3 * Copyright (c) 2002-2007 The FFmpeg Project.
5 * This file is part of FFmpeg.
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.
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.
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
29 /* XXX: use same run/length optimization as mpeg decoders */
30 //FIXME maybe split decode / encode or pass flag
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)
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;
42 init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
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));
52 l = levels_table[k++];
55 level_table[i] = level;
60 *prun_table = run_table;
61 *plevel_table = level_table;
62 *pint_table= int_table;
65 int ff_wma_init(AVCodecContext * avctx, int flags2)
67 WMADecodeContext *s = avctx->priv_data;
70 float bps1, high_freq;
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;
80 dsputil_init(&s->dsp, avctx);
82 if (avctx->codec->id == CODEC_ID_WMAV1) {
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;
95 s->frame_len_bits = 11;
97 s->frame_len = 1 << s->frame_len_bits;
98 if (s->use_variable_block_len) {
100 nb = ((flags2 >> 3) & 3) + 1;
101 if ((s->bit_rate / s->nb_channels) >= 32000)
103 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
106 s->nb_block_sizes = nb + 1;
108 s->nb_block_sizes = 1;
111 /* init rate dependent parameters */
112 s->use_noise_coding = 1;
113 high_freq = s->sample_rate * 0.5;
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)
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;
133 /* compute high frequency value and choose if noise coding should
136 if (s->nb_channels == 2)
138 if (sample_rate1 == 44100) {
140 s->use_noise_coding = 0;
142 high_freq = high_freq * 0.4;
143 } else if (sample_rate1 == 22050) {
145 s->use_noise_coding = 0;
146 else if (bps1 >= 0.72)
147 high_freq = high_freq * 0.7;
149 high_freq = high_freq * 0.6;
150 } else if (sample_rate1 == 16000) {
152 high_freq = high_freq * 0.5;
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) {
159 high_freq = high_freq * 0.5;
160 } else if (bps > 0.75) {
161 s->use_noise_coding = 0;
163 high_freq = high_freq * 0.65;
167 high_freq = high_freq * 0.75;
168 } else if (bps >= 0.6) {
169 high_freq = high_freq * 0.6;
171 high_freq = high_freq * 0.5;
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,
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);
183 /* compute the scale factor band sizes for each MDCT block size */
185 int a, b, pos, lpos, k, block_len, i, j, n;
186 const uint8_t *table;
188 if (s->version == 1) {
193 for(k = 0; k < s->nb_block_sizes; k++) {
194 block_len = s->frame_len >> k;
196 if (s->version == 1) {
199 a = wma_critical_freqs[i];
201 pos = ((block_len * 2 * a) + (b >> 1)) / b;
204 s->exponent_bands[0][i] = pos - lpos;
205 if (pos >= block_len) {
211 s->exponent_sizes[0] = i;
213 /* hardcoded tables */
215 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
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];
227 s->exponent_bands[k][i] = table[i];
228 s->exponent_sizes[k] = n;
233 a = wma_critical_freqs[i];
235 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
240 s->exponent_bands[k][j++] = pos - lpos;
241 if (pos >= block_len)
245 s->exponent_sizes[k] = j;
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];
260 pos += s->exponent_bands[k][i];
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];
267 s->exponent_high_bands[k][j++] = end - start;
269 s->exponent_high_sizes[k] = j;
271 tprintf("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
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]);
286 for(i = 0; i < s->nb_block_sizes; i++) {
287 tprintf("%5d: n=%2d:",
289 s->exponent_sizes[i]);
290 for(j=0;j<s->exponent_sizes[i];j++)
291 tprintf(" %d", s->exponent_bands[i][j]);
297 /* init MDCT windows : simple sinus window */
298 for(i = 0; i < s->nb_block_sizes; i++) {
301 n = 1 << (s->frame_len_bits - i);
302 window = av_malloc(sizeof(float) * n);
303 alpha = M_PI / (2.0 * n);
305 window[n - j - 1] = sin((j + 0.5) * alpha);
307 s->windows[i] = window;
310 s->reset_block_lengths = 1;
312 if (s->use_noise_coding) {
314 /* init the noise generator */
316 s->noise_mult = 0.02;
318 s->noise_mult = 0.04;
321 for(i=0;i<NOISE_TAB_SIZE;i++)
322 s->noise_table[i] = 1.0 * s->noise_mult;
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;
337 /* choose the VLC tables for the coefficients */
339 if (s->sample_rate >= 32000) {
342 else if (bps1 < 1.16)
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],
349 init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
355 int 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;
363 int ff_wma_end(AVCodecContext *avctx)
365 WMADecodeContext *s = avctx->priv_data;
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]);
373 if (s->use_exp_vlc) {
374 free_vlc(&s->exp_vlc);
376 if (s->use_noise_coding) {
377 free_vlc(&s->hgain_vlc);
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]);