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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 
22 /**
23  * @file
24  * WMA compatible decoder.
25  * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
26  * WMA v1 is identified by audio format 0x160 in Microsoft media files
27  * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
28  *
29  * To use this decoder, a calling application must supply the extra data
30  * bytes provided with the WMA data. These are the extra, codec-specific
31  * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
32  * to the decoder using the extradata[_size] fields in AVCodecContext. There
33  * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
34  */
35 
36 #include "libavutil/attributes.h"
37 
38 #include "avcodec.h"
39 #include "internal.h"
40 #include "wma.h"
41 
42 #define EXPVLCBITS 8
43 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
44 
45 #define HGAINVLCBITS 9
46 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
47 
48 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
49 
50 #ifdef TRACE
51 static void dump_floats(WMACodecContext *s, const char *name,
52  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 /* TRACE */
68 
70 {
71  WMACodecContext *s = avctx->priv_data;
72  int i, flags2;
73  uint8_t *extradata;
74 
75  if (!avctx->block_align) {
76  av_log(avctx, AV_LOG_ERROR, "block_align is not set\n");
77  return AVERROR(EINVAL);
78  }
79 
80  s->avctx = avctx;
81 
82  /* extract flag infos */
83  flags2 = 0;
84  extradata = avctx->extradata;
85  if (avctx->codec->id == AV_CODEC_ID_WMAV1 && avctx->extradata_size >= 4)
86  flags2 = AV_RL16(extradata + 2);
87  else if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 6)
88  flags2 = AV_RL16(extradata + 4);
89 
90  s->use_exp_vlc = flags2 & 0x0001;
91  s->use_bit_reservoir = flags2 & 0x0002;
92  s->use_variable_block_len = flags2 & 0x0004;
93 
94  if (avctx->codec->id == AV_CODEC_ID_WMAV2 && avctx->extradata_size >= 8){
95  if (AV_RL16(extradata+4)==0xd && s->use_variable_block_len){
96  av_log(avctx, AV_LOG_WARNING, "Disabling use_variable_block_len, if this fails contact the ffmpeg developers and send us the file\n");
97  s->use_variable_block_len= 0; // this fixes issue1503
98  }
99  }
100 
101  for (i=0; i<MAX_CHANNELS; i++)
102  s->max_exponent[i] = 1.0;
103 
104  if (ff_wma_init(avctx, flags2) < 0)
105  return -1;
106 
107  /* init MDCT */
108  for (i = 0; i < s->nb_block_sizes; i++)
109  ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0 / 32768.0);
110 
111  if (s->use_noise_coding) {
113  ff_wma_hgain_huffbits, 1, 1,
114  ff_wma_hgain_huffcodes, 2, 2, 0);
115  }
116 
117  if (s->use_exp_vlc)
118  init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), // FIXME move out of context
120  ff_aac_scalefactor_code, 4, 4, 0);
121  else
123 
125 
126  return 0;
127 }
128 
129 /**
130  * compute x^-0.25 with an exponent and mantissa table. We use linear
131  * interpolation to reduce the mantissa table size at a small speed
132  * expense (linear interpolation approximately doubles the number of
133  * bits of precision).
134  */
135 static inline float pow_m1_4(WMACodecContext *s, float x)
136 {
137  union {
138  float f;
139  unsigned int v;
140  } u, t;
141  unsigned int e, m;
142  float a, b;
143 
144  u.f = x;
145  e = u.v >> 23;
146  m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
147  /* build interpolation scale: 1 <= t < 2. */
148  t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
149  a = s->lsp_pow_m_table1[m];
150  b = s->lsp_pow_m_table2[m];
151  return s->lsp_pow_e_table[e] * (a + b * t.f);
152 }
153 
154 static av_cold void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
155 {
156  float wdel, a, b;
157  int i, e, m;
158 
159  wdel = M_PI / frame_len;
160  for (i = 0; i < frame_len; i++)
161  s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
162 
163  /* tables for x^-0.25 computation */
164  for (i = 0; i < 256; i++) {
165  e = i - 126;
166  s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
167  }
168 
169  /* NOTE: these two tables are needed to avoid two operations in
170  * pow_m1_4 */
171  b = 1.0;
172  for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
173  m = (1 << LSP_POW_BITS) + i;
174  a = (float) m * (0.5 / (1 << LSP_POW_BITS));
175  a = pow(a, -0.25);
176  s->lsp_pow_m_table1[i] = 2 * a - b;
177  s->lsp_pow_m_table2[i] = b - a;
178  b = a;
179  }
180 }
181 
182 /**
183  * NOTE: We use the same code as Vorbis here
184  * @todo optimize it further with SSE/3Dnow
185  */
186 static void wma_lsp_to_curve(WMACodecContext *s, float *out, float *val_max_ptr,
187  int n, float *lsp)
188 {
189  int i, j;
190  float p, q, w, v, val_max;
191 
192  val_max = 0;
193  for (i = 0; i < n; i++) {
194  p = 0.5f;
195  q = 0.5f;
196  w = s->lsp_cos_table[i];
197  for (j = 1; j < NB_LSP_COEFS; j += 2) {
198  q *= w - lsp[j - 1];
199  p *= w - lsp[j];
200  }
201  p *= p * (2.0f - w);
202  q *= q * (2.0f + w);
203  v = p + q;
204  v = pow_m1_4(s, v);
205  if (v > val_max)
206  val_max = v;
207  out[i] = v;
208  }
209  *val_max_ptr = val_max;
210 }
211 
212 /**
213  * decode exponents coded with LSP coefficients (same idea as Vorbis)
214  */
215 static void decode_exp_lsp(WMACodecContext *s, int ch)
216 {
217  float lsp_coefs[NB_LSP_COEFS];
218  int val, i;
219 
220  for (i = 0; i < NB_LSP_COEFS; i++) {
221  if (i == 0 || i >= 8)
222  val = get_bits(&s->gb, 3);
223  else
224  val = get_bits(&s->gb, 4);
225  lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
226  }
227 
228  wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
229  s->block_len, lsp_coefs);
230 }
231 
232 /** pow(10, i / 16.0) for i in -60..95 */
233 static const float pow_tab[] = {
234  1.7782794100389e-04, 2.0535250264571e-04,
235  2.3713737056617e-04, 2.7384196342644e-04,
236  3.1622776601684e-04, 3.6517412725484e-04,
237  4.2169650342858e-04, 4.8696752516586e-04,
238  5.6234132519035e-04, 6.4938163157621e-04,
239  7.4989420933246e-04, 8.6596432336006e-04,
240  1.0000000000000e-03, 1.1547819846895e-03,
241  1.3335214321633e-03, 1.5399265260595e-03,
242  1.7782794100389e-03, 2.0535250264571e-03,
243  2.3713737056617e-03, 2.7384196342644e-03,
244  3.1622776601684e-03, 3.6517412725484e-03,
245  4.2169650342858e-03, 4.8696752516586e-03,
246  5.6234132519035e-03, 6.4938163157621e-03,
247  7.4989420933246e-03, 8.6596432336006e-03,
248  1.0000000000000e-02, 1.1547819846895e-02,
249  1.3335214321633e-02, 1.5399265260595e-02,
250  1.7782794100389e-02, 2.0535250264571e-02,
251  2.3713737056617e-02, 2.7384196342644e-02,
252  3.1622776601684e-02, 3.6517412725484e-02,
253  4.2169650342858e-02, 4.8696752516586e-02,
254  5.6234132519035e-02, 6.4938163157621e-02,
255  7.4989420933246e-02, 8.6596432336007e-02,
256  1.0000000000000e-01, 1.1547819846895e-01,
257  1.3335214321633e-01, 1.5399265260595e-01,
258  1.7782794100389e-01, 2.0535250264571e-01,
259  2.3713737056617e-01, 2.7384196342644e-01,
260  3.1622776601684e-01, 3.6517412725484e-01,
261  4.2169650342858e-01, 4.8696752516586e-01,
262  5.6234132519035e-01, 6.4938163157621e-01,
263  7.4989420933246e-01, 8.6596432336007e-01,
264  1.0000000000000e+00, 1.1547819846895e+00,
265  1.3335214321633e+00, 1.5399265260595e+00,
266  1.7782794100389e+00, 2.0535250264571e+00,
267  2.3713737056617e+00, 2.7384196342644e+00,
268  3.1622776601684e+00, 3.6517412725484e+00,
269  4.2169650342858e+00, 4.8696752516586e+00,
270  5.6234132519035e+00, 6.4938163157621e+00,
271  7.4989420933246e+00, 8.6596432336007e+00,
272  1.0000000000000e+01, 1.1547819846895e+01,
273  1.3335214321633e+01, 1.5399265260595e+01,
274  1.7782794100389e+01, 2.0535250264571e+01,
275  2.3713737056617e+01, 2.7384196342644e+01,
276  3.1622776601684e+01, 3.6517412725484e+01,
277  4.2169650342858e+01, 4.8696752516586e+01,
278  5.6234132519035e+01, 6.4938163157621e+01,
279  7.4989420933246e+01, 8.6596432336007e+01,
280  1.0000000000000e+02, 1.1547819846895e+02,
281  1.3335214321633e+02, 1.5399265260595e+02,
282  1.7782794100389e+02, 2.0535250264571e+02,
283  2.3713737056617e+02, 2.7384196342644e+02,
284  3.1622776601684e+02, 3.6517412725484e+02,
285  4.2169650342858e+02, 4.8696752516586e+02,
286  5.6234132519035e+02, 6.4938163157621e+02,
287  7.4989420933246e+02, 8.6596432336007e+02,
288  1.0000000000000e+03, 1.1547819846895e+03,
289  1.3335214321633e+03, 1.5399265260595e+03,
290  1.7782794100389e+03, 2.0535250264571e+03,
291  2.3713737056617e+03, 2.7384196342644e+03,
292  3.1622776601684e+03, 3.6517412725484e+03,
293  4.2169650342858e+03, 4.8696752516586e+03,
294  5.6234132519035e+03, 6.4938163157621e+03,
295  7.4989420933246e+03, 8.6596432336007e+03,
296  1.0000000000000e+04, 1.1547819846895e+04,
297  1.3335214321633e+04, 1.5399265260595e+04,
298  1.7782794100389e+04, 2.0535250264571e+04,
299  2.3713737056617e+04, 2.7384196342644e+04,
300  3.1622776601684e+04, 3.6517412725484e+04,
301  4.2169650342858e+04, 4.8696752516586e+04,
302  5.6234132519035e+04, 6.4938163157621e+04,
303  7.4989420933246e+04, 8.6596432336007e+04,
304  1.0000000000000e+05, 1.1547819846895e+05,
305  1.3335214321633e+05, 1.5399265260595e+05,
306  1.7782794100389e+05, 2.0535250264571e+05,
307  2.3713737056617e+05, 2.7384196342644e+05,
308  3.1622776601684e+05, 3.6517412725484e+05,
309  4.2169650342858e+05, 4.8696752516586e+05,
310  5.6234132519035e+05, 6.4938163157621e+05,
311  7.4989420933246e+05, 8.6596432336007e+05,
312 };
313 
314 /**
315  * decode exponents coded with VLC codes
316  */
317 static int decode_exp_vlc(WMACodecContext *s, int ch)
318 {
319  int last_exp, n, code;
320  const uint16_t *ptr;
321  float v, max_scale;
322  uint32_t *q, *q_end, iv;
323  const float *ptab = pow_tab + 60;
324  const uint32_t *iptab = (const uint32_t *) ptab;
325 
326  ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
327  q = (uint32_t *) s->exponents[ch];
328  q_end = q + s->block_len;
329  max_scale = 0;
330  if (s->version == 1) {
331  last_exp = get_bits(&s->gb, 5) + 10;
332  v = ptab[last_exp];
333  iv = iptab[last_exp];
334  max_scale = v;
335  n = *ptr++;
336  switch (n & 3) do {
337  case 0: *q++ = iv;
338  case 3: *q++ = iv;
339  case 2: *q++ = iv;
340  case 1: *q++ = iv;
341  } while ((n -= 4) > 0);
342  } else
343  last_exp = 36;
344 
345  while (q < q_end) {
346  code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
347  if (code < 0) {
348  av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
349  return -1;
350  }
351  /* NOTE: this offset is the same as MPEG4 AAC ! */
352  last_exp += code - 60;
353  if ((unsigned) last_exp + 60 >= FF_ARRAY_ELEMS(pow_tab)) {
354  av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
355  last_exp);
356  return -1;
357  }
358  v = ptab[last_exp];
359  iv = iptab[last_exp];
360  if (v > max_scale)
361  max_scale = v;
362  n = *ptr++;
363  switch (n & 3) do {
364  case 0: *q++ = iv;
365  case 3: *q++ = iv;
366  case 2: *q++ = iv;
367  case 1: *q++ = iv;
368  } while ((n -= 4) > 0);
369  }
370  s->max_exponent[ch] = max_scale;
371  return 0;
372 }
373 
374 /**
375  * Apply MDCT window and add into output.
376  *
377  * We ensure that when the windows overlap their squared sum
378  * is always 1 (MDCT reconstruction rule).
379  */
380 static void wma_window(WMACodecContext *s, float *out)
381 {
382  float *in = s->output;
383  int block_len, bsize, n;
384 
385  /* left part */
386  if (s->block_len_bits <= s->prev_block_len_bits) {
387  block_len = s->block_len;
388  bsize = s->frame_len_bits - s->block_len_bits;
389 
390  s->fdsp->vector_fmul_add(out, in, s->windows[bsize],
391  out, block_len);
392  } else {
393  block_len = 1 << s->prev_block_len_bits;
394  n = (s->block_len - block_len) / 2;
395  bsize = s->frame_len_bits - s->prev_block_len_bits;
396 
397  s->fdsp->vector_fmul_add(out + n, in + n, s->windows[bsize],
398  out + n, block_len);
399 
400  memcpy(out + n + block_len, in + n + block_len, n * sizeof(float));
401  }
402 
403  out += s->block_len;
404  in += s->block_len;
405 
406  /* right part */
407  if (s->block_len_bits <= s->next_block_len_bits) {
408  block_len = s->block_len;
409  bsize = s->frame_len_bits - s->block_len_bits;
410 
411  s->fdsp->vector_fmul_reverse(out, in, s->windows[bsize], block_len);
412  } else {
413  block_len = 1 << s->next_block_len_bits;
414  n = (s->block_len - block_len) / 2;
415  bsize = s->frame_len_bits - s->next_block_len_bits;
416 
417  memcpy(out, in, n * sizeof(float));
418 
419  s->fdsp->vector_fmul_reverse(out + n, in + n, s->windows[bsize],
420  block_len);
421 
422  memset(out + n + block_len, 0, n * sizeof(float));
423  }
424 }
425 
426 /**
427  * @return 0 if OK. 1 if last block of frame. return -1 if
428  * unrecorrable error.
429  */
431 {
432  int n, v, a, ch, bsize;
433  int coef_nb_bits, total_gain;
434  int nb_coefs[MAX_CHANNELS];
435  float mdct_norm;
436  FFTContext *mdct;
437 
438 #ifdef TRACE
439  tprintf(s->avctx, "***decode_block: %d:%d\n",
440  s->frame_count - 1, s->block_num);
441 #endif /* TRACE */
442 
443  /* compute current block length */
444  if (s->use_variable_block_len) {
445  n = av_log2(s->nb_block_sizes - 1) + 1;
446 
447  if (s->reset_block_lengths) {
448  s->reset_block_lengths = 0;
449  v = get_bits(&s->gb, n);
450  if (v >= s->nb_block_sizes) {
452  "prev_block_len_bits %d out of range\n",
453  s->frame_len_bits - v);
454  return -1;
455  }
457  v = get_bits(&s->gb, n);
458  if (v >= s->nb_block_sizes) {
460  "block_len_bits %d out of range\n",
461  s->frame_len_bits - v);
462  return -1;
463  }
464  s->block_len_bits = s->frame_len_bits - v;
465  } else {
466  /* update block lengths */
469  }
470  v = get_bits(&s->gb, n);
471  if (v >= s->nb_block_sizes) {
473  "next_block_len_bits %d out of range\n",
474  s->frame_len_bits - v);
475  return -1;
476  }
478  } else {
479  /* fixed block len */
483  }
484 
485  if (s->frame_len_bits - s->block_len_bits >= s->nb_block_sizes){
486  av_log(s->avctx, AV_LOG_ERROR, "block_len_bits not initialized to a valid value\n");
487  return -1;
488  }
489 
490  /* now check if the block length is coherent with the frame length */
491  s->block_len = 1 << s->block_len_bits;
492  if ((s->block_pos + s->block_len) > s->frame_len) {
493  av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
494  return -1;
495  }
496 
497  if (s->avctx->channels == 2)
498  s->ms_stereo = get_bits1(&s->gb);
499  v = 0;
500  for (ch = 0; ch < s->avctx->channels; ch++) {
501  a = get_bits1(&s->gb);
502  s->channel_coded[ch] = a;
503  v |= a;
504  }
505 
506  bsize = s->frame_len_bits - s->block_len_bits;
507 
508  /* if no channel coded, no need to go further */
509  /* XXX: fix potential framing problems */
510  if (!v)
511  goto next;
512 
513  /* read total gain and extract corresponding number of bits for
514  * coef escape coding */
515  total_gain = 1;
516  for (;;) {
517  if (get_bits_left(&s->gb) < 7) {
518  av_log(s->avctx, AV_LOG_ERROR, "total_gain overread\n");
519  return AVERROR_INVALIDDATA;
520  }
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->avctx->channels; ch++)
532  nb_coefs[ch] = n;
533 
534  /* complex coding */
535  if (s->use_noise_coding) {
536  for (ch = 0; ch < s->avctx->channels; ch++) {
537  if (s->channel_coded[ch]) {
538  int i, n, a;
539  n = s->exponent_high_sizes[bsize];
540  for (i = 0; i < n; i++) {
541  a = get_bits1(&s->gb);
542  s->high_band_coded[ch][i] = a;
543  /* if noise coding, the coefficients are not transmitted */
544  if (a)
545  nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
546  }
547  }
548  }
549  for (ch = 0; ch < s->avctx->channels; ch++) {
550  if (s->channel_coded[ch]) {
551  int i, n, val, code;
552 
553  n = s->exponent_high_sizes[bsize];
554  val = (int) 0x80000000;
555  for (i = 0; i < n; i++) {
556  if (s->high_band_coded[ch][i]) {
557  if (val == (int) 0x80000000) {
558  val = get_bits(&s->gb, 7) - 19;
559  } else {
560  code = get_vlc2(&s->gb, s->hgain_vlc.table,
562  if (code < 0) {
564  "hgain vlc invalid\n");
565  return -1;
566  }
567  val += code - 18;
568  }
569  s->high_band_values[ch][i] = val;
570  }
571  }
572  }
573  }
574  }
575 
576  /* exponents can be reused in short blocks. */
577  if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {
578  for (ch = 0; ch < s->avctx->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->avctx->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->avctx->channels >= 2)
607  align_get_bits(&s->gb);
608  }
609 
610  /* normalize */
611  {
612  int n4 = s->block_len / 2;
613  mdct_norm = 1.0 / (float) n4;
614  if (s->version == 1)
615  mdct_norm *= sqrt(n4);
616  }
617 
618  /* finally compute the MDCT coefficients */
619  for (ch = 0; ch < s->avctx->channels; ch++) {
620  if (s->channel_coded[ch]) {
621  WMACoef *coefs1;
622  float *coefs, *exponents, mult, mult1, noise;
623  int i, j, n, n1, last_high_band, esize;
624  float exp_power[HIGH_BAND_MAX_SIZE];
625 
626  coefs1 = s->coefs1[ch];
627  exponents = s->exponents[ch];
628  esize = s->exponents_bsize[ch];
629  mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
630  mult *= mdct_norm;
631  coefs = s->coefs[ch];
632  if (s->use_noise_coding) {
633  mult1 = mult;
634  /* very low freqs : noise */
635  for (i = 0; i < s->coefs_start; i++) {
636  *coefs++ = s->noise_table[s->noise_index] *
637  exponents[i << bsize >> esize] * mult1;
638  s->noise_index = (s->noise_index + 1) &
639  (NOISE_TAB_SIZE - 1);
640  }
641 
642  n1 = s->exponent_high_sizes[bsize];
643 
644  /* compute power of high bands */
645  exponents = s->exponents[ch] +
646  (s->high_band_start[bsize] << bsize >> esize);
647  last_high_band = 0; /* avoid warning */
648  for (j = 0; j < n1; j++) {
650  s->block_len_bits][j];
651  if (s->high_band_coded[ch][j]) {
652  float e2, v;
653  e2 = 0;
654  for (i = 0; i < n; i++) {
655  v = exponents[i << bsize >> esize];
656  e2 += v * v;
657  }
658  exp_power[j] = e2 / n;
659  last_high_band = j;
660  tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
661  }
662  exponents += n << bsize >> esize;
663  }
664 
665  /* main freqs and high freqs */
666  exponents = s->exponents[ch] + (s->coefs_start << bsize >> esize);
667  for (j = -1; j < n1; j++) {
668  if (j < 0)
669  n = s->high_band_start[bsize] - s->coefs_start;
670  else
672  s->block_len_bits][j];
673  if (j >= 0 && s->high_band_coded[ch][j]) {
674  /* use noise with specified power */
675  mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
676  /* XXX: use a table */
677  mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
678  mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
679  mult1 *= mdct_norm;
680  for (i = 0; i < n; i++) {
681  noise = s->noise_table[s->noise_index];
682  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
683  *coefs++ = noise * exponents[i << bsize >> esize] * mult1;
684  }
685  exponents += n << bsize >> esize;
686  } else {
687  /* coded values + small noise */
688  for (i = 0; i < n; i++) {
689  noise = s->noise_table[s->noise_index];
690  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
691  *coefs++ = ((*coefs1++) + noise) *
692  exponents[i << bsize >> esize] * mult;
693  }
694  exponents += n << bsize >> esize;
695  }
696  }
697 
698  /* very high freqs : noise */
699  n = s->block_len - s->coefs_end[bsize];
700  mult1 = mult * exponents[((-1 << bsize)) >> esize];
701  for (i = 0; i < n; i++) {
702  *coefs++ = s->noise_table[s->noise_index] * mult1;
703  s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
704  }
705  } else {
706  /* XXX: optimize more */
707  for (i = 0; i < s->coefs_start; i++)
708  *coefs++ = 0.0;
709  n = nb_coefs[ch];
710  for (i = 0; i < n; i++)
711  *coefs++ = coefs1[i] * exponents[i << bsize >> esize] * mult;
712  n = s->block_len - s->coefs_end[bsize];
713  for (i = 0; i < n; i++)
714  *coefs++ = 0.0;
715  }
716  }
717  }
718 
719 #ifdef TRACE
720  for (ch = 0; ch < s->avctx->channels; ch++) {
721  if (s->channel_coded[ch]) {
722  dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
723  dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
724  }
725  }
726 #endif /* TRACE */
727 
728  if (s->ms_stereo && s->channel_coded[1]) {
729  /* nominal case for ms stereo: we do it before mdct */
730  /* no need to optimize this case because it should almost
731  * never happen */
732  if (!s->channel_coded[0]) {
733  tprintf(s->avctx, "rare ms-stereo case happened\n");
734  memset(s->coefs[0], 0, sizeof(float) * s->block_len);
735  s->channel_coded[0] = 1;
736  }
737 
738  s->fdsp->butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
739  }
740 
741 next:
742  mdct = &s->mdct_ctx[bsize];
743 
744  for (ch = 0; ch < s->avctx->channels; ch++) {
745  int n4, index;
746 
747  n4 = s->block_len / 2;
748  if (s->channel_coded[ch])
749  mdct->imdct_calc(mdct, s->output, s->coefs[ch]);
750  else if (!(s->ms_stereo && ch == 1))
751  memset(s->output, 0, sizeof(s->output));
752 
753  /* multiply by the window and add in the frame */
754  index = (s->frame_len / 2) + s->block_pos - n4;
755  wma_window(s, &s->frame_out[ch][index]);
756  }
757 
758  /* update block number */
759  s->block_num++;
760  s->block_pos += s->block_len;
761  if (s->block_pos >= s->frame_len)
762  return 1;
763  else
764  return 0;
765 }
766 
767 /* decode a frame of frame_len samples */
768 static int wma_decode_frame(WMACodecContext *s, float **samples,
769  int samples_offset)
770 {
771  int ret, ch;
772 
773 #ifdef TRACE
774  tprintf(s->avctx, "***decode_frame: %d size=%d\n",
775  s->frame_count++, s->frame_len);
776 #endif /* TRACE */
777 
778  /* read each block */
779  s->block_num = 0;
780  s->block_pos = 0;
781  for (;;) {
782  ret = wma_decode_block(s);
783  if (ret < 0)
784  return -1;
785  if (ret)
786  break;
787  }
788 
789  for (ch = 0; ch < s->avctx->channels; ch++) {
790  /* copy current block to output */
791  memcpy(samples[ch] + samples_offset, s->frame_out[ch],
792  s->frame_len * sizeof(*s->frame_out[ch]));
793  /* prepare for next block */
794  memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
795  s->frame_len * sizeof(*s->frame_out[ch]));
796 
797 #ifdef TRACE
798  dump_floats(s, "samples", 6, samples[ch] + samples_offset,
799  s->frame_len);
800 #endif /* TRACE */
801  }
802 
803  return 0;
804 }
805 
806 static int wma_decode_superframe(AVCodecContext *avctx, void *data,
807  int *got_frame_ptr, AVPacket *avpkt)
808 {
809  AVFrame *frame = data;
810  const uint8_t *buf = avpkt->data;
811  int buf_size = avpkt->size;
812  WMACodecContext *s = avctx->priv_data;
813  int nb_frames, bit_offset, i, pos, len, ret;
814  uint8_t *q;
815  float **samples;
816  int samples_offset;
817 
818  tprintf(avctx, "***decode_superframe:\n");
819 
820  if (buf_size == 0) {
821  s->last_superframe_len = 0;
822  return 0;
823  }
824  if (buf_size < avctx->block_align) {
825  av_log(avctx, AV_LOG_ERROR,
826  "Input packet size too small (%d < %d)\n",
827  buf_size, avctx->block_align);
828  return AVERROR_INVALIDDATA;
829  }
830  if (avctx->block_align)
831  buf_size = avctx->block_align;
832 
833  init_get_bits(&s->gb, buf, buf_size * 8);
834 
835  if (s->use_bit_reservoir) {
836  /* read super frame header */
837  skip_bits(&s->gb, 4); /* super frame index */
838  nb_frames = get_bits(&s->gb, 4) - (s->last_superframe_len <= 0);
839  if (nb_frames <= 0) {
840  int is_error = nb_frames < 0 || get_bits_left(&s->gb) <= 8;
841  av_log(avctx, is_error ? AV_LOG_ERROR : AV_LOG_WARNING,
842  "nb_frames is %d bits left %d\n",
843  nb_frames, get_bits_left(&s->gb));
844  if (is_error)
845  return AVERROR_INVALIDDATA;
846 
847  if ((s->last_superframe_len + buf_size - 1) >
849  goto fail;
850 
852  len = buf_size - 1;
853  while (len > 0) {
854  *q++ = get_bits (&s->gb, 8);
855  len --;
856  }
857  memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
858 
859  s->last_superframe_len += 8*buf_size - 8;
860 // s->reset_block_lengths = 1; //XXX is this needed ?
861  *got_frame_ptr = 0;
862  return buf_size;
863  }
864  } else
865  nb_frames = 1;
866 
867  /* get output buffer */
868  frame->nb_samples = nb_frames * s->frame_len;
869  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
870  return ret;
871  samples = (float **) frame->extended_data;
872  samples_offset = 0;
873 
874  if (s->use_bit_reservoir) {
875  bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
876  if (bit_offset > get_bits_left(&s->gb)) {
877  av_log(avctx, AV_LOG_ERROR,
878  "Invalid last frame bit offset %d > buf size %d (%d)\n",
879  bit_offset, get_bits_left(&s->gb), buf_size);
880  goto fail;
881  }
882 
883  if (s->last_superframe_len > 0) {
884  /* add bit_offset bits to last frame */
885  if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
887  goto fail;
889  len = bit_offset;
890  while (len > 7) {
891  *q++ = (get_bits) (&s->gb, 8);
892  len -= 8;
893  }
894  if (len > 0)
895  *q++ = (get_bits) (&s->gb, len) << (8 - len);
896  memset(q, 0, FF_INPUT_BUFFER_PADDING_SIZE);
897 
898  /* XXX: bit_offset bits into last frame */
900  s->last_superframe_len * 8 + bit_offset);
901  /* skip unused bits */
902  if (s->last_bitoffset > 0)
903  skip_bits(&s->gb, s->last_bitoffset);
904  /* this frame is stored in the last superframe and in the
905  * current one */
906  if (wma_decode_frame(s, samples, samples_offset) < 0)
907  goto fail;
908  samples_offset += s->frame_len;
909  nb_frames--;
910  }
911 
912  /* read each frame starting from bit_offset */
913  pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
914  if (pos >= MAX_CODED_SUPERFRAME_SIZE * 8 || pos > buf_size * 8)
915  return AVERROR_INVALIDDATA;
916  init_get_bits(&s->gb, buf + (pos >> 3), (buf_size - (pos >> 3)) * 8);
917  len = pos & 7;
918  if (len > 0)
919  skip_bits(&s->gb, len);
920 
921  s->reset_block_lengths = 1;
922  for (i = 0; i < nb_frames; i++) {
923  if (wma_decode_frame(s, samples, samples_offset) < 0)
924  goto fail;
925  samples_offset += s->frame_len;
926  }
927 
928  /* we copy the end of the frame in the last frame buffer */
929  pos = get_bits_count(&s->gb) +
930  ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
931  s->last_bitoffset = pos & 7;
932  pos >>= 3;
933  len = buf_size - pos;
934  if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
935  av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
936  goto fail;
937  }
939  memcpy(s->last_superframe, buf + pos, len);
940  } else {
941  /* single frame decode */
942  if (wma_decode_frame(s, samples, samples_offset) < 0)
943  goto fail;
944  samples_offset += s->frame_len;
945  }
946 
947  av_dlog(s->avctx, "%d %d %d %d outbytes:%"PTRDIFF_SPECIFIER" eaten:%d\n",
949  (int8_t *) samples - (int8_t *) data, avctx->block_align);
950 
951  *got_frame_ptr = 1;
952 
953  return buf_size;
954 
955 fail:
956  /* when error, we reset the bit reservoir */
957  s->last_superframe_len = 0;
958  return -1;
959 }
960 
961 static av_cold void flush(AVCodecContext *avctx)
962 {
963  WMACodecContext *s = avctx->priv_data;
964 
965  s->last_bitoffset =
966  s->last_superframe_len = 0;
967 }
968 
969 #if CONFIG_WMAV1_DECODER
970 AVCodec ff_wmav1_decoder = {
971  .name = "wmav1",
972  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
973  .type = AVMEDIA_TYPE_AUDIO,
974  .id = AV_CODEC_ID_WMAV1,
975  .priv_data_size = sizeof(WMACodecContext),
977  .close = ff_wma_end,
979  .flush = flush,
980  .capabilities = CODEC_CAP_DR1,
981  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
983 };
984 #endif
985 #if CONFIG_WMAV2_DECODER
986 AVCodec ff_wmav2_decoder = {
987  .name = "wmav2",
988  .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
989  .type = AVMEDIA_TYPE_AUDIO,
990  .id = AV_CODEC_ID_WMAV2,
991  .priv_data_size = sizeof(WMACodecContext),
993  .close = ff_wma_end,
995  .flush = flush,
996  .capabilities = CODEC_CAP_DR1,
997  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
999 };
1000 #endif