wmadec.c
Go to the documentation of this file.
1 /*
2  * WMA compatible decoder
3  * Copyright (c) 2002 The Libav Project
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
36 #include "avcodec.h"
37 #include "internal.h"
38 #include "wma.h"
39 
40 #undef NDEBUG
41 #include <assert.h>
42 
43 #define EXPVLCBITS 8
44 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
45 
46 #define HGAINVLCBITS 9
47 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
48 
49 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
50 
51 #ifdef TRACE
52 static void dump_shorts(WMACodecContext *s, const char *name, const short *tab, int n)
53 {
54  int i;
55 
56  tprintf(s->avctx, "%s[%d]:\n", name, n);
57  for(i=0;i<n;i++) {
58  if ((i & 7) == 0)
59  tprintf(s->avctx, "%4d: ", i);
60  tprintf(s->avctx, " %5d.0", tab[i]);
61  if ((i & 7) == 7)
62  tprintf(s->avctx, "\n");
63  }
64 }
65 
66 static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)
67 {
68  int i;
69 
70  tprintf(s->avctx, "%s[%d]:\n", name, n);
71  for(i=0;i<n;i++) {
72  if ((i & 7) == 0)
73  tprintf(s->avctx, "%4d: ", i);
74  tprintf(s->avctx, " %8.*f", prec, tab[i]);
75  if ((i & 7) == 7)
76  tprintf(s->avctx, "\n");
77  }
78  if ((i & 7) != 0)
79  tprintf(s->avctx, "\n");
80 }
81 #endif
82 
83 static int wma_decode_init(AVCodecContext * avctx)
84 {
85  WMACodecContext *s = avctx->priv_data;
86  int i, flags2;
87  uint8_t *extradata;
88 
89  if (!avctx->block_align) {
90  av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
91  return AVERROR(EINVAL);
92  }
93 
94  s->avctx = avctx;
95 
96  /* extract flag infos */
97  flags2 = 0;
98  extradata = avctx->extradata;
99  if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
100  flags2 = AV_RL16(extradata+2);
101  } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
102  flags2 = AV_RL16(extradata+4);
103  }
104 // for(i=0; i<avctx->extradata_size; i++)
105 // av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
106 
107  s->use_exp_vlc = flags2 & 0x0001;
108  s->use_bit_reservoir = flags2 & 0x0002;
109  s->use_variable_block_len = flags2 & 0x0004;
110 
111  if(ff_wma_init(avctx, flags2)<0)
112  return -1;
113 
114  /* init MDCT */
115  for(i = 0; i < s->nb_block_sizes; i++)
116  ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
117 
118  if (s->use_noise_coding) {
120  ff_wma_hgain_huffbits, 1, 1,
121  ff_wma_hgain_huffcodes, 2, 2, 0);
122  }
123 
124  if (s->use_exp_vlc) {
125  init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
127  ff_aac_scalefactor_code, 4, 4, 0);
128  } else {
130  }
131 
132  avctx->sample_fmt = AV_SAMPLE_FMT_S16;
133 
135  avctx->coded_frame = &s->frame;
136 
137  return 0;
138 }
139 
146 static inline float pow_m1_4(WMACodecContext *s, float x)
147 {
148  union {
149  float f;
150  unsigned int v;
151  } u, t;
152  unsigned int e, m;
153  float a, b;
154 
155  u.f = x;
156  e = u.v >> 23;
157  m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
158  /* build interpolation scale: 1 <= t < 2. */
159  t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
160  a = s->lsp_pow_m_table1[m];
161  b = s->lsp_pow_m_table2[m];
162  return s->lsp_pow_e_table[e] * (a + b * t.f);
163 }
164 
165 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
166 {
167  float wdel, a, b;
168  int i, e, m;
169 
170  wdel = M_PI / frame_len;
171  for(i=0;i<frame_len;i++)
172  s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
173 
174  /* tables for x^-0.25 computation */
175  for(i=0;i<256;i++) {
176  e = i - 126;
177  s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
178  }
179 
180  /* NOTE: these two tables are needed to avoid two operations in
181  pow_m1_4 */
182  b = 1.0;
183  for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
184  m = (1 << LSP_POW_BITS) + i;
185  a = (float)m * (0.5 / (1 << LSP_POW_BITS));
186  a = pow(a, -0.25);
187  s->lsp_pow_m_table1[i] = 2 * a - b;
188  s->lsp_pow_m_table2[i] = b - a;
189  b = a;
190  }
191 }
192 
198  float *out, float *val_max_ptr,
199  int n, float *lsp)
200 {
201  int i, j;
202  float p, q, w, v, val_max;
203 
204  val_max = 0;
205  for(i=0;i<n;i++) {
206  p = 0.5f;
207  q = 0.5f;
208  w = s->lsp_cos_table[i];
209  for(j=1;j<NB_LSP_COEFS;j+=2){
210  q *= w - lsp[j - 1];
211  p *= w - lsp[j];
212  }
213  p *= p * (2.0f - w);
214  q *= q * (2.0f + w);
215  v = p + q;
216  v = pow_m1_4(s, v);
217  if (v > val_max)
218  val_max = v;
219  out[i] = v;
220  }
221  *val_max_ptr = val_max;
222 }
223 
227 static void decode_exp_lsp(WMACodecContext *s, int ch)
228 {
229  float lsp_coefs[NB_LSP_COEFS];
230  int val, i;
231 
232  for(i = 0; i < NB_LSP_COEFS; i++) {
233  if (i == 0 || i >= 8)
234  val = get_bits(&s->gb, 3);
235  else
236  val = get_bits(&s->gb, 4);
237  lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
238  }
239 
240  wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
241  s->block_len, lsp_coefs);
242 }
243 
245 static const float pow_tab[] = {
246  1.7782794100389e-04, 2.0535250264571e-04,
247  2.3713737056617e-04, 2.7384196342644e-04,
248  3.1622776601684e-04, 3.6517412725484e-04,
249  4.2169650342858e-04, 4.8696752516586e-04,
250  5.6234132519035e-04, 6.4938163157621e-04,
251  7.4989420933246e-04, 8.6596432336006e-04,
252  1.0000000000000e-03, 1.1547819846895e-03,
253  1.3335214321633e-03, 1.5399265260595e-03,
254  1.7782794100389e-03, 2.0535250264571e-03,
255  2.3713737056617e-03, 2.7384196342644e-03,
256  3.1622776601684e-03, 3.6517412725484e-03,
257  4.2169650342858e-03, 4.8696752516586e-03,
258  5.6234132519035e-03, 6.4938163157621e-03,
259  7.4989420933246e-03, 8.6596432336006e-03,
260  1.0000000000000e-02, 1.1547819846895e-02,
261  1.3335214321633e-02, 1.5399265260595e-02,
262  1.7782794100389e-02, 2.0535250264571e-02,
263  2.3713737056617e-02, 2.7384196342644e-02,
264  3.1622776601684e-02, 3.6517412725484e-02,
265  4.2169650342858e-02, 4.8696752516586e-02,
266  5.6234132519035e-02, 6.4938163157621e-02,
267  7.4989420933246e-02, 8.6596432336007e-02,
268  1.0000000000000e-01, 1.1547819846895e-01,
269  1.3335214321633e-01, 1.5399265260595e-01,
270  1.7782794100389e-01, 2.0535250264571e-01,
271  2.3713737056617e-01, 2.7384196342644e-01,
272  3.1622776601684e-01, 3.6517412725484e-01,
273  4.2169650342858e-01, 4.8696752516586e-01,
274  5.6234132519035e-01, 6.4938163157621e-01,
275  7.4989420933246e-01, 8.6596432336007e-01,
276  1.0000000000000e+00, 1.1547819846895e+00,
277  1.3335214321633e+00, 1.5399265260595e+00,
278  1.7782794100389e+00, 2.0535250264571e+00,
279  2.3713737056617e+00, 2.7384196342644e+00,
280  3.1622776601684e+00, 3.6517412725484e+00,
281  4.2169650342858e+00, 4.8696752516586e+00,
282  5.6234132519035e+00, 6.4938163157621e+00,
283  7.4989420933246e+00, 8.6596432336007e+00,
284  1.0000000000000e+01, 1.1547819846895e+01,
285  1.3335214321633e+01, 1.5399265260595e+01,
286  1.7782794100389e+01, 2.0535250264571e+01,
287  2.3713737056617e+01, 2.7384196342644e+01,
288  3.1622776601684e+01, 3.6517412725484e+01,
289  4.2169650342858e+01, 4.8696752516586e+01,
290  5.6234132519035e+01, 6.4938163157621e+01,
291  7.4989420933246e+01, 8.6596432336007e+01,
292  1.0000000000000e+02, 1.1547819846895e+02,
293  1.3335214321633e+02, 1.5399265260595e+02,
294  1.7782794100389e+02, 2.0535250264571e+02,
295  2.3713737056617e+02, 2.7384196342644e+02,
296  3.1622776601684e+02, 3.6517412725484e+02,
297  4.2169650342858e+02, 4.8696752516586e+02,
298  5.6234132519035e+02, 6.4938163157621e+02,
299  7.4989420933246e+02, 8.6596432336007e+02,
300  1.0000000000000e+03, 1.1547819846895e+03,
301  1.3335214321633e+03, 1.5399265260595e+03,
302  1.7782794100389e+03, 2.0535250264571e+03,
303  2.3713737056617e+03, 2.7384196342644e+03,
304  3.1622776601684e+03, 3.6517412725484e+03,
305  4.2169650342858e+03, 4.8696752516586e+03,
306  5.6234132519035e+03, 6.4938163157621e+03,
307  7.4989420933246e+03, 8.6596432336007e+03,
308  1.0000000000000e+04, 1.1547819846895e+04,
309  1.3335214321633e+04, 1.5399265260595e+04,
310  1.7782794100389e+04, 2.0535250264571e+04,
311  2.3713737056617e+04, 2.7384196342644e+04,
312  3.1622776601684e+04, 3.6517412725484e+04,
313  4.2169650342858e+04, 4.8696752516586e+04,
314  5.6234132519035e+04, 6.4938163157621e+04,
315  7.4989420933246e+04, 8.6596432336007e+04,
316  1.0000000000000e+05, 1.1547819846895e+05,
317  1.3335214321633e+05, 1.5399265260595e+05,
318  1.7782794100389e+05, 2.0535250264571e+05,
319  2.3713737056617e+05, 2.7384196342644e+05,
320  3.1622776601684e+05, 3.6517412725484e+05,
321  4.2169650342858e+05, 4.8696752516586e+05,
322  5.6234132519035e+05, 6.4938163157621e+05,
323  7.4989420933246e+05, 8.6596432336007e+05,
324 };
325 
329 static int decode_exp_vlc(WMACodecContext *s, int ch)
330 {
331  int last_exp, n, code;
332  const uint16_t *ptr;
333  float v, max_scale;
334  uint32_t *q, *q_end, iv;
335  const float *ptab = pow_tab + 60;
336  const uint32_t *iptab = (const uint32_t*)ptab;
337 
338  ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
339  q = (uint32_t *)s->exponents[ch];
340  q_end = q + s->block_len;
341  max_scale = 0;
342  if (s->version == 1) {
343  last_exp = get_bits(&s->gb, 5) + 10;
344  v = ptab[last_exp];
345  iv = iptab[last_exp];
346  max_scale = v;
347  n = *ptr++;
348  switch (n & 3) do {
349  case 0: *q++ = iv;
350  case 3: *q++ = iv;
351  case 2: *q++ = iv;
352  case 1: *q++ = iv;
353  } while ((n -= 4) > 0);
354  }else
355  last_exp = 36;
356 
357  while (q < q_end) {
358  code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
359  if (code < 0){
360  av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
361  return -1;
362  }
363  /* NOTE: this offset is the same as MPEG4 AAC ! */
364  last_exp += code - 60;
365  if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
366  av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
367  last_exp);
368  return -1;
369  }
370  v = ptab[last_exp];
371  iv = iptab[last_exp];
372  if (v > max_scale)
373  max_scale = v;
374  n = *ptr++;
375  switch (n & 3) do {
376  case 0: *q++ = iv;
377  case 3: *q++ = iv;
378  case 2: *q++ = iv;
379  case 1: *q++ = iv;
380  } while ((n -= 4) > 0);
381  }
382  s->max_exponent[ch] = max_scale;
383  return 0;
384 }
385 
386 
393 static void wma_window(WMACodecContext *s, float *out)
394 {
395  float *in = s->output;
396  int block_len, bsize, n;
397 
398  /* left part */
399  if (s->block_len_bits <= s->prev_block_len_bits) {
400  block_len = s->block_len;
401  bsize = s->frame_len_bits - s->block_len_bits;
402 
403  s->dsp.vector_fmul_add(out, in, s->windows[bsize],
404  out, block_len);
405 
406  } else {
407  block_len = 1 << s->prev_block_len_bits;
408  n = (s->block_len - block_len) / 2;
409  bsize = s->frame_len_bits - s->prev_block_len_bits;
410 
411  s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
412  out+n, block_len);
413 
414  memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
415  }
416 
417  out += s->block_len;
418  in += s->block_len;
419 
420  /* right part */
421  if (s->block_len_bits <= s->next_block_len_bits) {
422  block_len = s->block_len;
423  bsize = s->frame_len_bits - s->block_len_bits;
424 
425  s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
426 
427  } else {
428  block_len = 1 << s->next_block_len_bits;
429  n = (s->block_len - block_len) / 2;
430  bsize = s->frame_len_bits - s->next_block_len_bits;
431 
432  memcpy(out, in, n*sizeof(float));
433 
434  s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
435 
436  memset(out+n+block_len, 0, n*sizeof(float));
437  }
438 }
439 
440 
446 {
447  int n, v, a, ch, bsize;
448  int coef_nb_bits, total_gain;
449  int nb_coefs[MAX_CHANNELS];
450  float mdct_norm;
451  FFTContext *mdct;
452 
453 #ifdef TRACE
454  tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
455 #endif
456 
457  /* compute current block length */
458  if (s->use_variable_block_len) {
459  n = av_log2(s->nb_block_sizes - 1) + 1;
460 
461  if (s->reset_block_lengths) {
462  s->reset_block_lengths = 0;
463  v = get_bits(&s->gb, n);
464  if (v >= s->nb_block_sizes){
465  av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
466  return -1;
467  }
469  v = get_bits(&s->gb, n);
470  if (v >= s->nb_block_sizes){
471  av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
472  return -1;
473  }
474  s->block_len_bits = s->frame_len_bits - v;
475  } else {
476  /* update block lengths */
479  }
480  v = get_bits(&s->gb, n);
481  if (v >= s->nb_block_sizes){
482  av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
483  return -1;
484  }
486  } else {
487  /* fixed block len */
491  }
492 
493  /* now check if the block length is coherent with the frame length */
494  s->block_len = 1 << s->block_len_bits;
495  if ((s->block_pos + s->block_len) > s->frame_len){
496  av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
497  return -1;
498  }
499 
500  if (s->nb_channels == 2) {
501  s->ms_stereo = get_bits1(&s->gb);
502  }
503  v = 0;
504  for(ch = 0; ch < s->nb_channels; ch++) {
505  a = get_bits1(&s->gb);
506  s->channel_coded[ch] = a;
507  v |= a;
508  }
509 
510  bsize = s->frame_len_bits - s->block_len_bits;
511 
512  /* if no channel coded, no need to go further */
513  /* XXX: fix potential framing problems */
514  if (!v)
515  goto next;
516 
517  /* read total gain and extract corresponding number of bits for
518  coef escape coding */
519  total_gain = 1;
520  for(;;) {
521  a = get_bits(&s->gb, 7);
522  total_gain += a;
523  if (a != 127)
524  break;
525  }
526 
527  coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
528 
529  /* compute number of coefficients */
530  n = s->coefs_end[bsize] - s->coefs_start;
531  for(ch = 0; ch < s->nb_channels; ch++)
532  nb_coefs[ch] = n;
533 
534  /* complex coding */
535  if (s->use_noise_coding) {
536 
537  for(ch = 0; ch < s->nb_channels; ch++) {
538  if (s->channel_coded[ch]) {
539  int i, n, a;
540  n = s->exponent_high_sizes[bsize];
541  for(i=0;i<n;i++) {
542  a = get_bits1(&s->gb);
543  s->high_band_coded[ch][i] = a;
544  /* if noise coding, the coefficients are not transmitted */
545  if (a)
546  nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
547  }
548  }
549  }
550  for(ch = 0; ch < s->nb_channels; ch++) {
551  if (s->channel_coded[ch]) {
552  int i, n, val, code;
553 
554  n = s->exponent_high_sizes[bsize];
555  val = (int)0x80000000;
556  for(i=0;i<n;i++) {
557  if (s->high_band_coded[ch][i]) {
558  if (val == (int)0x80000000) {
559  val = get_bits(&s->gb, 7) - 19;
560  } else {
561  code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
562  if (code < 0){
563  av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
564  return -1;
565  }
566  val += code - 18;
567  }
568  s->high_band_values[ch][i] = val;
569  }
570  }
571  }
572  }
573  }
574 
575  /* exponents can be reused in short blocks. */
576  if ((s->block_len_bits == s->frame_len_bits) ||
577  get_bits1(&s->gb)) {
578  for(ch = 0; ch < s->nb_channels; ch++) {
579  if (s->channel_coded[ch]) {
580  if (s->use_exp_vlc) {
581  if (decode_exp_vlc(s, ch) < 0)
582  return -1;
583  } else {
584  decode_exp_lsp(s, ch);
585  }
586  s->exponents_bsize[ch] = bsize;
587  }
588  }
589  }
590 
591  /* parse spectral coefficients : just RLE encoding */
592  for(ch = 0; ch < s->nb_channels; ch++) {
593  if (s->channel_coded[ch]) {
594  int tindex;
595  WMACoef* ptr = &s->coefs1[ch][0];
596 
597  /* special VLC tables are used for ms stereo because
598  there is potentially less energy there */
599  tindex = (ch == 1 && s->ms_stereo);
600  memset(ptr, 0, s->block_len * sizeof(WMACoef));
601  ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
602  s->level_table[tindex], s->run_table[tindex],
603  0, ptr, 0, nb_coefs[ch],
604  s->block_len, s->frame_len_bits, coef_nb_bits);
605  }
606  if (s->version == 1 && s->nb_channels >= 2) {
607  align_get_bits(&s->gb);
608  }
609  }
610 
611  /* normalize */
612  {
613  int n4 = s->block_len / 2;
614  mdct_norm = 1.0 / (float)n4;
615  if (s->version == 1) {
616  mdct_norm *= sqrt(n4);
617  }
618  }
619 
620  /* finally compute the MDCT coefficients */
621  for(ch = 0; ch < s->nb_channels; ch++) {
622  if (s->channel_coded[ch]) {
623  WMACoef *coefs1;
624  float *coefs, *exponents, mult, mult1, noise;
625  int i, j, n, n1, last_high_band, esize;
626  float exp_power[HIGH_BAND_MAX_SIZE];
627 
628  coefs1 = s->coefs1[ch];
629  exponents = s->exponents[ch];
630  esize = s->exponents_bsize[ch];
631  mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
632  mult *= mdct_norm;
633  coefs = s->coefs[ch];
634  if (s->use_noise_coding) {
635  mult1 = mult;
636  /* very low freqs : noise */
637  for(i = 0;i < s->coefs_start; i++) {
638  *coefs++ = s->noise_table[s->noise_index] *
639  exponents[i<<bsize>>esize] * mult1;
640  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
641  }
642 
643  n1 = s->exponent_high_sizes[bsize];
644 
645  /* compute power of high bands */
646  exponents = s->exponents[ch] +
647  (s->high_band_start[bsize]<<bsize>>esize);
648  last_high_band = 0; /* avoid warning */
649  for(j=0;j<n1;j++) {
651  s->block_len_bits][j];
652  if (s->high_band_coded[ch][j]) {
653  float e2, v;
654  e2 = 0;
655  for(i = 0;i < n; i++) {
656  v = exponents[i<<bsize>>esize];
657  e2 += v * v;
658  }
659  exp_power[j] = e2 / n;
660  last_high_band = j;
661  tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
662  }
663  exponents += n<<bsize>>esize;
664  }
665 
666  /* main freqs and high freqs */
667  exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
668  for(j=-1;j<n1;j++) {
669  if (j < 0) {
670  n = s->high_band_start[bsize] -
671  s->coefs_start;
672  } else {
674  s->block_len_bits][j];
675  }
676  if (j >= 0 && s->high_band_coded[ch][j]) {
677  /* use noise with specified power */
678  mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
679  /* XXX: use a table */
680  mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
681  mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
682  mult1 *= mdct_norm;
683  for(i = 0;i < n; i++) {
684  noise = s->noise_table[s->noise_index];
685  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
686  *coefs++ = noise *
687  exponents[i<<bsize>>esize] * mult1;
688  }
689  exponents += n<<bsize>>esize;
690  } else {
691  /* coded values + small noise */
692  for(i = 0;i < n; i++) {
693  noise = s->noise_table[s->noise_index];
694  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
695  *coefs++ = ((*coefs1++) + noise) *
696  exponents[i<<bsize>>esize] * mult;
697  }
698  exponents += n<<bsize>>esize;
699  }
700  }
701 
702  /* very high freqs : noise */
703  n = s->block_len - s->coefs_end[bsize];
704  mult1 = mult * exponents[((-1<<bsize))>>esize];
705  for(i = 0; i < n; i++) {
706  *coefs++ = s->noise_table[s->noise_index] * mult1;
707  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
708  }
709  } else {
710  /* XXX: optimize more */
711  for(i = 0;i < s->coefs_start; i++)
712  *coefs++ = 0.0;
713  n = nb_coefs[ch];
714  for(i = 0;i < n; i++) {
715  *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
716  }
717  n = s->block_len - s->coefs_end[bsize];
718  for(i = 0;i < n; i++)
719  *coefs++ = 0.0;
720  }
721  }
722  }
723 
724 #ifdef TRACE
725  for(ch = 0; ch < s->nb_channels; ch++) {
726  if (s->channel_coded[ch]) {
727  dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
728  dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
729  }
730  }
731 #endif
732 
733  if (s->ms_stereo && s->channel_coded[1]) {
734  /* nominal case for ms stereo: we do it before mdct */
735  /* no need to optimize this case because it should almost
736  never happen */
737  if (!s->channel_coded[0]) {
738  tprintf(s->avctx, "rare ms-stereo case happened\n");
739  memset(s->coefs[0], 0, sizeof(float) * s->block_len);
740  s->channel_coded[0] = 1;
741  }
742 
743  s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
744  }
745 
746 next:
747  mdct = &s->mdct_ctx[bsize];
748 
749  for(ch = 0; ch < s->nb_channels; ch++) {
750  int n4, index;
751 
752  n4 = s->block_len / 2;
753  if(s->channel_coded[ch]){
754  mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
755  }else if(!(s->ms_stereo && ch==1))
756  memset(s->output, 0, sizeof(s->output));
757 
758  /* multiply by the window and add in the frame */
759  index = (s->frame_len / 2) + s->block_pos - n4;
760  wma_window(s, &s->frame_out[ch][index]);
761  }
762 
763  /* update block number */
764  s->block_num++;
765  s->block_pos += s->block_len;
766  if (s->block_pos >= s->frame_len)
767  return 1;
768  else
769  return 0;
770 }
771 
772 /* decode a frame of frame_len samples */
773 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
774 {
775  int ret, n, ch, incr;
776  const float *output[MAX_CHANNELS];
777 
778 #ifdef TRACE
779  tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
780 #endif
781 
782  /* read each block */
783  s->block_num = 0;
784  s->block_pos = 0;
785  for(;;) {
786  ret = wma_decode_block(s);
787  if (ret < 0)
788  return -1;
789  if (ret)
790  break;
791  }
792 
793  /* convert frame to integer */
794  n = s->frame_len;
795  incr = s->nb_channels;
796  for (ch = 0; ch < MAX_CHANNELS; ch++)
797  output[ch] = s->frame_out[ch];
798  s->fmt_conv.float_to_int16_interleave(samples, output, n, incr);
799  for (ch = 0; ch < incr; ch++) {
800  /* prepare for next block */
801  memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
802  }
803 
804 #ifdef TRACE
805  dump_shorts(s, "samples", samples, n * s->nb_channels);
806 #endif
807  return 0;
808 }
809 
810 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
811  int *got_frame_ptr, AVPacket *avpkt)
812 {
813  const uint8_t *buf = avpkt->data;
814  int buf_size = avpkt->size;
815  WMACodecContext *s = avctx->priv_data;
816  int nb_frames, bit_offset, i, pos, len, ret;
817  uint8_t *q;
818  int16_t *samples;
819 
820  tprintf(avctx, "***decode_superframe:\n");
821 
822  if(buf_size==0){
823  s->last_superframe_len = 0;
824  return 0;
825  }
826  if (buf_size < s->block_align) {
827  av_log(avctx, AV_LOG_ERROR,
828  "Input packet size too small (%d < %d)\n",
829  buf_size, s->block_align);
830  return AVERROR_INVALIDDATA;
831  }
832  buf_size = s->block_align;
833 
834  init_get_bits(&s->gb, buf, buf_size*8);
835 
836  if (s->use_bit_reservoir) {
837  /* read super frame header */
838  skip_bits(&s->gb, 4); /* super frame index */
839  nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
840  } else {
841  nb_frames = 1;
842  }
843 
844  /* get output buffer */
845  s->frame.nb_samples = nb_frames * s->frame_len;
846  if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
847  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
848  return ret;
849  }
850  samples = (int16_t *)s->frame.data[0];
851 
852  if (s->use_bit_reservoir) {
853  bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
854  if (bit_offset > get_bits_left(&s->gb)) {
855  av_log(avctx, AV_LOG_ERROR,
856  "Invalid last frame bit offset %d > buf size %d (%d)\n",
857  bit_offset, get_bits_left(&s->gb), buf_size);
858  goto fail;
859  }
860 
861  if (s->last_superframe_len > 0) {
862  // printf("skip=%d\n", s->last_bitoffset);
863  /* add bit_offset bits to last frame */
864  if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
866  goto fail;
868  len = bit_offset;
869  while (len > 7) {
870  *q++ = (get_bits)(&s->gb, 8);
871  len -= 8;
872  }
873  if (len > 0) {
874  *q++ = (get_bits)(&s->gb, len) << (8 - len);
875  }
876  memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
877 
878  /* XXX: bit_offset bits into last frame */
879  init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
880  /* skip unused bits */
881  if (s->last_bitoffset > 0)
882  skip_bits(&s->gb, s->last_bitoffset);
883  /* this frame is stored in the last superframe and in the
884  current one */
885  if (wma_decode_frame(s, samples) < 0)
886  goto fail;
887  samples += s->nb_channels * s->frame_len;
888  nb_frames--;
889  }
890 
891  /* read each frame starting from bit_offset */
892  pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
893  if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
894  return AVERROR_INVALIDDATA;
895  init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
896  len = pos & 7;
897  if (len > 0)
898  skip_bits(&s->gb, len);
899 
900  s->reset_block_lengths = 1;
901  for(i=0;i<nb_frames;i++) {
902  if (wma_decode_frame(s, samples) < 0)
903  goto fail;
904  samples += s->nb_channels * s->frame_len;
905  }
906 
907  /* we copy the end of the frame in the last frame buffer */
908  pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
909  s->last_bitoffset = pos & 7;
910  pos >>= 3;
911  len = buf_size - pos;
912  if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
913  av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
914  goto fail;
915  }
917  memcpy(s->last_superframe, buf + pos, len);
918  } else {
919  /* single frame decode */
920  if (wma_decode_frame(s, samples) < 0)
921  goto fail;
922  samples += s->nb_channels * s->frame_len;
923  }
924 
925 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d outbytes:%d eaten:%d\n", s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len, (int8_t *)samples - (int8_t *)data, s->block_align);
926 
927  *got_frame_ptr = 1;
928  *(AVFrame *)data = s->frame;
929 
930  return s->block_align;
931  fail:
932  /* when error, we reset the bit reservoir */
933  s->last_superframe_len = 0;
934  return -1;
935 }
936 
937 static av_cold void flush(AVCodecContext *avctx)
938 {
939  WMACodecContext *s = avctx->priv_data;
940 
941  s->last_bitoffset=
942  s->last_superframe_len= 0;
943 }
944 
946  .name = "wmav1",
947  .type = AVMEDIA_TYPE_AUDIO,
948  .id = CODEC_ID_WMAV1,
949  .priv_data_size = sizeof(WMACodecContext),
951  .close = ff_wma_end,
953  .flush = flush,
954  .capabilities = CODEC_CAP_DR1,
955  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
956 };
957 
959  .name = "wmav2",
960  .type = AVMEDIA_TYPE_AUDIO,
961  .id = CODEC_ID_WMAV2,
962  .priv_data_size = sizeof(WMACodecContext),
964  .close = ff_wma_end,
966  .flush = flush,
967  .capabilities = CODEC_CAP_DR1,
968  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
969 };