Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / ra144enc.c
1 /*
2 * Real Audio 1.0 (14.4K) encoder
3 * Copyright (c) 2010 Francesco Lavra <francescolavra@interfree.it>
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 * Real Audio 1.0 (14.4K) encoder
25 * @author Francesco Lavra <francescolavra@interfree.it>
26 */
27
28 #include <float.h>
29
30 #include "avcodec.h"
31 #include "audio_frame_queue.h"
32 #include "celp_filters.h"
33 #include "internal.h"
34 #include "mathops.h"
35 #include "put_bits.h"
36 #include "ra144.h"
37
38 static av_cold int ra144_encode_close(AVCodecContext *avctx)
39 {
40 RA144Context *ractx = avctx->priv_data;
41 ff_lpc_end(&ractx->lpc_ctx);
42 ff_af_queue_close(&ractx->afq);
43 return 0;
44 }
45
46
47 static av_cold int ra144_encode_init(AVCodecContext * avctx)
48 {
49 RA144Context *ractx;
50 int ret;
51
52 if (avctx->channels != 1) {
53 av_log(avctx, AV_LOG_ERROR, "invalid number of channels: %d\n",
54 avctx->channels);
55 return -1;
56 }
57 avctx->frame_size = NBLOCKS * BLOCKSIZE;
58 avctx->initial_padding = avctx->frame_size;
59 avctx->bit_rate = 8000;
60 ractx = avctx->priv_data;
61 ractx->lpc_coef[0] = ractx->lpc_tables[0];
62 ractx->lpc_coef[1] = ractx->lpc_tables[1];
63 ractx->avctx = avctx;
64 ff_audiodsp_init(&ractx->adsp);
65 ret = ff_lpc_init(&ractx->lpc_ctx, avctx->frame_size, LPC_ORDER,
66 FF_LPC_TYPE_LEVINSON);
67 if (ret < 0)
68 goto error;
69
70 ff_af_queue_init(avctx, &ractx->afq);
71
72 return 0;
73 error:
74 ra144_encode_close(avctx);
75 return ret;
76 }
77
78
79 /**
80 * Quantize a value by searching a sorted table for the element with the
81 * nearest value
82 *
83 * @param value value to quantize
84 * @param table array containing the quantization table
85 * @param size size of the quantization table
86 * @return index of the quantization table corresponding to the element with the
87 * nearest value
88 */
89 static int quantize(int value, const int16_t *table, unsigned int size)
90 {
91 unsigned int low = 0, high = size - 1;
92
93 while (1) {
94 int index = (low + high) >> 1;
95 int error = table[index] - value;
96
97 if (index == low)
98 return table[high] + error > value ? low : high;
99 if (error > 0) {
100 high = index;
101 } else {
102 low = index;
103 }
104 }
105 }
106
107
108 /**
109 * Orthogonalize a vector to another vector
110 *
111 * @param v vector to orthogonalize
112 * @param u vector against which orthogonalization is performed
113 */
114 static void orthogonalize(float *v, const float *u)
115 {
116 int i;
117 float num = 0, den = 0;
118
119 for (i = 0; i < BLOCKSIZE; i++) {
120 num += v[i] * u[i];
121 den += u[i] * u[i];
122 }
123 num /= den;
124 for (i = 0; i < BLOCKSIZE; i++)
125 v[i] -= num * u[i];
126 }
127
128
129 /**
130 * Calculate match score and gain of an LPC-filtered vector with respect to
131 * input data, possibly othogonalizing it to up to 2 other vectors
132 *
133 * @param work array used to calculate the filtered vector
134 * @param coefs coefficients of the LPC filter
135 * @param vect original vector
136 * @param ortho1 first vector against which orthogonalization is performed
137 * @param ortho2 second vector against which orthogonalization is performed
138 * @param data input data
139 * @param score pointer to variable where match score is returned
140 * @param gain pointer to variable where gain is returned
141 */
142 static void get_match_score(float *work, const float *coefs, float *vect,
143 const float *ortho1, const float *ortho2,
144 const float *data, float *score, float *gain)
145 {
146 float c, g;
147 int i;
148
149 ff_celp_lp_synthesis_filterf(work, coefs, vect, BLOCKSIZE, LPC_ORDER);
150 if (ortho1)
151 orthogonalize(work, ortho1);
152 if (ortho2)
153 orthogonalize(work, ortho2);
154 c = g = 0;
155 for (i = 0; i < BLOCKSIZE; i++) {
156 g += work[i] * work[i];
157 c += data[i] * work[i];
158 }
159 if (c <= 0) {
160 *score = 0;
161 return;
162 }
163 *gain = c / g;
164 *score = *gain * c;
165 }
166
167
168 /**
169 * Create a vector from the adaptive codebook at a given lag value
170 *
171 * @param vect array where vector is stored
172 * @param cb adaptive codebook
173 * @param lag lag value
174 */
175 static void create_adapt_vect(float *vect, const int16_t *cb, int lag)
176 {
177 int i;
178
179 cb += BUFFERSIZE - lag;
180 for (i = 0; i < FFMIN(BLOCKSIZE, lag); i++)
181 vect[i] = cb[i];
182 if (lag < BLOCKSIZE)
183 for (i = 0; i < BLOCKSIZE - lag; i++)
184 vect[lag + i] = cb[i];
185 }
186
187
188 /**
189 * Search the adaptive codebook for the best entry and gain and remove its
190 * contribution from input data
191 *
192 * @param adapt_cb array from which the adaptive codebook is extracted
193 * @param work array used to calculate LPC-filtered vectors
194 * @param coefs coefficients of the LPC filter
195 * @param data input data
196 * @return index of the best entry of the adaptive codebook
197 */
198 static int adaptive_cb_search(const int16_t *adapt_cb, float *work,
199 const float *coefs, float *data)
200 {
201 int i, av_uninit(best_vect);
202 float score, gain, best_score, av_uninit(best_gain);
203 float exc[BLOCKSIZE];
204
205 gain = best_score = 0;
206 for (i = BLOCKSIZE / 2; i <= BUFFERSIZE; i++) {
207 create_adapt_vect(exc, adapt_cb, i);
208 get_match_score(work, coefs, exc, NULL, NULL, data, &score, &gain);
209 if (score > best_score) {
210 best_score = score;
211 best_vect = i;
212 best_gain = gain;
213 }
214 }
215 if (!best_score)
216 return 0;
217
218 /**
219 * Re-calculate the filtered vector from the vector with maximum match score
220 * and remove its contribution from input data.
221 */
222 create_adapt_vect(exc, adapt_cb, best_vect);
223 ff_celp_lp_synthesis_filterf(work, coefs, exc, BLOCKSIZE, LPC_ORDER);
224 for (i = 0; i < BLOCKSIZE; i++)
225 data[i] -= best_gain * work[i];
226 return best_vect - BLOCKSIZE / 2 + 1;
227 }
228
229
230 /**
231 * Find the best vector of a fixed codebook by applying an LPC filter to
232 * codebook entries, possibly othogonalizing them to up to 2 other vectors and
233 * matching the results with input data
234 *
235 * @param work array used to calculate the filtered vectors
236 * @param coefs coefficients of the LPC filter
237 * @param cb fixed codebook
238 * @param ortho1 first vector against which orthogonalization is performed
239 * @param ortho2 second vector against which orthogonalization is performed
240 * @param data input data
241 * @param idx pointer to variable where the index of the best codebook entry is
242 * returned
243 * @param gain pointer to variable where the gain of the best codebook entry is
244 * returned
245 */
246 static void find_best_vect(float *work, const float *coefs,
247 const int8_t cb[][BLOCKSIZE], const float *ortho1,
248 const float *ortho2, float *data, int *idx,
249 float *gain)
250 {
251 int i, j;
252 float g, score, best_score;
253 float vect[BLOCKSIZE];
254
255 *idx = *gain = best_score = 0;
256 for (i = 0; i < FIXED_CB_SIZE; i++) {
257 for (j = 0; j < BLOCKSIZE; j++)
258 vect[j] = cb[i][j];
259 get_match_score(work, coefs, vect, ortho1, ortho2, data, &score, &g);
260 if (score > best_score) {
261 best_score = score;
262 *idx = i;
263 *gain = g;
264 }
265 }
266 }
267
268
269 /**
270 * Search the two fixed codebooks for the best entry and gain
271 *
272 * @param work array used to calculate LPC-filtered vectors
273 * @param coefs coefficients of the LPC filter
274 * @param data input data
275 * @param cba_idx index of the best entry of the adaptive codebook
276 * @param cb1_idx pointer to variable where the index of the best entry of the
277 * first fixed codebook is returned
278 * @param cb2_idx pointer to variable where the index of the best entry of the
279 * second fixed codebook is returned
280 */
281 static void fixed_cb_search(float *work, const float *coefs, float *data,
282 int cba_idx, int *cb1_idx, int *cb2_idx)
283 {
284 int i, ortho_cb1;
285 float gain;
286 float cba_vect[BLOCKSIZE], cb1_vect[BLOCKSIZE];
287 float vect[BLOCKSIZE];
288
289 /**
290 * The filtered vector from the adaptive codebook can be retrieved from
291 * work, because this function is called just after adaptive_cb_search().
292 */
293 if (cba_idx)
294 memcpy(cba_vect, work, sizeof(cba_vect));
295
296 find_best_vect(work, coefs, ff_cb1_vects, cba_idx ? cba_vect : NULL, NULL,
297 data, cb1_idx, &gain);
298
299 /**
300 * Re-calculate the filtered vector from the vector with maximum match score
301 * and remove its contribution from input data.
302 */
303 if (gain) {
304 for (i = 0; i < BLOCKSIZE; i++)
305 vect[i] = ff_cb1_vects[*cb1_idx][i];
306 ff_celp_lp_synthesis_filterf(work, coefs, vect, BLOCKSIZE, LPC_ORDER);
307 if (cba_idx)
308 orthogonalize(work, cba_vect);
309 for (i = 0; i < BLOCKSIZE; i++)
310 data[i] -= gain * work[i];
311 memcpy(cb1_vect, work, sizeof(cb1_vect));
312 ortho_cb1 = 1;
313 } else
314 ortho_cb1 = 0;
315
316 find_best_vect(work, coefs, ff_cb2_vects, cba_idx ? cba_vect : NULL,
317 ortho_cb1 ? cb1_vect : NULL, data, cb2_idx, &gain);
318 }
319
320
321 /**
322 * Encode a subblock of the current frame
323 *
324 * @param ractx encoder context
325 * @param sblock_data input data of the subblock
326 * @param lpc_coefs coefficients of the LPC filter
327 * @param rms RMS of the reflection coefficients
328 * @param pb pointer to PutBitContext of the current frame
329 */
330 static void ra144_encode_subblock(RA144Context *ractx,
331 const int16_t *sblock_data,
332 const int16_t *lpc_coefs, unsigned int rms,
333 PutBitContext *pb)
334 {
335 float data[BLOCKSIZE] = { 0 }, work[LPC_ORDER + BLOCKSIZE];
336 float coefs[LPC_ORDER];
337 float zero[BLOCKSIZE], cba[BLOCKSIZE], cb1[BLOCKSIZE], cb2[BLOCKSIZE];
338 int cba_idx, cb1_idx, cb2_idx, gain;
339 int i, n;
340 unsigned m[3];
341 float g[3];
342 float error, best_error;
343
344 for (i = 0; i < LPC_ORDER; i++) {
345 work[i] = ractx->curr_sblock[BLOCKSIZE + i];
346 coefs[i] = lpc_coefs[i] * (1/4096.0);
347 }
348
349 /**
350 * Calculate the zero-input response of the LPC filter and subtract it from
351 * input data.
352 */
353 ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, data, BLOCKSIZE,
354 LPC_ORDER);
355 for (i = 0; i < BLOCKSIZE; i++) {
356 zero[i] = work[LPC_ORDER + i];
357 data[i] = sblock_data[i] - zero[i];
358 }
359
360 /**
361 * Codebook search is performed without taking into account the contribution
362 * of the previous subblock, since it has been just subtracted from input
363 * data.
364 */
365 memset(work, 0, LPC_ORDER * sizeof(*work));
366
367 cba_idx = adaptive_cb_search(ractx->adapt_cb, work + LPC_ORDER, coefs,
368 data);
369 if (cba_idx) {
370 /**
371 * The filtered vector from the adaptive codebook can be retrieved from
372 * work, see implementation of adaptive_cb_search().
373 */
374 memcpy(cba, work + LPC_ORDER, sizeof(cba));
375
376 ff_copy_and_dup(ractx->buffer_a, ractx->adapt_cb, cba_idx + BLOCKSIZE / 2 - 1);
377 m[0] = (ff_irms(&ractx->adsp, ractx->buffer_a) * rms) >> 12;
378 }
379 fixed_cb_search(work + LPC_ORDER, coefs, data, cba_idx, &cb1_idx, &cb2_idx);
380 for (i = 0; i < BLOCKSIZE; i++) {
381 cb1[i] = ff_cb1_vects[cb1_idx][i];
382 cb2[i] = ff_cb2_vects[cb2_idx][i];
383 }
384 ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, cb1, BLOCKSIZE,
385 LPC_ORDER);
386 memcpy(cb1, work + LPC_ORDER, sizeof(cb1));
387 m[1] = (ff_cb1_base[cb1_idx] * rms) >> 8;
388 ff_celp_lp_synthesis_filterf(work + LPC_ORDER, coefs, cb2, BLOCKSIZE,
389 LPC_ORDER);
390 memcpy(cb2, work + LPC_ORDER, sizeof(cb2));
391 m[2] = (ff_cb2_base[cb2_idx] * rms) >> 8;
392 best_error = FLT_MAX;
393 gain = 0;
394 for (n = 0; n < 256; n++) {
395 g[1] = ((ff_gain_val_tab[n][1] * m[1]) >> ff_gain_exp_tab[n]) *
396 (1/4096.0);
397 g[2] = ((ff_gain_val_tab[n][2] * m[2]) >> ff_gain_exp_tab[n]) *
398 (1/4096.0);
399 error = 0;
400 if (cba_idx) {
401 g[0] = ((ff_gain_val_tab[n][0] * m[0]) >> ff_gain_exp_tab[n]) *
402 (1/4096.0);
403 for (i = 0; i < BLOCKSIZE; i++) {
404 data[i] = zero[i] + g[0] * cba[i] + g[1] * cb1[i] +
405 g[2] * cb2[i];
406 error += (data[i] - sblock_data[i]) *
407 (data[i] - sblock_data[i]);
408 }
409 } else {
410 for (i = 0; i < BLOCKSIZE; i++) {
411 data[i] = zero[i] + g[1] * cb1[i] + g[2] * cb2[i];
412 error += (data[i] - sblock_data[i]) *
413 (data[i] - sblock_data[i]);
414 }
415 }
416 if (error < best_error) {
417 best_error = error;
418 gain = n;
419 }
420 }
421 put_bits(pb, 7, cba_idx);
422 put_bits(pb, 8, gain);
423 put_bits(pb, 7, cb1_idx);
424 put_bits(pb, 7, cb2_idx);
425 ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, rms,
426 gain);
427 }
428
429
430 static int ra144_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
431 const AVFrame *frame, int *got_packet_ptr)
432 {
433 static const uint8_t sizes[LPC_ORDER] = {64, 32, 32, 16, 16, 8, 8, 8, 8, 4};
434 static const uint8_t bit_sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
435 RA144Context *ractx = avctx->priv_data;
436 PutBitContext pb;
437 int32_t lpc_data[NBLOCKS * BLOCKSIZE];
438 int32_t lpc_coefs[LPC_ORDER][MAX_LPC_ORDER];
439 int shift[LPC_ORDER];
440 int16_t block_coefs[NBLOCKS][LPC_ORDER];
441 int lpc_refl[LPC_ORDER]; /**< reflection coefficients of the frame */
442 unsigned int refl_rms[NBLOCKS]; /**< RMS of the reflection coefficients */
443 const int16_t *samples = frame ? (const int16_t *)frame->data[0] : NULL;
444 int energy = 0;
445 int i, idx, ret;
446
447 if (ractx->last_frame)
448 return 0;
449
450 if ((ret = ff_alloc_packet2(avctx, avpkt, FRAME_SIZE)) < 0)
451 return ret;
452
453 /**
454 * Since the LPC coefficients are calculated on a frame centered over the
455 * fourth subframe, to encode a given frame, data from the next frame is
456 * needed. In each call to this function, the previous frame (whose data are
457 * saved in the encoder context) is encoded, and data from the current frame
458 * are saved in the encoder context to be used in the next function call.
459 */
460 for (i = 0; i < (2 * BLOCKSIZE + BLOCKSIZE / 2); i++) {
461 lpc_data[i] = ractx->curr_block[BLOCKSIZE + BLOCKSIZE / 2 + i];
462 energy += (lpc_data[i] * lpc_data[i]) >> 4;
463 }
464 if (frame) {
465 int j;
466 for (j = 0; j < frame->nb_samples && i < NBLOCKS * BLOCKSIZE; i++, j++) {
467 lpc_data[i] = samples[j] >> 2;
468 energy += (lpc_data[i] * lpc_data[i]) >> 4;
469 }
470 }
471 if (i < NBLOCKS * BLOCKSIZE)
472 memset(&lpc_data[i], 0, (NBLOCKS * BLOCKSIZE - i) * sizeof(*lpc_data));
473 energy = ff_energy_tab[quantize(ff_t_sqrt(energy >> 5) >> 10, ff_energy_tab,
474 32)];
475
476 ff_lpc_calc_coefs(&ractx->lpc_ctx, lpc_data, NBLOCKS * BLOCKSIZE, LPC_ORDER,
477 LPC_ORDER, 16, lpc_coefs, shift, FF_LPC_TYPE_LEVINSON,
478 0, ORDER_METHOD_EST, 12, 0);
479 for (i = 0; i < LPC_ORDER; i++)
480 block_coefs[NBLOCKS - 1][i] = -(lpc_coefs[LPC_ORDER - 1][i] <<
481 (12 - shift[LPC_ORDER - 1]));
482
483 /**
484 * TODO: apply perceptual weighting of the input speech through bandwidth
485 * expansion of the LPC filter.
486 */
487
488 if (ff_eval_refl(lpc_refl, block_coefs[NBLOCKS - 1], avctx)) {
489 /**
490 * The filter is unstable: use the coefficients of the previous frame.
491 */
492 ff_int_to_int16(block_coefs[NBLOCKS - 1], ractx->lpc_coef[1]);
493 if (ff_eval_refl(lpc_refl, block_coefs[NBLOCKS - 1], avctx)) {
494 /* the filter is still unstable. set reflection coeffs to zero. */
495 memset(lpc_refl, 0, sizeof(lpc_refl));
496 }
497 }
498 init_put_bits(&pb, avpkt->data, avpkt->size);
499 for (i = 0; i < LPC_ORDER; i++) {
500 idx = quantize(lpc_refl[i], ff_lpc_refl_cb[i], sizes[i]);
501 put_bits(&pb, bit_sizes[i], idx);
502 lpc_refl[i] = ff_lpc_refl_cb[i][idx];
503 }
504 ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
505 ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
506 refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
507 refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
508 energy <= ractx->old_energy,
509 ff_t_sqrt(energy * ractx->old_energy) >> 12);
510 refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
511 refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
512 ff_int_to_int16(block_coefs[NBLOCKS - 1], ractx->lpc_coef[0]);
513 put_bits(&pb, 5, quantize(energy, ff_energy_tab, 32));
514 for (i = 0; i < NBLOCKS; i++)
515 ra144_encode_subblock(ractx, ractx->curr_block + i * BLOCKSIZE,
516 block_coefs[i], refl_rms[i], &pb);
517 flush_put_bits(&pb);
518 ractx->old_energy = energy;
519 ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
520 FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
521
522 /* copy input samples to current block for processing in next call */
523 i = 0;
524 if (frame) {
525 for (; i < frame->nb_samples; i++)
526 ractx->curr_block[i] = samples[i] >> 2;
527
528 if ((ret = ff_af_queue_add(&ractx->afq, frame)) < 0)
529 return ret;
530 } else
531 ractx->last_frame = 1;
532 memset(&ractx->curr_block[i], 0,
533 (NBLOCKS * BLOCKSIZE - i) * sizeof(*ractx->curr_block));
534
535 /* Get the next frame pts/duration */
536 ff_af_queue_remove(&ractx->afq, avctx->frame_size, &avpkt->pts,
537 &avpkt->duration);
538
539 avpkt->size = FRAME_SIZE;
540 *got_packet_ptr = 1;
541 return 0;
542 }
543
544
545 AVCodec ff_ra_144_encoder = {
546 .name = "real_144",
547 .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
548 .type = AVMEDIA_TYPE_AUDIO,
549 .id = AV_CODEC_ID_RA_144,
550 .priv_data_size = sizeof(RA144Context),
551 .init = ra144_encode_init,
552 .encode2 = ra144_encode_frame,
553 .close = ra144_encode_close,
554 .capabilities = CODEC_CAP_DELAY | CODEC_CAP_SMALL_LAST_FRAME,
555 .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
556 AV_SAMPLE_FMT_NONE },
557 .supported_samplerates = (const int[]){ 8000, 0 },
558 .channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
559 };