non-perfect reconstruction */
1010     put_bits(&c->pb, 1, 0);
1011 
1012     /* Encoder software revision: 7 */
1013     put_bits(&c->pb, 4, 7);
1014 
1015     /* Copy history: 0 */
1016     put_bits(&c->pb, 2, 0);
1017 
1018     /* Source PCM resolution: 16 bits, not DTS ES */
1019     put_bits(&c->pb, 3, 0);
1020 
1021     /* Front sum/difference coding: no */
1022     put_bits(&c->pb, 1, 0);
1023 
1024     /* Surrounds sum/difference coding: no */
1025     put_bits(&c->pb, 1, 0);
1026 
1027     /* Dialog normalization: 0 dB */
1028     put_bits(&c->pb, 4, 0);
1029 }
1030 
put_primary_audio_header(DCAEncContext *c)1031 static void put_primary_audio_header(DCAEncContext *c)
1032 {
1033     int ch, i;
1034     /* Number of subframes */
1035     put_bits(&c->pb, 4, SUBFRAMES - 1);
1036 
1037     /* Number of primary audio channels */
1038     put_bits(&c->pb, 3, c->fullband_channels - 1);
1039 
1040     /* Subband activity count */
1041     for (ch = 0; ch < c->fullband_channels; ch++)
1042         put_bits(&c->pb, 5, DCAENC_SUBBANDS - 2);
1043 
1044     /* High frequency VQ start subband */
1045     for (ch = 0; ch < c->fullband_channels; ch++)
1046         put_bits(&c->pb, 5, DCAENC_SUBBANDS - 1);
1047 
1048     /* Joint intensity coding index: 0, 0 */
1049     for (ch = 0; ch < c->fullband_channels; ch++)
1050         put_bits(&c->pb, 3, 0);
1051 
1052     /* Transient mode codebook: A4, A4 (arbitrary) */
1053     for (ch = 0; ch < c->fullband_channels; ch++)
1054         put_bits(&c->pb, 2, 0);
1055 
1056     /* Scale factor code book: 7 bit linear, 7-bit sqrt table (for each channel) */
1057     for (ch = 0; ch < c->fullband_channels; ch++)
1058         put_bits(&c->pb, 3, 6);
1059 
1060     /* Bit allocation quantizer select: linear 5-bit */
1061     for (ch = 0; ch < c->fullband_channels; ch++)
1062         put_bits(&c->pb, 3, c->bit_allocation_sel[ch]);
1063 
1064     /* Quantization index codebook select */
1065     for (i = 0; i < DCA_CODE_BOOKS; i++)
1066         for (ch = 0; ch < c->fullband_channels; ch++)
1067             put_bits(&c->pb, ff_dca_quant_index_sel_nbits[i], c->quant_index_sel[ch][i]);
1068 
1069     /* Scale factor adjustment index: transmitted in case of Huffman coding */
1070     for (i = 0; i < DCA_CODE_BOOKS; i++)
1071         for (ch = 0; ch < c->fullband_channels; ch++)
1072             if (c->quant_index_sel[ch][i] < ff_dca_quant_index_group_size[i])
1073                 put_bits(&c->pb, 2, 0);
1074 
1075     /* Audio header CRC check word: not transmitted */
1076 }
1077 
put_subframe_samples(DCAEncContext *c, int ss, int band, int ch)1078 static void put_subframe_samples(DCAEncContext *c, int ss, int band, int ch)
1079 {
1080     int i, j, sum, bits, sel;
1081     if (c->abits[ch][band] <= DCA_CODE_BOOKS) {
1082         av_assert0(c->abits[ch][band] > 0);
1083         sel = c->quant_index_sel[ch][c->abits[ch][band] - 1];
1084         // Huffman codes
1085         if (sel < ff_dca_quant_index_group_size[c->abits[ch][band] - 1]) {
1086             ff_dca_vlc_enc_quant(&c->pb, &c->quantized[ch][band][ss * 8], 8,
1087                                  sel, c->abits[ch][band] - 1);
1088             return;
1089         }
1090 
1091         // Block codes
1092         if (c->abits[ch][band] <= 7) {
1093             for (i = 0; i < 8; i += 4) {
1094                 sum = 0;
1095                 for (j = 3; j >= 0; j--) {
1096                     sum *= ff_dca_quant_levels[c->abits[ch][band]];
1097                     sum += c->quantized[ch][band][ss * 8 + i + j];
1098                     sum += (ff_dca_quant_levels[c->abits[ch][band]] - 1) / 2;
1099                 }
1100                 put_bits(&c->pb, bit_consumption[c->abits[ch][band]] / 4, sum);
1101             }
1102             return;
1103         }
1104     }
1105 
1106     for (i = 0; i < 8; i++) {
1107         bits = bit_consumption[c->abits[ch][band]] / 16;
1108         put_sbits(&c->pb, bits, c->quantized[ch][band][ss * 8 + i]);
1109     }
1110 }
1111 
put_subframe(DCAEncContext *c, int subframe)1112 static void put_subframe(DCAEncContext *c, int subframe)
1113 {
1114     int i, band, ss, ch;
1115 
1116     /* Subsubframes count */
1117     put_bits(&c->pb, 2, SUBSUBFRAMES -1);
1118 
1119     /* Partial subsubframe sample count: dummy */
1120     put_bits(&c->pb, 3, 0);
1121 
1122     /* Prediction mode: no ADPCM, in each channel and subband */
1123     for (ch = 0; ch < c->fullband_channels; ch++)
1124         for (band = 0; band < DCAENC_SUBBANDS; band++)
1125             put_bits(&c->pb, 1, !(c->prediction_mode[ch][band] == -1));
1126 
1127     /* Prediction VQ address */
1128     for (ch = 0; ch < c->fullband_channels; ch++)
1129         for (band = 0; band < DCAENC_SUBBANDS; band++)
1130             if (c->prediction_mode[ch][band] >= 0)
1131                 put_bits(&c->pb, 12, c->prediction_mode[ch][band]);
1132 
1133     /* Bit allocation index */
1134     for (ch = 0; ch < c->fullband_channels; ch++) {
1135         if (c->bit_allocation_sel[ch] == 6) {
1136             for (band = 0; band < DCAENC_SUBBANDS; band++) {
1137                 put_bits(&c->pb, 5, c->abits[ch][band]);
1138             }
1139         } else {
1140             ff_dca_vlc_enc_alloc(&c->pb, c->abits[ch], DCAENC_SUBBANDS,
1141                                  c->bit_allocation_sel[ch]);
1142         }
1143     }
1144 
1145     if (SUBSUBFRAMES > 1) {
1146         /* Transition mode: none for each channel and subband */
1147         for (ch = 0; ch < c->fullband_channels; ch++)
1148             for (band = 0; band < DCAENC_SUBBANDS; band++)
1149                 if (c->abits[ch][band])
1150                     put_bits(&c->pb, 1, 0); /* codebook A4 */
1151     }
1152 
1153     /* Scale factors */
1154     for (ch = 0; ch < c->fullband_channels; ch++)
1155         for (band = 0; band < DCAENC_SUBBANDS; band++)
1156             if (c->abits[ch][band])
1157                 put_bits(&c->pb, 7, c->scale_factor[ch][band]);
1158 
1159     /* Joint subband scale factor codebook select: not transmitted */
1160     /* Scale factors for joint subband coding: not transmitted */
1161     /* Stereo down-mix coefficients: not transmitted */
1162     /* Dynamic range coefficient: not transmitted */
1163     /* Stde information CRC check word: not transmitted */
1164     /* VQ encoded high frequency subbands: not transmitted */
1165 
1166     /* LFE data: 8 samples and scalefactor */
1167     if (c->lfe_channel) {
1168         for (i = 0; i < DCA_LFE_SAMPLES; i++)
1169             put_bits(&c->pb, 8, quantize_value(c->downsampled_lfe[i], c->lfe_quant) & 0xff);
1170         put_bits(&c->pb, 8, c->lfe_scale_factor);
1171     }
1172 
1173     /* Audio data (subsubframes) */
1174     for (ss = 0; ss < SUBSUBFRAMES ; ss++)
1175         for (ch = 0; ch < c->fullband_channels; ch++)
1176             for (band = 0; band < DCAENC_SUBBANDS; band++)
1177                 if (c->abits[ch][band])
1178                     put_subframe_samples(c, ss, band, ch);
1179 
1180     /* DSYNC */
1181     put_bits(&c->pb, 16, 0xffff);
1182 }
1183 
encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)1184 static int encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
1185                         const AVFrame *frame, int *got_packet_ptr)
1186 {
1187     DCAEncContext *c = avctx->priv_data;
1188     const int32_t *samples;
1189     int ret, i;
1190 
1191     if ((ret = ff_get_encode_buffer(avctx, avpkt, c->frame_size, 0)) < 0)
1192         return ret;
1193 
1194     samples = (const int32_t *)frame->data[0];
1195 
1196     subband_transform(c, samples);
1197     if (c->lfe_channel)
1198         lfe_downsample(c, samples);
1199 
1200     calc_masking(c, samples);
1201     if (c->options.adpcm_mode)
1202         adpcm_analysis(c);
1203     find_peaks(c);
1204     assign_bits(c);
1205     calc_lfe_scales(c);
1206     shift_history(c, samples);
1207 
1208     init_put_bits(&c->pb, avpkt->data, avpkt->size);
1209     fill_in_adpcm_bufer(c);
1210     put_frame_header(c);
1211     put_primary_audio_header(c);
1212     for (i = 0; i < SUBFRAMES; i++)
1213         put_subframe(c, i);
1214 
1215     flush_put_bits(&c->pb);
1216     memset(put_bits_ptr(&c->pb), 0, put_bytes_left(&c->pb, 0));
1217 
1218     avpkt->pts      = frame->pts;
1219     avpkt->duration = ff_samples_to_time_base(avctx, frame->nb_samples);
1220     *got_packet_ptr = 1;
1221     return 0;
1222 }
1223 
1224 #define DCAENC_FLAGS AV_OPT_FLAG_ENCODING_PARAM | AV_OPT_FLAG_AUDIO_PARAM
1225 
1226 static const AVOption options[] = {
1227     { "dca_adpcm", "Use ADPCM encoding", offsetof(DCAEncContext, options.adpcm_mode), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DCAENC_FLAGS },
1228     { NULL },
1229 };
1230 
1231 static const AVClass dcaenc_class = {
1232     .class_name = "DCA (DTS Coherent Acoustics)",
1233     .item_name = av_default_item_name,
1234     .option = options,
1235     .version = LIBAVUTIL_VERSION_INT,
1236 };
1237 
1238 static const FFCodecDefault defaults[] = {
1239     { "b",          "1411200" },
1240     { NULL },
1241 };
1242 
1243 const FFCodec ff_dca_encoder = {
1244     .p.name                = "dca",
1245     .p.long_name           = NULL_IF_CONFIG_SMALL("DCA (DTS Coherent Acoustics)"),
1246     .p.type                = AVMEDIA_TYPE_AUDIO,
1247     .p.id                  = AV_CODEC_ID_DTS,
1248     .p.capabilities        = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_EXPERIMENTAL,
1249     .priv_data_size        = sizeof(DCAEncContext),
1250     .init                  = encode_init,
1251     .close                 = encode_close,
1252     FF_CODEC_ENCODE_CB(encode_frame),
1253     .caps_internal         = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1254     .p.sample_fmts         = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32,
1255                                                             AV_SAMPLE_FMT_NONE },
1256     .p.supported_samplerates = sample_rates,
1257 #if FF_API_OLD_CHANNEL_LAYOUT
1258     .p.channel_layouts     = (const uint64_t[]) { AV_CH_LAYOUT_MONO,
1259                                                   AV_CH_LAYOUT_STEREO,
1260                                                   AV_CH_LAYOUT_2_2,
1261                                                   AV_CH_LAYOUT_5POINT0,
1262                                                   AV_CH_LAYOUT_5POINT1,
1263                                                   0 },
1264 #endif
1265     .p.ch_layouts     = (const AVChannelLayout[]){
1266         AV_CHANNEL_LAYOUT_MONO,
1267         AV_CHANNEL_LAYOUT_STEREO,
1268         AV_CHANNEL_LAYOUT_2_2,
1269         AV_CHANNEL_LAYOUT_5POINT0,
1270         AV_CHANNEL_LAYOUT_5POINT1,
1271         { 0 },
1272     },
1273     .defaults              = defaults,
1274     .p.priv_class          = &dcaenc_class,
1275 };
1276