libavcodec/wma.c

   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
  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
  65 int ff_wma_init(AVCodecContext * avctx, int flags2)
  66 {
  67     WMACodecContext *s = avctx->priv_data;
  68     int i;
  69     float bps1, high_freq;
  70     volatile float bps;
  71     int sample_rate1;
  72     int coef_vlc_table;
  73
  74     if(   avctx->sample_rate<=0 || avctx->sample_rate>50000
  75        || avctx->channels<=0 || avctx->channels>8
  76        || avctx->bit_rate<=0)
  77         return -1;
  78
  79     s->sample_rate = avctx->sample_rate;
  80     s->nb_channels = avctx->channels;
  81     s->bit_rate = avctx->bit_rate;
  82     s->block_align = avctx->block_align;
  83
  84     dsputil_init(&s->dsp, avctx);
  85
  86     if (avctx->codec->id == CODEC_ID_WMAV1) {
  87         s->version = 1;
  88     } else {
  89         s->version = 2;
  90     }
  91
  92     /* compute MDCT block size */
  93     if (s->sample_rate <= 16000) {
  94         s->frame_len_bits = 9;
  95     } else if (s->sample_rate <= 22050 ||
  96                (s->sample_rate <= 32000 && s->version == 1)) {
  97         s->frame_len_bits = 10;
  98     } else {
  99         s->frame_len_bits = 11;
 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 ((s->bit_rate / s->nb_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 = s->sample_rate * 0.5;
 118
 119     /* if version 2, then the rates are normalized */
 120     sample_rate1 = s->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     bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
 135     s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
 136
 137     /* compute high frequency value and choose if noise coding should
 138        be activated */
 139     bps1 = bps;
 140     if (s->nb_channels == 2)
 141         bps1 = bps * 1.6;
 142     if (sample_rate1 == 44100) {
 143         if (bps1 >= 0.61)
 144             s->use_noise_coding = 0;
 145         else
 146             high_freq = high_freq * 0.4;
 147     } else if (sample_rate1 == 22050) {
 148         if (bps1 >= 1.16)
 149             s->use_noise_coding = 0;
 150         else if (bps1 >= 0.72)
 151             high_freq = high_freq * 0.7;
 152         else
 153             high_freq = high_freq * 0.6;
 154     } else if (sample_rate1 == 16000) {
 155         if (bps > 0.5)
 156             high_freq = high_freq * 0.5;
 157         else
 158             high_freq = high_freq * 0.3;
 159     } else if (sample_rate1 == 11025) {
 160         high_freq = high_freq * 0.7;
 161     } else if (sample_rate1 == 8000) {
 162         if (bps <= 0.625) {
 163             high_freq = high_freq * 0.5;
 164         } else if (bps > 0.75) {
 165             s->use_noise_coding = 0;
 166         } else {
 167             high_freq = high_freq * 0.65;
 168         }
 169     } else {
 170         if (bps >= 0.8) {
 171             high_freq = high_freq * 0.75;
 172         } else if (bps >= 0.6) {
 173             high_freq = high_freq * 0.6;
 174         } else {
 175             high_freq = high_freq * 0.5;
 176         }
 177     }
 178     dprintf(s->avctx, "flags2=0x%x\n", flags2);
 179     dprintf(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
 180            s->version, s->nb_channels, s->sample_rate, s->bit_rate,
 181            s->block_align);
 182     dprintf(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
 183            bps, bps1, high_freq, s->byte_offset_bits);
 184     dprintf(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 185            s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 186
 187     /* compute the scale factor band sizes for each MDCT block size */
 188     {
 189         int a, b, pos, lpos, k, block_len, i, j, n;
 190         const uint8_t *table;
 191
 192         if (s->version == 1) {
 193             s->coefs_start = 3;
 194         } else {
 195             s->coefs_start = 0;
 196         }
 197         for(k = 0; k < s->nb_block_sizes; k++) {
 198             block_len = s->frame_len >> k;
 199
 200             if (s->version == 1) {
 201                 lpos = 0;
 202                 for(i=0;i<25;i++) {
 203                     a = wma_critical_freqs[i];
 204                     b = s->sample_rate;
 205                     pos = ((block_len * 2 * a)  + (b >> 1)) / b;
 206                     if (pos > block_len)
 207                         pos = block_len;
 208                     s->exponent_bands[0][i] = pos - lpos;
 209                     if (pos >= block_len) {
 210                         i++;
 211                         break;
 212                     }
 213                     lpos = pos;
 214                 }
 215                 s->exponent_sizes[0] = i;
 216             } else {
 217                 /* hardcoded tables */
 218                 table = NULL;
 219                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 220                 if (a < 3) {
 221                     if (s->sample_rate >= 44100)
 222                         table = exponent_band_44100[a];
 223                     else if (s->sample_rate >= 32000)
 224                         table = exponent_band_32000[a];
 225                     else if (s->sample_rate >= 22050)
 226                         table = exponent_band_22050[a];
 227                 }
 228                 if (table) {
 229                     n = *table++;
 230                     for(i=0;i<n;i++)
 231                         s->exponent_bands[k][i] = table[i];
 232                     s->exponent_sizes[k] = n;
 233                 } else {
 234                     j = 0;
 235                     lpos = 0;
 236                     for(i=0;i<25;i++) {
 237                         a = wma_critical_freqs[i];
 238                         b = s->sample_rate;
 239                         pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
 240                         pos <<= 2;
 241                         if (pos > block_len)
 242                             pos = block_len;
 243                         if (pos > lpos)
 244                             s->exponent_bands[k][j++] = pos - lpos;
 245                         if (pos >= block_len)
 246                             break;
 247                         lpos = pos;
 248                     }
 249                     s->exponent_sizes[k] = j;
 250                 }
 251             }
 252
 253             /* max number of coefs */
 254             s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 255             /* high freq computation */
 256             s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
 257                                           s->sample_rate + 0.5);
 258             n = s->exponent_sizes[k];
 259             j = 0;
 260             pos = 0;
 261             for(i=0;i<n;i++) {
 262                 int start, end;
 263                 start = pos;
 264                 pos += s->exponent_bands[k][i];
 265                 end = pos;
 266                 if (start < s->high_band_start[k])
 267                     start = s->high_band_start[k];
 268                 if (end > s->coefs_end[k])
 269                     end = s->coefs_end[k];
 270                 if (end > start)
 271                     s->exponent_high_bands[k][j++] = end - start;
 272             }
 273             s->exponent_high_sizes[k] = j;
 274 #if 0
 275             tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
 276                   s->frame_len >> k,
 277                   s->coefs_end[k],
 278                   s->high_band_start[k],
 279                   s->exponent_high_sizes[k]);
 280             for(j=0;j<s->exponent_high_sizes[k];j++)
 281                 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
 282             tprintf(s->avctx, "\n");
 283 #endif
 284         }
 285     }
 286
 287 #ifdef TRACE
 288     {
 289         int i, j;
 290         for(i = 0; i < s->nb_block_sizes; i++) {
 291             tprintf(s->avctx, "%5d: n=%2d:",
 292                    s->frame_len >> i,
 293                    s->exponent_sizes[i]);
 294             for(j=0;j<s->exponent_sizes[i];j++)
 295                 tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
 296             tprintf(s->avctx, "\n");
 297         }
 298     }
 299 #endif
 300
 301     /* init MDCT windows : simple sinus window */
 302     for(i = 0; i < s->nb_block_sizes; i++) {
 303         int n;
 304         n = 1 << (s->frame_len_bits - i);
 305         ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
 306         s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
 307     }
 308
 309     s->reset_block_lengths = 1;
 310
 311     if (s->use_noise_coding) {
 312
 313         /* init the noise generator */
 314         if (s->use_exp_vlc)
 315             s->noise_mult = 0.02;
 316         else
 317             s->noise_mult = 0.04;
 318
 319 #ifdef TRACE
 320         for(i=0;i<NOISE_TAB_SIZE;i++)
 321             s->noise_table[i] = 1.0 * s->noise_mult;
 322 #else
 323         {
 324             unsigned int seed;
 325             float norm;
 326             seed = 1;
 327             norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
 328             for(i=0;i<NOISE_TAB_SIZE;i++) {
 329                 seed = seed * 314159 + 1;
 330                 s->noise_table[i] = (float)((int)seed) * norm;
 331             }
 332         }
 333 #endif
 334     }
 335
 336     /* choose the VLC tables for the coefficients */
 337     coef_vlc_table = 2;
 338     if (s->sample_rate >= 32000) {
 339         if (bps1 < 0.72)
 340             coef_vlc_table = 0;
 341         else if (bps1 < 1.16)
 342             coef_vlc_table = 1;
 343     }
 344     s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
 345     s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
 346     init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
 347                   s->coef_vlcs[0]);
 348     init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
 349                   s->coef_vlcs[1]);
 350
 351     return 0;
 352 }
 353
 354 int ff_wma_total_gain_to_bits(int total_gain){
 355          if (total_gain < 15) return 13;
 356     else if (total_gain < 32) return 12;
 357     else if (total_gain < 40) return 11;
 358     else if (total_gain < 45) return 10;
 359     else                      return  9;
 360 }
 361
 362 int ff_wma_end(AVCodecContext *avctx)
 363 {
 364     WMACodecContext *s = avctx->priv_data;
 365     int i;
 366
 367     for(i = 0; i < s->nb_block_sizes; i++)
 368         ff_mdct_end(&s->mdct_ctx[i]);
 369
 370     if (s->use_exp_vlc) {
 371         free_vlc(&s->exp_vlc);
 372     }
 373     if (s->use_noise_coding) {
 374         free_vlc(&s->hgain_vlc);
 375     }
 376     for(i = 0;i < 2; i++) {
 377         free_vlc(&s->coef_vlc[i]);
 378         av_free(s->run_table[i]);
 379         av_free(s->level_table[i]);
 380         av_free(s->int_table[i]);
 381     }
 382
 383     return 0;
 384 }