libavcodec/wmadec.c

   1 /*
   2  * WMA compatible decoder
   3  * Copyright (c) 2002 The FFmpeg Project.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avcodec.h"
  20 #include "dsputil.h"
  21
  22 //#define DEBUG_PARAMS
  23 //#define DEBUG_TRACE
  24
  25 /* size of blocks */
  26 #define BLOCK_MIN_BITS 7
  27 #define BLOCK_MAX_BITS 11
  28 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  29
  30 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  31
  32 /* XXX: find exact max size */
  33 #define HIGH_BAND_MAX_SIZE 16
  34
  35 #define NB_LSP_COEFS 10
  36
  37 /* XXX: is it a suitable value ? */
  38 #define MAX_CODED_SUPERFRAME_SIZE 4096
  39
  40 #define MAX_CHANNELS 2
  41
  42 #define NOISE_TAB_SIZE 8192
  43
  44 #define LSP_POW_BITS 7
  45
  46 typedef struct WMADecodeContext {
  47     GetBitContext gb;
  48     int sample_rate;
  49     int nb_channels;
  50     int bit_rate;
  51     int version; /* 1 = 0x160 (WMAV1), 2 = 0x161 (WMAV2) */
  52     int block_align;
  53     int use_bit_reservoir;
  54     int use_variable_block_len;
  55     int use_exp_vlc;  /* exponent coding: 0 = lsp, 1 = vlc + delta */
  56     int use_noise_coding; /* true if perceptual noise is added */
  57     int byte_offset_bits;
  58     VLC exp_vlc;
  59     int exponent_sizes[BLOCK_NB_SIZES];
  60     uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  61     int high_band_start[BLOCK_NB_SIZES]; /* index of first coef in high band */
  62     int coefs_start;               /* first coded coef */
  63     int coefs_end[BLOCK_NB_SIZES]; /* max number of coded coefficients */
  64     int exponent_high_sizes[BLOCK_NB_SIZES];
  65     int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  66     VLC hgain_vlc;
  67
  68     /* coded values in high bands */
  69     int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  70     int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  71
  72     /* there are two possible tables for spectral coefficients */
  73     VLC coef_vlc[2];
  74     uint16_t *run_table[2];
  75     uint16_t *level_table[2];
  76     /* frame info */
  77     int frame_len;       /* frame length in samples */
  78     int frame_len_bits;  /* frame_len = 1 << frame_len_bits */
  79     int nb_block_sizes;  /* number of block sizes */
  80     /* block info */
  81     int reset_block_lengths;
  82     int block_len_bits; /* log2 of current block length */
  83     int next_block_len_bits; /* log2 of next block length */
  84     int prev_block_len_bits; /* log2 of prev block length */
  85     int block_len; /* block length in samples */
  86     int block_num; /* block number in current frame */
  87     int block_pos; /* current position in frame */
  88     uint8_t ms_stereo; /* true if mid/side stereo mode */
  89     uint8_t channel_coded[MAX_CHANNELS]; /* true if channel is coded */
  90     float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
  91     float max_exponent[MAX_CHANNELS];
  92     int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
  93     float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE] __attribute__((aligned(16)));
  94     MDCTContext mdct_ctx[BLOCK_NB_SIZES];
  95     float *windows[BLOCK_NB_SIZES] __attribute__((aligned(16)));
  96     FFTSample mdct_tmp[BLOCK_MAX_SIZE] __attribute__((aligned(16))); /* temporary storage for imdct */
  97     /* output buffer for one frame and the last for IMDCT windowing */
  98     float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
  99     /* last frame info */
 100     uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 101     int last_bitoffset;
 102     int last_superframe_len;
 103     float noise_table[NOISE_TAB_SIZE];
 104     int noise_index;
 105     float noise_mult; /* XXX: suppress that and integrate it in the noise array */
 106     /* lsp_to_curve tables */
 107     float lsp_cos_table[BLOCK_MAX_SIZE];
 108     float lsp_pow_e_table[256];
 109     float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 110     float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 111 } WMADecodeContext;
 112
 113 typedef struct CoefVLCTable {
 114     int n; /* total number of codes */
 115     const uint32_t *huffcodes; /* VLC bit values */
 116     const uint8_t *huffbits;   /* VLC bit size */
 117     const uint16_t *levels; /* table to build run/level tables */
 118 } CoefVLCTable;
 119
 120 static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len);
 121
 122 #include "wmadata.h"
 123
 124 #ifdef DEBUG_TRACE
 125 #include <stdarg.h>
 126 int frame_count;
 127
 128 static FILE *flog;
 129
 130 void trace(const char *fmt, ...)
 131 {
 132     va_list ap;
 133
 134
 135     if (!flog) {
 136         flog = fopen("/tmp/out.log", "w");
 137         setlinebuf(flog);
 138     }
 139
 140     va_start(ap, fmt);
 141     vfprintf(flog, fmt, ap);
 142     va_end(ap);
 143 }
 144
 145 #define get_bits(s, n) get_bits_trace(s, n)
 146 #define get_vlc(s, vlc) get_vlc_trace(s, vlc)
 147
 148 unsigned int get_bits_trace(GetBitContext *s, int n)
 149 {
 150     unsigned int val;
 151     val = (get_bits)(s, n);
 152     trace("get_bits(%d) : 0x%x\n", n, val);
 153     return val;
 154 }
 155
 156 static int get_vlc_trace(GetBitContext *s, VLC *vlc)
 157 {
 158     int code;
 159     code = (get_vlc)(s, vlc);
 160     trace("get_vlc() : %d\n", code);
 161     return code;
 162 }
 163
 164 static void dump_shorts(const char *name, const short *tab, int n)
 165 {
 166     int i;
 167
 168     trace("%s[%d]:\n", name, n);
 169     for(i=0;i<n;i++) {
 170         if ((i & 7) == 0)
 171             trace("%4d: ", i);
 172         trace(" %5d.0", tab[i]);
 173         if ((i & 7) == 7)
 174             trace("\n");
 175     }
 176 }
 177
 178 static void dump_floats(const char *name, int prec, const float *tab, int n)
 179 {
 180     int i;
 181
 182     trace("%s[%d]:\n", name, n);
 183     for(i=0;i<n;i++) {
 184         if ((i & 7) == 0)
 185             trace("%4d: ", i);
 186         trace(" %8.*f", prec, tab[i]);
 187         if ((i & 7) == 7)
 188             trace("\n");
 189     }
 190     if ((i & 7) != 0)
 191         trace("\n");
 192 }
 193
 194 #else
 195
 196 #define trace(fmt, ...)
 197
 198 #endif
 199
 200 /* XXX: use same run/length optimization as mpeg decoders */
 201 static void init_coef_vlc(VLC *vlc,
 202                           uint16_t **prun_table, uint16_t **plevel_table,
 203                           const CoefVLCTable *vlc_table)
 204 {
 205     int n = vlc_table->n;
 206     const uint8_t *table_bits = vlc_table->huffbits;
 207     const uint32_t *table_codes = vlc_table->huffcodes;
 208     const uint16_t *levels_table = vlc_table->levels;
 209     uint16_t *run_table, *level_table;
 210     const uint16_t *p;
 211     int i, l, j, level;
 212
 213     init_vlc(vlc, 9, n, table_bits, 1, 1, table_codes, 4, 4);
 214
 215     run_table = malloc(n * sizeof(uint16_t));
 216     level_table = malloc(n * sizeof(uint16_t));
 217     p = levels_table;
 218     i = 2;
 219     level = 1;
 220     while (i < n) {
 221         l = *p++;
 222         for(j=0;j<l;j++) {
 223             run_table[i] = j;
 224             level_table[i] = level;
 225             i++;
 226         }
 227         level++;
 228     }
 229     *prun_table = run_table;
 230     *plevel_table = level_table;
 231 }
 232
 233 static int wma_decode_init(AVCodecContext * avctx)
 234 {
 235     WMADecodeContext *s = avctx->priv_data;
 236     int i, flags1, flags2;
 237     float *window;
 238     uint8_t *extradata;
 239     float bps1, high_freq, bps;
 240     int sample_rate1;
 241     int coef_vlc_table;
 242
 243     s->sample_rate = avctx->sample_rate;
 244     s->nb_channels = avctx->channels;
 245     s->bit_rate = avctx->bit_rate;
 246     s->block_align = avctx->block_align;
 247
 248     if (avctx->codec->id == CODEC_ID_WMAV1) {
 249         s->version = 1;
 250     } else {
 251         s->version = 2;
 252     }
 253
 254     /* extract flag infos */
 255     flags1 = 0;
 256     flags2 = 0;
 257     extradata = avctx->extradata;
 258     if (s->version == 1 && avctx->extradata_size >= 4) {
 259         flags1 = extradata[0] | (extradata[1] << 8);
 260         flags2 = extradata[2] | (extradata[3] << 8);
 261     } else if (s->version == 2 && avctx->extradata_size >= 6) {
 262         flags1 = extradata[0] | (extradata[1] << 8) |
 263             (extradata[2] << 16) | (extradata[3] << 24);
 264         flags2 = extradata[4] | (extradata[5] << 8);
 265     }
 266     s->use_exp_vlc = flags2 & 0x0001;
 267     s->use_bit_reservoir = flags2 & 0x0002;
 268     s->use_variable_block_len = flags2 & 0x0004;
 269
 270     /* compute MDCT block size */
 271     if (s->sample_rate <= 16000) {
 272         s->frame_len_bits = 9;
 273     } else if (s->sample_rate <= 22050 ||
 274                (s->sample_rate <= 32000 && s->version == 1)) {
 275         s->frame_len_bits = 10;
 276     } else {
 277         s->frame_len_bits = 11;
 278     }
 279     s->frame_len = 1 << s->frame_len_bits;
 280     if (s->use_variable_block_len) {
 281         int nb_max, nb;
 282         nb = ((flags2 >> 3) & 3) + 1;
 283         if ((s->bit_rate / s->nb_channels) >= 32000)
 284             nb += 2;
 285         nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
 286         if (nb > nb_max)
 287             nb = nb_max;
 288         s->nb_block_sizes = nb + 1;
 289     } else {
 290         s->nb_block_sizes = 1;
 291     }
 292
 293     /* init rate dependant parameters */
 294     s->use_noise_coding = 1;
 295     high_freq = s->sample_rate * 0.5;
 296
 297     /* if version 2, then the rates are normalized */
 298     sample_rate1 = s->sample_rate;
 299     if (s->version == 2) {
 300         if (sample_rate1 >= 44100)
 301             sample_rate1 = 44100;
 302         else if (sample_rate1 >= 22050)
 303             sample_rate1 = 22050;
 304         else if (sample_rate1 >= 16000)
 305             sample_rate1 = 16000;
 306         else if (sample_rate1 >= 11025)
 307             sample_rate1 = 11025;
 308         else if (sample_rate1 >= 8000)
 309             sample_rate1 = 8000;
 310     }
 311
 312     bps = (float)s->bit_rate / (float)(s->nb_channels * s->sample_rate);
 313     s->byte_offset_bits = av_log2((int)(bps * s->frame_len / 8.0)) + 2;
 314
 315     /* compute high frequency value and choose if noise coding should
 316        be activated */
 317     bps1 = bps;
 318     if (s->nb_channels == 2)
 319         bps1 = bps * 1.6;
 320     if (sample_rate1 == 44100) {
 321         if (bps1 >= 0.61)
 322             s->use_noise_coding = 0;
 323         else
 324             high_freq = high_freq * 0.4;
 325     } else if (sample_rate1 == 22050) {
 326         if (bps1 >= 1.16)
 327             s->use_noise_coding = 0;
 328         else if (bps1 >= 0.72)
 329             high_freq = high_freq * 0.7;
 330         else
 331             high_freq = high_freq * 0.6;
 332     } else if (sample_rate1 == 16000) {
 333         if (bps > 0.5)
 334             high_freq = high_freq * 0.5;
 335         else
 336             high_freq = high_freq * 0.3;
 337     } else if (sample_rate1 == 11025) {
 338         high_freq = high_freq * 0.7;
 339     } else if (sample_rate1 == 8000) {
 340         if (bps <= 0.625) {
 341             high_freq = high_freq * 0.5;
 342         } else if (bps > 0.75) {
 343             s->use_noise_coding = 0;
 344         } else {
 345             high_freq = high_freq * 0.65;
 346         }
 347     } else {
 348         if (bps >= 0.8) {
 349             high_freq = high_freq * 0.75;
 350         } else if (bps >= 0.6) {
 351             high_freq = high_freq * 0.6;
 352         } else {
 353             high_freq = high_freq * 0.5;
 354         }
 355     }
 356 #ifdef DEBUG_PARAMS
 357     printf("flags1=0x%x flags2=0x%x\n", flags1, flags2);
 358     printf("version=%d channels=%d sample_rate=%d bitrate=%d block_align=%d\n",
 359            s->version, s->nb_channels, s->sample_rate, s->bit_rate,
 360            s->block_align);
 361     printf("bps=%f bps1=%f high_freq=%f bitoffset=%d\n",
 362            bps, bps1, high_freq, s->byte_offset_bits);
 363     printf("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 364            s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 365 #endif
 366
 367     /* compute the scale factor band sizes for each MDCT block size */
 368     {
 369         int a, b, pos, lpos, k, block_len, i, j, n;
 370         const uint8_t *table;
 371
 372         if (s->version == 1) {
 373             s->coefs_start = 3;
 374         } else {
 375             s->coefs_start = 0;
 376         }
 377         for(k = 0; k < s->nb_block_sizes; k++) {
 378             block_len = s->frame_len >> k;
 379
 380             if (s->version == 1) {
 381                 lpos = 0;
 382                 for(i=0;i<25;i++) {
 383                     a = wma_critical_freqs[i];
 384                     b = s->sample_rate;
 385                     pos = ((block_len * 2 * a)  + (b >> 1)) / b;
 386                     if (pos > block_len)
 387                         pos = block_len;
 388                     s->exponent_bands[0][i] = pos - lpos;
 389                     if (pos >= block_len) {
 390                         i++;
 391                         break;
 392                     }
 393                     lpos = pos;
 394                 }
 395                 s->exponent_sizes[0] = i;
 396             } else {
 397                 /* hardcoded tables */
 398                 table = NULL;
 399                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 400                 if (a < 3) {
 401                     if (s->sample_rate >= 44100)
 402                         table = exponent_band_44100[a];
 403                     else if (s->sample_rate >= 32000)
 404                         table = exponent_band_32000[a];
 405                     else if (s->sample_rate >= 22050)
 406                         table = exponent_band_22050[a];
 407                 }
 408                 if (table) {
 409                     n = *table++;
 410                     for(i=0;i<n;i++)
 411                         s->exponent_bands[k][i] = table[i];
 412                     s->exponent_sizes[k] = n;
 413                 } else {
 414                     j = 0;
 415                     lpos = 0;
 416                     for(i=0;i<25;i++) {
 417                         a = wma_critical_freqs[i];
 418                         b = s->sample_rate;
 419                         pos = ((block_len * 2 * a)  + (b << 1)) / (4 * b);
 420                         pos <<= 2;
 421                         if (pos > block_len)
 422                             pos = block_len;
 423                         if (pos > lpos)
 424                             s->exponent_bands[k][j++] = pos - lpos;
 425                         if (pos >= block_len)
 426                             break;
 427                         lpos = pos;
 428                     }
 429                     s->exponent_sizes[k] = j;
 430                 }
 431             }
 432
 433             /* max number of coefs */
 434             s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 435             /* high freq computation */
 436             s->high_band_start[k] = (int)((block_len * 2 * high_freq) /
 437                                           s->sample_rate + 0.5);
 438             n = s->exponent_sizes[k];
 439             j = 0;
 440             pos = 0;
 441             for(i=0;i<n;i++) {
 442                 int start, end;
 443                 start = pos;
 444                 pos += s->exponent_bands[k][i];
 445                 end = pos;
 446                 if (start < s->high_band_start[k])
 447                     start = s->high_band_start[k];
 448                 if (end > s->coefs_end[k])
 449                     end = s->coefs_end[k];
 450                 if (end > start)
 451                     s->exponent_high_bands[k][j++] = end - start;
 452             }
 453             s->exponent_high_sizes[k] = j;
 454 #if 0
 455             trace("%5d: coefs_end=%d high_band_start=%d nb_high_bands=%d: ",
 456                   s->frame_len >> k,
 457                   s->coefs_end[k],
 458                   s->high_band_start[k],
 459                   s->exponent_high_sizes[k]);
 460             for(j=0;j<s->exponent_high_sizes[k];j++)
 461                 trace(" %d", s->exponent_high_bands[k][j]);
 462             trace("\n");
 463 #endif
 464         }
 465     }
 466
 467 #ifdef DEBUG_TRACE
 468     {
 469         int i, j;
 470         for(i = 0; i < s->nb_block_sizes; i++) {
 471             trace("%5d: n=%2d:",
 472                    s->frame_len >> i,
 473                    s->exponent_sizes[i]);
 474             for(j=0;j<s->exponent_sizes[i];j++)
 475                 trace(" %d", s->exponent_bands[i][j]);
 476             trace("\n");
 477         }
 478     }
 479 #endif
 480
 481     /* init MDCT */
 482     for(i = 0; i < s->nb_block_sizes; i++)
 483         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1);
 484
 485     /* init MDCT windows : simple sinus window */
 486     for(i = 0; i < s->nb_block_sizes; i++) {
 487         int n, j;
 488         float alpha;
 489         n = 1 << (s->frame_len_bits - i);
 490         window = av_malloc(sizeof(float) * n);
 491         alpha = M_PI / (2.0 * n);
 492         for(j=0;j<n;j++) {
 493             window[n - j - 1] = sin((j + 0.5) * alpha);
 494         }
 495         s->windows[i] = window;
 496     }
 497
 498     s->reset_block_lengths = 1;
 499
 500     if (s->use_noise_coding) {
 501
 502         /* init the noise generator */
 503         if (s->use_exp_vlc)
 504             s->noise_mult = 0.02;
 505         else
 506             s->noise_mult = 0.04;
 507
 508 #if defined(DEBUG_TRACE)
 509         for(i=0;i<NOISE_TAB_SIZE;i++)
 510             s->noise_table[i] = 1.0 * s->noise_mult;
 511 #else
 512         {
 513             unsigned int seed;
 514             float norm;
 515             seed = 1;
 516             norm = (1.0 / (float)(1LL << 31)) * sqrt(3) * s->noise_mult;
 517             for(i=0;i<NOISE_TAB_SIZE;i++) {
 518                 seed = seed * 314159 + 1;
 519                 s->noise_table[i] = (float)((int)seed) * norm;
 520             }
 521         }
 522 #endif
 523         init_vlc(&s->hgain_vlc, 9, sizeof(hgain_huffbits),
 524                  hgain_huffbits, 1, 1,
 525                  hgain_huffcodes, 2, 2);
 526     }
 527
 528     if (s->use_exp_vlc) {
 529         init_vlc(&s->exp_vlc, 9, sizeof(scale_huffbits),
 530                  scale_huffbits, 1, 1,
 531                  scale_huffcodes, 4, 4);
 532     } else {
 533         wma_lsp_to_curve_init(s, s->frame_len);
 534     }
 535
 536     /* choose the VLC tables for the coefficients */
 537     coef_vlc_table = 2;
 538     if (s->sample_rate >= 32000) {
 539         if (bps1 < 0.72)
 540             coef_vlc_table = 0;
 541         else if (bps1 < 1.16)
 542             coef_vlc_table = 1;
 543     }
 544
 545     init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
 546                   &coef_vlcs[coef_vlc_table * 2]);
 547     init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
 548                   &coef_vlcs[coef_vlc_table * 2 + 1]);
 549     return 0;
 550 }
 551
 552 /* interpolate values for a bigger or smaller block. The block must
 553    have multiple sizes */
 554 static void interpolate_array(float *scale, int old_size, int new_size)
 555 {
 556     int i, j, jincr, k;
 557     float v;
 558
 559     if (new_size > old_size) {
 560         jincr = new_size / old_size;
 561         j = new_size;
 562         for(i = old_size - 1; i >=0; i--) {
 563             v = scale[i];
 564             k = jincr;
 565             do {
 566                 scale[--j] = v;
 567             } while (--k);
 568         }
 569     } else if (new_size < old_size) {
 570         j = 0;
 571         jincr = old_size / new_size;
 572         for(i = 0; i < new_size; i++) {
 573             scale[i] = scale[j];
 574             j += jincr;
 575         }
 576     }
 577 }
 578
 579 /* compute x^-0.25 with an exponent and mantissa table. We use linear
 580    interpolation to reduce the mantissa table size at a small speed
 581    expense (linear interpolation approximately doubles the number of
 582    bits of precision). */
 583 static inline float pow_m1_4(WMADecodeContext *s, float x)
 584 {
 585     union {
 586         float f;
 587         unsigned int v;
 588     } u, t;
 589     unsigned int e, m;
 590     float a, b;
 591
 592     u.f = x;
 593     e = u.v >> 23;
 594     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 595     /* build interpolation scale: 1 <= t < 2. */
 596     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 597     a = s->lsp_pow_m_table1[m];
 598     b = s->lsp_pow_m_table2[m];
 599     return s->lsp_pow_e_table[e] * (a + b * t.f);
 600 }
 601
 602 static void wma_lsp_to_curve_init(WMADecodeContext *s, int frame_len)
 603 {
 604     float wdel, a, b;
 605     int i, e, m;
 606
 607     wdel = M_PI / frame_len;
 608     for(i=0;i<frame_len;i++)
 609         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 610
 611     /* tables for x^-0.25 computation */
 612     for(i=0;i<256;i++) {
 613         e = i - 126;
 614         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 615     }
 616
 617     /* NOTE: these two tables are needed to avoid two operations in
 618        pow_m1_4 */
 619     b = 1.0;
 620     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
 621         m = (1 << LSP_POW_BITS) + i;
 622         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
 623         a = pow(a, -0.25);
 624         s->lsp_pow_m_table1[i] = 2 * a - b;
 625         s->lsp_pow_m_table2[i] = b - a;
 626         b = a;
 627     }
 628 #if 0
 629     for(i=1;i<20;i++) {
 630         float v, r1, r2;
 631         v = 5.0 / i;
 632         r1 = pow_m1_4(s, v);
 633         r2 = pow(v,-0.25);
 634         printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
 635     }
 636 #endif
 637 }
 638
 639 /* NOTE: We use the same code as Vorbis here */
 640 /* XXX: optimize it further with SSE/3Dnow */
 641 static void wma_lsp_to_curve(WMADecodeContext *s,
 642                              float *out, float *val_max_ptr,
 643                              int n, float *lsp)
 644 {
 645     int i, j;
 646     float p, q, w, v, val_max;
 647
 648     val_max = 0;
 649     for(i=0;i<n;i++) {
 650         p = 0.5f;
 651         q = 0.5f;
 652         w = s->lsp_cos_table[i];
 653         for(j=1;j<NB_LSP_COEFS;j+=2){
 654             q *= w - lsp[j - 1];
 655             p *= w - lsp[j];
 656         }
 657         p *= p * (2.0f - w);
 658         q *= q * (2.0f + w);
 659         v = p + q;
 660         v = pow_m1_4(s, v);
 661         if (v > val_max)
 662             val_max = v;
 663         out[i] = v;
 664     }
 665     *val_max_ptr = val_max;
 666 }
 667
 668 /* decode exponents coded with LSP coefficients (same idea as Vorbis) */
 669 static void decode_exp_lsp(WMADecodeContext *s, int ch)
 670 {
 671     float lsp_coefs[NB_LSP_COEFS];
 672     int val, i;
 673
 674     for(i = 0; i < NB_LSP_COEFS; i++) {
 675         if (i == 0 || i >= 8)
 676             val = get_bits(&s->gb, 3);
 677         else
 678             val = get_bits(&s->gb, 4);
 679         lsp_coefs[i] = lsp_codebook[i][val];
 680     }
 681
 682     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
 683                      s->block_len, lsp_coefs);
 684 }
 685
 686 /* decode exponents coded with VLC codes */
 687 static int decode_exp_vlc(WMADecodeContext *s, int ch)
 688 {
 689     int last_exp, n, code;
 690     const uint16_t *ptr, *band_ptr;
 691     float v, *q, max_scale, *q_end;
 692
 693     band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
 694     ptr = band_ptr;
 695     q = s->exponents[ch];
 696     q_end = q + s->block_len;
 697     max_scale = 0;
 698     if (s->version == 1) {
 699         last_exp = get_bits(&s->gb, 5) + 10;
 700         /* XXX: use a table */
 701         v = pow(10, last_exp * (1.0 / 16.0));
 702         max_scale = v;
 703         n = *ptr++;
 704         do {
 705             *q++ = v;
 706         } while (--n);
 707     }
 708     last_exp = 36;
 709     while (q < q_end) {
 710         code = get_vlc(&s->gb, &s->exp_vlc);
 711         if (code < 0)
 712             return -1;
 713         /* NOTE: this offset is the same as MPEG4 AAC ! */
 714         last_exp += code - 60;
 715         /* XXX: use a table */
 716         v = pow(10, last_exp * (1.0 / 16.0));
 717         if (v > max_scale)
 718             max_scale = v;
 719         n = *ptr++;
 720         do {
 721             *q++ = v;
 722         } while (--n);
 723     }
 724     s->max_exponent[ch] = max_scale;
 725     return 0;
 726 }
 727
 728 /* return 0 if OK. return 1 if last block of frame. return -1 if
 729    unrecorrable error. */
 730 static int wma_decode_block(WMADecodeContext *s)
 731 {
 732     int n, v, a, ch, code, bsize;
 733     int coef_nb_bits, total_gain, parse_exponents;
 734     float window[BLOCK_MAX_SIZE * 2];
 735     int nb_coefs[MAX_CHANNELS];
 736     float mdct_norm;
 737
 738     trace("***decode_block: %d:%d\n", frame_count - 1, s->block_num);
 739
 740     /* compute current block length */
 741     if (s->use_variable_block_len) {
 742         n = av_log2(s->nb_block_sizes - 1) + 1;
 743
 744         if (s->reset_block_lengths) {
 745             s->reset_block_lengths = 0;
 746             v = get_bits(&s->gb, n);
 747             if (v >= s->nb_block_sizes)
 748                 return -1;
 749             s->prev_block_len_bits = s->frame_len_bits - v;
 750             v = get_bits(&s->gb, n);
 751             if (v >= s->nb_block_sizes)
 752                 return -1;
 753             s->block_len_bits = s->frame_len_bits - v;
 754         } else {
 755             /* update block lengths */
 756             s->prev_block_len_bits = s->block_len_bits;
 757             s->block_len_bits = s->next_block_len_bits;
 758         }
 759         v = get_bits(&s->gb, n);
 760         if (v >= s->nb_block_sizes)
 761             return -1;
 762         s->next_block_len_bits = s->frame_len_bits - v;
 763     } else {
 764         /* fixed block len */
 765         s->next_block_len_bits = s->frame_len_bits;
 766         s->prev_block_len_bits = s->frame_len_bits;
 767         s->block_len_bits = s->frame_len_bits;
 768     }
 769
 770     /* now check if the block length is coherent with the frame length */
 771     s->block_len = 1 << s->block_len_bits;
 772     if ((s->block_pos + s->block_len) > s->frame_len)
 773         return -1;
 774
 775     if (s->nb_channels == 2) {
 776         s->ms_stereo = get_bits(&s->gb, 1);
 777     }
 778     v = 0;
 779     for(ch = 0; ch < s->nb_channels; ch++) {
 780         a = get_bits(&s->gb, 1);
 781         s->channel_coded[ch] = a;
 782         v |= a;
 783     }
 784     /* if no channel coded, no need to go further */
 785     /* XXX: fix potential framing problems */
 786     if (!v)
 787         goto next;
 788
 789     bsize = s->frame_len_bits - s->block_len_bits;
 790
 791     /* read total gain and extract corresponding number of bits for
 792        coef escape coding */
 793     total_gain = 1;
 794     for(;;) {
 795         a = get_bits(&s->gb, 7);
 796         total_gain += a;
 797         if (a != 127)
 798             break;
 799     }
 800
 801     if (total_gain < 15)
 802         coef_nb_bits = 13;
 803     else if (total_gain < 32)
 804         coef_nb_bits = 12;
 805     else if (total_gain < 40)
 806         coef_nb_bits = 11;
 807     else if (total_gain < 45)
 808         coef_nb_bits = 10;
 809     else
 810         coef_nb_bits = 9;
 811
 812     /* compute number of coefficients */
 813     n = s->coefs_end[bsize] - s->coefs_start;
 814     for(ch = 0; ch < s->nb_channels; ch++)
 815         nb_coefs[ch] = n;
 816
 817     /* complex coding */
 818     if (s->use_noise_coding) {
 819
 820         for(ch = 0; ch < s->nb_channels; ch++) {
 821             if (s->channel_coded[ch]) {
 822                 int i, n, a;
 823                 n = s->exponent_high_sizes[bsize];
 824                 for(i=0;i<n;i++) {
 825                     a = get_bits(&s->gb, 1);
 826                     s->high_band_coded[ch][i] = a;
 827                     /* if noise coding, the coefficients are not transmitted */
 828                     if (a)
 829                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
 830                 }
 831             }
 832         }
 833         for(ch = 0; ch < s->nb_channels; ch++) {
 834             if (s->channel_coded[ch]) {
 835                 int i, n, val, code;
 836
 837                 n = s->exponent_high_sizes[bsize];
 838                 val = (int)0x80000000;
 839                 for(i=0;i<n;i++) {
 840                     if (s->high_band_coded[ch][i]) {
 841                         if (val == (int)0x80000000) {
 842                             val = get_bits(&s->gb, 7) - 19;
 843                         } else {
 844                             code = get_vlc(&s->gb, &s->hgain_vlc);
 845                             if (code < 0)
 846                                 return -1;
 847                             val += code - 18;
 848                         }
 849                         s->high_band_values[ch][i] = val;
 850                     }
 851                 }
 852             }
 853         }
 854     }
 855
 856     /* exposant can be interpolated in short blocks. */
 857     parse_exponents = 1;
 858     if (s->block_len_bits != s->frame_len_bits) {
 859         parse_exponents = get_bits(&s->gb, 1);
 860     }
 861
 862     if (parse_exponents) {
 863         for(ch = 0; ch < s->nb_channels; ch++) {
 864             if (s->channel_coded[ch]) {
 865                 if (s->use_exp_vlc) {
 866                     if (decode_exp_vlc(s, ch) < 0)
 867                         return -1;
 868                 } else {
 869                     decode_exp_lsp(s, ch);
 870                 }
 871             }
 872         }
 873     } else {
 874         for(ch = 0; ch < s->nb_channels; ch++) {
 875             if (s->channel_coded[ch]) {
 876                 interpolate_array(s->exponents[ch], 1 << s->prev_block_len_bits,
 877                                   s->block_len);
 878             }
 879         }
 880     }
 881
 882     /* parse spectral coefficients : just RLE encoding */
 883     for(ch = 0; ch < s->nb_channels; ch++) {
 884         if (s->channel_coded[ch]) {
 885             VLC *coef_vlc;
 886             int level, run, sign, tindex;
 887             int16_t *ptr, *eptr;
 888             const int16_t *level_table, *run_table;
 889
 890             /* special VLC tables are used for ms stereo because
 891                there is potentially less energy there */
 892             tindex = (ch == 1 && s->ms_stereo);
 893             coef_vlc = &s->coef_vlc[tindex];
 894             run_table = s->run_table[tindex];
 895             level_table = s->level_table[tindex];
 896             /* XXX: optimize */
 897             ptr = &s->coefs1[ch][0];
 898             eptr = ptr + nb_coefs[ch];
 899             memset(ptr, 0, s->block_len * sizeof(int16_t));
 900             for(;;) {
 901                 code = get_vlc(&s->gb, coef_vlc);
 902                 if (code < 0)
 903                     return -1;
 904                 if (code == 1) {
 905                     /* EOB */
 906                     break;
 907                 } else if (code == 0) {
 908                     /* escape */
 909                     level = get_bits(&s->gb, coef_nb_bits);
 910                     /* NOTE: this is rather suboptimal. reading
 911                        block_len_bits would be better */
 912                     run = get_bits(&s->gb, s->frame_len_bits);
 913                 } else {
 914                     /* normal code */
 915                     run = run_table[code];
 916                     level = level_table[code];
 917                 }
 918                 sign = get_bits(&s->gb, 1);
 919                 if (!sign)
 920                     level = -level;
 921                 ptr += run;
 922                 if (ptr >= eptr)
 923                     return -1;
 924                 *ptr++ = level;
 925                 /* NOTE: EOB can be omitted */
 926                 if (ptr >= eptr)
 927                     break;
 928             }
 929         }
 930         if (s->version == 1 && s->nb_channels >= 2) {
 931             align_get_bits(&s->gb);
 932         }
 933     }
 934
 935     /* normalize */
 936     {
 937         int n4 = s->block_len / 2;
 938         mdct_norm = 1.0 / (float)n4;
 939         if (s->version == 1) {
 940             mdct_norm *= sqrt(n4);
 941         }
 942     }
 943
 944     /* finally compute the MDCT coefficients */
 945     for(ch = 0; ch < s->nb_channels; ch++) {
 946         if (s->channel_coded[ch]) {
 947             int16_t *coefs1;
 948             float *coefs, *exponents, mult, mult1, noise, *exp_ptr;
 949             int i, j, n, n1, last_high_band;
 950             float exp_power[HIGH_BAND_MAX_SIZE];
 951
 952             coefs1 = s->coefs1[ch];
 953             exponents = s->exponents[ch];
 954             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
 955             mult *= mdct_norm;
 956             coefs = s->coefs[ch];
 957             if (s->use_noise_coding) {
 958                 mult1 = mult;
 959                 /* very low freqs : noise */
 960                 for(i = 0;i < s->coefs_start; i++) {
 961                     *coefs++ = s->noise_table[s->noise_index] * (*exponents++) * mult1;
 962                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
 963                 }
 964
 965                 n1 = s->exponent_high_sizes[bsize];
 966
 967                 /* compute power of high bands */
 968                 exp_ptr = exponents +
 969                     s->high_band_start[bsize] -
 970                     s->coefs_start;
 971                 last_high_band = 0; /* avoid warning */
 972                 for(j=0;j<n1;j++) {
 973                     n = s->exponent_high_bands[s->frame_len_bits -
 974                                               s->block_len_bits][j];
 975                     if (s->high_band_coded[ch][j]) {
 976                         float e2, v;
 977                         e2 = 0;
 978                         for(i = 0;i < n; i++) {
 979                             v = exp_ptr[i];
 980                             e2 += v * v;
 981                         }
 982                         exp_power[j] = e2 / n;
 983                         last_high_band = j;
 984                         trace("%d: power=%f (%d)\n", j, exp_power[j], n);
 985                     }
 986                     exp_ptr += n;
 987                 }
 988
 989                 /* main freqs and high freqs */
 990                 for(j=-1;j<n1;j++) {
 991                     if (j < 0) {
 992                         n = s->high_band_start[bsize] -
 993                             s->coefs_start;
 994                     } else {
 995                         n = s->exponent_high_bands[s->frame_len_bits -
 996                                                   s->block_len_bits][j];
 997                     }
 998                     if (j >= 0 && s->high_band_coded[ch][j]) {
 999                         /* use noise with specified power */
1000                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
1001                         /* XXX: use a table */
1002                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
1003                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
1004                         mult1 *= mdct_norm;
1005                         for(i = 0;i < n; i++) {
1006                             noise = s->noise_table[s->noise_index];
1007                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1008                             *coefs++ = (*exponents++) * noise * mult1;
1009                         }
1010                     } else {
1011                         /* coded values + small noise */
1012                         for(i = 0;i < n; i++) {
1013                             noise = s->noise_table[s->noise_index];
1014                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1015                             *coefs++ = ((*coefs1++) + noise) * (*exponents++) * mult;
1016                         }
1017                     }
1018                 }
1019
1020                 /* very high freqs : noise */
1021                 n = s->block_len - s->coefs_end[bsize];
1022                 mult1 = mult * exponents[-1];
1023                 for(i = 0; i < n; i++) {
1024                     *coefs++ = s->noise_table[s->noise_index] * mult1;
1025                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
1026                 }
1027             } else {
1028                 /* XXX: optimize more */
1029                 for(i = 0;i < s->coefs_start; i++)
1030                     *coefs++ = 0.0;
1031                 n = nb_coefs[ch];
1032                 for(i = 0;i < n; i++) {
1033                     *coefs++ = coefs1[i] * exponents[i] * mult;
1034                 }
1035                 n = s->block_len - s->coefs_end[bsize];
1036                 for(i = 0;i < n; i++)
1037                     *coefs++ = 0.0;
1038             }
1039         }
1040     }
1041
1042 #ifdef DEBUG_TRACE
1043     for(ch = 0; ch < s->nb_channels; ch++) {
1044         if (s->channel_coded[ch]) {
1045             dump_floats("exponents", 3, s->exponents[ch], s->block_len);
1046             dump_floats("coefs", 1, s->coefs[ch], s->block_len);
1047         }
1048     }
1049 #endif
1050
1051     if (s->ms_stereo && s->channel_coded[1]) {
1052         float a, b;
1053         int i;
1054
1055         /* nominal case for ms stereo: we do it before mdct */
1056         /* no need to optimize this case because it should almost
1057            never happen */
1058         if (!s->channel_coded[0]) {
1059 #ifdef DEBUG_TRACE
1060             trace("rare ms-stereo case happened\n");
1061 #endif
1062             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1063             s->channel_coded[0] = 1;
1064         }
1065
1066         for(i = 0; i < s->block_len; i++) {
1067             a = s->coefs[0][i];
1068             b = s->coefs[1][i];
1069             s->coefs[0][i] = a + b;
1070             s->coefs[1][i] = a - b;
1071         }
1072     }
1073
1074     /* build the window : we ensure that when the windows overlap
1075        their squared sum is always 1 (MDCT reconstruction rule) */
1076     /* XXX: merge with output */
1077     {
1078         int i, next_block_len, block_len, prev_block_len, n;
1079         float *wptr;
1080
1081         block_len = s->block_len;
1082         prev_block_len = 1 << s->prev_block_len_bits;
1083         next_block_len = 1 << s->next_block_len_bits;
1084
1085         /* right part */
1086         wptr = window + block_len;
1087         if (block_len <= next_block_len) {
1088             for(i=0;i<block_len;i++)
1089                 *wptr++ = s->windows[bsize][i];
1090         } else {
1091             /* overlap */
1092             n = (block_len / 2) - (next_block_len / 2);
1093             for(i=0;i<n;i++)
1094                 *wptr++ = 1.0;
1095             for(i=0;i<next_block_len;i++)
1096                 *wptr++ = s->windows[s->frame_len_bits - s->next_block_len_bits][i];
1097             for(i=0;i<n;i++)
1098                 *wptr++ = 0.0;
1099         }
1100
1101         /* left part */
1102         wptr = window + block_len;
1103         if (block_len <= prev_block_len) {
1104             for(i=0;i<block_len;i++)
1105                 *--wptr = s->windows[bsize][i];
1106         } else {
1107             /* overlap */
1108             n = (block_len / 2) - (prev_block_len / 2);
1109             for(i=0;i<n;i++)
1110                 *--wptr = 1.0;
1111             for(i=0;i<prev_block_len;i++)
1112                 *--wptr = s->windows[s->frame_len_bits - s->prev_block_len_bits][i];
1113             for(i=0;i<n;i++)
1114                 *--wptr = 0.0;
1115         }
1116     }
1117
1118
1119     for(ch = 0; ch < s->nb_channels; ch++) {
1120         if (s->channel_coded[ch]) {
1121             FFTSample output[BLOCK_MAX_SIZE * 2] __attribute__((aligned(16)));
1122             float *ptr;
1123             int i, n4, index, n;
1124
1125             n = s->block_len;
1126             n4 = s->block_len / 2;
1127             ff_imdct_calc(&s->mdct_ctx[bsize],
1128                           output, s->coefs[ch], s->mdct_tmp);
1129
1130             /* XXX: optimize all that by build the window and
1131                multipying/adding at the same time */
1132             /* multiply by the window */
1133             for(i=0;i<n * 2;i++) {
1134                 output[i] *= window[i];
1135             }
1136
1137             /* add in the frame */
1138             index = (s->frame_len / 2) + s->block_pos - n4;
1139             ptr = &s->frame_out[ch][index];
1140             for(i=0;i<n * 2;i++) {
1141                 *ptr += output[i];
1142                 ptr++;
1143             }
1144
1145             /* specific fast case for ms-stereo : add to second
1146                channel if it is not coded */
1147             if (s->ms_stereo && !s->channel_coded[1]) {
1148                 ptr = &s->frame_out[1][index];
1149                 for(i=0;i<n * 2;i++) {
1150                     *ptr += output[i];
1151                     ptr++;
1152                 }
1153             }
1154         }
1155     }
1156  next:
1157     /* update block number */
1158     s->block_num++;
1159     s->block_pos += s->block_len;
1160     if (s->block_pos >= s->frame_len)
1161         return 1;
1162     else
1163         return 0;
1164 }
1165
1166 /* decode a frame of frame_len samples */
1167 static int wma_decode_frame(WMADecodeContext *s, int16_t *samples)
1168 {
1169     int ret, i, n, a, ch, incr;
1170     int16_t *ptr;
1171     float *iptr;
1172
1173     trace("***decode_frame: %d size=%d\n", frame_count++, s->frame_len);
1174
1175     /* read each block */
1176     s->block_num = 0;
1177     s->block_pos = 0;
1178     for(;;) {
1179         ret = wma_decode_block(s);
1180         if (ret < 0)
1181             return -1;
1182         if (ret)
1183             break;
1184     }
1185
1186     /* convert frame to integer */
1187     n = s->frame_len;
1188     incr = s->nb_channels;
1189     for(ch = 0; ch < s->nb_channels; ch++) {
1190         ptr = samples + ch;
1191         iptr = s->frame_out[ch];
1192
1193         for(i=0;i<n;i++) {
1194             a = lrintf(*iptr++);
1195             if (a > 32767)
1196                 a = 32767;
1197             else if (a < -32768)
1198                 a = -32768;
1199             *ptr = a;
1200             ptr += incr;
1201         }
1202         /* prepare for next block */
1203         memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1204                 s->frame_len * sizeof(float));
1205         /* XXX: suppress this */
1206         memset(&s->frame_out[ch][s->frame_len], 0,
1207                s->frame_len * sizeof(float));
1208     }
1209
1210 #ifdef DEBUG_TRACE
1211     dump_shorts("samples", samples, n * s->nb_channels);
1212 #endif
1213     return 0;
1214 }
1215
1216 static int wma_decode_superframe(AVCodecContext *avctx,
1217                                  void *data, int *data_size,
1218                                  UINT8 *buf, int buf_size)
1219 {
1220     WMADecodeContext *s = avctx->priv_data;
1221     int nb_frames, bit_offset, i, pos, len;
1222     uint8_t *q;
1223     int16_t *samples;
1224
1225     trace("***decode_superframe:\n");
1226
1227     samples = data;
1228
1229     init_get_bits(&s->gb, buf, buf_size);
1230
1231     if (s->use_bit_reservoir) {
1232         /* read super frame header */
1233         get_bits(&s->gb, 4); /* super frame index */
1234         nb_frames = get_bits(&s->gb, 4) - 1;
1235
1236         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1237
1238         if (s->last_superframe_len > 0) {
1239             //        printf("skip=%d\n", s->last_bitoffset);
1240             /* add bit_offset bits to last frame */
1241             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1242                 MAX_CODED_SUPERFRAME_SIZE)
1243                 goto fail;
1244             q = s->last_superframe + s->last_superframe_len;
1245             len = bit_offset;
1246             while (len > 0) {
1247                 *q++ = (get_bits)(&s->gb, 8);
1248                 len -= 8;
1249             }
1250             if (len > 0) {
1251                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
1252             }
1253
1254             /* XXX: bit_offset bits into last frame */
1255             init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE);
1256             /* skip unused bits */
1257             if (s->last_bitoffset > 0)
1258                 skip_bits(&s->gb, s->last_bitoffset);
1259             /* this frame is stored in the last superframe and in the
1260                current one */
1261             if (wma_decode_frame(s, samples) < 0)
1262                 goto fail;
1263             samples += s->nb_channels * s->frame_len;
1264         }
1265
1266         /* read each frame starting from bit_offset */
1267         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1268         init_get_bits(&s->gb, buf + (pos >> 3), MAX_CODED_SUPERFRAME_SIZE - (pos >> 3));
1269         len = pos & 7;
1270         if (len > 0)
1271             skip_bits(&s->gb, len);
1272
1273         s->reset_block_lengths = 1;
1274         for(i=0;i<nb_frames;i++) {
1275             if (wma_decode_frame(s, samples) < 0)
1276                 goto fail;
1277             samples += s->nb_channels * s->frame_len;
1278         }
1279
1280         /* we copy the end of the frame in the last frame buffer */
1281         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1282         s->last_bitoffset = pos & 7;
1283         pos >>= 3;
1284         len = buf_size - pos;
1285         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1286             goto fail;
1287         }
1288         s->last_superframe_len = len;
1289         memcpy(s->last_superframe, buf + pos, len);
1290     } else {
1291         /* single frame decode */
1292         if (wma_decode_frame(s, samples) < 0)
1293             goto fail;
1294         samples += s->nb_channels * s->frame_len;
1295     }
1296     *data_size = (int8_t *)samples - (int8_t *)data;
1297     return s->block_align;
1298  fail:
1299     /* when error, we reset the bit reservoir */
1300     s->last_superframe_len = 0;
1301     return -1;
1302 }
1303
1304 static int wma_decode_end(AVCodecContext *avctx)
1305 {
1306     WMADecodeContext *s = avctx->priv_data;
1307     int i;
1308
1309     for(i = 0; i < s->nb_block_sizes; i++)
1310         ff_mdct_end(&s->mdct_ctx[i]);
1311     for(i = 0; i < s->nb_block_sizes; i++)
1312         av_free(s->windows[i]);
1313
1314     if (s->use_exp_vlc) {
1315         free_vlc(&s->exp_vlc);
1316     }
1317     if (s->use_noise_coding) {
1318         free_vlc(&s->hgain_vlc);
1319     }
1320     for(i = 0;i < 2; i++) {
1321         free_vlc(&s->coef_vlc[i]);
1322         av_free(s->run_table[i]);
1323         av_free(s->level_table[i]);
1324     }
1325
1326     return 0;
1327 }
1328
1329 AVCodec wmav1_decoder =
1330 {
1331     "wmav1",
1332     CODEC_TYPE_AUDIO,
1333     CODEC_ID_WMAV1,
1334     sizeof(WMADecodeContext),
1335     wma_decode_init,
1336     NULL,
1337     wma_decode_end,
1338     wma_decode_superframe,
1339 };
1340
1341 AVCodec wmav2_decoder =
1342 {
1343     "wmav2",
1344     CODEC_TYPE_AUDIO,
1345     CODEC_ID_WMAV2,
1346     sizeof(WMADecodeContext),
1347     wma_decode_init,
1348     NULL,
1349     wma_decode_end,
1350     wma_decode_superframe,
1351 };