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 "libavutil/attributes.h"
23
24 #include "avcodec.h"
25 #include "sinewin.h"
26 #include "wma.h"
27 #include "wma_common.h"
28 #include "wma_freqs.h"
29 #include "wmadata.h"
30
31 /* XXX: use same run/length optimization as mpeg decoders */
32 // FIXME maybe split decode / encode or pass flag
init_coef_vlc(VLC *vlc, uint16_t **prun_table, float **plevel_table, uint16_t **pint_table, const CoefVLCTable *vlc_table)33 static av_cold int 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, *int_table;
42 float *flevel_table;
43 int i, l, j, k, level, ret;
44
45 ret = init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
46 if (ret < 0)
47 return ret;
48
49 run_table = av_malloc_array(n, sizeof(uint16_t));
50 flevel_table = av_malloc_array(n, sizeof(*flevel_table));
51 int_table = av_malloc_array(n, sizeof(uint16_t));
52 if (!run_table || !flevel_table || !int_table) {
53 av_freep(&run_table);
54 av_freep(&flevel_table);
55 av_freep(&int_table);
56 return AVERROR(ENOMEM);
57 }
58 i = 2;
59 level = 1;
60 k = 0;
61 while (i < n) {
62 int_table[k] = i;
63 l = levels_table[k++];
64 for (j = 0; j < l; j++) {
65 run_table[i] = j;
66 flevel_table[i] = level;
67 i++;
68 }
69 level++;
70 }
71 *prun_table = run_table;
72 *plevel_table = flevel_table;
73 *pint_table = int_table;
74
75 return 0;
76 }
77
ff_wma_init(AVCodecContext *avctx, int flags2)78 av_cold int ff_wma_init(AVCodecContext *avctx, int flags2)
79 {
80 WMACodecContext *s = avctx->priv_data;
81 int channels = avctx->ch_layout.nb_channels;
82 int i, ret;
83 float bps1, high_freq;
84 float bps;
85 int sample_rate1;
86 int coef_vlc_table;
87
88 if (avctx->sample_rate <= 0 || avctx->sample_rate > 50000 ||
89 channels <= 0 || channels > 2 ||
90 avctx->bit_rate <= 0)
91 return -1;
92
93
94 if (avctx->codec->id == AV_CODEC_ID_WMAV1)
95 s->version = 1;
96 else
97 s->version = 2;
98
99 /* compute MDCT block size */
100 s->frame_len_bits = ff_wma_get_frame_len_bits(avctx->sample_rate,
101 s->version, 0);
102 s->next_block_len_bits = s->frame_len_bits;
103 s->prev_block_len_bits = s->frame_len_bits;
104 s->block_len_bits = s->frame_len_bits;
105
106 s->frame_len = 1 << s->frame_len_bits;
107 if (s->use_variable_block_len) {
108 int nb_max, nb;
109 nb = ((flags2 >> 3) & 3) + 1;
110 if ((avctx->bit_rate / channels) >= 32000)
111 nb += 2;
112 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
113 if (nb > nb_max)
114 nb = nb_max;
115 s->nb_block_sizes = nb + 1;
116 } else
117 s->nb_block_sizes = 1;
118
119 /* init rate dependent parameters */
120 s->use_noise_coding = 1;
121 high_freq = avctx->sample_rate * 0.5;
122
123 /* if version 2, then the rates are normalized */
124 sample_rate1 = avctx->sample_rate;
125 if (s->version == 2) {
126 if (sample_rate1 >= 44100)
127 sample_rate1 = 44100;
128 else if (sample_rate1 >= 22050)
129 sample_rate1 = 22050;
130 else if (sample_rate1 >= 16000)
131 sample_rate1 = 16000;
132 else if (sample_rate1 >= 11025)
133 sample_rate1 = 11025;
134 else if (sample_rate1 >= 8000)
135 sample_rate1 = 8000;
136 }
137
138 bps = (float) avctx->bit_rate /
139 (float) (channels * avctx->sample_rate);
140 s->byte_offset_bits = av_log2((int) (bps * s->frame_len / 8.0 + 0.5)) + 2;
141 if (s->byte_offset_bits + 3 > MIN_CACHE_BITS) {
142 av_log(avctx, AV_LOG_ERROR, "byte_offset_bits %d is too large\n", s->byte_offset_bits);
143 return AVERROR_PATCHWELCOME;
144 }
145
146 /* compute high frequency value and choose if noise coding should
147 * be activated */
148 bps1 = bps;
149 if (channels == 2)
150 bps1 = bps * 1.6;
151 if (sample_rate1 == 44100) {
152 if (bps1 >= 0.61)
153 s->use_noise_coding = 0;
154 else
155 high_freq = high_freq * 0.4;
156 } else if (sample_rate1 == 22050) {
157 if (bps1 >= 1.16)
158 s->use_noise_coding = 0;
159 else if (bps1 >= 0.72)
160 high_freq = high_freq * 0.7;
161 else
162 high_freq = high_freq * 0.6;
163 } else if (sample_rate1 == 16000) {
164 if (bps > 0.5)
165 high_freq = high_freq * 0.5;
166 else
167 high_freq = high_freq * 0.3;
168 } else if (sample_rate1 == 11025)
169 high_freq = high_freq * 0.7;
170 else if (sample_rate1 == 8000) {
171 if (bps <= 0.625)
172 high_freq = high_freq * 0.5;
173 else if (bps > 0.75)
174 s->use_noise_coding = 0;
175 else
176 high_freq = high_freq * 0.65;
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 ff_dlog(s->avctx, "flags2=0x%x\n", flags2);
186 ff_dlog(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%"PRId64" block_align=%d\n",
187 s->version, channels, avctx->sample_rate, avctx->bit_rate,
188 avctx->block_align);
189 ff_dlog(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
190 bps, bps1, high_freq, s->byte_offset_bits);
191 ff_dlog(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
192 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
193
194 /* compute the scale factor band sizes for each MDCT block size */
195 {
196 int a, b, pos, lpos, k, block_len, i, j, n;
197 const uint8_t *table;
198
199 if (s->version == 1)
200 s->coefs_start = 3;
201 else
202 s->coefs_start = 0;
203 for (k = 0; k < s->nb_block_sizes; k++) {
204 block_len = s->frame_len >> k;
205
206 if (s->version == 1) {
207 lpos = 0;
208 for (i = 0; i < 25; i++) {
209 a = ff_wma_critical_freqs[i];
210 b = avctx->sample_rate;
211 pos = ((block_len * 2 * a) + (b >> 1)) / b;
212 if (pos > block_len)
213 pos = block_len;
214 s->exponent_bands[0][i] = pos - lpos;
215 if (pos >= block_len) {
216 i++;
217 break;
218 }
219 lpos = pos;
220 }
221 s->exponent_sizes[0] = i;
222 } else {
223 /* hardcoded tables */
224 table = NULL;
225 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
226 if (a < 3) {
227 if (avctx->sample_rate >= 44100)
228 table = exponent_band_44100[a];
229 else if (avctx->sample_rate >= 32000)
230 table = exponent_band_32000[a];
231 else if (avctx->sample_rate >= 22050)
232 table = exponent_band_22050[a];
233 }
234 if (table) {
235 n = *table++;
236 for (i = 0; i < n; i++)
237 s->exponent_bands[k][i] = table[i];
238 s->exponent_sizes[k] = n;
239 } else {
240 j = 0;
241 lpos = 0;
242 for (i = 0; i < 25; i++) {
243 a = ff_wma_critical_freqs[i];
244 b = avctx->sample_rate;
245 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
246 pos <<= 2;
247 if (pos > block_len)
248 pos = block_len;
249 if (pos > lpos)
250 s->exponent_bands[k][j++] = pos - lpos;
251 if (pos >= block_len)
252 break;
253 lpos = pos;
254 }
255 s->exponent_sizes[k] = j;
256 }
257 }
258
259 /* max number of coefs */
260 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
261 /* high freq computation */
262 s->high_band_start[k] = (int) ((block_len * 2 * high_freq) /
263 avctx->sample_rate + 0.5);
264 n = s->exponent_sizes[k];
265 j = 0;
266 pos = 0;
267 for (i = 0; i < n; i++) {
268 int start, end;
269 start = pos;
270 pos += s->exponent_bands[k][i];
271 end = pos;
272 if (start < s->high_band_start[k])
273 start = s->high_band_start[k];
274 if (end > s->coefs_end[k])
275 end = s->coefs_end[k];
276 if (end > start)
277 s->exponent_high_bands[k][j++] = end - start;
278 }
279 s->exponent_high_sizes[k] = j;
280 }
281 }
282
283 #ifdef TRACE
284 {
285 int i, j;
286 for (i = 0; i < s->nb_block_sizes; i++) {
287 ff_tlog(s->avctx, "%5d: n=%2d:",
288 s->frame_len >> i,
289 s->exponent_sizes[i]);
290 for (j = 0; j < s->exponent_sizes[i]; j++)
291 ff_tlog(s->avctx, " %d", s->exponent_bands[i][j]);
292 ff_tlog(s->avctx, "\n");
293 }
294 }
295 #endif /* TRACE */
296
297 /* init MDCT windows : simple sine window */
298 for (i = 0; i < s->nb_block_sizes; i++) {
299 ff_init_ff_sine_windows(s->frame_len_bits - i);
300 s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
301 }
302
303 s->reset_block_lengths = 1;
304
305 if (s->use_noise_coding) {
306 /* init the noise generator */
307 if (s->use_exp_vlc)
308 s->noise_mult = 0.02;
309 else
310 s->noise_mult = 0.04;
311
312 #ifdef TRACE
313 for (i = 0; i < NOISE_TAB_SIZE; i++)
314 s->noise_table[i] = 1.0 * s->noise_mult;
315 #else
316 {
317 unsigned int seed;
318 float norm;
319 seed = 1;
320 norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * s->noise_mult;
321 for (i = 0; i < NOISE_TAB_SIZE; i++) {
322 seed = seed * 314159 + 1;
323 s->noise_table[i] = (float) ((int) seed) * norm;
324 }
325 }
326 #endif /* TRACE */
327 }
328
329 s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
330 if (!s->fdsp)
331 return AVERROR(ENOMEM);
332
333 /* choose the VLC tables for the coefficients */
334 coef_vlc_table = 2;
335 if (avctx->sample_rate >= 32000) {
336 if (bps1 < 0.72)
337 coef_vlc_table = 0;
338 else if (bps1 < 1.16)
339 coef_vlc_table = 1;
340 }
341 s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
342 s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
343 ret = init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
344 &s->int_table[0], s->coef_vlcs[0]);
345 if (ret < 0)
346 return ret;
347
348 return init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
349 &s->int_table[1], s->coef_vlcs[1]);
350 }
351
ff_wma_total_gain_to_bits(int total_gain)352 int ff_wma_total_gain_to_bits(int total_gain)
353 {
354 if (total_gain < 15)
355 return 13;
356 else if (total_gain < 32)
357 return 12;
358 else if (total_gain < 40)
359 return 11;
360 else if (total_gain < 45)
361 return 10;
362 else
363 return 9;
364 }
365
ff_wma_end(AVCodecContext *avctx)366 int ff_wma_end(AVCodecContext *avctx)
367 {
368 WMACodecContext *s = avctx->priv_data;
369 int i;
370
371 for (i = 0; i < s->nb_block_sizes; i++)
372 ff_mdct_end(&s->mdct_ctx[i]);
373
374 if (s->use_exp_vlc)
375 ff_free_vlc(&s->exp_vlc);
376 if (s->use_noise_coding)
377 ff_free_vlc(&s->hgain_vlc);
378 for (i = 0; i < 2; i++) {
379 ff_free_vlc(&s->coef_vlc[i]);
380 av_freep(&s->run_table[i]);
381 av_freep(&s->level_table[i]);
382 av_freep(&s->int_table[i]);
383 }
384 av_freep(&s->fdsp);
385
386 return 0;
387 }
388
389 /**
390 * Decode an uncompressed coefficient.
391 * @param gb GetBitContext
392 * @return the decoded coefficient
393 */
ff_wma_get_large_val(GetBitContext *gb)394 unsigned int ff_wma_get_large_val(GetBitContext *gb)
395 {
396 /** consumes up to 34 bits */
397 int n_bits = 8;
398 /** decode length */
399 if (get_bits1(gb)) {
400 n_bits += 8;
401 if (get_bits1(gb)) {
402 n_bits += 8;
403 if (get_bits1(gb))
404 n_bits += 7;
405 }
406 }
407 return get_bits_long(gb, n_bits);
408 }
409
410 /**
411 * Decode run level compressed coefficients.
412 * @param avctx codec context
413 * @param gb bitstream reader context
414 * @param vlc vlc table for get_vlc2
415 * @param level_table level codes
416 * @param run_table run codes
417 * @param version 0 for wma1,2 1 for wmapro
418 * @param ptr output buffer
419 * @param offset offset in the output buffer
420 * @param num_coefs number of input coefficients
421 * @param block_len input buffer length (2^n)
422 * @param frame_len_bits number of bits for escaped run codes
423 * @param coef_nb_bits number of bits for escaped level codes
424 * @return 0 on success, -1 otherwise
425 */
ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb, VLC *vlc, const float *level_table, const uint16_t *run_table, int version, WMACoef *ptr, int offset, int num_coefs, int block_len, int frame_len_bits, int coef_nb_bits)426 int ff_wma_run_level_decode(AVCodecContext *avctx, GetBitContext *gb,
427 VLC *vlc, const float *level_table,
428 const uint16_t *run_table, int version,
429 WMACoef *ptr, int offset, int num_coefs,
430 int block_len, int frame_len_bits,
431 int coef_nb_bits)
432 {
433 int code, level, sign;
434 const uint32_t *ilvl = (const uint32_t *) level_table;
435 uint32_t *iptr = (uint32_t *) ptr;
436 const unsigned int coef_mask = block_len - 1;
437 for (; offset < num_coefs; offset++) {
438 code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
439 if (code > 1) {
440 /** normal code */
441 offset += run_table[code];
442 sign = get_bits1(gb) - 1;
443 iptr[offset & coef_mask] = ilvl[code] ^ (sign & 0x80000000);
444 } else if (code == 1) {
445 /** EOB */
446 break;
447 } else {
448 /** escape */
449 if (!version) {
450 level = get_bits(gb, coef_nb_bits);
451 /** NOTE: this is rather suboptimal. reading
452 * block_len_bits would be better */
453 offset += get_bits(gb, frame_len_bits);
454 } else {
455 level = ff_wma_get_large_val(gb);
456 /** escape decode */
457 if (get_bits1(gb)) {
458 if (get_bits1(gb)) {
459 if (get_bits1(gb)) {
460 av_log(avctx, AV_LOG_ERROR,
461 "broken escape sequence\n");
462 return AVERROR_INVALIDDATA;
463 } else
464 offset += get_bits(gb, frame_len_bits) + 4;
465 } else
466 offset += get_bits(gb, 2) + 1;
467 }
468 }
469 sign = get_bits1(gb) - 1;
470 ptr[offset & coef_mask] = (level ^ sign) - sign;
471 }
472 }
473 /** NOTE: EOB can be omitted */
474 if (offset > num_coefs) {
475 av_log(avctx, AV_LOG_ERROR,
476 "overflow (%d > %d) in spectral RLE, ignoring\n",
477 offset,
478 num_coefs
479 );
480 return AVERROR_INVALIDDATA;
481 }
482
483 return 0;
484 }
485