FFmpeg  1.2.4
wmadec.c
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1 /*
2  * WMA compatible decoder
3  * Copyright (c) 2002 The FFmpeg Project
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 
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_floats(WMACodecContext *s, const char *name, int prec, const float *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, " %8.*f", prec, tab[i]);
61  if ((i & 7) == 7)
62  tprintf(s->avctx, "\n");
63  }
64  if ((i & 7) != 0)
65  tprintf(s->avctx, "\n");
66 }
67 #endif
68 
69 static int wma_decode_init(AVCodecContext * avctx)
70 {
71  WMACodecContext *s = avctx->priv_data;
72  int i, flags2;
73  uint8_t *extradata;
74 
75  s->avctx = avctx;
76 
77  /* extract flag infos */
78  flags2 = 0;
79  extradata = avctx->extradata;
80  if (avctx->codec->id == AV_CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
81  flags2 = AV_RL16(extradata+2);
82  } else if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
83  flags2 = AV_RL16(extradata+4);
84  }
85 
86  s->use_exp_vlc = flags2 & 0x0001;
87  s->use_bit_reservoir = flags2 & 0x0002;
88  s->use_variable_block_len = flags2 & 0x0004;
89 
90  if(avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 8){
91  if(AV_RL16(extradata+4)==0xd && s->use_variable_block_len){
92  av_log(avctx, AV_LOG_WARNING, "Disabling use_variable_block_len, if this fails contact the ffmpeg developers and send us the file\n");
93  s->use_variable_block_len= 0; // this fixes issue1503
94  }
95  }
96 
97  if(ff_wma_init(avctx, flags2)<0)
98  return -1;
99 
100  /* init MDCT */
101  for(i = 0; i < s->nb_block_sizes; i++)
102  ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0 / 32768.0);
103 
104  if (s->use_noise_coding) {
106  ff_wma_hgain_huffbits, 1, 1,
107  ff_wma_hgain_huffcodes, 2, 2, 0);
108  }
109 
110  if (s->use_exp_vlc) {
111  init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
113  ff_aac_scalefactor_code, 4, 4, 0);
114  } else {
116  }
117 
119 
120  return 0;
121 }
122 
129 static inline float pow_m1_4(WMACodecContext *s, float x)
130 {
131  union {
132  float f;
133  unsigned int v;
134  } u, t;
135  unsigned int e, m;
136  float a, b;
137 
138  u.f = x;
139  e = u.v >> 23;
140  m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
141  /* build interpolation scale: 1 <= t < 2. */
142  t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
143  a = s->lsp_pow_m_table1[m];
144  b = s->lsp_pow_m_table2[m];
145  return s->lsp_pow_e_table[e] * (a + b * t.f);
146 }
147 
148 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
149 {
150  float wdel, a, b;
151  int i, e, m;
152 
153  wdel = M_PI / frame_len;
154  for(i=0;i<frame_len;i++)
155  s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
156 
157  /* tables for x^-0.25 computation */
158  for(i=0;i<256;i++) {
159  e = i - 126;
160  s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
161  }
162 
163  /* NOTE: these two tables are needed to avoid two operations in
164  pow_m1_4 */
165  b = 1.0;
166  for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
167  m = (1 << LSP_POW_BITS) + i;
168  a = (float)m * (0.5 / (1 << LSP_POW_BITS));
169  a = pow(a, -0.25);
170  s->lsp_pow_m_table1[i] = 2 * a - b;
171  s->lsp_pow_m_table2[i] = b - a;
172  b = a;
173  }
174 }
175 
181  float *out, float *val_max_ptr,
182  int n, float *lsp)
183 {
184  int i, j;
185  float p, q, w, v, val_max;
186 
187  val_max = 0;
188  for(i=0;i<n;i++) {
189  p = 0.5f;
190  q = 0.5f;
191  w = s->lsp_cos_table[i];
192  for(j=1;j<NB_LSP_COEFS;j+=2){
193  q *= w - lsp[j - 1];
194  p *= w - lsp[j];
195  }
196  p *= p * (2.0f - w);
197  q *= q * (2.0f + w);
198  v = p + q;
199  v = pow_m1_4(s, v);
200  if (v > val_max)
201  val_max = v;
202  out[i] = v;
203  }
204  *val_max_ptr = val_max;
205 }
206 
210 static void decode_exp_lsp(WMACodecContext *s, int ch)
211 {
212  float lsp_coefs[NB_LSP_COEFS];
213  int val, i;
214 
215  for(i = 0; i < NB_LSP_COEFS; i++) {
216  if (i == 0 || i >= 8)
217  val = get_bits(&s->gb, 3);
218  else
219  val = get_bits(&s->gb, 4);
220  lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
221  }
222 
223  wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
224  s->block_len, lsp_coefs);
225 }
226 
228 static const float pow_tab[] = {
229  1.7782794100389e-04, 2.0535250264571e-04,
230  2.3713737056617e-04, 2.7384196342644e-04,
231  3.1622776601684e-04, 3.6517412725484e-04,
232  4.2169650342858e-04, 4.8696752516586e-04,
233  5.6234132519035e-04, 6.4938163157621e-04,
234  7.4989420933246e-04, 8.6596432336006e-04,
235  1.0000000000000e-03, 1.1547819846895e-03,
236  1.3335214321633e-03, 1.5399265260595e-03,
237  1.7782794100389e-03, 2.0535250264571e-03,
238  2.3713737056617e-03, 2.7384196342644e-03,
239  3.1622776601684e-03, 3.6517412725484e-03,
240  4.2169650342858e-03, 4.8696752516586e-03,
241  5.6234132519035e-03, 6.4938163157621e-03,
242  7.4989420933246e-03, 8.6596432336006e-03,
243  1.0000000000000e-02, 1.1547819846895e-02,
244  1.3335214321633e-02, 1.5399265260595e-02,
245  1.7782794100389e-02, 2.0535250264571e-02,
246  2.3713737056617e-02, 2.7384196342644e-02,
247  3.1622776601684e-02, 3.6517412725484e-02,
248  4.2169650342858e-02, 4.8696752516586e-02,
249  5.6234132519035e-02, 6.4938163157621e-02,
250  7.4989420933246e-02, 8.6596432336007e-02,
251  1.0000000000000e-01, 1.1547819846895e-01,
252  1.3335214321633e-01, 1.5399265260595e-01,
253  1.7782794100389e-01, 2.0535250264571e-01,
254  2.3713737056617e-01, 2.7384196342644e-01,
255  3.1622776601684e-01, 3.6517412725484e-01,
256  4.2169650342858e-01, 4.8696752516586e-01,
257  5.6234132519035e-01, 6.4938163157621e-01,
258  7.4989420933246e-01, 8.6596432336007e-01,
259  1.0000000000000e+00, 1.1547819846895e+00,
260  1.3335214321633e+00, 1.5399265260595e+00,
261  1.7782794100389e+00, 2.0535250264571e+00,
262  2.3713737056617e+00, 2.7384196342644e+00,
263  3.1622776601684e+00, 3.6517412725484e+00,
264  4.2169650342858e+00, 4.8696752516586e+00,
265  5.6234132519035e+00, 6.4938163157621e+00,
266  7.4989420933246e+00, 8.6596432336007e+00,
267  1.0000000000000e+01, 1.1547819846895e+01,
268  1.3335214321633e+01, 1.5399265260595e+01,
269  1.7782794100389e+01, 2.0535250264571e+01,
270  2.3713737056617e+01, 2.7384196342644e+01,
271  3.1622776601684e+01, 3.6517412725484e+01,
272  4.2169650342858e+01, 4.8696752516586e+01,
273  5.6234132519035e+01, 6.4938163157621e+01,
274  7.4989420933246e+01, 8.6596432336007e+01,
275  1.0000000000000e+02, 1.1547819846895e+02,
276  1.3335214321633e+02, 1.5399265260595e+02,
277  1.7782794100389e+02, 2.0535250264571e+02,
278  2.3713737056617e+02, 2.7384196342644e+02,
279  3.1622776601684e+02, 3.6517412725484e+02,
280  4.2169650342858e+02, 4.8696752516586e+02,
281  5.6234132519035e+02, 6.4938163157621e+02,
282  7.4989420933246e+02, 8.6596432336007e+02,
283  1.0000000000000e+03, 1.1547819846895e+03,
284  1.3335214321633e+03, 1.5399265260595e+03,
285  1.7782794100389e+03, 2.0535250264571e+03,
286  2.3713737056617e+03, 2.7384196342644e+03,
287  3.1622776601684e+03, 3.6517412725484e+03,
288  4.2169650342858e+03, 4.8696752516586e+03,
289  5.6234132519035e+03, 6.4938163157621e+03,
290  7.4989420933246e+03, 8.6596432336007e+03,
291  1.0000000000000e+04, 1.1547819846895e+04,
292  1.3335214321633e+04, 1.5399265260595e+04,
293  1.7782794100389e+04, 2.0535250264571e+04,
294  2.3713737056617e+04, 2.7384196342644e+04,
295  3.1622776601684e+04, 3.6517412725484e+04,
296  4.2169650342858e+04, 4.8696752516586e+04,
297  5.6234132519035e+04, 6.4938163157621e+04,
298  7.4989420933246e+04, 8.6596432336007e+04,
299  1.0000000000000e+05, 1.1547819846895e+05,
300  1.3335214321633e+05, 1.5399265260595e+05,
301  1.7782794100389e+05, 2.0535250264571e+05,
302  2.3713737056617e+05, 2.7384196342644e+05,
303  3.1622776601684e+05, 3.6517412725484e+05,
304  4.2169650342858e+05, 4.8696752516586e+05,
305  5.6234132519035e+05, 6.4938163157621e+05,
306  7.4989420933246e+05, 8.6596432336007e+05,
307 };
308 
312 static int decode_exp_vlc(WMACodecContext *s, int ch)
313 {
314  int last_exp, n, code;
315  const uint16_t *ptr;
316  float v, max_scale;
317  uint32_t *q, *q_end, iv;
318  const float *ptab = pow_tab + 60;
319  const uint32_t *iptab = (const uint32_t*)ptab;
320 
321  ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
322  q = (uint32_t *)s->exponents[ch];
323  q_end = q + s->block_len;
324  max_scale = 0;
325  if (s->version == 1) {
326  last_exp = get_bits(&s->gb, 5) + 10;
327  v = ptab[last_exp];
328  iv = iptab[last_exp];
329  max_scale = v;
330  n = *ptr++;
331  switch (n & 3) do {
332  case 0: *q++ = iv;
333  case 3: *q++ = iv;
334  case 2: *q++ = iv;
335  case 1: *q++ = iv;
336  } while ((n -= 4) > 0);
337  }else
338  last_exp = 36;
339 
340  while (q < q_end) {
341  code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
342  if (code < 0){
343  av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
344  return -1;
345  }
346  /* NOTE: this offset is the same as MPEG4 AAC ! */
347  last_exp += code - 60;
348  if ((unsigned)last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
349  av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
350  last_exp);
351  return -1;
352  }
353  v = ptab[last_exp];
354  iv = iptab[last_exp];
355  if (v > max_scale)
356  max_scale = v;
357  n = *ptr++;
358  switch (n & 3) do {
359  case 0: *q++ = iv;
360  case 3: *q++ = iv;
361  case 2: *q++ = iv;
362  case 1: *q++ = iv;
363  } while ((n -= 4) > 0);
364  }
365  s->max_exponent[ch] = max_scale;
366  return 0;
367 }
368 
369 
376 static void wma_window(WMACodecContext *s, float *out)
377 {
378  float *in = s->output;
379  int block_len, bsize, n;
380 
381  /* left part */
382  if (s->block_len_bits <= s->prev_block_len_bits) {
383  block_len = s->block_len;
384  bsize = s->frame_len_bits - s->block_len_bits;
385 
386  s->fdsp.vector_fmul_add(out, in, s->windows[bsize],
387  out, block_len);
388 
389  } else {
390  block_len = 1 << s->prev_block_len_bits;
391  n = (s->block_len - block_len) / 2;
392  bsize = s->frame_len_bits - s->prev_block_len_bits;
393 
394  s->fdsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
395  out+n, block_len);
396 
397  memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
398  }
399 
400  out += s->block_len;
401  in += s->block_len;
402 
403  /* right part */
404  if (s->block_len_bits <= s->next_block_len_bits) {
405  block_len = s->block_len;
406  bsize = s->frame_len_bits - s->block_len_bits;
407 
408  s->fdsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
409 
410  } else {
411  block_len = 1 << s->next_block_len_bits;
412  n = (s->block_len - block_len) / 2;
413  bsize = s->frame_len_bits - s->next_block_len_bits;
414 
415  memcpy(out, in, n*sizeof(float));
416 
417  s->fdsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
418 
419  memset(out+n+block_len, 0, n*sizeof(float));
420  }
421 }
422 
423 
429 {
430  int n, v, a, ch, bsize;
431  int coef_nb_bits, total_gain;
432  int nb_coefs[MAX_CHANNELS];
433  float mdct_norm;
434  FFTContext *mdct;
435 
436 #ifdef TRACE
437  tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
438 #endif
439 
440  /* compute current block length */
441  if (s->use_variable_block_len) {
442  n = av_log2(s->nb_block_sizes - 1) + 1;
443 
444  if (s->reset_block_lengths) {
445  s->reset_block_lengths = 0;
446  v = get_bits(&s->gb, n);
447  if (v >= s->nb_block_sizes){
448  av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
449  return -1;
450  }
452  v = get_bits(&s->gb, n);
453  if (v >= s->nb_block_sizes){
454  av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
455  return -1;
456  }
457  s->block_len_bits = s->frame_len_bits - v;
458  } else {
459  /* update block lengths */
462  }
463  v = get_bits(&s->gb, n);
464  if (v >= s->nb_block_sizes){
465  av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
466  return -1;
467  }
469  } else {
470  /* fixed block len */
474  }
475 
476  if (s->frame_len_bits - s->block_len_bits >= s->nb_block_sizes){
477  av_log(s->avctx, AV_LOG_ERROR, "block_len_bits not initialized to a valid value\n");
478  return -1;
479  }
480 
481  /* now check if the block length is coherent with the frame length */
482  s->block_len = 1 << s->block_len_bits;
483  if ((s->block_pos + s->block_len) > s->frame_len){
484  av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
485  return -1;
486  }
487 
488  if (s->avctx->channels == 2) {
489  s->ms_stereo = get_bits1(&s->gb);
490  }
491  v = 0;
492  for(ch = 0; ch < s->avctx->channels; ch++) {
493  a = get_bits1(&s->gb);
494  s->channel_coded[ch] = a;
495  v |= a;
496  }
497 
498  bsize = s->frame_len_bits - s->block_len_bits;
499 
500  /* if no channel coded, no need to go further */
501  /* XXX: fix potential framing problems */
502  if (!v)
503  goto next;
504 
505  /* read total gain and extract corresponding number of bits for
506  coef escape coding */
507  total_gain = 1;
508  for(;;) {
509  if (get_bits_left(&s->gb) < 7) {
510  av_log(s->avctx, AV_LOG_ERROR, "total_gain overread\n");
511  return AVERROR_INVALIDDATA;
512  }
513  a = get_bits(&s->gb, 7);
514  total_gain += a;
515  if (a != 127)
516  break;
517  }
518 
519  coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
520 
521  /* compute number of coefficients */
522  n = s->coefs_end[bsize] - s->coefs_start;
523  for(ch = 0; ch < s->avctx->channels; ch++)
524  nb_coefs[ch] = n;
525 
526  /* complex coding */
527  if (s->use_noise_coding) {
528 
529  for(ch = 0; ch < s->avctx->channels; ch++) {
530  if (s->channel_coded[ch]) {
531  int i, n, a;
532  n = s->exponent_high_sizes[bsize];
533  for(i=0;i<n;i++) {
534  a = get_bits1(&s->gb);
535  s->high_band_coded[ch][i] = a;
536  /* if noise coding, the coefficients are not transmitted */
537  if (a)
538  nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
539  }
540  }
541  }
542  for(ch = 0; ch < s->avctx->channels; ch++) {
543  if (s->channel_coded[ch]) {
544  int i, n, val, code;
545 
546  n = s->exponent_high_sizes[bsize];
547  val = (int)0x80000000;
548  for(i=0;i<n;i++) {
549  if (s->high_band_coded[ch][i]) {
550  if (val == (int)0x80000000) {
551  val = get_bits(&s->gb, 7) - 19;
552  } else {
553  code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
554  if (code < 0){
555  av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
556  return -1;
557  }
558  val += code - 18;
559  }
560  s->high_band_values[ch][i] = val;
561  }
562  }
563  }
564  }
565  }
566 
567  /* exponents can be reused in short blocks. */
568  if ((s->block_len_bits == s->frame_len_bits) ||
569  get_bits1(&s->gb)) {
570  for(ch = 0; ch < s->avctx->channels; ch++) {
571  if (s->channel_coded[ch]) {
572  if (s->use_exp_vlc) {
573  if (decode_exp_vlc(s, ch) < 0)
574  return -1;
575  } else {
576  decode_exp_lsp(s, ch);
577  }
578  s->exponents_bsize[ch] = bsize;
579  }
580  }
581  }
582 
583  /* parse spectral coefficients : just RLE encoding */
584  for (ch = 0; ch < s->avctx->channels; ch++) {
585  if (s->channel_coded[ch]) {
586  int tindex;
587  WMACoef* ptr = &s->coefs1[ch][0];
588 
589  /* special VLC tables are used for ms stereo because
590  there is potentially less energy there */
591  tindex = (ch == 1 && s->ms_stereo);
592  memset(ptr, 0, s->block_len * sizeof(WMACoef));
593  ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
594  s->level_table[tindex], s->run_table[tindex],
595  0, ptr, 0, nb_coefs[ch],
596  s->block_len, s->frame_len_bits, coef_nb_bits);
597  }
598  if (s->version == 1 && s->avctx->channels >= 2) {
599  align_get_bits(&s->gb);
600  }
601  }
602 
603  /* normalize */
604  {
605  int n4 = s->block_len / 2;
606  mdct_norm = 1.0 / (float)n4;
607  if (s->version == 1) {
608  mdct_norm *= sqrt(n4);
609  }
610  }
611 
612  /* finally compute the MDCT coefficients */
613  for (ch = 0; ch < s->avctx->channels; ch++) {
614  if (s->channel_coded[ch]) {
615  WMACoef *coefs1;
616  float *coefs, *exponents, mult, mult1, noise;
617  int i, j, n, n1, last_high_band, esize;
618  float exp_power[HIGH_BAND_MAX_SIZE];
619 
620  coefs1 = s->coefs1[ch];
621  exponents = s->exponents[ch];
622  esize = s->exponents_bsize[ch];
623  mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
624  mult *= mdct_norm;
625  coefs = s->coefs[ch];
626  if (s->use_noise_coding) {
627  mult1 = mult;
628  /* very low freqs : noise */
629  for(i = 0;i < s->coefs_start; i++) {
630  *coefs++ = s->noise_table[s->noise_index] *
631  exponents[i<<bsize>>esize] * mult1;
632  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
633  }
634 
635  n1 = s->exponent_high_sizes[bsize];
636 
637  /* compute power of high bands */
638  exponents = s->exponents[ch] +
639  (s->high_band_start[bsize]<<bsize>>esize);
640  last_high_band = 0; /* avoid warning */
641  for(j=0;j<n1;j++) {
643  s->block_len_bits][j];
644  if (s->high_band_coded[ch][j]) {
645  float e2, v;
646  e2 = 0;
647  for(i = 0;i < n; i++) {
648  v = exponents[i<<bsize>>esize];
649  e2 += v * v;
650  }
651  exp_power[j] = e2 / n;
652  last_high_band = j;
653  tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
654  }
655  exponents += n<<bsize>>esize;
656  }
657 
658  /* main freqs and high freqs */
659  exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
660  for(j=-1;j<n1;j++) {
661  if (j < 0) {
662  n = s->high_band_start[bsize] -
663  s->coefs_start;
664  } else {
666  s->block_len_bits][j];
667  }
668  if (j >= 0 && s->high_band_coded[ch][j]) {
669  /* use noise with specified power */
670  mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
671  /* XXX: use a table */
672  mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
673  mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
674  mult1 *= mdct_norm;
675  for(i = 0;i < n; i++) {
676  noise = s->noise_table[s->noise_index];
677  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
678  *coefs++ = noise *
679  exponents[i<<bsize>>esize] * mult1;
680  }
681  exponents += n<<bsize>>esize;
682  } else {
683  /* coded values + small noise */
684  for(i = 0;i < n; i++) {
685  noise = s->noise_table[s->noise_index];
686  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
687  *coefs++ = ((*coefs1++) + noise) *
688  exponents[i<<bsize>>esize] * mult;
689  }
690  exponents += n<<bsize>>esize;
691  }
692  }
693 
694  /* very high freqs : noise */
695  n = s->block_len - s->coefs_end[bsize];
696  mult1 = mult * exponents[((-1<<bsize))>>esize];
697  for(i = 0; i < n; i++) {
698  *coefs++ = s->noise_table[s->noise_index] * mult1;
699  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
700  }
701  } else {
702  /* XXX: optimize more */
703  for(i = 0;i < s->coefs_start; i++)
704  *coefs++ = 0.0;
705  n = nb_coefs[ch];
706  for(i = 0;i < n; i++) {
707  *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
708  }
709  n = s->block_len - s->coefs_end[bsize];
710  for(i = 0;i < n; i++)
711  *coefs++ = 0.0;
712  }
713  }
714  }
715 
716 #ifdef TRACE
717  for (ch = 0; ch < s->avctx->channels; ch++) {
718  if (s->channel_coded[ch]) {
719  dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
720  dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
721  }
722  }
723 #endif
724 
725  if (s->ms_stereo && s->channel_coded[1]) {
726  /* nominal case for ms stereo: we do it before mdct */
727  /* no need to optimize this case because it should almost
728  never happen */
729  if (!s->channel_coded[0]) {
730  tprintf(s->avctx, "rare ms-stereo case happened\n");
731  memset(s->coefs[0], 0, sizeof(float) * s->block_len);
732  s->channel_coded[0] = 1;
733  }
734 
735  s->fdsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
736  }
737 
738 next:
739  mdct = &s->mdct_ctx[bsize];
740 
741  for (ch = 0; ch < s->avctx->channels; ch++) {
742  int n4, index;
743 
744  n4 = s->block_len / 2;
745  if(s->channel_coded[ch]){
746  mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
747  }else if(!(s->ms_stereo && ch==1))
748  memset(s->output, 0, sizeof(s->output));
749 
750  /* multiply by the window and add in the frame */
751  index = (s->frame_len / 2) + s->block_pos - n4;
752  wma_window(s, &s->frame_out[ch][index]);
753  }
754 
755  /* update block number */
756  s->block_num++;
757  s->block_pos += s->block_len;
758  if (s->block_pos >= s->frame_len)
759  return 1;
760  else
761  return 0;
762 }
763 
764 /* decode a frame of frame_len samples */
765 static int wma_decode_frame(WMACodecContext *s, float **samples,
766  int samples_offset)
767 {
768  int ret, ch;
769 
770 #ifdef TRACE
771  tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
772 #endif
773 
774  /* read each block */
775  s->block_num = 0;
776  s->block_pos = 0;
777  for(;;) {
778  ret = wma_decode_block(s);
779  if (ret < 0)
780  return -1;
781  if (ret)
782  break;
783  }
784 
785  for (ch = 0; ch < s->avctx->channels; ch++) {
786  /* copy current block to output */
787  memcpy(samples[ch] + samples_offset, s->frame_out[ch],
788  s->frame_len * sizeof(*s->frame_out[ch]));
789  /* prepare for next block */
790  memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
791  s->frame_len * sizeof(*s->frame_out[ch]));
792 
793 #ifdef TRACE
794  dump_floats(s, "samples", 6, samples[ch] + samples_offset, s->frame_len);
795 #endif
796  }
797 
798  return 0;
799 }
800 
801 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
802  int *got_frame_ptr, AVPacket *avpkt)
803 {
804  AVFrame *frame = data;
805  const uint8_t *buf = avpkt->data;
806  int buf_size = avpkt->size;
807  WMACodecContext *s = avctx->priv_data;
808  int nb_frames, bit_offset, i, pos, len, ret;
809  uint8_t *q;
810  float **samples;
811  int samples_offset;
812 
813  tprintf(avctx, "***decode_superframe:\n");
814 
815  if(buf_size==0){
816  s->last_superframe_len = 0;
817  return 0;
818  }
819  if (buf_size < avctx->block_align) {
820  av_log(avctx, AV_LOG_ERROR,
821  "Input packet size too small (%d < %d)\n",
822  buf_size, avctx->block_align);
823  return AVERROR_INVALIDDATA;
824  }
825  if(avctx->block_align)
826  buf_size = avctx->block_align;
827 
828  init_get_bits(&s->gb, buf, buf_size*8);
829 
830  if (s->use_bit_reservoir) {
831  /* read super frame header */
832  skip_bits(&s->gb, 4); /* super frame index */
833  nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
834  if (nb_frames <= 0) {
835  av_log(avctx, AV_LOG_ERROR, "nb_frames is %d\n", nb_frames);
836  return AVERROR_INVALIDDATA;
837  }
838  } else {
839  nb_frames = 1;
840  }
841 
842  /* get output buffer */
843  frame->nb_samples = nb_frames * s->frame_len;
844  if ((ret = ff_get_buffer(avctx, frame)) < 0) {
845  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
846  return ret;
847  }
848  samples = (float **)frame->extended_data;
849  samples_offset = 0;
850 
851  if (s->use_bit_reservoir) {
852  bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
853  if (bit_offset > get_bits_left(&s->gb)) {
854  av_log(avctx, AV_LOG_ERROR,
855  "Invalid last frame bit offset %d > buf size %d (%d)\n",
856  bit_offset, get_bits_left(&s->gb), buf_size);
857  goto fail;
858  }
859 
860  if (s->last_superframe_len > 0) {
861  /* add bit_offset bits to last frame */
862  if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
864  goto fail;
866  len = bit_offset;
867  while (len > 7) {
868  *q++ = (get_bits)(&s->gb, 8);
869  len -= 8;
870  }
871  if (len > 0) {
872  *q++ = (get_bits)(&s->gb, len) << (8 - len);
873  }
874  memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
875 
876  /* XXX: bit_offset bits into last frame */
877  init_get_bits(&s->gb, s->last_superframe, s->last_superframe_len * 8 + bit_offset);
878  /* skip unused bits */
879  if (s->last_bitoffset > 0)
880  skip_bits(&s->gb, s->last_bitoffset);
881  /* this frame is stored in the last superframe and in the
882  current one */
883  if (wma_decode_frame(s, samples, samples_offset) < 0)
884  goto fail;
885  samples_offset += s->frame_len;
886  nb_frames--;
887  }
888 
889  /* read each frame starting from bit_offset */
890  pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
891  if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
892  return AVERROR_INVALIDDATA;
893  init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3))*8);
894  len = pos & 7;
895  if (len > 0)
896  skip_bits(&s->gb, len);
897 
898  s->reset_block_lengths = 1;
899  for(i=0;i<nb_frames;i++) {
900  if (wma_decode_frame(s, samples, samples_offset) < 0)
901  goto fail;
902  samples_offset += s->frame_len;
903  }
904 
905  /* we copy the end of the frame in the last frame buffer */
906  pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
907  s->last_bitoffset = pos & 7;
908  pos >>= 3;
909  len = buf_size - pos;
910  if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
911  av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
912  goto fail;
913  }
915  memcpy(s->last_superframe, buf + pos, len);
916  } else {
917  /* single frame decode */
918  if (wma_decode_frame(s, samples, samples_offset) < 0)
919  goto fail;
920  samples_offset += s->frame_len;
921  }
922 
923  av_dlog(s->avctx, "%d %d %d %d outbytes:%td eaten:%d\n",
925  (int8_t *)samples - (int8_t *)data, avctx->block_align);
926 
927  *got_frame_ptr = 1;
928 
929  return buf_size;
930  fail:
931  /* when error, we reset the bit reservoir */
932  s->last_superframe_len = 0;
933  return -1;
934 }
935 
936 static av_cold void flush(AVCodecContext *avctx)
937 {
938  WMACodecContext *s = avctx->priv_data;
939 
940  s->last_bitoffset=
941  s->last_superframe_len= 0;
942 }
943 
944 #if CONFIG_WMAV1_DECODER
945 AVCodec ff_wmav1_decoder = {
946  .name = "wmav1",
947  .type = AVMEDIA_TYPE_AUDIO,
948  .id = AV_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  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
958 };
959 #endif
960 #if CONFIG_WMAV2_DECODER
961 AVCodec ff_wmav2_decoder = {
962  .name = "wmav2",
963  .type = AVMEDIA_TYPE_AUDIO,
964  .id = AV_CODEC_ID_WMAV2,
965  .priv_data_size = sizeof(WMACodecContext),
967  .close = ff_wma_end,
969  .flush = flush,
970  .capabilities = CODEC_CAP_DR1,
971  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
972  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
974 };
975 #endif