wma encoder
[libav.git] / libavcodec / wma.c
CommitLineData
59686073
MN
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
31static 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
65int ff_wma_init(AVCodecContext * avctx, int flags2)
66{
67 WMADecodeContext *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 s->sample_rate = avctx->sample_rate;
76 s->nb_channels = avctx->channels;
77 s->bit_rate = avctx->bit_rate;
78 s->block_align = avctx->block_align;
79
80 dsputil_init(&s->dsp, avctx);
81
82 if (avctx->codec->id == CODEC_ID_WMAV1) {
83 s->version = 1;
84 } else {
85 s->version = 2;
86 }
87
88 /* compute MDCT block size */
89 if (s->sample_rate <= 16000) {
90 s->frame_len_bits = 9;
91 } else if (s->sample_rate <= 22050 ||
92 (s->sample_rate <= 32000 && s->version == 1)) {
93 s->frame_len_bits = 10;
94 } else {
95 s->frame_len_bits = 11;
96 }
97 s->frame_len = 1 << s->frame_len_bits;
98 if (s->use_variable_block_len) {
99 int nb_max, nb;
100 nb = ((flags2 >> 3) & 3) + 1;
101 if ((s->bit_rate / s->nb_channels) >= 32000)
102 nb += 2;
103 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
104 if (nb > nb_max)
105 nb = nb_max;
106 s->nb_block_sizes = nb + 1;
107 } else {
108 s->nb_block_sizes = 1;
109 }
110
111 /* init rate dependant parameters */
112 s->use_noise_coding = 1;
113 high_freq = s->sample_rate * 0.5;
114
115 /* if version 2, then the rates are normalized */
116 sample_rate1 = s->sample_rate;
117 if (s->version == 2) {
118 if (sample_rate1 >= 44100)
119 sample_rate1 = 44100;
120 else if (sample_rate1 >= 22050)
121 sample_rate1 = 22050;
122 else if (sample_rate1 >= 16000)
123 sample_rate1 = 16000;
124 else if (sample_rate1 >= 11025)
125 sample_rate1 = 11025;
126 else if (sample_rate1 >= 8000)
127 sample_rate1 = 8000;
128 }
129
130 bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
131 s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
132
133 /* compute high frequency value and choose if noise coding should
134 be activated */
135 bps1 = bps;
136 if (s->nb_channels == 2)
137 bps1 = bps * 1.6;
138 if (sample_rate1 == 44100) {
139 if (bps1 >= 0.61)
140 s->use_noise_coding = 0;
141 else
142 high_freq = high_freq * 0.4;
143 } else if (sample_rate1 == 22050) {
144 if (bps1 >= 1.16)
145 s->use_noise_coding = 0;
146 else if (bps1 >= 0.72)
147 high_freq = high_freq * 0.7;
148 else
149 high_freq = high_freq * 0.6;
150 } else if (sample_rate1 == 16000) {
151 if (bps > 0.5)
152 high_freq = high_freq * 0.5;
153 else
154 high_freq = high_freq * 0.3;
155 } else if (sample_rate1 == 11025) {
156 high_freq = high_freq * 0.7;
157 } else if (sample_rate1 == 8000) {
158 if (bps <= 0.625) {
159 high_freq = high_freq * 0.5;
160 } else if (bps > 0.75) {
161 s->use_noise_coding = 0;
162 } else {
163 high_freq = high_freq * 0.65;
164 }
165 } else {
166 if (bps >= 0.8) {
167 high_freq = high_freq * 0.75;
168 } else if (bps >= 0.6) {
169 high_freq = high_freq * 0.6;
170 } else {
171 high_freq = high_freq * 0.5;
172 }
173 }
174 dprintf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
175 dprintf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
176 s->version, s->nb_channels, s->sample_rate, s->bit_rate,
177 s->block_align);
178 dprintf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
179 bps, bps1, high_freq, s->byte_offset_bits);
180 dprintf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
181 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
182
183 /* compute the scale factor band sizes for each MDCT block size */
184 {
185 int a, b, pos, lpos, k, block_len, i, j, n;
186 const uint8_t *table;
187
188 if (s->version == 1) {
189 s->coefs_start = 3;
190 } else {
191 s->coefs_start = 0;
192 }
193 for(k = 0; k < s->nb_block_sizes; k++) {
194 block_len = s->frame_len >> k;
195
196 if (s->version == 1) {
197 lpos = 0;
198 for(i=0;i<25;i++) {
199 a = wma_critical_freqs[i];
200 b = s->sample_rate;
201 pos = ((block_len * 2 * a) + (b >> 1)) / b;
202 if (pos > block_len)
203 pos = block_len;
204 s->exponent_bands[0][i] = pos - lpos;
205 if (pos >= block_len) {
206 i++;
207 break;
208 }
209 lpos = pos;
210 }
211 s->exponent_sizes[0] = i;
212 } else {
213 /* hardcoded tables */
214 table = NULL;
215 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
216 if (a < 3) {
217 if (s->sample_rate >= 44100)
218 table = exponent_band_44100[a];
219 else if (s->sample_rate >= 32000)
220 table = exponent_band_32000[a];
221 else if (s->sample_rate >= 22050)
222 table = exponent_band_22050[a];
223 }
224 if (table) {
225 n = *table++;
226 for(i=0;i<n;i++)
227 s->exponent_bands[k][i] = table[i];
228 s->exponent_sizes[k] = n;
229 } else {
230 j = 0;
231 lpos = 0;
232 for(i=0;i<25;i++) {
233 a = wma_critical_freqs[i];
234 b = s->sample_rate;
235 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
236 pos <<= 2;
237 if (pos > block_len)
238 pos = block_len;
239 if (pos > lpos)
240 s->exponent_bands[k][j++] = pos - lpos;
241 if (pos >= block_len)
242 break;
243 lpos = pos;
244 }
245 s->exponent_sizes[k] = j;
246 }
247 }
248
249 /* max number of coefs */
250 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
251 /* high freq computation */
252 s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
253 s->sample_rate + 0.5);
254 n = s->exponent_sizes[k];
255 j = 0;
256 pos = 0;
257 for(i=0;i<n;i++) {
258 int start, end;
259 start = pos;
260 pos += s->exponent_bands[k][i];
261 end = pos;
262 if (start < s->high_band_start[k])
263 start = s->high_band_start[k];
264 if (end > s->coefs_end[k])
265 end = s->coefs_end[k];
266 if (end > start)
267 s->exponent_high_bands[k][j++] = end - start;
268 }
269 s->exponent_high_sizes[k] = j;
270#if 0
271 tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
272 s->frame_len >> k,
273 s->coefs_end[k],
274 s->high_band_start[k],
275 s->exponent_high_sizes[k]);
276 for(j=0;j<s->exponent_high_sizes[k];j++)
277 tprintf(" %d", s->exponent_high_bands[k][j]);
278 tprintf("\n");
279#endif
280 }
281 }
282
283#ifdef TRACE
284 {
285 int i, j;
286 for(i = 0; i < s->nb_block_sizes; i++) {
287 tprintf("%5d: n=%2d:",
288 s->frame_len >> i,
289 s->exponent_sizes[i]);
290 for(j=0;j<s->exponent_sizes[i];j++)
291 tprintf(" %d", s->exponent_bands[i][j]);
292 tprintf("\n");
293 }
294 }
295#endif
296
297 /* init MDCT windows : simple sinus window */
298 for(i = 0; i < s->nb_block_sizes; i++) {
299 int n, j;
300 float alpha;
301 n = 1 << (s->frame_len_bits - i);
302 window = av_malloc(sizeof(float) * n);
303 alpha = M_PI / (2.0 * n);
304 for(j=0;j<n;j++) {
305 window[n - j - 1] = sin((j + 0.5) * alpha);
306 }
307 s->windows[i] = window;
308 }
309
310 s->reset_block_lengths = 1;
311
312 if (s->use_noise_coding) {
313
314 /* init the noise generator */
315 if (s->use_exp_vlc)
316 s->noise_mult = 0.02;
317 else
318 s->noise_mult = 0.04;
319
320#ifdef TRACE
321 for(i=0;i<NOISE_TAB_SIZE;i++)
322 s->noise_table[i] = 1.0 * s->noise_mult;
323#else
324 {
325 unsigned int seed;
326 float norm;
327 seed = 1;
328 norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
329 for(i=0;i<NOISE_TAB_SIZE;i++) {
330 seed = seed * 314159 + 1;
331 s->noise_table[i] = (float)((int)seed) * norm;
332 }
333 }
334#endif
335 }
336
337 /* choose the VLC tables for the coefficients */
338 coef_vlc_table = 2;
339 if (s->sample_rate >= 32000) {
340 if (bps1 < 0.72)
341 coef_vlc_table = 0;
342 else if (bps1 < 1.16)
343 coef_vlc_table = 1;
344 }
345 s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2 ];
346 s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
347 init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
348 s->coef_vlcs[0]);
349 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
350 s->coef_vlcs[1]);
351
352 return 0;
353}
354
355int ff_wma_total_gain_to_bits(int total_gain){
356 if (total_gain < 15) return 13;
357 else if (total_gain < 32) return 12;
358 else if (total_gain < 40) return 11;
359 else if (total_gain < 45) return 10;
360 else return 9;
361}
362
363int ff_wma_end(AVCodecContext *avctx)
364{
365 WMADecodeContext *s = avctx->priv_data;
366 int i;
367
368 for(i = 0; i < s->nb_block_sizes; i++)
369 ff_mdct_end(&s->mdct_ctx[i]);
370 for(i = 0; i < s->nb_block_sizes; i++)
371 av_free(s->windows[i]);
372
373 if (s->use_exp_vlc) {
374 free_vlc(&s->exp_vlc);
375 }
376 if (s->use_noise_coding) {
377 free_vlc(&s->hgain_vlc);
378 }
379 for(i = 0;i < 2; i++) {
380 free_vlc(&s->coef_vlc[i]);
381 av_free(s->run_table[i]);
382 av_free(s->level_table[i]);
383 }
384
385 return 0;
386}