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 "wma.h"
24 #include "wmadata.h"
25
26 #undef NDEBUG
27 #include <assert.h>
28
29 /* XXX: use same run/length optimization as mpeg decoders */
30 //FIXME maybe split decode / encode or pass flag
init_coef_vlc(VLC * vlc,uint16_t ** prun_table,uint16_t ** plevel_table,uint16_t ** pint_table,const CoefVLCTable * vlc_table)31 static void init_coef_vlc(VLC *vlc,
32 uint16_t **prun_table, uint16_t **plevel_table, uint16_t **pint_table,
33 const CoefVLCTable *vlc_table)
34 {
35 int n = vlc_table->n;
36 const uint8_t *table_bits = vlc_table->huffbits;
37 const uint32_t *table_codes = vlc_table->huffcodes;
38 const uint16_t *levels_table = vlc_table->levels;
39 uint16_t *run_table, *level_table, *int_table;
40 int i, l, j, k, level;
41
42 init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
43
44 run_table = av_malloc(n * sizeof(uint16_t));
45 level_table = av_malloc(n * sizeof(uint16_t));
46 int_table = av_malloc(n * sizeof(uint16_t));
47 i = 2;
48 level = 1;
49 k = 0;
50 while (i < n) {
51 int_table[k]= i;
52 l = levels_table[k++];
53 for(j=0;j<l;j++) {
54 run_table[i] = j;
55 level_table[i] = level;
56 i++;
57 }
58 level++;
59 }
60 *prun_table = run_table;
61 *plevel_table = level_table;
62 *pint_table= int_table;
63 }
64
ff_wma_init(AVCodecContext * avctx,int flags2)65 int ff_wma_init(AVCodecContext * avctx, int flags2)
66 {
67 WMACodecContext *s = avctx->priv_data;
68 int i;
69 float *window;
70 float bps1, high_freq;
71 volatile float bps;
72 int sample_rate1;
73 int coef_vlc_table;
74
75 if( avctx->sample_rate<=0 || avctx->sample_rate>50000
76 || avctx->channels<=0 || avctx->channels>8
77 || avctx->bit_rate<=0)
78 return -1;
79
80 s->sample_rate = avctx->sample_rate;
81 s->nb_channels = avctx->channels;
82 s->bit_rate = avctx->bit_rate;
83 s->block_align = avctx->block_align;
84
85 dsputil_init(&s->dsp, avctx);
86
87 if (avctx->codec->id == CODEC_ID_WMAV1) {
88 s->version = 1;
89 } else {
90 s->version = 2;
91 }
92
93 /* compute MDCT block size */
94 if (s->sample_rate <= 16000) {
95 s->frame_len_bits = 9;
96 } else if (s->sample_rate <= 22050 ||
97 (s->sample_rate <= 32000 && s->version == 1)) {
98 s->frame_len_bits = 10;
99 } else {
100 s->frame_len_bits = 11;
101 }
102 s->frame_len = 1 << s->frame_len_bits;
103 if (s->use_variable_block_len) {
104 int nb_max, nb;
105 nb = ((flags2 >> 3) & 3) + 1;
106 if ((s->bit_rate / s->nb_channels) >= 32000)
107 nb += 2;
108 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
109 if (nb > nb_max)
110 nb = nb_max;
111 s->nb_block_sizes = nb + 1;
112 } else {
113 s->nb_block_sizes = 1;
114 }
115
116 /* init rate dependent parameters */
117 s->use_noise_coding = 1;
118 high_freq = s->sample_rate * 0.5;
119
120 /* if version 2, then the rates are normalized */
121 sample_rate1 = s->sample_rate;
122 if (s->version == 2) {
123 if (sample_rate1 >= 44100)
124 sample_rate1 = 44100;
125 else if (sample_rate1 >= 22050)
126 sample_rate1 = 22050;
127 else if (sample_rate1 >= 16000)
128 sample_rate1 = 16000;
129 else if (sample_rate1 >= 11025)
130 sample_rate1 = 11025;
131 else if (sample_rate1 >= 8000)
132 sample_rate1 = 8000;
133 }
134
135 bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
136 s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
137
138 /* compute high frequency value and choose if noise coding should
139 be activated */
140 bps1 = bps;
141 if (s->nb_channels == 2)
142 bps1 = bps * 1.6;
143 if (sample_rate1 == 44100) {
144 if (bps1 >= 0.61)
145 s->use_noise_coding = 0;
146 else
147 high_freq = high_freq * 0.4;
148 } else if (sample_rate1 == 22050) {
149 if (bps1 >= 1.16)
150 s->use_noise_coding = 0;
151 else if (bps1 >= 0.72)
152 high_freq = high_freq * 0.7;
153 else
154 high_freq = high_freq * 0.6;
155 } else if (sample_rate1 == 16000) {
156 if (bps > 0.5)
157 high_freq = high_freq * 0.5;
158 else
159 high_freq = high_freq * 0.3;
160 } else if (sample_rate1 == 11025) {
161 high_freq = high_freq * 0.7;
162 } else if (sample_rate1 == 8000) {
163 if (bps <= 0.625) {
164 high_freq = high_freq * 0.5;
165 } else if (bps > 0.75) {
166 s->use_noise_coding = 0;
167 } else {
168 high_freq = high_freq * 0.65;
169 }
170 } else {
171 if (bps >= 0.8) {
172 high_freq = high_freq * 0.75;
173 } else if (bps >= 0.6) {
174 high_freq = high_freq * 0.6;
175 } else {
176 high_freq = high_freq * 0.5;
177 }
178 }
179 dprintf(s->avctx, "flags2=0x%x\n", flags2);
180 dprintf(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
181 s->version, s->nb_channels, s->sample_rate, s->bit_rate,
182 s->block_align);
183 dprintf(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
184 bps, bps1, high_freq, s->byte_offset_bits);
185 dprintf(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
186 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
187
188 /* compute the scale factor band sizes for each MDCT block size */
189 {
190 int a, b, pos, lpos, k, block_len, i, j, n;
191 const uint8_t *table;
192
193 if (s->version == 1) {
194 s->coefs_start = 3;
195 } else {
196 s->coefs_start = 0;
197 }
198 for(k = 0; k < s->nb_block_sizes; k++) {
199 block_len = s->frame_len >> k;
200
201 if (s->version == 1) {
202 lpos = 0;
203 for(i=0;i<25;i++) {
204 a = wma_critical_freqs[i];
205 b = s->sample_rate;
206 pos = ((block_len * 2 * a) + (b >> 1)) / b;
207 if (pos > block_len)
208 pos = block_len;
209 s->exponent_bands[0][i] = pos - lpos;
210 if (pos >= block_len) {
211 i++;
212 break;
213 }
214 lpos = pos;
215 }
216 s->exponent_sizes[0] = i;
217 } else {
218 /* hardcoded tables */
219 table = NULL;
220 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
221 if (a < 3) {
222 if (s->sample_rate >= 44100)
223 table = exponent_band_44100[a];
224 else if (s->sample_rate >= 32000)
225 table = exponent_band_32000[a];
226 else if (s->sample_rate >= 22050)
227 table = exponent_band_22050[a];
228 }
229 if (table) {
230 n = *table++;
231 for(i=0;i<n;i++)
232 s->exponent_bands[k][i] = table[i];
233 s->exponent_sizes[k] = n;
234 } else {
235 j = 0;
236 lpos = 0;
237 for(i=0;i<25;i++) {
238 a = wma_critical_freqs[i];
239 b = s->sample_rate;
240 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
241 pos <<= 2;
242 if (pos > block_len)
243 pos = block_len;
244 if (pos > lpos)
245 s->exponent_bands[k][j++] = pos - lpos;
246 if (pos >= block_len)
247 break;
248 lpos = pos;
249 }
250 s->exponent_sizes[k] = j;
251 }
252 }
253
254 /* max number of coefs */
255 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
256 /* high freq computation */
257 s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
258 s->sample_rate + 0.5);
259 n = s->exponent_sizes[k];
260 j = 0;
261 pos = 0;
262 for(i=0;i<n;i++) {
263 int start, end;
264 start = pos;
265 pos += s->exponent_bands[k][i];
266 end = pos;
267 if (start < s->high_band_start[k])
268 start = s->high_band_start[k];
269 if (end > s->coefs_end[k])
270 end = s->coefs_end[k];
271 if (end > start)
272 s->exponent_high_bands[k][j++] = end - start;
273 }
274 s->exponent_high_sizes[k] = j;
275 #if 0
276 tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
277 s->frame_len >> k,
278 s->coefs_end[k],
279 s->high_band_start[k],
280 s->exponent_high_sizes[k]);
281 for(j=0;j<s->exponent_high_sizes[k];j++)
282 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
283 tprintf(s->avctx, "\n");
284 #endif
285 }
286 }
287
288 #ifdef TRACE
289 {
290 int i, j;
291 for(i = 0; i < s->nb_block_sizes; i++) {
292 tprintf(s->avctx, "%5d: n=%2d:",
293 s->frame_len >> i,
294 s->exponent_sizes[i]);
295 for(j=0;j<s->exponent_sizes[i];j++)
296 tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
297 tprintf(s->avctx, "\n");
298 }
299 }
300 #endif
301
302 /* init MDCT windows : simple sinus window */
303 for(i = 0; i < s->nb_block_sizes; i++) {
304 int n, j;
305 float alpha;
306 n = 1 << (s->frame_len_bits - i);
307 window = av_malloc(sizeof(float) * n);
308 alpha = M_PI / (2.0 * n);
309 for(j=0;j<n;j++) {
310 window[j] = sin((j + 0.5) * alpha);
311 }
312 s->windows[i] = window;
313 }
314
315 s->reset_block_lengths = 1;
316
317 if (s->use_noise_coding) {
318
319 /* init the noise generator */
320 if (s->use_exp_vlc)
321 s->noise_mult = 0.02;
322 else
323 s->noise_mult = 0.04;
324
325 #ifdef TRACE
326 for(i=0;i<NOISE_TAB_SIZE;i++)
327 s->noise_table[i] = 1.0 * s->noise_mult;
328 #else
329 {
330 unsigned int seed;
331 float norm;
332 seed = 1;
333 norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
334 for(i=0;i<NOISE_TAB_SIZE;i++) {
335 seed = seed * 314159 + 1;
336 s->noise_table[i] = (float)((int)seed) * norm;
337 }
338 }
339 #endif
340 }
341
342 /* choose the VLC tables for the coefficients */
343 coef_vlc_table = 2;
344 if (s->sample_rate >= 32000) {
345 if (bps1 < 0.72)
346 coef_vlc_table = 0;
347 else if (bps1 < 1.16)
348 coef_vlc_table = 1;
349 }
350 s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ];
351 s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
352 init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
353 s->coef_vlcs[0]);
354 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
355 s->coef_vlcs[1]);
356
357 return 0;
358 }
359
ff_wma_total_gain_to_bits(int total_gain)360 int ff_wma_total_gain_to_bits(int total_gain){
361 if (total_gain < 15) return 13;
362 else if (total_gain < 32) return 12;
363 else if (total_gain < 40) return 11;
364 else if (total_gain < 45) return 10;
365 else return 9;
366 }
367
ff_wma_end(AVCodecContext * avctx)368 int ff_wma_end(AVCodecContext *avctx)
369 {
370 WMACodecContext *s = avctx->priv_data;
371 int i;
372
373 for(i = 0; i < s->nb_block_sizes; i++)
374 ff_mdct_end(&s->mdct_ctx[i]);
375 for(i = 0; i < s->nb_block_sizes; i++)
376 av_free(s->windows[i]);
377
378 if (s->use_exp_vlc) {
379 free_vlc(&s->exp_vlc);
380 }
381 if (s->use_noise_coding) {
382 free_vlc(&s->hgain_vlc);
383 }
384 for(i = 0;i < 2; i++) {
385 free_vlc(&s->coef_vlc[i]);
386 av_free(s->run_table[i]);
387 av_free(s->level_table[i]);
388 av_free(s->int_table[i]);
389 }
390
391 return 0;
392 }
393