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wma.c
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1 /*
2  * WMA compatible codec
3  * Copyright (c) 2002-2007 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 #include "avcodec.h"
23 #include "sinewin.h"
24 #include "wma.h"
25 #include "wma_common.h"
26 #include "wmadata.h"
27 
28 #undef NDEBUG
29 #include <assert.h>
30 
31 /* XXX: use same run/length optimization as mpeg decoders */
32 //FIXME maybe split decode / encode or pass flag
33 static void init_coef_vlc(VLC *vlc, uint16_t **prun_table,
34  float **plevel_table, uint16_t **pint_table,
35  const CoefVLCTable *vlc_table)
36 {
37  int n = vlc_table->n;
38  const uint8_t *table_bits = vlc_table->huffbits;
39  const uint32_t *table_codes = vlc_table->huffcodes;
40  const uint16_t *levels_table = vlc_table->levels;
41  uint16_t *run_table, *level_table, *int_table;
42  float *flevel_table;
43  int i, l, j, k, level;
44 
45  init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
46 
47  run_table = av_malloc(n * sizeof(uint16_t));
48  level_table = av_malloc(n * sizeof(uint16_t));
49  flevel_table= av_malloc(n * sizeof(*flevel_table));
50  int_table = av_malloc(n * sizeof(uint16_t));
51  i = 2;
52  level = 1;
53  k = 0;
54  while (i < n) {
55  int_table[k] = i;
56  l = levels_table[k++];
57  for (j = 0; j < l; j++) {
58  run_table[i] = j;
59  level_table[i] = level;
60  flevel_table[i]= level;
61  i++;
62  }
63  level++;
64  }
65  *prun_table = run_table;
66  *plevel_table = flevel_table;
67  *pint_table = int_table;
68  av_free(level_table);
69 }
70 
71 int ff_wma_init(AVCodecContext *avctx, int flags2)
72 {
73  WMACodecContext *s = avctx->priv_data;
74  int i;
75  float bps1, high_freq;
76  volatile float bps;
77  int sample_rate1;
78  int coef_vlc_table;
79 
80  if ( avctx->sample_rate <= 0 || avctx->sample_rate > 50000
81  || avctx->channels <= 0 || avctx->channels > 2
82  || avctx->bit_rate <= 0)
83  return -1;
84 
85  ff_fmt_convert_init(&s->fmt_conv, avctx);
87 
88  if (avctx->codec->id == AV_CODEC_ID_WMAV1) {
89  s->version = 1;
90  } else {
91  s->version = 2;
92  }
93 
94  /* compute MDCT block size */
96  s->version, 0);
100 
101  s->frame_len = 1 << s->frame_len_bits;
102  if (s->use_variable_block_len) {
103  int nb_max, nb;
104  nb = ((flags2 >> 3) & 3) + 1;
105  if ((avctx->bit_rate / avctx->channels) >= 32000)
106  nb += 2;
107  nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
108  if (nb > nb_max)
109  nb = nb_max;
110  s->nb_block_sizes = nb + 1;
111  } else {
112  s->nb_block_sizes = 1;
113  }
114 
115  /* init rate dependent parameters */
116  s->use_noise_coding = 1;
117  high_freq = avctx->sample_rate * 0.5;
118 
119  /* if version 2, then the rates are normalized */
120  sample_rate1 = avctx->sample_rate;
121  if (s->version == 2) {
122  if (sample_rate1 >= 44100) {
123  sample_rate1 = 44100;
124  } else if (sample_rate1 >= 22050) {
125  sample_rate1 = 22050;
126  } else if (sample_rate1 >= 16000) {
127  sample_rate1 = 16000;
128  } else if (sample_rate1 >= 11025) {
129  sample_rate1 = 11025;
130  } else if (sample_rate1 >= 8000) {
131  sample_rate1 = 8000;
132  }
133  }
134 
135  bps = (float)avctx->bit_rate / (float)(avctx->channels * avctx->sample_rate);
136  s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
137  if (s->byte_offset_bits + 3 > MIN_CACHE_BITS) {
138  av_log(avctx, AV_LOG_ERROR, "byte_offset_bits %d is too large\n", s->byte_offset_bits);
139  return AVERROR_PATCHWELCOME;
140  }
141 
142  /* compute high frequency value and choose if noise coding should
143  be activated */
144  bps1 = bps;
145  if (avctx->channels == 2)
146  bps1 = bps * 1.6;
147  if (sample_rate1 == 44100) {
148  if (bps1 >= 0.61) {
149  s->use_noise_coding = 0;
150  } else {
151  high_freq = high_freq * 0.4;
152  }
153  } else if (sample_rate1 == 22050) {
154  if (bps1 >= 1.16) {
155  s->use_noise_coding = 0;
156  } else if (bps1 >= 0.72) {
157  high_freq = high_freq * 0.7;
158  } else {
159  high_freq = high_freq * 0.6;
160  }
161  } else if (sample_rate1 == 16000) {
162  if (bps > 0.5) {
163  high_freq = high_freq * 0.5;
164  } else {
165  high_freq = high_freq * 0.3;
166  }
167  } else if (sample_rate1 == 11025) {
168  high_freq = high_freq * 0.7;
169  } else if (sample_rate1 == 8000) {
170  if (bps <= 0.625) {
171  high_freq = high_freq * 0.5;
172  } else if (bps > 0.75) {
173  s->use_noise_coding = 0;
174  } else {
175  high_freq = high_freq * 0.65;
176  }
177  } else {
178  if (bps >= 0.8) {
179  high_freq = high_freq * 0.75;
180  } else if (bps >= 0.6) {
181  high_freq = high_freq * 0.6;
182  } else {
183  high_freq = high_freq * 0.5;
184  }
185  }
186  av_dlog(s->avctx, "flags2=0x%x\n", flags2);
187  av_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
188  s->version, avctx->channels, avctx->sample_rate, avctx->bit_rate,
189  avctx->block_align);
190  av_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
191  bps, bps1, high_freq, s->byte_offset_bits);
192  av_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
194 
195  /* compute the scale factor band sizes for each MDCT block size */
196  {
197  int a, b, pos, lpos, k, block_len, i, j, n;
198  const uint8_t *table;
199 
200  if (s->version == 1) {
201  s->coefs_start = 3;
202  } else {
203  s->coefs_start = 0;
204  }
205  for (k = 0; k < s->nb_block_sizes; k++) {
206  block_len = s->frame_len >> k;
207 
208  if (s->version == 1) {
209  lpos = 0;
210  for (i = 0; i < 25; i++) {
211  a = ff_wma_critical_freqs[i];
212  b = avctx->sample_rate;
213  pos = ((block_len * 2 * a) + (b >> 1)) / b;
214  if (pos > block_len)
215  pos = block_len;
216  s->exponent_bands[0][i] = pos - lpos;
217  if (pos >= block_len) {
218  i++;
219  break;
220  }
221  lpos = pos;
222  }
223  s->exponent_sizes[0] = i;
224  } else {
225  /* hardcoded tables */
226  table = NULL;
227  a = s->frame_len_bits - BLOCK_MIN_BITS - k;
228  if (a < 3) {
229  if (avctx->sample_rate >= 44100) {
230  table = exponent_band_44100[a];
231  } else if (avctx->sample_rate >= 32000) {
232  table = exponent_band_32000[a];
233  } else if (avctx->sample_rate >= 22050) {
234  table = exponent_band_22050[a];
235  }
236  }
237  if (table) {
238  n = *table++;
239  for (i = 0; i < n; i++)
240  s->exponent_bands[k][i] = table[i];
241  s->exponent_sizes[k] = n;
242  } else {
243  j = 0;
244  lpos = 0;
245  for (i = 0; i < 25; i++) {
246  a = ff_wma_critical_freqs[i];
247  b = avctx->sample_rate;
248  pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
249  pos <<= 2;
250  if (pos > block_len)
251  pos = block_len;
252  if (pos > lpos)
253  s->exponent_bands[k][j++] = pos - lpos;
254  if (pos >= block_len)
255  break;
256  lpos = pos;
257  }
258  s->exponent_sizes[k] = j;
259  }
260  }
261 
262  /* max number of coefs */
263  s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
264  /* high freq computation */
265  s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
266  avctx->sample_rate + 0.5);
267  n = s->exponent_sizes[k];
268  j = 0;
269  pos = 0;
270  for (i = 0; i < n; i++) {
271  int start, end;
272  start = pos;
273  pos += s->exponent_bands[k][i];
274  end = pos;
275  if (start < s->high_band_start[k])
276  start = s->high_band_start[k];
277  if (end > s->coefs_end[k])
278  end = s->coefs_end[k];
279  if (end > start)
280  s->exponent_high_bands[k][j++] = end - start;
281  }
282  s->exponent_high_sizes[k] = j;
283 #if 0
284  tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
285  s->frame_len >> k,
286  s->coefs_end[k],
287  s->high_band_start[k],
288  s->exponent_high_sizes[k]);
289  for (j = 0; j < s->exponent_high_sizes[k]; j++)
290  tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
291  tprintf(s->avctx, "\n");
292 #endif
293  }
294  }
295 
296 #ifdef TRACE
297  {
298  int i, j;
299  for (i = 0; i < s->nb_block_sizes; i++) {
300  tprintf(s->avctx, "%5d: n=%2d:",
301  s->frame_len >> i,
302  s->exponent_sizes[i]);
303  for (j = 0; j < s->exponent_sizes[i]; j++)
304  tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
305  tprintf(s->avctx, "\n");
306  }
307  }
308 #endif
309 
310  /* init MDCT windows : simple sinus window */
311  for (i = 0; i < s->nb_block_sizes; i++) {
313  s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
314  }
315 
316  s->reset_block_lengths = 1;
317 
318  if (s->use_noise_coding) {
319 
320  /* init the noise generator */
321  if (s->use_exp_vlc) {
322  s->noise_mult = 0.02;
323  } else {
324  s->noise_mult = 0.04;
325  }
326 
327 #ifdef TRACE
328  for (i = 0; i < NOISE_TAB_SIZE; i++)
329  s->noise_table[i] = 1.0 * s->noise_mult;
330 #else
331  {
332  unsigned int seed;
333  float norm;
334  seed = 1;
335  norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
336  for (i = 0; i < NOISE_TAB_SIZE; i++) {
337  seed = seed * 314159 + 1;
338  s->noise_table[i] = (float)((int)seed) * norm;
339  }
340  }
341 #endif
342  }
343 
344  /* choose the VLC tables for the coefficients */
345  coef_vlc_table = 2;
346  if (avctx->sample_rate >= 32000) {
347  if (bps1 < 0.72) {
348  coef_vlc_table = 0;
349  } else if (bps1 < 1.16) {
350  coef_vlc_table = 1;
351  }
352  }
353  s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ];
354  s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
355  init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
356  s->coef_vlcs[0]);
357  init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
358  s->coef_vlcs[1]);
359 
360  return 0;
361 }
362 
363 int ff_wma_total_gain_to_bits(int total_gain)
364 {
365  if (total_gain < 15) return 13;
366  else if (total_gain < 32) return 12;
367  else if (total_gain < 40) return 11;
368  else if (total_gain < 45) return 10;
369  else return 9;
370 }
371 
373 {
374  WMACodecContext *s = avctx->priv_data;
375  int i;
376 
377  for (i = 0; i < s->nb_block_sizes; i++)
378  ff_mdct_end(&s->mdct_ctx[i]);
379 
380  if (s->use_exp_vlc) {
381  ff_free_vlc(&s->exp_vlc);
382  }
383  if (s->use_noise_coding) {
384  ff_free_vlc(&s->hgain_vlc);
385  }
386  for (i = 0; i < 2; i++) {
387  ff_free_vlc(&s->coef_vlc[i]);
388  av_free(s->run_table[i]);
389  av_free(s->level_table[i]);
390  av_free(s->int_table[i]);
391  }
392 
393 #if FF_API_OLD_ENCODE_AUDIO
394  if (av_codec_is_encoder(avctx->codec))
395  av_freep(&avctx->coded_frame);
396 #endif
397 
398  return 0;
399 }
400 
401 /**
402  * Decode an uncompressed coefficient.
403  * @param gb GetBitContext
404  * @return the decoded coefficient
405  */
407 {
408  /** consumes up to 34 bits */
409  int n_bits = 8;
410  /** decode length */
411  if (get_bits1(gb)) {
412  n_bits += 8;
413  if (get_bits1(gb)) {
414  n_bits += 8;
415  if (get_bits1(gb)) {
416  n_bits += 7;
417  }
418  }
419  }
420  return get_bits_long(gb, n_bits);
421 }
422 
423 /**
424  * Decode run level compressed coefficients.
425  * @param avctx codec context
426  * @param gb bitstream reader context
427  * @param vlc vlc table for get_vlc2
428  * @param level_table level codes
429  * @param run_table run codes
430  * @param version 0 for wma1,2 1 for wmapro
431  * @param ptr output buffer
432  * @param offset offset in the output buffer
433  * @param num_coefs number of input coefficents
434  * @param block_len input buffer length (2^n)
435  * @param frame_len_bits number of bits for escaped run codes
436  * @param coef_nb_bits number of bits for escaped level codes
437  * @return 0 on success, -1 otherwise
438  */
440  VLC *vlc,
441  const float *level_table, const uint16_t *run_table,
442  int version, WMACoef *ptr, int offset,
443  int num_coefs, int block_len, int frame_len_bits,
444  int coef_nb_bits)
445 {
446  int code, level, sign;
447  const uint32_t *ilvl = (const uint32_t*)level_table;
448  uint32_t *iptr = (uint32_t*)ptr;
449  const unsigned int coef_mask = block_len - 1;
450  for (; offset < num_coefs; offset++) {
451  code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
452  if (code > 1) {
453  /** normal code */
454  offset += run_table[code];
455  sign = get_bits1(gb) - 1;
456  iptr[offset & coef_mask] = ilvl[code] ^ sign<<31;
457  } else if (code == 1) {
458  /** EOB */
459  break;
460  } else {
461  /** escape */
462  if (!version) {
463  level = get_bits(gb, coef_nb_bits);
464  /** NOTE: this is rather suboptimal. reading
465  block_len_bits would be better */
466  offset += get_bits(gb, frame_len_bits);
467  } else {
468  level = ff_wma_get_large_val(gb);
469  /** escape decode */
470  if (get_bits1(gb)) {
471  if (get_bits1(gb)) {
472  if (get_bits1(gb)) {
473  av_log(avctx,AV_LOG_ERROR,
474  "broken escape sequence\n");
475  return -1;
476  } else
477  offset += get_bits(gb, frame_len_bits) + 4;
478  } else
479  offset += get_bits(gb, 2) + 1;
480  }
481  }
482  sign = get_bits1(gb) - 1;
483  ptr[offset & coef_mask] = (level^sign) - sign;
484  }
485  }
486  /** NOTE: EOB can be omitted */
487  if (offset > num_coefs) {
488  av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
489  return -1;
490  }
491 
492  return 0;
493 }