1 /*
2 * TwinVQ decoder
3 * Copyright (c) 2009 Vitor Sessak
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 #include <math.h>
23 #include <stdint.h>
24
25 #include "libavutil/channel_layout.h"
26 #include "libavutil/float_dsp.h"
27 #include "avcodec.h"
28 #include "fft.h"
29 #include "internal.h"
30 #include "lsp.h"
31 #include "sinewin.h"
32 #include "twinvq.h"
33
34 /**
35 * Evaluate a single LPC amplitude spectrum envelope coefficient from the line
36 * spectrum pairs.
37 *
38 * @param lsp a vector of the cosine of the LSP values
39 * @param cos_val cos(PI*i/N) where i is the index of the LPC amplitude
40 * @param order the order of the LSP (and the size of the *lsp buffer). Must
41 * be a multiple of four.
42 * @return the LPC value
43 *
44 * @todo reuse code from Vorbis decoder: vorbis_floor0_decode
45 */
eval_lpc_spectrum(const float *lsp, float cos_val, int order)46 static float eval_lpc_spectrum(const float *lsp, float cos_val, int order)
47 {
48 int j;
49 float p = 0.5f;
50 float q = 0.5f;
51 float two_cos_w = 2.0f * cos_val;
52
53 for (j = 0; j + 1 < order; j += 2 * 2) {
54 // Unroll the loop once since order is a multiple of four
55 q *= lsp[j] - two_cos_w;
56 p *= lsp[j + 1] - two_cos_w;
57
58 q *= lsp[j + 2] - two_cos_w;
59 p *= lsp[j + 3] - two_cos_w;
60 }
61
62 p *= p * (2.0f - two_cos_w);
63 q *= q * (2.0f + two_cos_w);
64
65 return 0.5 / (p + q);
66 }
67
68 /**
69 * Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
70 */
eval_lpcenv(TwinVQContext *tctx, const float *cos_vals, float *lpc)71 static void eval_lpcenv(TwinVQContext *tctx, const float *cos_vals, float *lpc)
72 {
73 int i;
74 const TwinVQModeTab *mtab = tctx->mtab;
75 int size_s = mtab->size / mtab->fmode[TWINVQ_FT_SHORT].sub;
76
77 for (i = 0; i < size_s / 2; i++) {
78 float cos_i = tctx->cos_tabs[0][i];
79 lpc[i] = eval_lpc_spectrum(cos_vals, cos_i, mtab->n_lsp);
80 lpc[size_s - i - 1] = eval_lpc_spectrum(cos_vals, -cos_i, mtab->n_lsp);
81 }
82 }
83
interpolate(float *out, float v1, float v2, int size)84 static void interpolate(float *out, float v1, float v2, int size)
85 {
86 int i;
87 float step = (v1 - v2) / (size + 1);
88
89 for (i = 0; i < size; i++) {
90 v2 += step;
91 out[i] = v2;
92 }
93 }
94
get_cos(int idx, int part, const float *cos_tab, int size)95 static inline float get_cos(int idx, int part, const float *cos_tab, int size)
96 {
97 return part ? -cos_tab[size - idx - 1]
98 : cos_tab[idx];
99 }
100
101 /**
102 * Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
103 * Probably for speed reasons, the coefficients are evaluated as
104 * siiiibiiiisiiiibiiiisiiiibiiiisiiiibiiiis ...
105 * where s is an evaluated value, i is a value interpolated from the others
106 * and b might be either calculated or interpolated, depending on an
107 * unexplained condition.
108 *
109 * @param step the size of a block "siiiibiiii"
110 * @param in the cosine of the LSP data
111 * @param part is 0 for 0...PI (positive cosine values) and 1 for PI...2PI
112 * (negative cosine values)
113 * @param size the size of the whole output
114 */
eval_lpcenv_or_interp(TwinVQContext *tctx, enum TwinVQFrameType ftype, float *out, const float *in, int size, int step, int part)115 static inline void eval_lpcenv_or_interp(TwinVQContext *tctx,
116 enum TwinVQFrameType ftype,
117 float *out, const float *in,
118 int size, int step, int part)
119 {
120 int i;
121 const TwinVQModeTab *mtab = tctx->mtab;
122 const float *cos_tab = tctx->cos_tabs[ftype];
123
124 // Fill the 's'
125 for (i = 0; i < size; i += step)
126 out[i] =
127 eval_lpc_spectrum(in,
128 get_cos(i, part, cos_tab, size),
129 mtab->n_lsp);
130
131 // Fill the 'iiiibiiii'
132 for (i = step; i <= size - 2 * step; i += step) {
133 if (out[i + step] + out[i - step] > 1.95 * out[i] ||
134 out[i + step] >= out[i - step]) {
135 interpolate(out + i - step + 1, out[i], out[i - step], step - 1);
136 } else {
137 out[i - step / 2] =
138 eval_lpc_spectrum(in,
139 get_cos(i - step / 2, part, cos_tab, size),
140 mtab->n_lsp);
141 interpolate(out + i - step + 1, out[i - step / 2],
142 out[i - step], step / 2 - 1);
143 interpolate(out + i - step / 2 + 1, out[i],
144 out[i - step / 2], step / 2 - 1);
145 }
146 }
147
148 interpolate(out + size - 2 * step + 1, out[size - step],
149 out[size - 2 * step], step - 1);
150 }
151
eval_lpcenv_2parts(TwinVQContext *tctx, enum TwinVQFrameType ftype, const float *buf, float *lpc, int size, int step)152 static void eval_lpcenv_2parts(TwinVQContext *tctx, enum TwinVQFrameType ftype,
153 const float *buf, float *lpc,
154 int size, int step)
155 {
156 eval_lpcenv_or_interp(tctx, ftype, lpc, buf, size / 2, step, 0);
157 eval_lpcenv_or_interp(tctx, ftype, lpc + size / 2, buf, size / 2,
158 2 * step, 1);
159
160 interpolate(lpc + size / 2 - step + 1, lpc[size / 2],
161 lpc[size / 2 - step], step);
162
163 twinvq_memset_float(lpc + size - 2 * step + 1, lpc[size - 2 * step],
164 2 * step - 1);
165 }
166
167 /**
168 * Inverse quantization. Read CB coefficients for cb1 and cb2 from the
169 * bitstream, sum the corresponding vectors and write the result to *out
170 * after permutation.
171 */
dequant(TwinVQContext *tctx, const uint8_t *cb_bits, float *out, enum TwinVQFrameType ftype, const int16_t *cb0, const int16_t *cb1, int cb_len)172 static void dequant(TwinVQContext *tctx, const uint8_t *cb_bits, float *out,
173 enum TwinVQFrameType ftype,
174 const int16_t *cb0, const int16_t *cb1, int cb_len)
175 {
176 int pos = 0;
177 int i, j;
178
179 for (i = 0; i < tctx->n_div[ftype]; i++) {
180 int tmp0, tmp1;
181 int sign0 = 1;
182 int sign1 = 1;
183 const int16_t *tab0, *tab1;
184 int length = tctx->length[ftype][i >= tctx->length_change[ftype]];
185 int bitstream_second_part = (i >= tctx->bits_main_spec_change[ftype]);
186
187 int bits = tctx->bits_main_spec[0][ftype][bitstream_second_part];
188 tmp0 = *cb_bits++;
189 if (bits == 7) {
190 if (tmp0 & 0x40)
191 sign0 = -1;
192 tmp0 &= 0x3F;
193 }
194
195 bits = tctx->bits_main_spec[1][ftype][bitstream_second_part];
196 tmp1 = *cb_bits++;
197 if (bits == 7) {
198 if (tmp1 & 0x40)
199 sign1 = -1;
200 tmp1 &= 0x3F;
201 }
202
203 tab0 = cb0 + tmp0 * cb_len;
204 tab1 = cb1 + tmp1 * cb_len;
205
206 for (j = 0; j < length; j++)
207 out[tctx->permut[ftype][pos + j]] = sign0 * tab0[j] +
208 sign1 * tab1[j];
209
210 pos += length;
211 }
212 }
213
dec_gain(TwinVQContext *tctx, enum TwinVQFrameType ftype, float *out)214 static void dec_gain(TwinVQContext *tctx,
215 enum TwinVQFrameType ftype, float *out)
216 {
217 const TwinVQModeTab *mtab = tctx->mtab;
218 const TwinVQFrameData *bits = &tctx->bits[tctx->cur_frame];
219 int i, j;
220 int channels = tctx->avctx->ch_layout.nb_channels;
221 int sub = mtab->fmode[ftype].sub;
222 float step = TWINVQ_AMP_MAX / ((1 << TWINVQ_GAIN_BITS) - 1);
223 float sub_step = TWINVQ_SUB_AMP_MAX / ((1 << TWINVQ_SUB_GAIN_BITS) - 1);
224
225 if (ftype == TWINVQ_FT_LONG) {
226 for (i = 0; i < channels; i++)
227 out[i] = (1.0 / (1 << 13)) *
228 twinvq_mulawinv(step * 0.5 + step * bits->gain_bits[i],
229 TWINVQ_AMP_MAX, TWINVQ_MULAW_MU);
230 } else {
231 for (i = 0; i < channels; i++) {
232 float val = (1.0 / (1 << 23)) *
233 twinvq_mulawinv(step * 0.5 + step * bits->gain_bits[i],
234 TWINVQ_AMP_MAX, TWINVQ_MULAW_MU);
235
236 for (j = 0; j < sub; j++)
237 out[i * sub + j] =
238 val * twinvq_mulawinv(sub_step * 0.5 +
239 sub_step * bits->sub_gain_bits[i * sub + j],
240 TWINVQ_SUB_AMP_MAX, TWINVQ_MULAW_MU);
241 }
242 }
243 }
244
245 /**
246 * Rearrange the LSP coefficients so that they have a minimum distance of
247 * min_dist. This function does it exactly as described in section of 3.2.4
248 * of the G.729 specification (but interestingly is different from what the
249 * reference decoder actually does).
250 */
rearrange_lsp(int order, float *lsp, float min_dist)251 static void rearrange_lsp(int order, float *lsp, float min_dist)
252 {
253 int i;
254 float min_dist2 = min_dist * 0.5;
255 for (i = 1; i < order; i++)
256 if (lsp[i] - lsp[i - 1] < min_dist) {
257 float avg = (lsp[i] + lsp[i - 1]) * 0.5;
258
259 lsp[i - 1] = avg - min_dist2;
260 lsp[i] = avg + min_dist2;
261 }
262 }
263
decode_lsp(TwinVQContext *tctx, int lpc_idx1, uint8_t *lpc_idx2, int lpc_hist_idx, float *lsp, float *hist)264 static void decode_lsp(TwinVQContext *tctx, int lpc_idx1, uint8_t *lpc_idx2,
265 int lpc_hist_idx, float *lsp, float *hist)
266 {
267 const TwinVQModeTab *mtab = tctx->mtab;
268 int i, j;
269
270 const float *cb = mtab->lspcodebook;
271 const float *cb2 = cb + (1 << mtab->lsp_bit1) * mtab->n_lsp;
272 const float *cb3 = cb2 + (1 << mtab->lsp_bit2) * mtab->n_lsp;
273
274 const int8_t funny_rounding[4] = {
275 -2,
276 mtab->lsp_split == 4 ? -2 : 1,
277 mtab->lsp_split == 4 ? -2 : 1,
278 0
279 };
280
281 j = 0;
282 for (i = 0; i < mtab->lsp_split; i++) {
283 int chunk_end = ((i + 1) * mtab->n_lsp + funny_rounding[i]) /
284 mtab->lsp_split;
285 for (; j < chunk_end; j++)
286 lsp[j] = cb[lpc_idx1 * mtab->n_lsp + j] +
287 cb2[lpc_idx2[i] * mtab->n_lsp + j];
288 }
289
290 rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
291
292 for (i = 0; i < mtab->n_lsp; i++) {
293 float tmp1 = 1.0 - cb3[lpc_hist_idx * mtab->n_lsp + i];
294 float tmp2 = hist[i] * cb3[lpc_hist_idx * mtab->n_lsp + i];
295 hist[i] = lsp[i];
296 lsp[i] = lsp[i] * tmp1 + tmp2;
297 }
298
299 rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
300 rearrange_lsp(mtab->n_lsp, lsp, 0.000095);
301 ff_sort_nearly_sorted_floats(lsp, mtab->n_lsp);
302 }
303
dec_lpc_spectrum_inv(TwinVQContext *tctx, float *lsp, enum TwinVQFrameType ftype, float *lpc)304 static void dec_lpc_spectrum_inv(TwinVQContext *tctx, float *lsp,
305 enum TwinVQFrameType ftype, float *lpc)
306 {
307 int i;
308 int size = tctx->mtab->size / tctx->mtab->fmode[ftype].sub;
309
310 for (i = 0; i < tctx->mtab->n_lsp; i++)
311 lsp[i] = 2 * cos(lsp[i]);
312
313 switch (ftype) {
314 case TWINVQ_FT_LONG:
315 eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 8);
316 break;
317 case TWINVQ_FT_MEDIUM:
318 eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 2);
319 break;
320 case TWINVQ_FT_SHORT:
321 eval_lpcenv(tctx, lsp, lpc);
322 break;
323 }
324 }
325
326 static const uint8_t wtype_to_wsize[] = { 0, 0, 2, 2, 2, 1, 0, 1, 1 };
327
imdct_and_window(TwinVQContext *tctx, enum TwinVQFrameType ftype, int wtype, float *in, float *prev, int ch)328 static void imdct_and_window(TwinVQContext *tctx, enum TwinVQFrameType ftype,
329 int wtype, float *in, float *prev, int ch)
330 {
331 FFTContext *mdct = &tctx->mdct_ctx[ftype];
332 const TwinVQModeTab *mtab = tctx->mtab;
333 int bsize = mtab->size / mtab->fmode[ftype].sub;
334 int size = mtab->size;
335 float *buf1 = tctx->tmp_buf;
336 int j, first_wsize, wsize; // Window size
337 float *out = tctx->curr_frame + 2 * ch * mtab->size;
338 float *out2 = out;
339 float *prev_buf;
340 int types_sizes[] = {
341 mtab->size / mtab->fmode[TWINVQ_FT_LONG].sub,
342 mtab->size / mtab->fmode[TWINVQ_FT_MEDIUM].sub,
343 mtab->size / (mtab->fmode[TWINVQ_FT_SHORT].sub * 2),
344 };
345
346 wsize = types_sizes[wtype_to_wsize[wtype]];
347 first_wsize = wsize;
348 prev_buf = prev + (size - bsize) / 2;
349
350 for (j = 0; j < mtab->fmode[ftype].sub; j++) {
351 int sub_wtype = ftype == TWINVQ_FT_MEDIUM ? 8 : wtype;
352
353 if (!j && wtype == 4)
354 sub_wtype = 4;
355 else if (j == mtab->fmode[ftype].sub - 1 && wtype == 7)
356 sub_wtype = 7;
357
358 wsize = types_sizes[wtype_to_wsize[sub_wtype]];
359
360 mdct->imdct_half(mdct, buf1 + bsize * j, in + bsize * j);
361
362 tctx->fdsp->vector_fmul_window(out2, prev_buf + (bsize - wsize) / 2,
363 buf1 + bsize * j,
364 ff_sine_windows[av_log2(wsize)],
365 wsize / 2);
366 out2 += wsize;
367
368 memcpy(out2, buf1 + bsize * j + wsize / 2,
369 (bsize - wsize / 2) * sizeof(float));
370
371 out2 += ftype == TWINVQ_FT_MEDIUM ? (bsize - wsize) / 2 : bsize - wsize;
372
373 prev_buf = buf1 + bsize * j + bsize / 2;
374 }
375
376 tctx->last_block_pos[ch] = (size + first_wsize) / 2;
377 }
378
imdct_output(TwinVQContext *tctx, enum TwinVQFrameType ftype, int wtype, float **out, int offset)379 static void imdct_output(TwinVQContext *tctx, enum TwinVQFrameType ftype,
380 int wtype, float **out, int offset)
381 {
382 const TwinVQModeTab *mtab = tctx->mtab;
383 float *prev_buf = tctx->prev_frame + tctx->last_block_pos[0];
384 int channels = tctx->avctx->ch_layout.nb_channels;
385 int size1, size2, i;
386 float *out1, *out2;
387
388 for (i = 0; i < channels; i++)
389 imdct_and_window(tctx, ftype, wtype,
390 tctx->spectrum + i * mtab->size,
391 prev_buf + 2 * i * mtab->size,
392 i);
393
394 if (!out)
395 return;
396
397 size2 = tctx->last_block_pos[0];
398 size1 = mtab->size - size2;
399
400 out1 = &out[0][0] + offset;
401 memcpy(out1, prev_buf, size1 * sizeof(*out1));
402 memcpy(out1 + size1, tctx->curr_frame, size2 * sizeof(*out1));
403
404 if (channels == 2) {
405 out2 = &out[1][0] + offset;
406 memcpy(out2, &prev_buf[2 * mtab->size],
407 size1 * sizeof(*out2));
408 memcpy(out2 + size1, &tctx->curr_frame[2 * mtab->size],
409 size2 * sizeof(*out2));
410 tctx->fdsp->butterflies_float(out1, out2, mtab->size);
411 }
412 }
413
read_and_decode_spectrum(TwinVQContext *tctx, float *out, enum TwinVQFrameType ftype)414 static void read_and_decode_spectrum(TwinVQContext *tctx, float *out,
415 enum TwinVQFrameType ftype)
416 {
417 const TwinVQModeTab *mtab = tctx->mtab;
418 TwinVQFrameData *bits = &tctx->bits[tctx->cur_frame];
419 int channels = tctx->avctx->ch_layout.nb_channels;
420 int sub = mtab->fmode[ftype].sub;
421 int block_size = mtab->size / sub;
422 float gain[TWINVQ_CHANNELS_MAX * TWINVQ_SUBBLOCKS_MAX];
423 float ppc_shape[TWINVQ_PPC_SHAPE_LEN_MAX * TWINVQ_CHANNELS_MAX * 4];
424
425 int i, j;
426
427 dequant(tctx, bits->main_coeffs, out, ftype,
428 mtab->fmode[ftype].cb0, mtab->fmode[ftype].cb1,
429 mtab->fmode[ftype].cb_len_read);
430
431 dec_gain(tctx, ftype, gain);
432
433 if (ftype == TWINVQ_FT_LONG) {
434 int cb_len_p = (tctx->n_div[3] + mtab->ppc_shape_len * channels - 1) /
435 tctx->n_div[3];
436 dequant(tctx, bits->ppc_coeffs, ppc_shape,
437 TWINVQ_FT_PPC, mtab->ppc_shape_cb,
438 mtab->ppc_shape_cb + cb_len_p * TWINVQ_PPC_SHAPE_CB_SIZE,
439 cb_len_p);
440 }
441
442 for (i = 0; i < channels; i++) {
443 float *chunk = out + mtab->size * i;
444 float lsp[TWINVQ_LSP_COEFS_MAX];
445
446 for (j = 0; j < sub; j++) {
447 tctx->dec_bark_env(tctx, bits->bark1[i][j],
448 bits->bark_use_hist[i][j], i,
449 tctx->tmp_buf, gain[sub * i + j], ftype);
450
451 tctx->fdsp->vector_fmul(chunk + block_size * j,
452 chunk + block_size * j,
453 tctx->tmp_buf, block_size);
454 }
455
456 if (ftype == TWINVQ_FT_LONG)
457 tctx->decode_ppc(tctx, bits->p_coef[i], bits->g_coef[i],
458 ppc_shape + i * mtab->ppc_shape_len, chunk);
459
460 decode_lsp(tctx, bits->lpc_idx1[i], bits->lpc_idx2[i],
461 bits->lpc_hist_idx[i], lsp, tctx->lsp_hist[i]);
462
463 dec_lpc_spectrum_inv(tctx, lsp, ftype, tctx->tmp_buf);
464
465 for (j = 0; j < mtab->fmode[ftype].sub; j++) {
466 tctx->fdsp->vector_fmul(chunk, chunk, tctx->tmp_buf, block_size);
467 chunk += block_size;
468 }
469 }
470 }
471
472 const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[] = {
473 TWINVQ_FT_LONG, TWINVQ_FT_LONG, TWINVQ_FT_SHORT, TWINVQ_FT_LONG,
474 TWINVQ_FT_MEDIUM, TWINVQ_FT_LONG, TWINVQ_FT_LONG, TWINVQ_FT_MEDIUM,
475 TWINVQ_FT_MEDIUM
476 };
477
ff_twinvq_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)478 int ff_twinvq_decode_frame(AVCodecContext *avctx, AVFrame *frame,
479 int *got_frame_ptr, AVPacket *avpkt)
480 {
481 const uint8_t *buf = avpkt->data;
482 int buf_size = avpkt->size;
483 TwinVQContext *tctx = avctx->priv_data;
484 const TwinVQModeTab *mtab = tctx->mtab;
485 float **out = NULL;
486 int ret;
487
488 /* get output buffer */
489 if (tctx->discarded_packets >= 2) {
490 frame->nb_samples = mtab->size * tctx->frames_per_packet;
491 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
492 return ret;
493 out = (float **)frame->extended_data;
494 }
495
496 if (buf_size < avctx->block_align) {
497 av_log(avctx, AV_LOG_ERROR,
498 "Frame too small (%d bytes). Truncated file?\n", buf_size);
499 return AVERROR(EINVAL);
500 }
501
502 if ((ret = tctx->read_bitstream(avctx, tctx, buf, buf_size)) < 0)
503 return ret;
504
505 for (tctx->cur_frame = 0; tctx->cur_frame < tctx->frames_per_packet;
506 tctx->cur_frame++) {
507 read_and_decode_spectrum(tctx, tctx->spectrum,
508 tctx->bits[tctx->cur_frame].ftype);
509
510 imdct_output(tctx, tctx->bits[tctx->cur_frame].ftype,
511 tctx->bits[tctx->cur_frame].window_type, out,
512 tctx->cur_frame * mtab->size);
513
514 FFSWAP(float *, tctx->curr_frame, tctx->prev_frame);
515 }
516
517 if (tctx->discarded_packets < 2) {
518 tctx->discarded_packets++;
519 *got_frame_ptr = 0;
520 return buf_size;
521 }
522
523 *got_frame_ptr = 1;
524
525 // VQF can deliver packets 1 byte greater than block align
526 if (buf_size == avctx->block_align + 1)
527 return buf_size;
528 return avctx->block_align;
529 }
530
531 /**
532 * Init IMDCT and windowing tables
533 */
init_mdct_win(TwinVQContext *tctx)534 static av_cold int init_mdct_win(TwinVQContext *tctx)
535 {
536 int i, j, ret;
537 const TwinVQModeTab *mtab = tctx->mtab;
538 int size_s = mtab->size / mtab->fmode[TWINVQ_FT_SHORT].sub;
539 int size_m = mtab->size / mtab->fmode[TWINVQ_FT_MEDIUM].sub;
540 int channels = tctx->avctx->ch_layout.nb_channels;
541 float norm = channels == 1 ? 2.0 : 1.0;
542 int table_size = 2 * mtab->size * channels;
543
544 for (i = 0; i < 3; i++) {
545 int bsize = tctx->mtab->size / tctx->mtab->fmode[i].sub;
546 if ((ret = ff_mdct_init(&tctx->mdct_ctx[i], av_log2(bsize) + 1, 1,
547 -sqrt(norm / bsize) / (1 << 15))))
548 return ret;
549 }
550
551 if (!FF_ALLOC_TYPED_ARRAY(tctx->tmp_buf, mtab->size) ||
552 !FF_ALLOC_TYPED_ARRAY(tctx->spectrum, table_size) ||
553 !FF_ALLOC_TYPED_ARRAY(tctx->curr_frame, table_size) ||
554 !FF_ALLOC_TYPED_ARRAY(tctx->prev_frame, table_size))
555 return AVERROR(ENOMEM);
556
557 for (i = 0; i < 3; i++) {
558 int m = 4 * mtab->size / mtab->fmode[i].sub;
559 double freq = 2 * M_PI / m;
560 if (!FF_ALLOC_TYPED_ARRAY(tctx->cos_tabs[i], m / 4))
561 return AVERROR(ENOMEM);
562 for (j = 0; j <= m / 8; j++)
563 tctx->cos_tabs[i][j] = cos((2 * j + 1) * freq);
564 for (j = 1; j < m / 8; j++)
565 tctx->cos_tabs[i][m / 4 - j] = tctx->cos_tabs[i][j];
566 }
567
568 ff_init_ff_sine_windows(av_log2(size_m));
569 ff_init_ff_sine_windows(av_log2(size_s / 2));
570 ff_init_ff_sine_windows(av_log2(mtab->size));
571
572 return 0;
573 }
574
575 /**
576 * Interpret the data as if it were a num_blocks x line_len[0] matrix and for
577 * each line do a cyclic permutation, i.e.
578 * abcdefghijklm -> defghijklmabc
579 * where the amount to be shifted is evaluated depending on the column.
580 */
permutate_in_line(int16_t *tab, int num_vect, int num_blocks, int block_size, const uint8_t line_len[2], int length_div, enum TwinVQFrameType ftype)581 static void permutate_in_line(int16_t *tab, int num_vect, int num_blocks,
582 int block_size,
583 const uint8_t line_len[2], int length_div,
584 enum TwinVQFrameType ftype)
585 {
586 int i, j;
587
588 for (i = 0; i < line_len[0]; i++) {
589 int shift;
590
591 if (num_blocks == 1 ||
592 (ftype == TWINVQ_FT_LONG && num_vect % num_blocks) ||
593 (ftype != TWINVQ_FT_LONG && num_vect & 1) ||
594 i == line_len[1]) {
595 shift = 0;
596 } else if (ftype == TWINVQ_FT_LONG) {
597 shift = i;
598 } else
599 shift = i * i;
600
601 for (j = 0; j < num_vect && (j + num_vect * i < block_size * num_blocks); j++)
602 tab[i * num_vect + j] = i * num_vect + (j + shift) % num_vect;
603 }
604 }
605
606 /**
607 * Interpret the input data as in the following table:
608 *
609 * @verbatim
610 *
611 * abcdefgh
612 * ijklmnop
613 * qrstuvw
614 * x123456
615 *
616 * @endverbatim
617 *
618 * and transpose it, giving the output
619 * aiqxbjr1cks2dlt3emu4fvn5gow6hp
620 */
transpose_perm(int16_t *out, int16_t *in, int num_vect, const uint8_t line_len[2], int length_div)621 static void transpose_perm(int16_t *out, int16_t *in, int num_vect,
622 const uint8_t line_len[2], int length_div)
623 {
624 int i, j;
625 int cont = 0;
626
627 for (i = 0; i < num_vect; i++)
628 for (j = 0; j < line_len[i >= length_div]; j++)
629 out[cont++] = in[j * num_vect + i];
630 }
631
linear_perm(int16_t *out, int16_t *in, int n_blocks, int size)632 static void linear_perm(int16_t *out, int16_t *in, int n_blocks, int size)
633 {
634 int block_size = size / n_blocks;
635 int i;
636
637 for (i = 0; i < size; i++)
638 out[i] = block_size * (in[i] % n_blocks) + in[i] / n_blocks;
639 }
640
construct_perm_table(TwinVQContext *tctx, enum TwinVQFrameType ftype)641 static av_cold void construct_perm_table(TwinVQContext *tctx,
642 enum TwinVQFrameType ftype)
643 {
644 int block_size, size;
645 const TwinVQModeTab *mtab = tctx->mtab;
646 int16_t *tmp_perm = (int16_t *)tctx->tmp_buf;
647
648 if (ftype == TWINVQ_FT_PPC) {
649 size = tctx->avctx->ch_layout.nb_channels;
650 block_size = mtab->ppc_shape_len;
651 } else {
652 size = tctx->avctx->ch_layout.nb_channels * mtab->fmode[ftype].sub;
653 block_size = mtab->size / mtab->fmode[ftype].sub;
654 }
655
656 permutate_in_line(tmp_perm, tctx->n_div[ftype], size,
657 block_size, tctx->length[ftype],
658 tctx->length_change[ftype], ftype);
659
660 transpose_perm(tctx->permut[ftype], tmp_perm, tctx->n_div[ftype],
661 tctx->length[ftype], tctx->length_change[ftype]);
662
663 linear_perm(tctx->permut[ftype], tctx->permut[ftype], size,
664 size * block_size);
665 }
666
init_bitstream_params(TwinVQContext *tctx)667 static av_cold void init_bitstream_params(TwinVQContext *tctx)
668 {
669 const TwinVQModeTab *mtab = tctx->mtab;
670 int n_ch = tctx->avctx->ch_layout.nb_channels;
671 int total_fr_bits = tctx->avctx->bit_rate * mtab->size /
672 tctx->avctx->sample_rate;
673
674 int lsp_bits_per_block = n_ch * (mtab->lsp_bit0 + mtab->lsp_bit1 +
675 mtab->lsp_split * mtab->lsp_bit2);
676
677 int ppc_bits = n_ch * (mtab->pgain_bit + mtab->ppc_shape_bit +
678 mtab->ppc_period_bit);
679
680 int bsize_no_main_cb[3], bse_bits[3], i;
681 enum TwinVQFrameType frametype;
682
683 for (i = 0; i < 3; i++)
684 // +1 for history usage switch
685 bse_bits[i] = n_ch *
686 (mtab->fmode[i].bark_n_coef *
687 mtab->fmode[i].bark_n_bit + 1);
688
689 bsize_no_main_cb[2] = bse_bits[2] + lsp_bits_per_block + ppc_bits +
690 TWINVQ_WINDOW_TYPE_BITS + n_ch * TWINVQ_GAIN_BITS;
691
692 for (i = 0; i < 2; i++)
693 bsize_no_main_cb[i] =
694 lsp_bits_per_block + n_ch * TWINVQ_GAIN_BITS +
695 TWINVQ_WINDOW_TYPE_BITS +
696 mtab->fmode[i].sub * (bse_bits[i] + n_ch * TWINVQ_SUB_GAIN_BITS);
697
698 if (tctx->codec == TWINVQ_CODEC_METASOUND && !tctx->is_6kbps) {
699 bsize_no_main_cb[1] += 2;
700 bsize_no_main_cb[2] += 2;
701 }
702
703 // The remaining bits are all used for the main spectrum coefficients
704 for (i = 0; i < 4; i++) {
705 int bit_size, vect_size;
706 int rounded_up, rounded_down, num_rounded_down, num_rounded_up;
707 if (i == 3) {
708 bit_size = n_ch * mtab->ppc_shape_bit;
709 vect_size = n_ch * mtab->ppc_shape_len;
710 } else {
711 bit_size = total_fr_bits - bsize_no_main_cb[i];
712 vect_size = n_ch * mtab->size;
713 }
714
715 tctx->n_div[i] = (bit_size + 13) / 14;
716
717 rounded_up = (bit_size + tctx->n_div[i] - 1) /
718 tctx->n_div[i];
719 rounded_down = (bit_size) / tctx->n_div[i];
720 num_rounded_down = rounded_up * tctx->n_div[i] - bit_size;
721 num_rounded_up = tctx->n_div[i] - num_rounded_down;
722 tctx->bits_main_spec[0][i][0] = (rounded_up + 1) / 2;
723 tctx->bits_main_spec[1][i][0] = rounded_up / 2;
724 tctx->bits_main_spec[0][i][1] = (rounded_down + 1) / 2;
725 tctx->bits_main_spec[1][i][1] = rounded_down / 2;
726 tctx->bits_main_spec_change[i] = num_rounded_up;
727
728 rounded_up = (vect_size + tctx->n_div[i] - 1) /
729 tctx->n_div[i];
730 rounded_down = (vect_size) / tctx->n_div[i];
731 num_rounded_down = rounded_up * tctx->n_div[i] - vect_size;
732 num_rounded_up = tctx->n_div[i] - num_rounded_down;
733 tctx->length[i][0] = rounded_up;
734 tctx->length[i][1] = rounded_down;
735 tctx->length_change[i] = num_rounded_up;
736 }
737
738 for (frametype = TWINVQ_FT_SHORT; frametype <= TWINVQ_FT_PPC; frametype++)
739 construct_perm_table(tctx, frametype);
740 }
741
ff_twinvq_decode_close(AVCodecContext *avctx)742 av_cold int ff_twinvq_decode_close(AVCodecContext *avctx)
743 {
744 TwinVQContext *tctx = avctx->priv_data;
745 int i;
746
747 for (i = 0; i < 3; i++) {
748 ff_mdct_end(&tctx->mdct_ctx[i]);
749 av_freep(&tctx->cos_tabs[i]);
750 }
751
752 av_freep(&tctx->curr_frame);
753 av_freep(&tctx->spectrum);
754 av_freep(&tctx->prev_frame);
755 av_freep(&tctx->tmp_buf);
756 av_freep(&tctx->fdsp);
757
758 return 0;
759 }
760
ff_twinvq_decode_init(AVCodecContext *avctx)761 av_cold int ff_twinvq_decode_init(AVCodecContext *avctx)
762 {
763 int ret;
764 TwinVQContext *tctx = avctx->priv_data;
765 int64_t frames_per_packet;
766
767 tctx->avctx = avctx;
768 avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
769
770 if (!avctx->block_align) {
771 avctx->block_align = tctx->frame_size + 7 >> 3;
772 }
773 frames_per_packet = avctx->block_align * 8LL / tctx->frame_size;
774 if (frames_per_packet <= 0) {
775 av_log(avctx, AV_LOG_ERROR, "Block align is %"PRId64" bits, expected %d\n",
776 avctx->block_align * (int64_t)8, tctx->frame_size);
777 return AVERROR_INVALIDDATA;
778 }
779 if (frames_per_packet > TWINVQ_MAX_FRAMES_PER_PACKET) {
780 av_log(avctx, AV_LOG_ERROR, "Too many frames per packet (%"PRId64")\n",
781 frames_per_packet);
782 return AVERROR_INVALIDDATA;
783 }
784 tctx->frames_per_packet = frames_per_packet;
785
786 tctx->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
787 if (!tctx->fdsp)
788 return AVERROR(ENOMEM);
789 if ((ret = init_mdct_win(tctx))) {
790 av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n");
791 return ret;
792 }
793 init_bitstream_params(tctx);
794
795 twinvq_memset_float(tctx->bark_hist[0][0], 0.1,
796 FF_ARRAY_ELEMS(tctx->bark_hist));
797
798 return 0;
799 }
800