FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
twinvq.c
Go to the documentation of this file.
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 
23 #include "libavutil/float_dsp.h"
24 #include "avcodec.h"
25 #include "get_bits.h"
26 #include "dsputil.h"
27 #include "fft.h"
28 #include "internal.h"
29 #include "lsp.h"
30 #include "sinewin.h"
31 
32 #include <math.h>
33 #include <stdint.h>
34 
35 #include "twinvq_data.h"
36 
37 enum FrameType {
38  FT_SHORT = 0, ///< Short frame (divided in n sub-blocks)
39  FT_MEDIUM, ///< Medium frame (divided in m<n sub-blocks)
40  FT_LONG, ///< Long frame (single sub-block + PPC)
41  FT_PPC, ///< Periodic Peak Component (part of the long frame)
42 };
43 
44 /**
45  * Parameters and tables that are different for each frame type
46  */
47 struct FrameMode {
48  uint8_t sub; ///< Number subblocks in each frame
49  const uint16_t *bark_tab;
50 
51  /** number of distinct bark scale envelope values */
53 
54  const int16_t *bark_cb; ///< codebook for the bark scale envelope (BSE)
55  uint8_t bark_n_coef;///< number of BSE CB coefficients to read
56  uint8_t bark_n_bit; ///< number of bits of the BSE coefs
57 
58  //@{
59  /** main codebooks for spectrum data */
60  const int16_t *cb0;
61  const int16_t *cb1;
62  //@}
63 
64  uint8_t cb_len_read; ///< number of spectrum coefficients to read
65 };
66 
67 /**
68  * Parameters and tables that are different for every combination of
69  * bitrate/sample rate
70  */
71 typedef struct {
72  struct FrameMode fmode[3]; ///< frame type-dependant parameters
73 
74  uint16_t size; ///< frame size in samples
75  uint8_t n_lsp; ///< number of lsp coefficients
76  const float *lspcodebook;
77 
78  /* number of bits of the different LSP CB coefficients */
82 
83  uint8_t lsp_split; ///< number of CB entries for the LSP decoding
84  const int16_t *ppc_shape_cb; ///< PPC shape CB
85 
86  /** number of the bits for the PPC period value */
88 
89  uint8_t ppc_shape_bit; ///< number of bits of the PPC shape CB coeffs
90  uint8_t ppc_shape_len; ///< size of PPC shape CB
91  uint8_t pgain_bit; ///< bits for PPC gain
92 
93  /** constant for peak period to peak width conversion */
94  uint16_t peak_per2wid;
95 } ModeTab;
96 
97 static const ModeTab mode_08_08 = {
98  {
99  { 8, bark_tab_s08_64, 10, tab.fcb08s , 1, 5, tab.cb0808s0, tab.cb0808s1, 18},
100  { 2, bark_tab_m08_256, 20, tab.fcb08m , 2, 5, tab.cb0808m0, tab.cb0808m1, 16},
101  { 1, bark_tab_l08_512, 30, tab.fcb08l , 3, 6, tab.cb0808l0, tab.cb0808l1, 17}
102  },
103  512 , 12, tab.lsp08, 1, 5, 3, 3, tab.shape08 , 8, 28, 20, 6, 40
104 };
105 
106 static const ModeTab mode_11_08 = {
107  {
108  { 8, bark_tab_s11_64, 10, tab.fcb11s , 1, 5, tab.cb1108s0, tab.cb1108s1, 29},
109  { 2, bark_tab_m11_256, 20, tab.fcb11m , 2, 5, tab.cb1108m0, tab.cb1108m1, 24},
110  { 1, bark_tab_l11_512, 30, tab.fcb11l , 3, 6, tab.cb1108l0, tab.cb1108l1, 27}
111  },
112  512 , 16, tab.lsp11, 1, 6, 4, 3, tab.shape11 , 9, 36, 30, 7, 90
113 };
114 
115 static const ModeTab mode_11_10 = {
116  {
117  { 8, bark_tab_s11_64, 10, tab.fcb11s , 1, 5, tab.cb1110s0, tab.cb1110s1, 21},
118  { 2, bark_tab_m11_256, 20, tab.fcb11m , 2, 5, tab.cb1110m0, tab.cb1110m1, 18},
119  { 1, bark_tab_l11_512, 30, tab.fcb11l , 3, 6, tab.cb1110l0, tab.cb1110l1, 20}
120  },
121  512 , 16, tab.lsp11, 1, 6, 4, 3, tab.shape11 , 9, 36, 30, 7, 90
122 };
123 
124 static const ModeTab mode_16_16 = {
125  {
126  { 8, bark_tab_s16_128, 10, tab.fcb16s , 1, 5, tab.cb1616s0, tab.cb1616s1, 16},
127  { 2, bark_tab_m16_512, 20, tab.fcb16m , 2, 5, tab.cb1616m0, tab.cb1616m1, 15},
128  { 1, bark_tab_l16_1024,30, tab.fcb16l , 3, 6, tab.cb1616l0, tab.cb1616l1, 16}
129  },
130  1024, 16, tab.lsp16, 1, 6, 4, 3, tab.shape16 , 9, 56, 60, 7, 180
131 };
132 
133 static const ModeTab mode_22_20 = {
134  {
135  { 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2220s0, tab.cb2220s1, 18},
136  { 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2220m0, tab.cb2220m1, 17},
137  { 1, bark_tab_l22_1024,32, tab.fcb22l_1, 4, 6, tab.cb2220l0, tab.cb2220l1, 18}
138  },
139  1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
140 };
141 
142 static const ModeTab mode_22_24 = {
143  {
144  { 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2224s0, tab.cb2224s1, 15},
145  { 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2224m0, tab.cb2224m1, 14},
146  { 1, bark_tab_l22_1024,32, tab.fcb22l_1, 4, 6, tab.cb2224l0, tab.cb2224l1, 15}
147  },
148  1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
149 };
150 
151 static const ModeTab mode_22_32 = {
152  {
153  { 4, bark_tab_s22_128, 10, tab.fcb22s_2, 1, 6, tab.cb2232s0, tab.cb2232s1, 11},
154  { 2, bark_tab_m22_256, 20, tab.fcb22m_2, 2, 6, tab.cb2232m0, tab.cb2232m1, 11},
155  { 1, bark_tab_l22_512, 32, tab.fcb22l_2, 4, 6, tab.cb2232l0, tab.cb2232l1, 12}
156  },
157  512 , 16, tab.lsp22_2, 1, 6, 4, 4, tab.shape22_2, 9, 56, 36, 7, 72
158 };
159 
160 static const ModeTab mode_44_40 = {
161  {
162  {16, bark_tab_s44_128, 10, tab.fcb44s , 1, 6, tab.cb4440s0, tab.cb4440s1, 18},
163  { 4, bark_tab_m44_512, 20, tab.fcb44m , 2, 6, tab.cb4440m0, tab.cb4440m1, 17},
164  { 1, bark_tab_l44_2048,40, tab.fcb44l , 4, 6, tab.cb4440l0, tab.cb4440l1, 17}
165  },
166  2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44 , 9, 84, 54, 7, 432
167 };
168 
169 static const ModeTab mode_44_48 = {
170  {
171  {16, bark_tab_s44_128, 10, tab.fcb44s , 1, 6, tab.cb4448s0, tab.cb4448s1, 15},
172  { 4, bark_tab_m44_512, 20, tab.fcb44m , 2, 6, tab.cb4448m0, tab.cb4448m1, 14},
173  { 1, bark_tab_l44_2048,40, tab.fcb44l , 4, 6, tab.cb4448l0, tab.cb4448l1, 14}
174  },
175  2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44 , 9, 84, 54, 7, 432
176 };
177 
178 typedef struct TwinContext {
184 
185  const ModeTab *mtab;
186 
187  // history
188  float lsp_hist[2][20]; ///< LSP coefficients of the last frame
189  float bark_hist[3][2][40]; ///< BSE coefficients of last frame
190 
191  // bitstream parameters
192  int16_t permut[4][4096];
193  uint8_t length[4][2]; ///< main codebook stride
195  uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
197  int n_div[4];
198 
199  float *spectrum;
200  float *curr_frame; ///< non-interleaved output
201  float *prev_frame; ///< non-interleaved previous frame
204 
205  float *cos_tabs[3];
206 
207  // scratch buffers
208  float *tmp_buf;
209 } TwinContext;
210 
211 #define PPC_SHAPE_CB_SIZE 64
212 #define PPC_SHAPE_LEN_MAX 60
213 #define SUB_AMP_MAX 4500.0
214 #define MULAW_MU 100.0
215 #define GAIN_BITS 8
216 #define AMP_MAX 13000.0
217 #define SUB_GAIN_BITS 5
218 #define WINDOW_TYPE_BITS 4
219 #define PGAIN_MU 200
220 #define LSP_COEFS_MAX 20
221 #define LSP_SPLIT_MAX 4
222 #define CHANNELS_MAX 2
223 #define SUBBLOCKS_MAX 16
224 #define BARK_N_COEF_MAX 4
225 
226 /** @note not speed critical, hence not optimized */
227 static void memset_float(float *buf, float val, int size)
228 {
229  while (size--)
230  *buf++ = val;
231 }
232 
233 /**
234  * Evaluate a single LPC amplitude spectrum envelope coefficient from the line
235  * spectrum pairs.
236  *
237  * @param lsp a vector of the cosinus of the LSP values
238  * @param cos_val cos(PI*i/N) where i is the index of the LPC amplitude
239  * @param order the order of the LSP (and the size of the *lsp buffer). Must
240  * be a multiple of four.
241  * @return the LPC value
242  *
243  * @todo reuse code from Vorbis decoder: vorbis_floor0_decode
244  */
245 static float eval_lpc_spectrum(const float *lsp, float cos_val, int order)
246 {
247  int j;
248  float p = 0.5f;
249  float q = 0.5f;
250  float two_cos_w = 2.0f*cos_val;
251 
252  for (j = 0; j + 1 < order; j += 2*2) {
253  // Unroll the loop once since order is a multiple of four
254  q *= lsp[j ] - two_cos_w;
255  p *= lsp[j+1] - two_cos_w;
256 
257  q *= lsp[j+2] - two_cos_w;
258  p *= lsp[j+3] - two_cos_w;
259  }
260 
261  p *= p * (2.0f - two_cos_w);
262  q *= q * (2.0f + two_cos_w);
263 
264  return 0.5 / (p + q);
265 }
266 
267 /**
268  * Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
269  */
270 static void eval_lpcenv(TwinContext *tctx, const float *cos_vals, float *lpc)
271 {
272  int i;
273  const ModeTab *mtab = tctx->mtab;
274  int size_s = mtab->size / mtab->fmode[FT_SHORT].sub;
275 
276  for (i = 0; i < size_s/2; i++) {
277  float cos_i = tctx->cos_tabs[0][i];
278  lpc[i] = eval_lpc_spectrum(cos_vals, cos_i, mtab->n_lsp);
279  lpc[size_s-i-1] = eval_lpc_spectrum(cos_vals, -cos_i, mtab->n_lsp);
280  }
281 }
282 
283 static void interpolate(float *out, float v1, float v2, int size)
284 {
285  int i;
286  float step = (v1 - v2)/(size + 1);
287 
288  for (i = 0; i < size; i++) {
289  v2 += step;
290  out[i] = v2;
291  }
292 }
293 
294 static inline float get_cos(int idx, int part, const float *cos_tab, int size)
295 {
296  return part ? -cos_tab[size - idx - 1] :
297  cos_tab[ idx ];
298 }
299 
300 /**
301  * Evaluate the LPC amplitude spectrum envelope from the line spectrum pairs.
302  * Probably for speed reasons, the coefficients are evaluated as
303  * siiiibiiiisiiiibiiiisiiiibiiiisiiiibiiiis ...
304  * where s is an evaluated value, i is a value interpolated from the others
305  * and b might be either calculated or interpolated, depending on an
306  * unexplained condition.
307  *
308  * @param step the size of a block "siiiibiiii"
309  * @param in the cosinus of the LSP data
310  * @param part is 0 for 0...PI (positive cossinus values) and 1 for PI...2PI
311  (negative cossinus values)
312  * @param size the size of the whole output
313  */
314 static inline void eval_lpcenv_or_interp(TwinContext *tctx,
315  enum FrameType ftype,
316  float *out, const float *in,
317  int size, int step, int part)
318 {
319  int i;
320  const ModeTab *mtab = tctx->mtab;
321  const float *cos_tab = tctx->cos_tabs[ftype];
322 
323  // Fill the 's'
324  for (i = 0; i < size; i += step)
325  out[i] =
327  get_cos(i, part, cos_tab, size),
328  mtab->n_lsp);
329 
330  // Fill the 'iiiibiiii'
331  for (i = step; i <= size - 2*step; i += step) {
332  if (out[i + step] + out[i - step] > 1.95*out[i] ||
333  out[i + step] >= out[i - step]) {
334  interpolate(out + i - step + 1, out[i], out[i-step], step - 1);
335  } else {
336  out[i - step/2] =
338  get_cos(i-step/2, part, cos_tab, size),
339  mtab->n_lsp);
340  interpolate(out + i - step + 1, out[i-step/2], out[i-step ], step/2 - 1);
341  interpolate(out + i - step/2 + 1, out[i ], out[i-step/2], step/2 - 1);
342  }
343  }
344 
345  interpolate(out + size - 2*step + 1, out[size-step], out[size - 2*step], step - 1);
346 }
347 
348 static void eval_lpcenv_2parts(TwinContext *tctx, enum FrameType ftype,
349  const float *buf, float *lpc,
350  int size, int step)
351 {
352  eval_lpcenv_or_interp(tctx, ftype, lpc , buf, size/2, step, 0);
353  eval_lpcenv_or_interp(tctx, ftype, lpc + size/2, buf, size/2, 2*step, 1);
354 
355  interpolate(lpc+size/2-step+1, lpc[size/2], lpc[size/2-step], step);
356 
357  memset_float(lpc + size - 2*step + 1, lpc[size - 2*step], 2*step - 1);
358 }
359 
360 /**
361  * Inverse quantization. Read CB coefficients for cb1 and cb2 from the
362  * bitstream, sum the corresponding vectors and write the result to *out
363  * after permutation.
364  */
365 static void dequant(TwinContext *tctx, GetBitContext *gb, float *out,
366  enum FrameType ftype,
367  const int16_t *cb0, const int16_t *cb1, int cb_len)
368 {
369  int pos = 0;
370  int i, j;
371 
372  for (i = 0; i < tctx->n_div[ftype]; i++) {
373  int tmp0, tmp1;
374  int sign0 = 1;
375  int sign1 = 1;
376  const int16_t *tab0, *tab1;
377  int length = tctx->length[ftype][i >= tctx->length_change[ftype]];
378  int bitstream_second_part = (i >= tctx->bits_main_spec_change[ftype]);
379 
380  int bits = tctx->bits_main_spec[0][ftype][bitstream_second_part];
381  if (bits == 7) {
382  if (get_bits1(gb))
383  sign0 = -1;
384  bits = 6;
385  }
386  tmp0 = get_bits(gb, bits);
387 
388  bits = tctx->bits_main_spec[1][ftype][bitstream_second_part];
389 
390  if (bits == 7) {
391  if (get_bits1(gb))
392  sign1 = -1;
393 
394  bits = 6;
395  }
396  tmp1 = get_bits(gb, bits);
397 
398  tab0 = cb0 + tmp0*cb_len;
399  tab1 = cb1 + tmp1*cb_len;
400 
401  for (j = 0; j < length; j++)
402  out[tctx->permut[ftype][pos+j]] = sign0*tab0[j] + sign1*tab1[j];
403 
404  pos += length;
405  }
406 
407 }
408 
409 static inline float mulawinv(float y, float clip, float mu)
410 {
411  y = av_clipf(y/clip, -1, 1);
412  return clip * FFSIGN(y) * (exp(log(1+mu) * fabs(y)) - 1) / mu;
413 }
414 
415 /**
416  * Evaluate a*b/400 rounded to the nearest integer. When, for example,
417  * a*b == 200 and the nearest integer is ill-defined, use a table to emulate
418  * the following broken float-based implementation used by the binary decoder:
419  *
420  * @code
421  * static int very_broken_op(int a, int b)
422  * {
423  * static float test; // Ugh, force gcc to do the division first...
424  *
425  * test = a/400.;
426  * return b * test + 0.5;
427  * }
428  * @endcode
429  *
430  * @note if this function is replaced by just ROUNDED_DIV(a*b,400.), the stddev
431  * between the original file (before encoding with Yamaha encoder) and the
432  * decoded output increases, which leads one to believe that the encoder expects
433  * exactly this broken calculation.
434  */
435 static int very_broken_op(int a, int b)
436 {
437  int x = a*b + 200;
438  int size;
439  const uint8_t *rtab;
440 
441  if (x%400 || b%5)
442  return x/400;
443 
444  x /= 400;
445 
446  size = tabs[b/5].size;
447  rtab = tabs[b/5].tab;
448  return x - rtab[size*av_log2(2*(x - 1)/size)+(x - 1)%size];
449 }
450 
451 /**
452  * Sum to data a periodic peak of a given period, width and shape.
453  *
454  * @param period the period of the peak divised by 400.0
455  */
456 static void add_peak(int period, int width, const float *shape,
457  float ppc_gain, float *speech, int len)
458 {
459  int i, j;
460 
461  const float *shape_end = shape + len;
462  int center;
463 
464  // First peak centered around zero
465  for (i = 0; i < width/2; i++)
466  speech[i] += ppc_gain * *shape++;
467 
468  for (i = 1; i < ROUNDED_DIV(len,width) ; i++) {
469  center = very_broken_op(period, i);
470  for (j = -width/2; j < (width+1)/2; j++)
471  speech[j+center] += ppc_gain * *shape++;
472  }
473 
474  // For the last block, be careful not to go beyond the end of the buffer
475  center = very_broken_op(period, i);
476  for (j = -width/2; j < (width + 1)/2 && shape < shape_end; j++)
477  speech[j+center] += ppc_gain * *shape++;
478 }
479 
480 static void decode_ppc(TwinContext *tctx, int period_coef, const float *shape,
481  float ppc_gain, float *speech)
482 {
483  const ModeTab *mtab = tctx->mtab;
484  int isampf = tctx->avctx->sample_rate/1000;
485  int ibps = tctx->avctx->bit_rate/(1000 * tctx->avctx->channels);
486  int min_period = ROUNDED_DIV( 40*2*mtab->size, isampf);
487  int max_period = ROUNDED_DIV(6*40*2*mtab->size, isampf);
488  int period_range = max_period - min_period;
489 
490  // This is actually the period multiplied by 400. It is just linearly coded
491  // between its maximum and minimum value.
492  int period = min_period +
493  ROUNDED_DIV(period_coef*period_range, (1 << mtab->ppc_period_bit) - 1);
494  int width;
495 
496  if (isampf == 22 && ibps == 32) {
497  // For some unknown reason, NTT decided to code this case differently...
498  width = ROUNDED_DIV((period + 800)* mtab->peak_per2wid, 400*mtab->size);
499  } else
500  width = (period )* mtab->peak_per2wid/(400*mtab->size);
501 
502  add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);
503 }
504 
505 static void dec_gain(TwinContext *tctx, GetBitContext *gb, enum FrameType ftype,
506  float *out)
507 {
508  const ModeTab *mtab = tctx->mtab;
509  int i, j;
510  int sub = mtab->fmode[ftype].sub;
511  float step = AMP_MAX / ((1 << GAIN_BITS) - 1);
512  float sub_step = SUB_AMP_MAX / ((1 << SUB_GAIN_BITS) - 1);
513 
514  if (ftype == FT_LONG) {
515  for (i = 0; i < tctx->avctx->channels; i++)
516  out[i] = (1./(1<<13)) *
517  mulawinv(step * 0.5 + step * get_bits(gb, GAIN_BITS),
518  AMP_MAX, MULAW_MU);
519  } else {
520  for (i = 0; i < tctx->avctx->channels; i++) {
521  float val = (1./(1<<23)) *
522  mulawinv(step * 0.5 + step * get_bits(gb, GAIN_BITS),
523  AMP_MAX, MULAW_MU);
524 
525  for (j = 0; j < sub; j++) {
526  out[i*sub + j] =
527  val*mulawinv(sub_step* 0.5 +
528  sub_step* get_bits(gb, SUB_GAIN_BITS),
530  }
531  }
532  }
533 }
534 
535 /**
536  * Rearrange the LSP coefficients so that they have a minimum distance of
537  * min_dist. This function does it exactly as described in section of 3.2.4
538  * of the G.729 specification (but interestingly is different from what the
539  * reference decoder actually does).
540  */
541 static void rearrange_lsp(int order, float *lsp, float min_dist)
542 {
543  int i;
544  float min_dist2 = min_dist * 0.5;
545  for (i = 1; i < order; i++)
546  if (lsp[i] - lsp[i-1] < min_dist) {
547  float avg = (lsp[i] + lsp[i-1]) * 0.5;
548 
549  lsp[i-1] = avg - min_dist2;
550  lsp[i ] = avg + min_dist2;
551  }
552 }
553 
554 static void decode_lsp(TwinContext *tctx, int lpc_idx1, uint8_t *lpc_idx2,
555  int lpc_hist_idx, float *lsp, float *hist)
556 {
557  const ModeTab *mtab = tctx->mtab;
558  int i, j;
559 
560  const float *cb = mtab->lspcodebook;
561  const float *cb2 = cb + (1 << mtab->lsp_bit1)*mtab->n_lsp;
562  const float *cb3 = cb2 + (1 << mtab->lsp_bit2)*mtab->n_lsp;
563 
564  const int8_t funny_rounding[4] = {
565  -2,
566  mtab->lsp_split == 4 ? -2 : 1,
567  mtab->lsp_split == 4 ? -2 : 1,
568  0
569  };
570 
571  j = 0;
572  for (i = 0; i < mtab->lsp_split; i++) {
573  int chunk_end = ((i + 1)*mtab->n_lsp + funny_rounding[i])/mtab->lsp_split;
574  for (; j < chunk_end; j++)
575  lsp[j] = cb [lpc_idx1 * mtab->n_lsp + j] +
576  cb2[lpc_idx2[i] * mtab->n_lsp + j];
577  }
578 
579  rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
580 
581  for (i = 0; i < mtab->n_lsp; i++) {
582  float tmp1 = 1. - cb3[lpc_hist_idx*mtab->n_lsp + i];
583  float tmp2 = hist[i] * cb3[lpc_hist_idx*mtab->n_lsp + i];
584  hist[i] = lsp[i];
585  lsp[i] = lsp[i] * tmp1 + tmp2;
586  }
587 
588  rearrange_lsp(mtab->n_lsp, lsp, 0.0001);
589  rearrange_lsp(mtab->n_lsp, lsp, 0.000095);
591 }
592 
593 static void dec_lpc_spectrum_inv(TwinContext *tctx, float *lsp,
594  enum FrameType ftype, float *lpc)
595 {
596  int i;
597  int size = tctx->mtab->size / tctx->mtab->fmode[ftype].sub;
598 
599  for (i = 0; i < tctx->mtab->n_lsp; i++)
600  lsp[i] = 2*cos(lsp[i]);
601 
602  switch (ftype) {
603  case FT_LONG:
604  eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 8);
605  break;
606  case FT_MEDIUM:
607  eval_lpcenv_2parts(tctx, ftype, lsp, lpc, size, 2);
608  break;
609  case FT_SHORT:
610  eval_lpcenv(tctx, lsp, lpc);
611  break;
612  }
613 }
614 
615 static void imdct_and_window(TwinContext *tctx, enum FrameType ftype, int wtype,
616  float *in, float *prev, int ch)
617 {
618  FFTContext *mdct = &tctx->mdct_ctx[ftype];
619  const ModeTab *mtab = tctx->mtab;
620  int bsize = mtab->size / mtab->fmode[ftype].sub;
621  int size = mtab->size;
622  float *buf1 = tctx->tmp_buf;
623  int j;
624  int wsize; // Window size
625  float *out = tctx->curr_frame + 2*ch*mtab->size;
626  float *out2 = out;
627  float *prev_buf;
628  int first_wsize;
629 
630  static const uint8_t wtype_to_wsize[] = {0, 0, 2, 2, 2, 1, 0, 1, 1};
631  int types_sizes[] = {
632  mtab->size / mtab->fmode[FT_LONG ].sub,
633  mtab->size / mtab->fmode[FT_MEDIUM].sub,
634  mtab->size / (2*mtab->fmode[FT_SHORT ].sub),
635  };
636 
637  wsize = types_sizes[wtype_to_wsize[wtype]];
638  first_wsize = wsize;
639  prev_buf = prev + (size - bsize)/2;
640 
641  for (j = 0; j < mtab->fmode[ftype].sub; j++) {
642  int sub_wtype = ftype == FT_MEDIUM ? 8 : wtype;
643 
644  if (!j && wtype == 4)
645  sub_wtype = 4;
646  else if (j == mtab->fmode[ftype].sub-1 && wtype == 7)
647  sub_wtype = 7;
648 
649  wsize = types_sizes[wtype_to_wsize[sub_wtype]];
650 
651  mdct->imdct_half(mdct, buf1 + bsize*j, in + bsize*j);
652 
653  tctx->dsp.vector_fmul_window(out2,
654  prev_buf + (bsize-wsize)/2,
655  buf1 + bsize*j,
656  ff_sine_windows[av_log2(wsize)],
657  wsize/2);
658  out2 += wsize;
659 
660  memcpy(out2, buf1 + bsize*j + wsize/2, (bsize - wsize/2)*sizeof(float));
661 
662  out2 += ftype == FT_MEDIUM ? (bsize-wsize)/2 : bsize - wsize;
663 
664  prev_buf = buf1 + bsize*j + bsize/2;
665  }
666 
667  tctx->last_block_pos[ch] = (size + first_wsize)/2;
668 }
669 
670 static void imdct_output(TwinContext *tctx, enum FrameType ftype, int wtype,
671  float **out)
672 {
673  const ModeTab *mtab = tctx->mtab;
674  int size1, size2;
675  float *prev_buf = tctx->prev_frame + tctx->last_block_pos[0];
676  int i;
677 
678  for (i = 0; i < tctx->avctx->channels; i++) {
679  imdct_and_window(tctx, ftype, wtype,
680  tctx->spectrum + i*mtab->size,
681  prev_buf + 2*i*mtab->size,
682  i);
683  }
684 
685  if (!out)
686  return;
687 
688  size2 = tctx->last_block_pos[0];
689  size1 = mtab->size - size2;
690 
691  memcpy(&out[0][0 ], prev_buf, size1 * sizeof(out[0][0]));
692  memcpy(&out[0][size1], tctx->curr_frame, size2 * sizeof(out[0][0]));
693 
694  if (tctx->avctx->channels == 2) {
695  memcpy(&out[1][0], &prev_buf[2*mtab->size], size1 * sizeof(out[1][0]));
696  memcpy(&out[1][size1], &tctx->curr_frame[2*mtab->size], size2 * sizeof(out[1][0]));
697  tctx->dsp.butterflies_float(out[0], out[1], mtab->size);
698  }
699 }
700 
701 static void dec_bark_env(TwinContext *tctx, const uint8_t *in, int use_hist,
702  int ch, float *out, float gain, enum FrameType ftype)
703 {
704  const ModeTab *mtab = tctx->mtab;
705  int i,j;
706  float *hist = tctx->bark_hist[ftype][ch];
707  float val = ((const float []) {0.4, 0.35, 0.28})[ftype];
708  int bark_n_coef = mtab->fmode[ftype].bark_n_coef;
709  int fw_cb_len = mtab->fmode[ftype].bark_env_size / bark_n_coef;
710  int idx = 0;
711 
712  for (i = 0; i < fw_cb_len; i++)
713  for (j = 0; j < bark_n_coef; j++, idx++) {
714  float tmp2 =
715  mtab->fmode[ftype].bark_cb[fw_cb_len*in[j] + i] * (1./4096);
716  float st = use_hist ?
717  (1. - val) * tmp2 + val*hist[idx] + 1. : tmp2 + 1.;
718 
719  hist[idx] = tmp2;
720  if (st < -1.) st = 1.;
721 
722  memset_float(out, st * gain, mtab->fmode[ftype].bark_tab[idx]);
723  out += mtab->fmode[ftype].bark_tab[idx];
724  }
725 
726 }
727 
729  float *out, enum FrameType ftype)
730 {
731  const ModeTab *mtab = tctx->mtab;
732  int channels = tctx->avctx->channels;
733  int sub = mtab->fmode[ftype].sub;
734  int block_size = mtab->size / sub;
735  float gain[CHANNELS_MAX*SUBBLOCKS_MAX];
736  float ppc_shape[PPC_SHAPE_LEN_MAX * CHANNELS_MAX * 4];
738  uint8_t bark_use_hist[CHANNELS_MAX][SUBBLOCKS_MAX];
739 
740  uint8_t lpc_idx1[CHANNELS_MAX];
742  uint8_t lpc_hist_idx[CHANNELS_MAX];
743 
744  int i, j, k;
745 
746  dequant(tctx, gb, out, ftype,
747  mtab->fmode[ftype].cb0, mtab->fmode[ftype].cb1,
748  mtab->fmode[ftype].cb_len_read);
749 
750  for (i = 0; i < channels; i++)
751  for (j = 0; j < sub; j++)
752  for (k = 0; k < mtab->fmode[ftype].bark_n_coef; k++)
753  bark1[i][j][k] =
754  get_bits(gb, mtab->fmode[ftype].bark_n_bit);
755 
756  for (i = 0; i < channels; i++)
757  for (j = 0; j < sub; j++)
758  bark_use_hist[i][j] = get_bits1(gb);
759 
760  dec_gain(tctx, gb, ftype, gain);
761 
762  for (i = 0; i < channels; i++) {
763  lpc_hist_idx[i] = get_bits(gb, tctx->mtab->lsp_bit0);
764  lpc_idx1 [i] = get_bits(gb, tctx->mtab->lsp_bit1);
765 
766  for (j = 0; j < tctx->mtab->lsp_split; j++)
767  lpc_idx2[i][j] = get_bits(gb, tctx->mtab->lsp_bit2);
768  }
769 
770  if (ftype == FT_LONG) {
771  int cb_len_p = (tctx->n_div[3] + mtab->ppc_shape_len*channels - 1)/
772  tctx->n_div[3];
773  dequant(tctx, gb, ppc_shape, FT_PPC, mtab->ppc_shape_cb,
774  mtab->ppc_shape_cb + cb_len_p*PPC_SHAPE_CB_SIZE, cb_len_p);
775  }
776 
777  for (i = 0; i < channels; i++) {
778  float *chunk = out + mtab->size * i;
779  float lsp[LSP_COEFS_MAX];
780 
781  for (j = 0; j < sub; j++) {
782  dec_bark_env(tctx, bark1[i][j], bark_use_hist[i][j], i,
783  tctx->tmp_buf, gain[sub*i+j], ftype);
784 
785  tctx->fdsp.vector_fmul(chunk + block_size*j, chunk + block_size*j,
786  tctx->tmp_buf, block_size);
787 
788  }
789 
790  if (ftype == FT_LONG) {
791  float pgain_step = 25000. / ((1 << mtab->pgain_bit) - 1);
792  int p_coef = get_bits(gb, tctx->mtab->ppc_period_bit);
793  int g_coef = get_bits(gb, tctx->mtab->pgain_bit);
794  float v = 1./8192*
795  mulawinv(pgain_step*g_coef+ pgain_step/2, 25000., PGAIN_MU);
796 
797  decode_ppc(tctx, p_coef, ppc_shape + i*mtab->ppc_shape_len, v,
798  chunk);
799  }
800 
801  decode_lsp(tctx, lpc_idx1[i], lpc_idx2[i], lpc_hist_idx[i], lsp,
802  tctx->lsp_hist[i]);
803 
804  dec_lpc_spectrum_inv(tctx, lsp, ftype, tctx->tmp_buf);
805 
806  for (j = 0; j < mtab->fmode[ftype].sub; j++) {
807  tctx->fdsp.vector_fmul(chunk, chunk, tctx->tmp_buf, block_size);
808  chunk += block_size;
809  }
810  }
811 }
812 
813 static int twin_decode_frame(AVCodecContext * avctx, void *data,
814  int *got_frame_ptr, AVPacket *avpkt)
815 {
816  const uint8_t *buf = avpkt->data;
817  int buf_size = avpkt->size;
818  TwinContext *tctx = avctx->priv_data;
819  GetBitContext gb;
820  const ModeTab *mtab = tctx->mtab;
821  float **out = NULL;
822  enum FrameType ftype;
823  int window_type, ret;
824  static const enum FrameType wtype_to_ftype_table[] = {
826  FT_MEDIUM, FT_LONG, FT_LONG, FT_MEDIUM, FT_MEDIUM
827  };
828 
829  if (buf_size*8 < avctx->bit_rate*mtab->size/avctx->sample_rate + 8) {
830  av_log(avctx, AV_LOG_ERROR,
831  "Frame too small (%d bytes). Truncated file?\n", buf_size);
832  return AVERROR(EINVAL);
833  }
834 
835  /* get output buffer */
836  if (tctx->discarded_packets >= 2) {
837  tctx->frame.nb_samples = mtab->size;
838  if ((ret = ff_get_buffer(avctx, &tctx->frame)) < 0) {
839  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
840  return ret;
841  }
842  out = (float **)tctx->frame.extended_data;
843  }
844 
845  init_get_bits(&gb, buf, buf_size * 8);
846  skip_bits(&gb, get_bits(&gb, 8));
847  window_type = get_bits(&gb, WINDOW_TYPE_BITS);
848 
849  if (window_type > 8) {
850  av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");
851  return -1;
852  }
853 
854  ftype = wtype_to_ftype_table[window_type];
855 
856  read_and_decode_spectrum(tctx, &gb, tctx->spectrum, ftype);
857 
858  imdct_output(tctx, ftype, window_type, out);
859 
860  FFSWAP(float*, tctx->curr_frame, tctx->prev_frame);
861 
862  if (tctx->discarded_packets < 2) {
863  tctx->discarded_packets++;
864  *got_frame_ptr = 0;
865  return buf_size;
866  }
867 
868  *got_frame_ptr = 1;
869  *(AVFrame *)data = tctx->frame;
870 
871  return buf_size;
872 }
873 
874 /**
875  * Init IMDCT and windowing tables
876  */
878 {
879  int i, j, ret;
880  const ModeTab *mtab = tctx->mtab;
881  int size_s = mtab->size / mtab->fmode[FT_SHORT].sub;
882  int size_m = mtab->size / mtab->fmode[FT_MEDIUM].sub;
883  int channels = tctx->avctx->channels;
884  float norm = channels == 1 ? 2. : 1.;
885 
886  for (i = 0; i < 3; i++) {
887  int bsize = tctx->mtab->size/tctx->mtab->fmode[i].sub;
888  if ((ret = ff_mdct_init(&tctx->mdct_ctx[i], av_log2(bsize) + 1, 1,
889  -sqrt(norm/bsize) / (1<<15))))
890  return ret;
891  }
892 
893  FF_ALLOC_OR_GOTO(tctx->avctx, tctx->tmp_buf,
894  mtab->size * sizeof(*tctx->tmp_buf), alloc_fail);
895 
896  FF_ALLOC_OR_GOTO(tctx->avctx, tctx->spectrum,
897  2 * mtab->size * channels * sizeof(*tctx->spectrum),
898  alloc_fail);
899  FF_ALLOC_OR_GOTO(tctx->avctx, tctx->curr_frame,
900  2 * mtab->size * channels * sizeof(*tctx->curr_frame),
901  alloc_fail);
902  FF_ALLOC_OR_GOTO(tctx->avctx, tctx->prev_frame,
903  2 * mtab->size * channels * sizeof(*tctx->prev_frame),
904  alloc_fail);
905 
906  for (i = 0; i < 3; i++) {
907  int m = 4*mtab->size/mtab->fmode[i].sub;
908  double freq = 2*M_PI/m;
909  FF_ALLOC_OR_GOTO(tctx->avctx, tctx->cos_tabs[i],
910  (m / 4) * sizeof(*tctx->cos_tabs[i]), alloc_fail);
911 
912  for (j = 0; j <= m/8; j++)
913  tctx->cos_tabs[i][j] = cos((2*j + 1)*freq);
914  for (j = 1; j < m/8; j++)
915  tctx->cos_tabs[i][m/4-j] = tctx->cos_tabs[i][j];
916  }
917 
918 
920  ff_init_ff_sine_windows(av_log2(size_s/2));
922 
923  return 0;
924 alloc_fail:
925  return AVERROR(ENOMEM);
926 }
927 
928 /**
929  * Interpret the data as if it were a num_blocks x line_len[0] matrix and for
930  * each line do a cyclic permutation, i.e.
931  * abcdefghijklm -> defghijklmabc
932  * where the amount to be shifted is evaluated depending on the column.
933  */
934 static void permutate_in_line(int16_t *tab, int num_vect, int num_blocks,
935  int block_size,
936  const uint8_t line_len[2], int length_div,
937  enum FrameType ftype)
938 
939 {
940  int i,j;
941 
942  for (i = 0; i < line_len[0]; i++) {
943  int shift;
944 
945  if (num_blocks == 1 ||
946  (ftype == FT_LONG && num_vect % num_blocks) ||
947  (ftype != FT_LONG && num_vect & 1 ) ||
948  i == line_len[1]) {
949  shift = 0;
950  } else if (ftype == FT_LONG) {
951  shift = i;
952  } else
953  shift = i*i;
954 
955  for (j = 0; j < num_vect && (j+num_vect*i < block_size*num_blocks); j++)
956  tab[i*num_vect+j] = i*num_vect + (j + shift) % num_vect;
957  }
958 }
959 
960 /**
961  * Interpret the input data as in the following table:
962  *
963  * @verbatim
964  *
965  * abcdefgh
966  * ijklmnop
967  * qrstuvw
968  * x123456
969  *
970  * @endverbatim
971  *
972  * and transpose it, giving the output
973  * aiqxbjr1cks2dlt3emu4fvn5gow6hp
974  */
975 static void transpose_perm(int16_t *out, int16_t *in, int num_vect,
976  const uint8_t line_len[2], int length_div)
977 {
978  int i,j;
979  int cont= 0;
980  for (i = 0; i < num_vect; i++)
981  for (j = 0; j < line_len[i >= length_div]; j++)
982  out[cont++] = in[j*num_vect + i];
983 }
984 
985 static void linear_perm(int16_t *out, int16_t *in, int n_blocks, int size)
986 {
987  int block_size = size/n_blocks;
988  int i;
989 
990  for (i = 0; i < size; i++)
991  out[i] = block_size * (in[i] % n_blocks) + in[i] / n_blocks;
992 }
993 
994 static av_cold void construct_perm_table(TwinContext *tctx,enum FrameType ftype)
995 {
996  int block_size;
997  const ModeTab *mtab = tctx->mtab;
998  int size;
999  int16_t *tmp_perm = (int16_t *) tctx->tmp_buf;
1000 
1001  if (ftype == FT_PPC) {
1002  size = tctx->avctx->channels;
1003  block_size = mtab->ppc_shape_len;
1004  } else {
1005  size = tctx->avctx->channels * mtab->fmode[ftype].sub;
1006  block_size = mtab->size / mtab->fmode[ftype].sub;
1007  }
1008 
1009  permutate_in_line(tmp_perm, tctx->n_div[ftype], size,
1010  block_size, tctx->length[ftype],
1011  tctx->length_change[ftype], ftype);
1012 
1013  transpose_perm(tctx->permut[ftype], tmp_perm, tctx->n_div[ftype],
1014  tctx->length[ftype], tctx->length_change[ftype]);
1015 
1016  linear_perm(tctx->permut[ftype], tctx->permut[ftype], size,
1017  size*block_size);
1018 }
1019 
1021 {
1022  const ModeTab *mtab = tctx->mtab;
1023  int n_ch = tctx->avctx->channels;
1024  int total_fr_bits = tctx->avctx->bit_rate*mtab->size/
1025  tctx->avctx->sample_rate;
1026 
1027  int lsp_bits_per_block = n_ch*(mtab->lsp_bit0 + mtab->lsp_bit1 +
1028  mtab->lsp_split*mtab->lsp_bit2);
1029 
1030  int ppc_bits = n_ch*(mtab->pgain_bit + mtab->ppc_shape_bit +
1031  mtab->ppc_period_bit);
1032 
1033  int bsize_no_main_cb[3];
1034  int bse_bits[3];
1035  int i;
1036  enum FrameType frametype;
1037 
1038  for (i = 0; i < 3; i++)
1039  // +1 for history usage switch
1040  bse_bits[i] = n_ch *
1041  (mtab->fmode[i].bark_n_coef * mtab->fmode[i].bark_n_bit + 1);
1042 
1043  bsize_no_main_cb[2] = bse_bits[2] + lsp_bits_per_block + ppc_bits +
1044  WINDOW_TYPE_BITS + n_ch*GAIN_BITS;
1045 
1046  for (i = 0; i < 2; i++)
1047  bsize_no_main_cb[i] =
1048  lsp_bits_per_block + n_ch*GAIN_BITS + WINDOW_TYPE_BITS +
1049  mtab->fmode[i].sub*(bse_bits[i] + n_ch*SUB_GAIN_BITS);
1050 
1051  // The remaining bits are all used for the main spectrum coefficients
1052  for (i = 0; i < 4; i++) {
1053  int bit_size;
1054  int vect_size;
1055  int rounded_up, rounded_down, num_rounded_down, num_rounded_up;
1056  if (i == 3) {
1057  bit_size = n_ch * mtab->ppc_shape_bit;
1058  vect_size = n_ch * mtab->ppc_shape_len;
1059  } else {
1060  bit_size = total_fr_bits - bsize_no_main_cb[i];
1061  vect_size = n_ch * mtab->size;
1062  }
1063 
1064  tctx->n_div[i] = (bit_size + 13) / 14;
1065 
1066  rounded_up = (bit_size + tctx->n_div[i] - 1)/tctx->n_div[i];
1067  rounded_down = (bit_size )/tctx->n_div[i];
1068  num_rounded_down = rounded_up * tctx->n_div[i] - bit_size;
1069  num_rounded_up = tctx->n_div[i] - num_rounded_down;
1070  tctx->bits_main_spec[0][i][0] = (rounded_up + 1)/2;
1071  tctx->bits_main_spec[1][i][0] = (rounded_up )/2;
1072  tctx->bits_main_spec[0][i][1] = (rounded_down + 1)/2;
1073  tctx->bits_main_spec[1][i][1] = (rounded_down )/2;
1074  tctx->bits_main_spec_change[i] = num_rounded_up;
1075 
1076  rounded_up = (vect_size + tctx->n_div[i] - 1)/tctx->n_div[i];
1077  rounded_down = (vect_size )/tctx->n_div[i];
1078  num_rounded_down = rounded_up * tctx->n_div[i] - vect_size;
1079  num_rounded_up = tctx->n_div[i] - num_rounded_down;
1080  tctx->length[i][0] = rounded_up;
1081  tctx->length[i][1] = rounded_down;
1082  tctx->length_change[i] = num_rounded_up;
1083  }
1084 
1085  for (frametype = FT_SHORT; frametype <= FT_PPC; frametype++)
1086  construct_perm_table(tctx, frametype);
1087 }
1088 
1090 {
1091  TwinContext *tctx = avctx->priv_data;
1092  int i;
1093 
1094  for (i = 0; i < 3; i++) {
1095  ff_mdct_end(&tctx->mdct_ctx[i]);
1096  av_free(tctx->cos_tabs[i]);
1097  }
1098 
1099 
1100  av_free(tctx->curr_frame);
1101  av_free(tctx->spectrum);
1102  av_free(tctx->prev_frame);
1103  av_free(tctx->tmp_buf);
1104 
1105  return 0;
1106 }
1107 
1109 {
1110  int ret;
1111  TwinContext *tctx = avctx->priv_data;
1112  int isampf, ibps;
1113 
1114  tctx->avctx = avctx;
1115  avctx->sample_fmt = AV_SAMPLE_FMT_FLTP;
1116 
1117  if (!avctx->extradata || avctx->extradata_size < 12) {
1118  av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");
1119  return AVERROR_INVALIDDATA;
1120  }
1121  avctx->channels = AV_RB32(avctx->extradata ) + 1;
1122  avctx->bit_rate = AV_RB32(avctx->extradata + 4) * 1000;
1123  isampf = AV_RB32(avctx->extradata + 8);
1124 
1125  if (isampf < 8 || isampf > 44) {
1126  av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate\n");
1127  return AVERROR_INVALIDDATA;
1128  }
1129  switch (isampf) {
1130  case 44: avctx->sample_rate = 44100; break;
1131  case 22: avctx->sample_rate = 22050; break;
1132  case 11: avctx->sample_rate = 11025; break;
1133  default: avctx->sample_rate = isampf * 1000; break;
1134  }
1135 
1136  if (avctx->channels <= 0 || avctx->channels > CHANNELS_MAX) {
1137  av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
1138  avctx->channels);
1139  return -1;
1140  }
1141  avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO :
1143 
1144  ibps = avctx->bit_rate / (1000 * avctx->channels);
1145 
1146  if (ibps > 255U) {
1147  av_log(avctx, AV_LOG_ERROR, "unsupported per channel bitrate %dkbps\n", ibps);
1148  return AVERROR_INVALIDDATA;
1149  }
1150 
1151  switch ((isampf << 8) + ibps) {
1152  case (8 <<8) + 8: tctx->mtab = &mode_08_08; break;
1153  case (11<<8) + 8: tctx->mtab = &mode_11_08; break;
1154  case (11<<8) + 10: tctx->mtab = &mode_11_10; break;
1155  case (16<<8) + 16: tctx->mtab = &mode_16_16; break;
1156  case (22<<8) + 20: tctx->mtab = &mode_22_20; break;
1157  case (22<<8) + 24: tctx->mtab = &mode_22_24; break;
1158  case (22<<8) + 32: tctx->mtab = &mode_22_32; break;
1159  case (44<<8) + 40: tctx->mtab = &mode_44_40; break;
1160  case (44<<8) + 48: tctx->mtab = &mode_44_48; break;
1161  default:
1162  av_log(avctx, AV_LOG_ERROR, "This version does not support %d kHz - %d kbit/s/ch mode.\n", isampf, isampf);
1163  return -1;
1164  }
1165 
1166  ff_dsputil_init(&tctx->dsp, avctx);
1168  if ((ret = init_mdct_win(tctx))) {
1169  av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n");
1170  twin_decode_close(avctx);
1171  return ret;
1172  }
1173  init_bitstream_params(tctx);
1174 
1175  memset_float(tctx->bark_hist[0][0], 0.1, FF_ARRAY_ELEMS(tctx->bark_hist));
1176 
1178  avctx->coded_frame = &tctx->frame;
1179 
1180  return 0;
1181 }
1182 
1184  .name = "twinvq",
1185  .type = AVMEDIA_TYPE_AUDIO,
1186  .id = AV_CODEC_ID_TWINVQ,
1187  .priv_data_size = sizeof(TwinContext),
1191  .capabilities = CODEC_CAP_DR1,
1192  .long_name = NULL_IF_CONFIG_SMALL("VQF TwinVQ"),
1193  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
1195 };