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, uint16_t **prun_table,
  32                           float **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     float *flevel_table;
  41     int i, l, j, k, level;
  42
  43     init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4, 0);
  44
  45     run_table   = av_malloc(n * sizeof(uint16_t));
  46     level_table = av_malloc(n * sizeof(uint16_t));
  47     flevel_table= av_malloc(n * sizeof(*flevel_table));
  48     int_table   = av_malloc(n * sizeof(uint16_t));
  49     i = 2;
  50     level = 1;
  51     k = 0;
  52     while (i < n) {
  53         int_table[k] = i;
  54         l = levels_table[k++];
  55         for (j = 0; j < l; j++) {
  56             run_table[i]   = j;
  57             level_table[i] = level;
  58             flevel_table[i]= level;
  59             i++;
  60         }
  61         level++;
  62     }
  63     *prun_table   = run_table;
  64     *plevel_table = flevel_table;
  65     *pint_table   = int_table;
  66     av_free(level_table);
  67 }
  68
  69 /**
  70  *@brief Get the samples per frame for this stream.
  71  *@param sample_rate output sample_rate
  72  *@param version wma version
  73  *@param decode_flags codec compression features
  74  *@return log2 of the number of output samples per frame
  75  */
  76 int av_cold ff_wma_get_frame_len_bits(int sample_rate, int version,
  77                                       unsigned int decode_flags)
  78 {
  79
  80     int frame_len_bits;
  81
  82     if (sample_rate <= 16000) {
  83         frame_len_bits = 9;
  84     } else if (sample_rate <= 22050 ||
  85              (sample_rate <= 32000 && version == 1)) {
  86         frame_len_bits = 10;
  87     } else if (sample_rate <= 48000) {
  88         frame_len_bits = 11;
  89     } else if (sample_rate <= 96000) {
  90         frame_len_bits = 12;
  91     } else {
  92         frame_len_bits = 13;
  93     }
  94
  95     if (version == 3) {
  96         int tmp = decode_flags & 0x6;
  97         if (tmp == 0x2) {
  98             ++frame_len_bits;
  99         } else if (tmp == 0x4) {
 100             --frame_len_bits;
 101         } else if (tmp == 0x6) {
 102             frame_len_bits -= 2;
 103         }
 104     }
 105
 106     return frame_len_bits;
 107 }
 108
 109 int ff_wma_init(AVCodecContext *avctx, int flags2)
 110 {
 111     WMACodecContext *s = avctx->priv_data;
 112     int i;
 113     float bps1, high_freq;
 114     volatile float bps;
 115     int sample_rate1;
 116     int coef_vlc_table;
 117
 118     if (   avctx->sample_rate <= 0 || avctx->sample_rate > 50000
 119         || avctx->channels    <= 0 || avctx->channels    > 8
 120         || avctx->bit_rate    <= 0)
 121         return -1;
 122
 123     s->sample_rate = avctx->sample_rate;
 124     s->nb_channels = avctx->channels;
 125     s->bit_rate    = avctx->bit_rate;
 126     s->block_align = avctx->block_align;
 127
 128     dsputil_init(&s->dsp, avctx);
 129
 130     if (avctx->codec->id == CODEC_ID_WMAV1) {
 131         s->version = 1;
 132     } else {
 133         s->version = 2;
 134     }
 135
 136     /* compute MDCT block size */
 137     s->frame_len_bits = ff_wma_get_frame_len_bits(s->sample_rate, s->version, 0);
 138
 139     s->frame_len = 1 << s->frame_len_bits;
 140     if (s->use_variable_block_len) {
 141         int nb_max, nb;
 142         nb = ((flags2 >> 3) & 3) + 1;
 143         if ((s->bit_rate / s->nb_channels) >= 32000)
 144             nb += 2;
 145         nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
 146         if (nb > nb_max)
 147             nb = nb_max;
 148         s->nb_block_sizes = nb + 1;
 149     } else {
 150         s->nb_block_sizes = 1;
 151     }
 152
 153     /* init rate dependent parameters */
 154     s->use_noise_coding = 1;
 155     high_freq = s->sample_rate * 0.5;
 156
 157     /* if version 2, then the rates are normalized */
 158     sample_rate1 = s->sample_rate;
 159     if (s->version == 2) {
 160         if (sample_rate1 >= 44100) {
 161             sample_rate1 = 44100;
 162         } else if (sample_rate1 >= 22050) {
 163             sample_rate1 = 22050;
 164         } else if (sample_rate1 >= 16000) {
 165             sample_rate1 = 16000;
 166         } else if (sample_rate1 >= 11025) {
 167             sample_rate1 = 11025;
 168         } else if (sample_rate1 >= 8000) {
 169             sample_rate1 = 8000;
 170         }
 171     }
 172
 173     bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
 174     s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0 + 0.5)) + 2;
 175
 176     /* compute high frequency value and choose if noise coding should
 177        be activated */
 178     bps1 = bps;
 179     if (s->nb_channels == 2)
 180         bps1 = bps * 1.6;
 181     if (sample_rate1 == 44100) {
 182         if (bps1 >= 0.61) {
 183             s->use_noise_coding = 0;
 184         } else {
 185             high_freq = high_freq * 0.4;
 186         }
 187     } else if (sample_rate1 == 22050) {
 188         if (bps1 >= 1.16) {
 189             s->use_noise_coding = 0;
 190         } else if (bps1 >= 0.72) {
 191             high_freq = high_freq * 0.7;
 192         } else {
 193             high_freq = high_freq * 0.6;
 194         }
 195     } else if (sample_rate1 == 16000) {
 196         if (bps > 0.5) {
 197             high_freq = high_freq * 0.5;
 198         } else {
 199             high_freq = high_freq * 0.3;
 200         }
 201     } else if (sample_rate1 == 11025) {
 202         high_freq = high_freq * 0.7;
 203     } else if (sample_rate1 == 8000) {
 204         if (bps <= 0.625) {
 205             high_freq = high_freq * 0.5;
 206         } else if (bps > 0.75) {
 207             s->use_noise_coding = 0;
 208         } else {
 209             high_freq = high_freq * 0.65;
 210         }
 211     } else {
 212         if (bps >= 0.8) {
 213             high_freq = high_freq * 0.75;
 214         } else if (bps >= 0.6) {
 215             high_freq = high_freq * 0.6;
 216         } else {
 217             high_freq = high_freq * 0.5;
 218         }
 219     }
 220     dprintf(s->avctx, "flags2=0x%x\n", flags2);
 221     dprintf(s->avctx, "version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
 222             s->version, s->nb_channels, s->sample_rate, s->bit_rate,
 223             s->block_align);
 224     dprintf(s->avctx, "bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
 225             bps, bps1, high_freq, s->byte_offset_bits);
 226     dprintf(s->avctx, "use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 227             s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 228
 229     /* compute the scale factor band sizes for each MDCT block size */
 230     {
 231         int a, b, pos, lpos, k, block_len, i, j, n;
 232         const uint8_t *table;
 233
 234         if (s->version == 1) {
 235             s->coefs_start = 3;
 236         } else {
 237             s->coefs_start = 0;
 238         }
 239         for (k = 0; k < s->nb_block_sizes; k++) {
 240             block_len = s->frame_len >> k;
 241
 242             if (s->version == 1) {
 243                 lpos = 0;
 244                 for (i = 0; i < 25; i++) {
 245                     a = wma_critical_freqs[i];
 246                     b = s->sample_rate;
 247                     pos = ((block_len * 2 * a) + (b >> 1)) / b;
 248                     if (pos > block_len)
 249                         pos = block_len;
 250                     s->exponent_bands[0][i] = pos - lpos;
 251                     if (pos >= block_len) {
 252                         i++;
 253                         break;
 254                     }
 255                     lpos = pos;
 256                 }
 257                 s->exponent_sizes[0] = i;
 258             } else {
 259                 /* hardcoded tables */
 260                 table = NULL;
 261                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 262                 if (a < 3) {
 263                     if (s->sample_rate >= 44100) {
 264                         table = exponent_band_44100[a];
 265                     } else if (s->sample_rate >= 32000) {
 266                         table = exponent_band_32000[a];
 267                     } else if (s->sample_rate >= 22050) {
 268                         table = exponent_band_22050[a];
 269                     }
 270                 }
 271                 if (table) {
 272                     n = *table++;
 273                     for (i = 0; i < n; i++)
 274                         s->exponent_bands[k][i] = table[i];
 275                     s->exponent_sizes[k] = n;
 276                 } else {
 277                     j = 0;
 278                     lpos = 0;
 279                     for (i = 0; i < 25; i++) {
 280                         a = wma_critical_freqs[i];
 281                         b = s->sample_rate;
 282                         pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 283                         pos <<= 2;
 284                         if (pos > block_len)
 285                             pos = block_len;
 286                         if (pos > lpos)
 287                             s->exponent_bands[k][j++] = pos - lpos;
 288                         if (pos >= block_len)
 289                             break;
 290                         lpos = pos;
 291                     }
 292                     s->exponent_sizes[k] = j;
 293                 }
 294             }
 295
 296             /* max number of coefs */
 297             s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 298             /* high freq computation */
 299             s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
 300                                           s->sample_rate + 0.5);
 301             n = s->exponent_sizes[k];
 302             j = 0;
 303             pos = 0;
 304             for (i = 0; i < n; i++) {
 305                 int start, end;
 306                 start = pos;
 307                 pos += s->exponent_bands[k][i];
 308                 end = pos;
 309                 if (start < s->high_band_start[k])
 310                     start = s->high_band_start[k];
 311                 if (end > s->coefs_end[k])
 312                     end = s->coefs_end[k];
 313                 if (end > start)
 314                     s->exponent_high_bands[k][j++] = end - start;
 315             }
 316             s->exponent_high_sizes[k] = j;
 317 #if 0
 318             tprintf(s->avctx, "%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
 319                     s->frame_len >> k,
 320                     s->coefs_end[k],
 321                     s->high_band_start[k],
 322                     s->exponent_high_sizes[k]);
 323             for (j = 0; j < s->exponent_high_sizes[k]; j++)
 324                 tprintf(s->avctx, " %d", s->exponent_high_bands[k][j]);
 325             tprintf(s->avctx, "\n");
 326 #endif
 327         }
 328     }
 329
 330 #ifdef TRACE
 331     {
 332         int i, j;
 333         for (i = 0; i < s->nb_block_sizes; i++) {
 334             tprintf(s->avctx, "%5d: n=%2d:",
 335                     s->frame_len >> i,
 336                     s->exponent_sizes[i]);
 337             for (j = 0; j < s->exponent_sizes[i]; j++)
 338                 tprintf(s->avctx, " %d", s->exponent_bands[i][j]);
 339             tprintf(s->avctx, "\n");
 340         }
 341     }
 342 #endif
 343
 344     /* init MDCT windows : simple sinus window */
 345     for (i = 0; i < s->nb_block_sizes; i++) {
 346         int n;
 347         n = 1 << (s->frame_len_bits - i);
 348         ff_sine_window_init(ff_sine_windows[s->frame_len_bits - i], n);
 349         s->windows[i] = ff_sine_windows[s->frame_len_bits - i];
 350     }
 351
 352     s->reset_block_lengths = 1;
 353
 354     if (s->use_noise_coding) {
 355
 356         /* init the noise generator */
 357         if (s->use_exp_vlc) {
 358             s->noise_mult = 0.02;
 359         } else {
 360             s->noise_mult = 0.04;
 361         }
 362
 363 #ifdef TRACE
 364         for (i = 0; i < NOISE_TAB_SIZE; i++)
 365             s->noise_table[i] = 1.0 * s->noise_mult;
 366 #else
 367         {
 368             unsigned int seed;
 369             float norm;
 370             seed = 1;
 371             norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
 372             for (i = 0; i < NOISE_TAB_SIZE; i++) {
 373                 seed = seed * 314159 + 1;
 374                 s->noise_table[i] = (float)((int)seed) * norm;
 375             }
 376         }
 377 #endif
 378     }
 379
 380     /* choose the VLC tables for the coefficients */
 381     coef_vlc_table = 2;
 382     if (s->sample_rate >= 32000) {
 383         if (bps1 < 0.72) {
 384             coef_vlc_table = 0;
 385         } else if (bps1 < 1.16) {
 386             coef_vlc_table = 1;
 387         }
 388     }
 389     s->coef_vlcs[0]= &coef_vlcs[coef_vlc_table * 2    ];
 390     s->coef_vlcs[1]= &coef_vlcs[coef_vlc_table * 2 + 1];
 391     init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0], &s->int_table[0],
 392                   s->coef_vlcs[0]);
 393     init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1], &s->int_table[1],
 394                   s->coef_vlcs[1]);
 395
 396     return 0;
 397 }
 398
 399 int ff_wma_total_gain_to_bits(int total_gain)
 400 {
 401          if (total_gain < 15) return 13;
 402     else if (total_gain < 32) return 12;
 403     else if (total_gain < 40) return 11;
 404     else if (total_gain < 45) return 10;
 405     else                      return  9;
 406 }
 407
 408 int ff_wma_end(AVCodecContext *avctx)
 409 {
 410     WMACodecContext *s = avctx->priv_data;
 411     int i;
 412
 413     for (i = 0; i < s->nb_block_sizes; i++)
 414         ff_mdct_end(&s->mdct_ctx[i]);
 415
 416     if (s->use_exp_vlc) {
 417         free_vlc(&s->exp_vlc);
 418     }
 419     if (s->use_noise_coding) {
 420         free_vlc(&s->hgain_vlc);
 421     }
 422     for (i = 0; i < 2; i++) {
 423         free_vlc(&s->coef_vlc[i]);
 424         av_free(s->run_table[i]);
 425         av_free(s->level_table[i]);
 426         av_free(s->int_table[i]);
 427     }
 428
 429     return 0;
 430 }
 431
 432 /**
 433  * Decode an uncompressed coefficient.
 434  * @param s codec context
 435  * @return the decoded coefficient
 436  */
 437 unsigned int ff_wma_get_large_val(GetBitContext* gb)
 438 {
 439     /** consumes up to 34 bits */
 440     int n_bits = 8;
 441     /** decode length */
 442     if (get_bits1(gb)) {
 443         n_bits += 8;
 444         if (get_bits1(gb)) {
 445             n_bits += 8;
 446             if (get_bits1(gb)) {
 447                 n_bits += 7;
 448             }
 449         }
 450     }
 451     return get_bits_long(gb, n_bits);
 452 }
 453
 454 /**
 455  * Decode run level compressed coefficients.
 456  * @param avctx codec context
 457  * @param gb bitstream reader context
 458  * @param vlc vlc table for get_vlc2
 459  * @param level_table level codes
 460  * @param run_table run codes
 461  * @param version 0 for wma1,2 1 for wmapro
 462  * @param ptr output buffer
 463  * @param offset offset in the output buffer
 464  * @param num_coefs number of input coefficents
 465  * @param block_len input buffer length (2^n)
 466  * @param frame_len_bits number of bits for escaped run codes
 467  * @param coef_nb_bits number of bits for escaped level codes
 468  * @return 0 on success, -1 otherwise
 469  */
 470 int ff_wma_run_level_decode(AVCodecContext* avctx, GetBitContext* gb,
 471                             VLC *vlc,
 472                             const float *level_table, const uint16_t *run_table,
 473                             int version, WMACoef *ptr, int offset,
 474                             int num_coefs, int block_len, int frame_len_bits,
 475                             int coef_nb_bits)
 476 {
 477     int code, level, sign;
 478     const uint32_t *ilvl = (const uint32_t*)level_table;
 479     uint32_t *iptr = (uint32_t*)ptr;
 480     const unsigned int coef_mask = block_len - 1;
 481     for (; offset < num_coefs; offset++) {
 482         code = get_vlc2(gb, vlc->table, VLCBITS, VLCMAX);
 483         if (code > 1) {
 484             /** normal code */
 485             offset += run_table[code];
 486             sign = get_bits1(gb) - 1;
 487             iptr[offset & coef_mask] = ilvl[code] ^ sign<<31;
 488         } else if (code == 1) {
 489             /** EOB */
 490             break;
 491         } else {
 492             /** escape */
 493             if (!version) {
 494                 level = get_bits(gb, coef_nb_bits);
 495                 /** NOTE: this is rather suboptimal. reading
 496                     block_len_bits would be better */
 497                 offset += get_bits(gb, frame_len_bits);
 498             } else {
 499                 level = ff_wma_get_large_val(gb);
 500                 /** escape decode */
 501                 if (get_bits1(gb)) {
 502                     if (get_bits1(gb)) {
 503                         if (get_bits1(gb)) {
 504                             av_log(avctx,AV_LOG_ERROR,
 505                                 "broken escape sequence\n");
 506                             return -1;
 507                         } else
 508                             offset += get_bits(gb, frame_len_bits) + 4;
 509                     } else
 510                         offset += get_bits(gb, 2) + 1;
 511                 }
 512             }
 513             sign = get_bits1(gb) - 1;
 514             ptr[offset & coef_mask] = (level^sign) - sign;
 515         }
 516     }
 517     /** NOTE: EOB can be omitted */
 518     if (offset > num_coefs) {
 519         av_log(avctx, AV_LOG_ERROR, "overflow in spectral RLE, ignoring\n");
 520         return -1;
 521     }
 522
 523     return 0;
 524 }
 525