libavcodec/wmadec.c

   1 /*
   2  * WMA compatible decoder
   3  * Copyright (c) 2002 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 /**
  23  * @file
  24  * WMA compatible decoder.
  25  * This decoder handles Microsoft Windows Media Audio data, versions 1 & 2.
  26  * WMA v1 is identified by audio format 0x160 in Microsoft media files
  27  * (ASF/AVI/WAV). WMA v2 is identified by audio format 0x161.
  28  *
  29  * To use this decoder, a calling application must supply the extra data
  30  * bytes provided with the WMA data. These are the extra, codec-specific
  31  * bytes at the end of a WAVEFORMATEX data structure. Transmit these bytes
  32  * to the decoder using the extradata[_size] fields in AVCodecContext. There
  33  * should be 4 extra bytes for v1 data and 6 extra bytes for v2 data.
  34  */
  35
  36 #include "avcodec.h"
  37 #include "wma.h"
  38
  39 #undef NDEBUG
  40 #include <assert.h>
  41
  42 #define EXPVLCBITS 8
  43 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
  44
  45 #define HGAINVLCBITS 9
  46 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
  47
  48 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len);
  49
  50 #ifdef TRACE
  51 static void dump_shorts(WMACodecContext *s, const char *name, const short *tab, int n)
  52 {
  53     int i;
  54
  55     tprintf(s->avctx, "%s[%d]:\n", name, n);
  56     for(i=0;i<n;i++) {
  57         if ((i & 7) == 0)
  58             tprintf(s->avctx, "%4d: ", i);
  59         tprintf(s->avctx, " %5d.0", tab[i]);
  60         if ((i & 7) == 7)
  61             tprintf(s->avctx, "\n");
  62     }
  63 }
  64
  65 static void dump_floats(WMACodecContext *s, const char *name, int prec, const float *tab, int n)
  66 {
  67     int i;
  68
  69     tprintf(s->avctx, "%s[%d]:\n", name, n);
  70     for(i=0;i<n;i++) {
  71         if ((i & 7) == 0)
  72             tprintf(s->avctx, "%4d: ", i);
  73         tprintf(s->avctx, " %8.*f", prec, tab[i]);
  74         if ((i & 7) == 7)
  75             tprintf(s->avctx, "\n");
  76     }
  77     if ((i & 7) != 0)
  78         tprintf(s->avctx, "\n");
  79 }
  80 #endif
  81
  82 static int wma_decode_init(AVCodecContext * avctx)
  83 {
  84     WMACodecContext *s = avctx->priv_data;
  85     int i, flags2;
  86     uint8_t *extradata;
  87
  88     s->avctx = avctx;
  89
  90     /* extract flag infos */
  91     flags2 = 0;
  92     extradata = avctx->extradata;
  93     if (avctx->codec->id == CODEC_ID_WMAV1 && avctx->extradata_size >= 4) {
  94         flags2 = AV_RL16(extradata+2);
  95     } else if (avctx->codec->id == CODEC_ID_WMAV2 && avctx->extradata_size >= 6) {
  96         flags2 = AV_RL16(extradata+4);
  97     }
  98 // for(i=0; i<avctx->extradata_size; i++)
  99 //     av_log(NULL, AV_LOG_ERROR, "%02X ", extradata[i]);
 100
 101     s->use_exp_vlc = flags2 & 0x0001;
 102     s->use_bit_reservoir = flags2 & 0x0002;
 103     s->use_variable_block_len = flags2 & 0x0004;
 104
 105     if(ff_wma_init(avctx, flags2)<0)
 106         return -1;
 107
 108     /* init MDCT */
 109     for(i = 0; i < s->nb_block_sizes; i++)
 110         ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 1, 1.0);
 111
 112     if (s->use_noise_coding) {
 113         init_vlc(&s->hgain_vlc, HGAINVLCBITS, sizeof(ff_wma_hgain_huffbits),
 114                  ff_wma_hgain_huffbits, 1, 1,
 115                  ff_wma_hgain_huffcodes, 2, 2, 0);
 116     }
 117
 118     if (s->use_exp_vlc) {
 119         init_vlc(&s->exp_vlc, EXPVLCBITS, sizeof(ff_aac_scalefactor_bits), //FIXME move out of context
 120                  ff_aac_scalefactor_bits, 1, 1,
 121                  ff_aac_scalefactor_code, 4, 4, 0);
 122     } else {
 123         wma_lsp_to_curve_init(s, s->frame_len);
 124     }
 125
 126     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
 127     return 0;
 128 }
 129
 130 /**
 131  * compute x^-0.25 with an exponent and mantissa table. We use linear
 132  * interpolation to reduce the mantissa table size at a small speed
 133  * expense (linear interpolation approximately doubles the number of
 134  * bits of precision).
 135  */
 136 static inline float pow_m1_4(WMACodecContext *s, float x)
 137 {
 138     union {
 139         float f;
 140         unsigned int v;
 141     } u, t;
 142     unsigned int e, m;
 143     float a, b;
 144
 145     u.f = x;
 146     e = u.v >> 23;
 147     m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 148     /* build interpolation scale: 1 <= t < 2. */
 149     t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 150     a = s->lsp_pow_m_table1[m];
 151     b = s->lsp_pow_m_table2[m];
 152     return s->lsp_pow_e_table[e] * (a + b * t.f);
 153 }
 154
 155 static void wma_lsp_to_curve_init(WMACodecContext *s, int frame_len)
 156 {
 157     float wdel, a, b;
 158     int i, e, m;
 159
 160     wdel = M_PI / frame_len;
 161     for(i=0;i<frame_len;i++)
 162         s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 163
 164     /* tables for x^-0.25 computation */
 165     for(i=0;i<256;i++) {
 166         e = i - 126;
 167         s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 168     }
 169
 170     /* NOTE: these two tables are needed to avoid two operations in
 171        pow_m1_4 */
 172     b = 1.0;
 173     for(i=(1 << LSP_POW_BITS) - 1;i>=0;i--) {
 174         m = (1 << LSP_POW_BITS) + i;
 175         a = (float)m * (0.5 / (1 << LSP_POW_BITS));
 176         a = pow(a, -0.25);
 177         s->lsp_pow_m_table1[i] = 2 * a - b;
 178         s->lsp_pow_m_table2[i] = b - a;
 179         b = a;
 180     }
 181 #if 0
 182     for(i=1;i<20;i++) {
 183         float v, r1, r2;
 184         v = 5.0 / i;
 185         r1 = pow_m1_4(s, v);
 186         r2 = pow(v,-0.25);
 187         printf("%f^-0.25=%f e=%f\n", v, r1, r2 - r1);
 188     }
 189 #endif
 190 }
 191
 192 /**
 193  * NOTE: We use the same code as Vorbis here
 194  * @todo optimize it further with SSE/3Dnow
 195  */
 196 static void wma_lsp_to_curve(WMACodecContext *s,
 197                              float *out, float *val_max_ptr,
 198                              int n, float *lsp)
 199 {
 200     int i, j;
 201     float p, q, w, v, val_max;
 202
 203     val_max = 0;
 204     for(i=0;i<n;i++) {
 205         p = 0.5f;
 206         q = 0.5f;
 207         w = s->lsp_cos_table[i];
 208         for(j=1;j<NB_LSP_COEFS;j+=2){
 209             q *= w - lsp[j - 1];
 210             p *= w - lsp[j];
 211         }
 212         p *= p * (2.0f - w);
 213         q *= q * (2.0f + w);
 214         v = p + q;
 215         v = pow_m1_4(s, v);
 216         if (v > val_max)
 217             val_max = v;
 218         out[i] = v;
 219     }
 220     *val_max_ptr = val_max;
 221 }
 222
 223 /**
 224  * decode exponents coded with LSP coefficients (same idea as Vorbis)
 225  */
 226 static void decode_exp_lsp(WMACodecContext *s, int ch)
 227 {
 228     float lsp_coefs[NB_LSP_COEFS];
 229     int val, i;
 230
 231     for(i = 0; i < NB_LSP_COEFS; i++) {
 232         if (i == 0 || i >= 8)
 233             val = get_bits(&s->gb, 3);
 234         else
 235             val = get_bits(&s->gb, 4);
 236         lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 237     }
 238
 239     wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
 240                      s->block_len, lsp_coefs);
 241 }
 242
 243 /** pow(10, i / 16.0) for i in -60..95 */
 244 static const float pow_tab[] = {
 245     1.7782794100389e-04, 2.0535250264571e-04,
 246     2.3713737056617e-04, 2.7384196342644e-04,
 247     3.1622776601684e-04, 3.6517412725484e-04,
 248     4.2169650342858e-04, 4.8696752516586e-04,
 249     5.6234132519035e-04, 6.4938163157621e-04,
 250     7.4989420933246e-04, 8.6596432336006e-04,
 251     1.0000000000000e-03, 1.1547819846895e-03,
 252     1.3335214321633e-03, 1.5399265260595e-03,
 253     1.7782794100389e-03, 2.0535250264571e-03,
 254     2.3713737056617e-03, 2.7384196342644e-03,
 255     3.1622776601684e-03, 3.6517412725484e-03,
 256     4.2169650342858e-03, 4.8696752516586e-03,
 257     5.6234132519035e-03, 6.4938163157621e-03,
 258     7.4989420933246e-03, 8.6596432336006e-03,
 259     1.0000000000000e-02, 1.1547819846895e-02,
 260     1.3335214321633e-02, 1.5399265260595e-02,
 261     1.7782794100389e-02, 2.0535250264571e-02,
 262     2.3713737056617e-02, 2.7384196342644e-02,
 263     3.1622776601684e-02, 3.6517412725484e-02,
 264     4.2169650342858e-02, 4.8696752516586e-02,
 265     5.6234132519035e-02, 6.4938163157621e-02,
 266     7.4989420933246e-02, 8.6596432336007e-02,
 267     1.0000000000000e-01, 1.1547819846895e-01,
 268     1.3335214321633e-01, 1.5399265260595e-01,
 269     1.7782794100389e-01, 2.0535250264571e-01,
 270     2.3713737056617e-01, 2.7384196342644e-01,
 271     3.1622776601684e-01, 3.6517412725484e-01,
 272     4.2169650342858e-01, 4.8696752516586e-01,
 273     5.6234132519035e-01, 6.4938163157621e-01,
 274     7.4989420933246e-01, 8.6596432336007e-01,
 275     1.0000000000000e+00, 1.1547819846895e+00,
 276     1.3335214321633e+00, 1.5399265260595e+00,
 277     1.7782794100389e+00, 2.0535250264571e+00,
 278     2.3713737056617e+00, 2.7384196342644e+00,
 279     3.1622776601684e+00, 3.6517412725484e+00,
 280     4.2169650342858e+00, 4.8696752516586e+00,
 281     5.6234132519035e+00, 6.4938163157621e+00,
 282     7.4989420933246e+00, 8.6596432336007e+00,
 283     1.0000000000000e+01, 1.1547819846895e+01,
 284     1.3335214321633e+01, 1.5399265260595e+01,
 285     1.7782794100389e+01, 2.0535250264571e+01,
 286     2.3713737056617e+01, 2.7384196342644e+01,
 287     3.1622776601684e+01, 3.6517412725484e+01,
 288     4.2169650342858e+01, 4.8696752516586e+01,
 289     5.6234132519035e+01, 6.4938163157621e+01,
 290     7.4989420933246e+01, 8.6596432336007e+01,
 291     1.0000000000000e+02, 1.1547819846895e+02,
 292     1.3335214321633e+02, 1.5399265260595e+02,
 293     1.7782794100389e+02, 2.0535250264571e+02,
 294     2.3713737056617e+02, 2.7384196342644e+02,
 295     3.1622776601684e+02, 3.6517412725484e+02,
 296     4.2169650342858e+02, 4.8696752516586e+02,
 297     5.6234132519035e+02, 6.4938163157621e+02,
 298     7.4989420933246e+02, 8.6596432336007e+02,
 299     1.0000000000000e+03, 1.1547819846895e+03,
 300     1.3335214321633e+03, 1.5399265260595e+03,
 301     1.7782794100389e+03, 2.0535250264571e+03,
 302     2.3713737056617e+03, 2.7384196342644e+03,
 303     3.1622776601684e+03, 3.6517412725484e+03,
 304     4.2169650342858e+03, 4.8696752516586e+03,
 305     5.6234132519035e+03, 6.4938163157621e+03,
 306     7.4989420933246e+03, 8.6596432336007e+03,
 307     1.0000000000000e+04, 1.1547819846895e+04,
 308     1.3335214321633e+04, 1.5399265260595e+04,
 309     1.7782794100389e+04, 2.0535250264571e+04,
 310     2.3713737056617e+04, 2.7384196342644e+04,
 311     3.1622776601684e+04, 3.6517412725484e+04,
 312     4.2169650342858e+04, 4.8696752516586e+04,
 313     5.6234132519035e+04, 6.4938163157621e+04,
 314     7.4989420933246e+04, 8.6596432336007e+04,
 315     1.0000000000000e+05, 1.1547819846895e+05,
 316     1.3335214321633e+05, 1.5399265260595e+05,
 317     1.7782794100389e+05, 2.0535250264571e+05,
 318     2.3713737056617e+05, 2.7384196342644e+05,
 319     3.1622776601684e+05, 3.6517412725484e+05,
 320     4.2169650342858e+05, 4.8696752516586e+05,
 321     5.6234132519035e+05, 6.4938163157621e+05,
 322     7.4989420933246e+05, 8.6596432336007e+05,
 323 };
 324
 325 /**
 326  * decode exponents coded with VLC codes
 327  */
 328 static int decode_exp_vlc(WMACodecContext *s, int ch)
 329 {
 330     int last_exp, n, code;
 331     const uint16_t *ptr;
 332     float v, max_scale;
 333     uint32_t *q, *q_end, iv;
 334     const float *ptab = pow_tab + 60;
 335     const uint32_t *iptab = (const uint32_t*)ptab;
 336
 337     ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
 338     q = (uint32_t *)s->exponents[ch];
 339     q_end = q + s->block_len;
 340     max_scale = 0;
 341     if (s->version == 1) {
 342         last_exp = get_bits(&s->gb, 5) + 10;
 343         v = ptab[last_exp];
 344         iv = iptab[last_exp];
 345         max_scale = v;
 346         n = *ptr++;
 347         switch (n & 3) do {
 348         case 0: *q++ = iv;
 349         case 3: *q++ = iv;
 350         case 2: *q++ = iv;
 351         case 1: *q++ = iv;
 352         } while ((n -= 4) > 0);
 353     }else
 354         last_exp = 36;
 355
 356     while (q < q_end) {
 357         code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
 358         if (code < 0){
 359             av_log(s->avctx, AV_LOG_ERROR, "Exponent vlc invalid\n");
 360             return -1;
 361         }
 362         /* NOTE: this offset is the same as MPEG4 AAC ! */
 363         last_exp += code - 60;
 364         if ((unsigned)last_exp + 60 > FF_ARRAY_ELEMS(pow_tab)) {
 365             av_log(s->avctx, AV_LOG_ERROR, "Exponent out of range: %d\n",
 366                    last_exp);
 367             return -1;
 368         }
 369         v = ptab[last_exp];
 370         iv = iptab[last_exp];
 371         if (v > max_scale)
 372             max_scale = v;
 373         n = *ptr++;
 374         switch (n & 3) do {
 375         case 0: *q++ = iv;
 376         case 3: *q++ = iv;
 377         case 2: *q++ = iv;
 378         case 1: *q++ = iv;
 379         } while ((n -= 4) > 0);
 380     }
 381     s->max_exponent[ch] = max_scale;
 382     return 0;
 383 }
 384
 385
 386 /**
 387  * Apply MDCT window and add into output.
 388  *
 389  * We ensure that when the windows overlap their squared sum
 390  * is always 1 (MDCT reconstruction rule).
 391  */
 392 static void wma_window(WMACodecContext *s, float *out)
 393 {
 394     float *in = s->output;
 395     int block_len, bsize, n;
 396
 397     /* left part */
 398     if (s->block_len_bits <= s->prev_block_len_bits) {
 399         block_len = s->block_len;
 400         bsize = s->frame_len_bits - s->block_len_bits;
 401
 402         s->dsp.vector_fmul_add(out, in, s->windows[bsize],
 403                                out, block_len);
 404
 405     } else {
 406         block_len = 1 << s->prev_block_len_bits;
 407         n = (s->block_len - block_len) / 2;
 408         bsize = s->frame_len_bits - s->prev_block_len_bits;
 409
 410         s->dsp.vector_fmul_add(out+n, in+n, s->windows[bsize],
 411                                out+n, block_len);
 412
 413         memcpy(out+n+block_len, in+n+block_len, n*sizeof(float));
 414     }
 415
 416     out += s->block_len;
 417     in += s->block_len;
 418
 419     /* right part */
 420     if (s->block_len_bits <= s->next_block_len_bits) {
 421         block_len = s->block_len;
 422         bsize = s->frame_len_bits - s->block_len_bits;
 423
 424         s->dsp.vector_fmul_reverse(out, in, s->windows[bsize], block_len);
 425
 426     } else {
 427         block_len = 1 << s->next_block_len_bits;
 428         n = (s->block_len - block_len) / 2;
 429         bsize = s->frame_len_bits - s->next_block_len_bits;
 430
 431         memcpy(out, in, n*sizeof(float));
 432
 433         s->dsp.vector_fmul_reverse(out+n, in+n, s->windows[bsize], block_len);
 434
 435         memset(out+n+block_len, 0, n*sizeof(float));
 436     }
 437 }
 438
 439
 440 /**
 441  * @return 0 if OK. 1 if last block of frame. return -1 if
 442  * unrecorrable error.
 443  */
 444 static int wma_decode_block(WMACodecContext *s)
 445 {
 446     int n, v, a, ch, bsize;
 447     int coef_nb_bits, total_gain;
 448     int nb_coefs[MAX_CHANNELS];
 449     float mdct_norm;
 450
 451 #ifdef TRACE
 452     tprintf(s->avctx, "***decode_block: %d:%d\n", s->frame_count - 1, s->block_num);
 453 #endif
 454
 455     /* compute current block length */
 456     if (s->use_variable_block_len) {
 457         n = av_log2(s->nb_block_sizes - 1) + 1;
 458
 459         if (s->reset_block_lengths) {
 460             s->reset_block_lengths = 0;
 461             v = get_bits(&s->gb, n);
 462             if (v >= s->nb_block_sizes){
 463                 av_log(s->avctx, AV_LOG_ERROR, "prev_block_len_bits %d out of range\n", s->frame_len_bits - v);
 464                 return -1;
 465             }
 466             s->prev_block_len_bits = s->frame_len_bits - v;
 467             v = get_bits(&s->gb, n);
 468             if (v >= s->nb_block_sizes){
 469                 av_log(s->avctx, AV_LOG_ERROR, "block_len_bits %d out of range\n", s->frame_len_bits - v);
 470                 return -1;
 471             }
 472             s->block_len_bits = s->frame_len_bits - v;
 473         } else {
 474             /* update block lengths */
 475             s->prev_block_len_bits = s->block_len_bits;
 476             s->block_len_bits = s->next_block_len_bits;
 477         }
 478         v = get_bits(&s->gb, n);
 479         if (v >= s->nb_block_sizes){
 480             av_log(s->avctx, AV_LOG_ERROR, "next_block_len_bits %d out of range\n", s->frame_len_bits - v);
 481             return -1;
 482         }
 483         s->next_block_len_bits = s->frame_len_bits - v;
 484     } else {
 485         /* fixed block len */
 486         s->next_block_len_bits = s->frame_len_bits;
 487         s->prev_block_len_bits = s->frame_len_bits;
 488         s->block_len_bits = s->frame_len_bits;
 489     }
 490
 491     /* now check if the block length is coherent with the frame length */
 492     s->block_len = 1 << s->block_len_bits;
 493     if ((s->block_pos + s->block_len) > s->frame_len){
 494         av_log(s->avctx, AV_LOG_ERROR, "frame_len overflow\n");
 495         return -1;
 496     }
 497
 498     if (s->nb_channels == 2) {
 499         s->ms_stereo = get_bits1(&s->gb);
 500     }
 501     v = 0;
 502     for(ch = 0; ch < s->nb_channels; ch++) {
 503         a = get_bits1(&s->gb);
 504         s->channel_coded[ch] = a;
 505         v |= a;
 506     }
 507
 508     bsize = s->frame_len_bits - s->block_len_bits;
 509
 510     /* if no channel coded, no need to go further */
 511     /* XXX: fix potential framing problems */
 512     if (!v)
 513         goto next;
 514
 515     /* read total gain and extract corresponding number of bits for
 516        coef escape coding */
 517     total_gain = 1;
 518     for(;;) {
 519         a = get_bits(&s->gb, 7);
 520         total_gain += a;
 521         if (a != 127)
 522             break;
 523     }
 524
 525     coef_nb_bits= ff_wma_total_gain_to_bits(total_gain);
 526
 527     /* compute number of coefficients */
 528     n = s->coefs_end[bsize] - s->coefs_start;
 529     for(ch = 0; ch < s->nb_channels; ch++)
 530         nb_coefs[ch] = n;
 531
 532     /* complex coding */
 533     if (s->use_noise_coding) {
 534
 535         for(ch = 0; ch < s->nb_channels; ch++) {
 536             if (s->channel_coded[ch]) {
 537                 int i, n, a;
 538                 n = s->exponent_high_sizes[bsize];
 539                 for(i=0;i<n;i++) {
 540                     a = get_bits1(&s->gb);
 541                     s->high_band_coded[ch][i] = a;
 542                     /* if noise coding, the coefficients are not transmitted */
 543                     if (a)
 544                         nb_coefs[ch] -= s->exponent_high_bands[bsize][i];
 545                 }
 546             }
 547         }
 548         for(ch = 0; ch < s->nb_channels; ch++) {
 549             if (s->channel_coded[ch]) {
 550                 int i, n, val, code;
 551
 552                 n = s->exponent_high_sizes[bsize];
 553                 val = (int)0x80000000;
 554                 for(i=0;i<n;i++) {
 555                     if (s->high_band_coded[ch][i]) {
 556                         if (val == (int)0x80000000) {
 557                             val = get_bits(&s->gb, 7) - 19;
 558                         } else {
 559                             code = get_vlc2(&s->gb, s->hgain_vlc.table, HGAINVLCBITS, HGAINMAX);
 560                             if (code < 0){
 561                                 av_log(s->avctx, AV_LOG_ERROR, "hgain vlc invalid\n");
 562                                 return -1;
 563                             }
 564                             val += code - 18;
 565                         }
 566                         s->high_band_values[ch][i] = val;
 567                     }
 568                 }
 569             }
 570         }
 571     }
 572
 573     /* exponents can be reused in short blocks. */
 574     if ((s->block_len_bits == s->frame_len_bits) ||
 575         get_bits1(&s->gb)) {
 576         for(ch = 0; ch < s->nb_channels; ch++) {
 577             if (s->channel_coded[ch]) {
 578                 if (s->use_exp_vlc) {
 579                     if (decode_exp_vlc(s, ch) < 0)
 580                         return -1;
 581                 } else {
 582                     decode_exp_lsp(s, ch);
 583                 }
 584                 s->exponents_bsize[ch] = bsize;
 585             }
 586         }
 587     }
 588
 589     /* parse spectral coefficients : just RLE encoding */
 590     for(ch = 0; ch < s->nb_channels; ch++) {
 591         if (s->channel_coded[ch]) {
 592             int tindex;
 593             WMACoef* ptr = &s->coefs1[ch][0];
 594
 595             /* special VLC tables are used for ms stereo because
 596                there is potentially less energy there */
 597             tindex = (ch == 1 && s->ms_stereo);
 598             memset(ptr, 0, s->block_len * sizeof(WMACoef));
 599             ff_wma_run_level_decode(s->avctx, &s->gb, &s->coef_vlc[tindex],
 600                   s->level_table[tindex], s->run_table[tindex],
 601                   0, ptr, 0, nb_coefs[ch],
 602                   s->block_len, s->frame_len_bits, coef_nb_bits);
 603         }
 604         if (s->version == 1 && s->nb_channels >= 2) {
 605             align_get_bits(&s->gb);
 606         }
 607     }
 608
 609     /* normalize */
 610     {
 611         int n4 = s->block_len / 2;
 612         mdct_norm = 1.0 / (float)n4;
 613         if (s->version == 1) {
 614             mdct_norm *= sqrt(n4);
 615         }
 616     }
 617
 618     /* finally compute the MDCT coefficients */
 619     for(ch = 0; ch < s->nb_channels; ch++) {
 620         if (s->channel_coded[ch]) {
 621             WMACoef *coefs1;
 622             float *coefs, *exponents, mult, mult1, noise;
 623             int i, j, n, n1, last_high_band, esize;
 624             float exp_power[HIGH_BAND_MAX_SIZE];
 625
 626             coefs1 = s->coefs1[ch];
 627             exponents = s->exponents[ch];
 628             esize = s->exponents_bsize[ch];
 629             mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
 630             mult *= mdct_norm;
 631             coefs = s->coefs[ch];
 632             if (s->use_noise_coding) {
 633                 mult1 = mult;
 634                 /* very low freqs : noise */
 635                 for(i = 0;i < s->coefs_start; i++) {
 636                     *coefs++ = s->noise_table[s->noise_index] *
 637                       exponents[i<<bsize>>esize] * mult1;
 638                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
 639                 }
 640
 641                 n1 = s->exponent_high_sizes[bsize];
 642
 643                 /* compute power of high bands */
 644                 exponents = s->exponents[ch] +
 645                     (s->high_band_start[bsize]<<bsize>>esize);
 646                 last_high_band = 0; /* avoid warning */
 647                 for(j=0;j<n1;j++) {
 648                     n = s->exponent_high_bands[s->frame_len_bits -
 649                                               s->block_len_bits][j];
 650                     if (s->high_band_coded[ch][j]) {
 651                         float e2, v;
 652                         e2 = 0;
 653                         for(i = 0;i < n; i++) {
 654                             v = exponents[i<<bsize>>esize];
 655                             e2 += v * v;
 656                         }
 657                         exp_power[j] = e2 / n;
 658                         last_high_band = j;
 659                         tprintf(s->avctx, "%d: power=%f (%d)\n", j, exp_power[j], n);
 660                     }
 661                     exponents += n<<bsize>>esize;
 662                 }
 663
 664                 /* main freqs and high freqs */
 665                 exponents = s->exponents[ch] + (s->coefs_start<<bsize>>esize);
 666                 for(j=-1;j<n1;j++) {
 667                     if (j < 0) {
 668                         n = s->high_band_start[bsize] -
 669                             s->coefs_start;
 670                     } else {
 671                         n = s->exponent_high_bands[s->frame_len_bits -
 672                                                   s->block_len_bits][j];
 673                     }
 674                     if (j >= 0 && s->high_band_coded[ch][j]) {
 675                         /* use noise with specified power */
 676                         mult1 = sqrt(exp_power[j] / exp_power[last_high_band]);
 677                         /* XXX: use a table */
 678                         mult1 = mult1 * pow(10, s->high_band_values[ch][j] * 0.05);
 679                         mult1 = mult1 / (s->max_exponent[ch] * s->noise_mult);
 680                         mult1 *= mdct_norm;
 681                         for(i = 0;i < n; i++) {
 682                             noise = s->noise_table[s->noise_index];
 683                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
 684                             *coefs++ =  noise *
 685                                 exponents[i<<bsize>>esize] * mult1;
 686                         }
 687                         exponents += n<<bsize>>esize;
 688                     } else {
 689                         /* coded values + small noise */
 690                         for(i = 0;i < n; i++) {
 691                             noise = s->noise_table[s->noise_index];
 692                             s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
 693                             *coefs++ = ((*coefs1++) + noise) *
 694                                 exponents[i<<bsize>>esize] * mult;
 695                         }
 696                         exponents += n<<bsize>>esize;
 697                     }
 698                 }
 699
 700                 /* very high freqs : noise */
 701                 n = s->block_len - s->coefs_end[bsize];
 702                 mult1 = mult * exponents[((-1<<bsize))>>esize];
 703                 for(i = 0; i < n; i++) {
 704                     *coefs++ = s->noise_table[s->noise_index] * mult1;
 705                     s->noise_index = (s->noise_index + 1) & (NOISE_TAB_SIZE - 1);
 706                 }
 707             } else {
 708                 /* XXX: optimize more */
 709                 for(i = 0;i < s->coefs_start; i++)
 710                     *coefs++ = 0.0;
 711                 n = nb_coefs[ch];
 712                 for(i = 0;i < n; i++) {
 713                     *coefs++ = coefs1[i] * exponents[i<<bsize>>esize] * mult;
 714                 }
 715                 n = s->block_len - s->coefs_end[bsize];
 716                 for(i = 0;i < n; i++)
 717                     *coefs++ = 0.0;
 718             }
 719         }
 720     }
 721
 722 #ifdef TRACE
 723     for(ch = 0; ch < s->nb_channels; ch++) {
 724         if (s->channel_coded[ch]) {
 725             dump_floats(s, "exponents", 3, s->exponents[ch], s->block_len);
 726             dump_floats(s, "coefs", 1, s->coefs[ch], s->block_len);
 727         }
 728     }
 729 #endif
 730
 731     if (s->ms_stereo && s->channel_coded[1]) {
 732         /* nominal case for ms stereo: we do it before mdct */
 733         /* no need to optimize this case because it should almost
 734            never happen */
 735         if (!s->channel_coded[0]) {
 736             tprintf(s->avctx, "rare ms-stereo case happened\n");
 737             memset(s->coefs[0], 0, sizeof(float) * s->block_len);
 738             s->channel_coded[0] = 1;
 739         }
 740
 741         s->dsp.butterflies_float(s->coefs[0], s->coefs[1], s->block_len);
 742     }
 743
 744 next:
 745     for(ch = 0; ch < s->nb_channels; ch++) {
 746         int n4, index;
 747
 748         n4 = s->block_len / 2;
 749         if(s->channel_coded[ch]){
 750             ff_imdct_calc(&s->mdct_ctx[bsize], s->output, s->coefs[ch]);
 751         }else if(!(s->ms_stereo && ch==1))
 752             memset(s->output, 0, sizeof(s->output));
 753
 754         /* multiply by the window and add in the frame */
 755         index = (s->frame_len / 2) + s->block_pos - n4;
 756         wma_window(s, &s->frame_out[ch][index]);
 757     }
 758
 759     /* update block number */
 760     s->block_num++;
 761     s->block_pos += s->block_len;
 762     if (s->block_pos >= s->frame_len)
 763         return 1;
 764     else
 765         return 0;
 766 }
 767
 768 /* decode a frame of frame_len samples */
 769 static int wma_decode_frame(WMACodecContext *s, int16_t *samples)
 770 {
 771     int ret, i, n, ch, incr;
 772     int16_t *ptr;
 773     float *iptr;
 774
 775 #ifdef TRACE
 776     tprintf(s->avctx, "***decode_frame: %d size=%d\n", s->frame_count++, s->frame_len);
 777 #endif
 778
 779     /* read each block */
 780     s->block_num = 0;
 781     s->block_pos = 0;
 782     for(;;) {
 783         ret = wma_decode_block(s);
 784         if (ret < 0)
 785             return -1;
 786         if (ret)
 787             break;
 788     }
 789
 790     /* convert frame to integer */
 791     n = s->frame_len;
 792     incr = s->nb_channels;
 793     if (s->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
 794         for(ch = 0; ch < s->nb_channels; ch++) {
 795             ptr = samples + ch;
 796             iptr = s->frame_out[ch];
 797
 798             for(i=0;i<n;i++) {
 799                 *ptr = av_clip_int16(lrintf(*iptr++));
 800                 ptr += incr;
 801             }
 802             /* prepare for next block */
 803             memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
 804                     s->frame_len * sizeof(float));
 805         }
 806     } else {
 807         const float *output[MAX_CHANNELS];
 808         for (ch = 0; ch < MAX_CHANNELS; ch++)
 809             output[ch] = s->frame_out[ch];
 810         s->dsp.float_to_int16_interleave(samples, output, n, incr);
 811         for(ch = 0; ch < incr; ch++) {
 812             /* prepare for next block */
 813             memmove(&s->frame_out[ch][0], &s->frame_out[ch][n], n * sizeof(float));
 814         }
 815     }
 816
 817 #ifdef TRACE
 818     dump_shorts(s, "samples", samples, n * s->nb_channels);
 819 #endif
 820     return 0;
 821 }
 822
 823 static int wma_decode_superframe(AVCodecContext *avctx,
 824                                  void *data, int *data_size,
 825                                  AVPacket *avpkt)
 826 {
 827     const uint8_t *buf = avpkt->data;
 828     int buf_size = avpkt->size;
 829     WMACodecContext *s = avctx->priv_data;
 830     int nb_frames, bit_offset, i, pos, len;
 831     uint8_t *q;
 832     int16_t *samples;
 833
 834     tprintf(avctx, "***decode_superframe:\n");
 835
 836     if(buf_size==0){
 837         s->last_superframe_len = 0;
 838         return 0;
 839     }
 840     if (buf_size < s->block_align)
 841         return 0;
 842     buf_size = s->block_align;
 843
 844     samples = data;
 845
 846     init_get_bits(&s->gb, buf, buf_size*8);
 847
 848     if (s->use_bit_reservoir) {
 849         /* read super frame header */
 850         skip_bits(&s->gb, 4); /* super frame index */
 851         nb_frames = get_bits(&s->gb, 4) - 1;
 852
 853         if((nb_frames+1) * s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
 854             av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
 855             goto fail;
 856         }
 857
 858         bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
 859
 860         if (s->last_superframe_len > 0) {
 861             //        printf("skip=%d\n", s->last_bitoffset);
 862             /* add bit_offset bits to last frame */
 863             if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
 864                 MAX_CODED_SUPERFRAME_SIZE)
 865                 goto fail;
 866             q = s->last_superframe + s->last_superframe_len;
 867             len = bit_offset;
 868             while (len > 7) {
 869                 *q++ = (get_bits)(&s->gb, 8);
 870                 len -= 8;
 871             }
 872             if (len > 0) {
 873                 *q++ = (get_bits)(&s->gb, len) << (8 - len);
 874             }
 875
 876             /* XXX: bit_offset bits into last frame */
 877             init_get_bits(&s->gb, s->last_superframe, MAX_CODED_SUPERFRAME_SIZE*8);
 878             /* skip unused bits */
 879             if (s->last_bitoffset > 0)
 880                 skip_bits(&s->gb, s->last_bitoffset);
 881             /* this frame is stored in the last superframe and in the
 882                current one */
 883             if (wma_decode_frame(s, samples) < 0)
 884                 goto fail;
 885             samples += s->nb_channels * s->frame_len;
 886         }
 887
 888         /* read each frame starting from bit_offset */
 889         pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
 890         init_get_bits(&s->gb, buf + (pos >> 3), (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3))*8);
 891         len = pos & 7;
 892         if (len > 0)
 893             skip_bits(&s->gb, len);
 894
 895         s->reset_block_lengths = 1;
 896         for(i=0;i<nb_frames;i++) {
 897             if (wma_decode_frame(s, samples) < 0)
 898                 goto fail;
 899             samples += s->nb_channels * s->frame_len;
 900         }
 901
 902         /* we copy the end of the frame in the last frame buffer */
 903         pos = get_bits_count(&s->gb) + ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
 904         s->last_bitoffset = pos & 7;
 905         pos >>= 3;
 906         len = buf_size - pos;
 907         if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
 908             av_log(s->avctx, AV_LOG_ERROR, "len %d invalid\n", len);
 909             goto fail;
 910         }
 911         s->last_superframe_len = len;
 912         memcpy(s->last_superframe, buf + pos, len);
 913     } else {
 914         if(s->nb_channels * s->frame_len * sizeof(int16_t) > *data_size){
 915             av_log(s->avctx, AV_LOG_ERROR, "Insufficient output space\n");
 916             goto fail;
 917         }
 918         /* single frame decode */
 919         if (wma_decode_frame(s, samples) < 0)
 920             goto fail;
 921         samples += s->nb_channels * s->frame_len;
 922     }
 923
 924 //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d outbytes:%d eaten:%d\n", s->frame_len_bits, s->block_len_bits, s->frame_len, s->block_len,        (int8_t *)samples - (int8_t *)data, s->block_align);
 925
 926     *data_size = (int8_t *)samples - (int8_t *)data;
 927     return s->block_align;
 928  fail:
 929     /* when error, we reset the bit reservoir */
 930     s->last_superframe_len = 0;
 931     return -1;
 932 }
 933
 934 static av_cold void flush(AVCodecContext *avctx)
 935 {
 936     WMACodecContext *s = avctx->priv_data;
 937
 938     s->last_bitoffset=
 939     s->last_superframe_len= 0;
 940 }
 941
 942 AVCodec wmav1_decoder =
 943 {
 944     "wmav1",
 945     AVMEDIA_TYPE_AUDIO,
 946     CODEC_ID_WMAV1,
 947     sizeof(WMACodecContext),
 948     wma_decode_init,
 949     NULL,
 950     ff_wma_end,
 951     wma_decode_superframe,
 952     .flush=flush,
 953     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 1"),
 954 };
 955
 956 AVCodec wmav2_decoder =
 957 {
 958     "wmav2",
 959     AVMEDIA_TYPE_AUDIO,
 960     CODEC_ID_WMAV2,
 961     sizeof(WMACodecContext),
 962     wma_decode_init,
 963     NULL,
 964     ff_wma_end,
 965     wma_decode_superframe,
 966     .flush=flush,
 967     .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 2"),
 968 };