wmadec_filter.c

   1 /*
   2  * WMA compatible decoder
   3  *
   4  * Extracted 2009 from the mplayer source code 2009-02-10.
   5  *
   6  * Copyright (c) 2002 The FFmpeg Project
   7  *
   8  * Licensed under the GNU Lesser General Public License.
   9  * For licencing details see COPYING.LIB.
  10  */
  11
  12 /** \file wmadec_filter.c paraslash's WMA decoder. */
  13
  14 /*
  15  * This decoder handles Microsoft Windows Media Audio data version 2.
  16  */
  17
  18 #define _XOPEN_SOURCE 600
  19
  20 #include <sys/time.h>
  21 #include <inttypes.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <math.h>
  25 #include <string.h>
  26 #include <regex.h>
  27
  28 #include "para.h"
  29 #include "error.h"
  30 #include "list.h"
  31 #include "ggo.h"
  32 #include "string.h"
  33 #include "sched.h"
  34 #include "filter.h"
  35 #include "bitstream.h"
  36 #include "imdct.h"
  37 #include "wma.h"
  38 #include "wmadata.h"
  39
  40
  41 /* size of blocks */
  42 #define BLOCK_MIN_BITS 7
  43 #define BLOCK_MAX_BITS 11
  44 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  45
  46 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  47
  48 /* XXX: find exact max size */
  49 #define HIGH_BAND_MAX_SIZE 16
  50
  51 /* XXX: is it a suitable value ? */
  52 #define MAX_CODED_SUPERFRAME_SIZE 16384
  53
  54 #define MAX_CHANNELS 2
  55
  56 #define NOISE_TAB_SIZE 8192
  57
  58 #define LSP_POW_BITS 7
  59
  60 struct private_wmadec_data {
  61         struct asf_header_info ahi;
  62         struct getbit_context gb;
  63         int use_bit_reservoir;
  64         int use_variable_block_len;
  65         int use_exp_vlc;        ///< exponent coding: 0 = lsp, 1 = vlc + delta
  66         int use_noise_coding;   ///< true if perceptual noise is added
  67         int byte_offset_bits;
  68         struct vlc exp_vlc;
  69         int exponent_sizes[BLOCK_NB_SIZES];
  70         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  71         int high_band_start[BLOCK_NB_SIZES];    ///< index of first coef in high band
  72         int coefs_start;        ///< first coded coef
  73         int coefs_end[BLOCK_NB_SIZES];  ///< max number of coded coefficients
  74         int exponent_high_sizes[BLOCK_NB_SIZES];
  75         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  76         struct vlc hgain_vlc;
  77
  78         /* coded values in high bands */
  79         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  80         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  81
  82         /* there are two possible tables for spectral coefficients */
  83         struct vlc coef_vlc[2];
  84         uint16_t *run_table[2];
  85         uint16_t *level_table[2];
  86         const struct coef_vlc_table *coef_vlcs[2];
  87         /* frame info */
  88         int frame_len;          ///< frame length in samples
  89         int frame_len_bits;     ///< frame_len = 1 << frame_len_bits
  90         int nb_block_sizes;     ///< number of block sizes
  91         /* block info */
  92         int reset_block_lengths;
  93         int block_len_bits;     ///< log2 of current block length
  94         int next_block_len_bits;        ///< log2 of next block length
  95         int prev_block_len_bits;        ///< log2 of prev block length
  96         int block_len;          ///< block length in samples
  97         int block_pos;          ///< current position in frame
  98         uint8_t ms_stereo;      ///< true if mid/side stereo mode
  99         uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
 100         int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
 101         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 102         float max_exponent[MAX_CHANNELS];
 103         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 104         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 105         float output[BLOCK_MAX_SIZE * 2];
 106         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 107         float *windows[BLOCK_NB_SIZES];
 108         /* output buffer for one frame and the last for IMDCT windowing */
 109         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 110         /* last frame info */
 111         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 112         int last_bitoffset;
 113         int last_superframe_len;
 114         float noise_table[NOISE_TAB_SIZE];
 115         int noise_index;
 116         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 117         /* lsp_to_curve tables */
 118         float lsp_cos_table[BLOCK_MAX_SIZE];
 119         float lsp_pow_e_table[256];
 120         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 121         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 122 };
 123
 124 #define EXPVLCBITS 8
 125 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
 126
 127 #define HGAINVLCBITS 9
 128 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
 129
 130 #define VLCBITS 9
 131 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
 132
 133 DECLARE_ALIGNED(16, float, ff_sine_128[128]);
 134 DECLARE_ALIGNED(16, float, ff_sine_256[256]);
 135 DECLARE_ALIGNED(16, float, ff_sine_512[512]);
 136 DECLARE_ALIGNED(16, float, ff_sine_1024[1024]);
 137 DECLARE_ALIGNED(16, float, ff_sine_2048[2048]);
 138 DECLARE_ALIGNED(16, float, ff_sine_4096[4096]);
 139
 140 static float *ff_sine_windows[6] = {
 141         ff_sine_128, ff_sine_256, ff_sine_512, ff_sine_1024,
 142         ff_sine_2048, ff_sine_4096
 143 };
 144
 145 /* Generate a sine window. */
 146 static void sine_window_init(float *window, int n)
 147 {
 148         int i;
 149
 150         for (i = 0; i < n; i++)
 151                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 152 }
 153
 154 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 155 {
 156         int i;
 157
 158         for (i = 0; i < pwd->nb_block_sizes; i++)
 159                 imdct_end(pwd->mdct_ctx[i]);
 160         if (pwd->use_exp_vlc)
 161                 free_vlc(&pwd->exp_vlc);
 162         if (pwd->use_noise_coding)
 163                 free_vlc(&pwd->hgain_vlc);
 164         for (i = 0; i < 2; i++) {
 165                 free_vlc(&pwd->coef_vlc[i]);
 166                 free(pwd->run_table[i]);
 167                 free(pwd->level_table[i]);
 168         }
 169 }
 170
 171 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 172                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 173 {
 174         int n = vlc_table->n;
 175         const uint8_t *table_bits = vlc_table->huffbits;
 176         const uint32_t *table_codes = vlc_table->huffcodes;
 177         const uint16_t *levels_table = vlc_table->levels;
 178         uint16_t *run_table, *level_table;
 179         int i, l, j, k, level;
 180
 181         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 182
 183         run_table = para_malloc(n * sizeof(uint16_t));
 184         level_table = para_malloc(n * sizeof(uint16_t));
 185         i = 2;
 186         level = 1;
 187         k = 0;
 188         while (i < n) {
 189                 l = levels_table[k++];
 190                 for (j = 0; j < l; j++) {
 191                         run_table[i] = j;
 192                         level_table[i] = level;
 193                         i++;
 194                 }
 195                 level++;
 196         }
 197         *prun_table = run_table;
 198         *plevel_table = level_table;
 199 }
 200
 201 /* compute the scale factor band sizes for each MDCT block size */
 202 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 203         float high_freq)
 204 {
 205         struct asf_header_info *ahi = &pwd->ahi;
 206         int a, b, pos, lpos, k, block_len, i, j, n;
 207         const uint8_t *table;
 208
 209         pwd->coefs_start = 0;
 210         for (k = 0; k < pwd->nb_block_sizes; k++) {
 211                 block_len = pwd->frame_len >> k;
 212
 213                 table = NULL;
 214                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 215                 if (a < 3) {
 216                         if (ahi->sample_rate >= 44100)
 217                                 table = exponent_band_44100[a];
 218                         else if (ahi->sample_rate >= 32000)
 219                                 table = exponent_band_32000[a];
 220                         else if (ahi->sample_rate >= 22050)
 221                                 table = exponent_band_22050[a];
 222                 }
 223                 if (table) {
 224                         n = *table++;
 225                         for (i = 0; i < n; i++)
 226                                 pwd->exponent_bands[k][i] = table[i];
 227                         pwd->exponent_sizes[k] = n;
 228                 } else {
 229                         j = 0;
 230                         lpos = 0;
 231                         for (i = 0; i < 25; i++) {
 232                                 a = wma_critical_freqs[i];
 233                                 b = ahi->sample_rate;
 234                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 235                                 pos <<= 2;
 236                                 if (pos > block_len)
 237                                         pos = block_len;
 238                                 if (pos > lpos)
 239                                         pwd->exponent_bands[k][j++] = pos - lpos;
 240                                 if (pos >= block_len)
 241                                         break;
 242                                 lpos = pos;
 243                         }
 244                         pwd->exponent_sizes[k] = j;
 245                 }
 246
 247                 /* max number of coefs */
 248                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 249                 /* high freq computation */
 250                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 251                         / ahi->sample_rate + 0.5);
 252                 n = pwd->exponent_sizes[k];
 253                 j = 0;
 254                 pos = 0;
 255                 for (i = 0; i < n; i++) {
 256                         int start, end;
 257                         start = pos;
 258                         pos += pwd->exponent_bands[k][i];
 259                         end = pos;
 260                         if (start < pwd->high_band_start[k])
 261                                 start = pwd->high_band_start[k];
 262                         if (end > pwd->coefs_end[k])
 263                                 end = pwd->coefs_end[k];
 264                         if (end > start)
 265                                 pwd->exponent_high_bands[k][j++] = end - start;
 266                 }
 267                 pwd->exponent_high_sizes[k] = j;
 268         }
 269 }
 270
 271 static int wma_init(struct private_wmadec_data *pwd)
 272 {
 273         int i;
 274         float bps1, high_freq;
 275         volatile float bps;
 276         int sample_rate1;
 277         int coef_vlc_table;
 278         struct asf_header_info *ahi = &pwd->ahi;
 279         int flags2 = ahi->flags2;
 280
 281         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 282                 || ahi->channels <= 0 || ahi->channels > 8
 283                 || ahi->bit_rate <= 0)
 284                 return -E_WMA_BAD_PARAMS;
 285
 286         /* compute MDCT block size */
 287         if (ahi->sample_rate <= 16000) {
 288                 pwd->frame_len_bits = 9;
 289         } else if (ahi->sample_rate <= 22050) {
 290                 pwd->frame_len_bits = 10;
 291         } else {
 292                 pwd->frame_len_bits = 11;
 293         }
 294         pwd->frame_len = 1 << pwd->frame_len_bits;
 295         if (pwd->use_variable_block_len) {
 296                 int nb_max, nb;
 297                 nb = ((flags2 >> 3) & 3) + 1;
 298                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 299                         nb += 2;
 300                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 301                 if (nb > nb_max)
 302                         nb = nb_max;
 303                 pwd->nb_block_sizes = nb + 1;
 304         } else
 305                 pwd->nb_block_sizes = 1;
 306
 307         /* init rate dependent parameters */
 308         pwd->use_noise_coding = 1;
 309         high_freq = ahi->sample_rate * 0.5;
 310
 311         /* wma2 rates are normalized */
 312         sample_rate1 = ahi->sample_rate;
 313         if (sample_rate1 >= 44100)
 314                 sample_rate1 = 44100;
 315         else if (sample_rate1 >= 22050)
 316                 sample_rate1 = 22050;
 317         else if (sample_rate1 >= 16000)
 318                 sample_rate1 = 16000;
 319         else if (sample_rate1 >= 11025)
 320                 sample_rate1 = 11025;
 321         else if (sample_rate1 >= 8000)
 322                 sample_rate1 = 8000;
 323
 324         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 325         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 326         /*
 327          * Compute high frequency value and choose if noise coding should be
 328          * activated.
 329          */
 330         bps1 = bps;
 331         if (ahi->channels == 2)
 332                 bps1 = bps * 1.6;
 333         if (sample_rate1 == 44100) {
 334                 if (bps1 >= 0.61)
 335                         pwd->use_noise_coding = 0;
 336                 else
 337                         high_freq = high_freq * 0.4;
 338         } else if (sample_rate1 == 22050) {
 339                 if (bps1 >= 1.16)
 340                         pwd->use_noise_coding = 0;
 341                 else if (bps1 >= 0.72)
 342                         high_freq = high_freq * 0.7;
 343                 else
 344                         high_freq = high_freq * 0.6;
 345         } else if (sample_rate1 == 16000) {
 346                 if (bps > 0.5)
 347                         high_freq = high_freq * 0.5;
 348                 else
 349                         high_freq = high_freq * 0.3;
 350         } else if (sample_rate1 == 11025) {
 351                 high_freq = high_freq * 0.7;
 352         } else if (sample_rate1 == 8000) {
 353                 if (bps <= 0.625) {
 354                         high_freq = high_freq * 0.5;
 355                 } else if (bps > 0.75) {
 356                         pwd->use_noise_coding = 0;
 357                 } else {
 358                         high_freq = high_freq * 0.65;
 359                 }
 360         } else {
 361                 if (bps >= 0.8) {
 362                         high_freq = high_freq * 0.75;
 363                 } else if (bps >= 0.6) {
 364                         high_freq = high_freq * 0.6;
 365                 } else {
 366                         high_freq = high_freq * 0.5;
 367                 }
 368         }
 369         PARA_INFO_LOG("channels=%d sample_rate=%d "
 370                 "bitrate=%d block_align=%d\n",
 371                 ahi->channels, ahi->sample_rate,
 372                 ahi->bit_rate, ahi->block_align);
 373         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 374                 "high_freq=%f bitoffset=%d\n",
 375                 pwd->frame_len, bps, bps1,
 376                 high_freq, pwd->byte_offset_bits);
 377         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 378                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 379
 380         compute_scale_factor_band_sizes(pwd, high_freq);
 381         /* init MDCT windows : simple sinus window */
 382         for (i = 0; i < pwd->nb_block_sizes; i++) {
 383                 int n;
 384                 n = 1 << (pwd->frame_len_bits - i);
 385                 sine_window_init(ff_sine_windows[pwd->frame_len_bits - i - 7], n);
 386                 pwd->windows[i] = ff_sine_windows[pwd->frame_len_bits - i - 7];
 387         }
 388
 389         pwd->reset_block_lengths = 1;
 390
 391         if (pwd->use_noise_coding) {
 392                 /* init the noise generator */
 393                 if (pwd->use_exp_vlc)
 394                         pwd->noise_mult = 0.02;
 395                 else
 396                         pwd->noise_mult = 0.04;
 397
 398                 {
 399                         unsigned int seed;
 400                         float norm;
 401                         seed = 1;
 402                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 403                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 404                                 seed = seed * 314159 + 1;
 405                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 406                         }
 407                 }
 408         }
 409
 410         /* choose the VLC tables for the coefficients */
 411         coef_vlc_table = 2;
 412         if (ahi->sample_rate >= 32000) {
 413                 if (bps1 < 0.72)
 414                         coef_vlc_table = 0;
 415                 else if (bps1 < 1.16)
 416                         coef_vlc_table = 1;
 417         }
 418         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 419         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 420         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 421                 pwd->coef_vlcs[0]);
 422         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 423                 pwd->coef_vlcs[1]);
 424         return 0;
 425 }
 426
 427 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 428 {
 429         float wdel, a, b;
 430         int i, e, m;
 431
 432         wdel = M_PI / frame_len;
 433         for (i = 0; i < frame_len; i++)
 434                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 435
 436         /* tables for x^-0.25 computation */
 437         for (i = 0; i < 256; i++) {
 438                 e = i - 126;
 439                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 440         }
 441
 442         /* These two tables are needed to avoid two operations in pow_m1_4. */
 443         b = 1.0;
 444         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 445                 m = (1 << LSP_POW_BITS) + i;
 446                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 447                 a = pow(a, -0.25);
 448                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 449                 pwd->lsp_pow_m_table2[i] = b - a;
 450                 b = a;
 451         }
 452 }
 453
 454 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 455 {
 456         struct private_wmadec_data *pwd;
 457         int ret, i;
 458
 459         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 460         pwd = para_calloc(sizeof(*pwd));
 461         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 462         if (ret <= 0) {
 463                 free(pwd);
 464                 return ret;
 465         }
 466
 467         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 468         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 469         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 470
 471         ret = wma_init(pwd);
 472         if (ret < 0)
 473                 return ret;
 474         /* init MDCT */
 475         for (i = 0; i < pwd->nb_block_sizes; i++) {
 476                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 477                 if (ret < 0)
 478                         return ret;
 479         }
 480         if (pwd->use_noise_coding) {
 481                 PARA_INFO_LOG("using noise coding\n");
 482                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 483                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 484                         ff_wma_hgain_huffcodes, 2);
 485         }
 486
 487         if (pwd->use_exp_vlc) {
 488                 PARA_INFO_LOG("using exp_vlc\n");
 489                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 490                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 491                 ff_wma_scale_huffcodes, 4);
 492         } else {
 493                 PARA_INFO_LOG("using curve\n");
 494                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 495         }
 496         *result = pwd;
 497         return pwd->ahi.header_len;
 498 }
 499
 500 /**
 501  * compute x^-0.25 with an exponent and mantissa table. We use linear
 502  * interpolation to reduce the mantissa table size at a small speed
 503  * expense (linear interpolation approximately doubles the number of
 504  * bits of precision).
 505  */
 506 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 507 {
 508         union {
 509                 float f;
 510                 unsigned int v;
 511         } u, t;
 512         unsigned int e, m;
 513         float a, b;
 514
 515         u.f = x;
 516         e = u.v >> 23;
 517         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 518         /* build interpolation scale: 1 <= t < 2. */
 519         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 520         a = pwd->lsp_pow_m_table1[m];
 521         b = pwd->lsp_pow_m_table2[m];
 522         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 523 }
 524
 525 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 526                 float *out, float *val_max_ptr, int n, float *lsp)
 527 {
 528         int i, j;
 529         float p, q, w, v, val_max;
 530
 531         val_max = 0;
 532         for (i = 0; i < n; i++) {
 533                 p = 0.5f;
 534                 q = 0.5f;
 535                 w = pwd->lsp_cos_table[i];
 536                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 537                         q *= w - lsp[j - 1];
 538                         p *= w - lsp[j];
 539                 }
 540                 p *= p * (2.0f - w);
 541                 q *= q * (2.0f + w);
 542                 v = p + q;
 543                 v = pow_m1_4(pwd, v);
 544                 if (v > val_max)
 545                         val_max = v;
 546                 out[i] = v;
 547         }
 548         *val_max_ptr = val_max;
 549 }
 550
 551 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 552 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 553 {
 554         float lsp_coefs[NB_LSP_COEFS];
 555         int val, i;
 556
 557         for (i = 0; i < NB_LSP_COEFS; i++) {
 558                 if (i == 0 || i >= 8)
 559                         val = get_bits(&pwd->gb, 3);
 560                 else
 561                         val = get_bits(&pwd->gb, 4);
 562                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 563         }
 564
 565         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 566                 pwd->block_len, lsp_coefs);
 567 }
 568
 569 /* Decode exponents coded with VLC codes. */
 570 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 571 {
 572         int last_exp, n, code;
 573         const uint16_t *ptr, *band_ptr;
 574         float v, *q, max_scale, *q_end;
 575
 576         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 577         ptr = band_ptr;
 578         q = pwd->exponents[ch];
 579         q_end = q + pwd->block_len;
 580         max_scale = 0;
 581         last_exp = 36;
 582
 583         while (q < q_end) {
 584                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 585                 if (code < 0)
 586                         return -1;
 587                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 588                 last_exp += code - 60;
 589                 /* XXX: use a table */
 590                 v = pow(10, last_exp * (1.0 / 16.0));
 591                 if (v > max_scale)
 592                         max_scale = v;
 593                 n = *ptr++;
 594                 do {
 595                         *q++ = v;
 596                 } while (--n);
 597         }
 598         pwd->max_exponent[ch] = max_scale;
 599         return 0;
 600 }
 601
 602 /* compute src0 * src1 + src2 */
 603 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 604                 const float *src2, int len)
 605 {
 606         int i;
 607
 608         for (i = 0; i < len; i++)
 609                 dst[i] = src0[i] * src1[i] + src2[i];
 610 }
 611
 612 static inline void vector_mult_reverse(float *dst, const float *src0,
 613                 const float *src1, int len)
 614 {
 615         int i;
 616
 617         src1 += len - 1;
 618         for (i = 0; i < len; i++)
 619                 dst[i] = src0[i] * src1[-i];
 620 }
 621
 622 /**
 623  * Apply MDCT window and add into output.
 624  *
 625  * We ensure that when the windows overlap their squared sum
 626  * is always 1 (MDCT reconstruction rule).
 627  */
 628 static void wma_window(struct private_wmadec_data *pwd, float *out)
 629 {
 630         float *in = pwd->output;
 631         int block_len, bsize, n;
 632
 633         /* left part */
 634         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 635                 block_len = pwd->block_len;
 636                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 637                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 638         } else {
 639                 block_len = 1 << pwd->prev_block_len_bits;
 640                 n = (pwd->block_len - block_len) / 2;
 641                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 642                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 643                         block_len);
 644                 memcpy(out + n + block_len, in + n + block_len,
 645                         n * sizeof(float));
 646         }
 647         out += pwd->block_len;
 648         in += pwd->block_len;
 649         /* right part */
 650         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 651                 block_len = pwd->block_len;
 652                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 653                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 654         } else {
 655                 block_len = 1 << pwd->next_block_len_bits;
 656                 n = (pwd->block_len - block_len) / 2;
 657                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 658                 memcpy(out, in, n * sizeof(float));
 659                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 660                         block_len);
 661                 memset(out + n + block_len, 0, n * sizeof(float));
 662         }
 663 }
 664
 665 static int wma_total_gain_to_bits(int total_gain)
 666 {
 667         if (total_gain < 15)
 668                 return 13;
 669         else if (total_gain < 32)
 670                 return 12;
 671         else if (total_gain < 40)
 672                 return 11;
 673         else if (total_gain < 45)
 674                 return 10;
 675         else
 676                 return 9;
 677 }
 678
 679 /**
 680  * @return 0 if OK. 1 if last block of frame. return -1 if
 681  * unrecorrable error.
 682  */
 683 static int wma_decode_block(struct private_wmadec_data *pwd)
 684 {
 685         int n, v, ch, code, bsize;
 686         int coef_nb_bits, total_gain;
 687         int nb_coefs[MAX_CHANNELS];
 688         float mdct_norm;
 689
 690         /* compute current block length */
 691         if (pwd->use_variable_block_len) {
 692                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 693
 694                 if (pwd->reset_block_lengths) {
 695                         pwd->reset_block_lengths = 0;
 696                         v = get_bits(&pwd->gb, n);
 697                         if (v >= pwd->nb_block_sizes)
 698                                 return -1;
 699                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 700                         v = get_bits(&pwd->gb, n);
 701                         if (v >= pwd->nb_block_sizes)
 702                                 return -1;
 703                         pwd->block_len_bits = pwd->frame_len_bits - v;
 704                 } else {
 705                         /* update block lengths */
 706                         pwd->prev_block_len_bits = pwd->block_len_bits;
 707                         pwd->block_len_bits = pwd->next_block_len_bits;
 708                 }
 709                 v = get_bits(&pwd->gb, n);
 710                 if (v >= pwd->nb_block_sizes)
 711                         return -1;
 712                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 713         } else {
 714                 /* fixed block len */
 715                 pwd->next_block_len_bits = pwd->frame_len_bits;
 716                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 717                 pwd->block_len_bits = pwd->frame_len_bits;
 718         }
 719
 720         /* now check if the block length is coherent with the frame length */
 721         pwd->block_len = 1 << pwd->block_len_bits;
 722         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 723                 return -E_INCOHERENT_BLOCK_LEN;
 724
 725         if (pwd->ahi.channels == 2)
 726                 pwd->ms_stereo = get_bit(&pwd->gb);
 727         v = 0;
 728         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 729                 int a = get_bit(&pwd->gb);
 730                 pwd->channel_coded[ch] = a;
 731                 v |= a;
 732         }
 733
 734         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 735
 736         /* if no channel coded, no need to go further */
 737         /* XXX: fix potential framing problems */
 738         if (!v)
 739                 goto next;
 740
 741         /* read total gain and extract corresponding number of bits for
 742            coef escape coding */
 743         total_gain = 1;
 744         for (;;) {
 745                 int a = get_bits(&pwd->gb, 7);
 746                 total_gain += a;
 747                 if (a != 127)
 748                         break;
 749         }
 750
 751         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 752
 753         /* compute number of coefficients */
 754         n = pwd->coefs_end[bsize] - pwd->coefs_start;
 755         for (ch = 0; ch < pwd->ahi.channels; ch++)
 756                 nb_coefs[ch] = n;
 757
 758         /* complex coding */
 759         if (pwd->use_noise_coding) {
 760                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 761                         if (pwd->channel_coded[ch]) {
 762                                 int i, m, a;
 763                                 m = pwd->exponent_high_sizes[bsize];
 764                                 for (i = 0; i < m; i++) {
 765                                         a = get_bit(&pwd->gb);
 766                                         pwd->high_band_coded[ch][i] = a;
 767                                         /* if noise coding, the coefficients are not transmitted */
 768                                         if (a)
 769                                                 nb_coefs[ch] -=
 770                                                     pwd->
 771                                                     exponent_high_bands[bsize]
 772                                                     [i];
 773                                 }
 774                         }
 775                 }
 776                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 777                         if (pwd->channel_coded[ch]) {
 778                                 int i, val;
 779
 780                                 n = pwd->exponent_high_sizes[bsize];
 781                                 val = (int) 0x80000000;
 782                                 for (i = 0; i < n; i++) {
 783                                         if (pwd->high_band_coded[ch][i]) {
 784                                                 if (val == (int) 0x80000000) {
 785                                                         val =
 786                                                             get_bits(&pwd->gb,
 787                                                                      7) - 19;
 788                                                 } else {
 789                                                         code =
 790                                                             get_vlc(&pwd->gb,
 791                                                                      pwd->
 792                                                                      hgain_vlc.
 793                                                                      table,
 794                                                                      HGAINVLCBITS,
 795                                                                      HGAINMAX);
 796                                                         if (code < 0)
 797                                                                 return -1;
 798                                                         val += code - 18;
 799                                                 }
 800                                                 pwd->high_band_values[ch][i] =
 801                                                     val;
 802                                         }
 803                                 }
 804                         }
 805                 }
 806         }
 807
 808         /* exponents can be reused in short blocks. */
 809         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 810                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 811                         if (pwd->channel_coded[ch]) {
 812                                 if (pwd->use_exp_vlc) {
 813                                         if (decode_exp_vlc(pwd, ch) < 0)
 814                                                 return -1;
 815                                 } else {
 816                                         decode_exp_lsp(pwd, ch);
 817                                 }
 818                                 pwd->exponents_bsize[ch] = bsize;
 819                         }
 820                 }
 821         }
 822
 823         /* parse spectral coefficients : just RLE encoding */
 824         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 825                 struct vlc *coef_vlc;
 826                 int level, run, tindex;
 827                 int16_t *ptr, *eptr;
 828                 const uint16_t *level_table, *run_table;
 829
 830                 if (!pwd->channel_coded[ch])
 831                         continue;
 832                 /*
 833                  * special VLC tables are used for ms stereo because there is
 834                  * potentially less energy there
 835                  */
 836                 tindex = (ch == 1 && pwd->ms_stereo);
 837                 coef_vlc = &pwd->coef_vlc[tindex];
 838                 run_table = pwd->run_table[tindex];
 839                 level_table = pwd->level_table[tindex];
 840                 /* XXX: optimize */
 841                 ptr = &pwd->coefs1[ch][0];
 842                 eptr = ptr + nb_coefs[ch];
 843                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 844                 for (;;) {
 845                         code = get_vlc(&pwd->gb, coef_vlc->table,
 846                                 VLCBITS, VLCMAX);
 847                         if (code < 0)
 848                                 return -1;
 849                         if (code == 1) /* EOB */
 850                                 break;
 851                         if (code == 0) { /* escape */
 852                                 level = get_bits(&pwd->gb, coef_nb_bits);
 853                                 /* reading block_len_bits would be better */
 854                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 855                         } else { /* normal code */
 856                                 run = run_table[code];
 857                                 level = level_table[code];
 858                         }
 859                         if (!get_bit(&pwd->gb))
 860                                 level = -level;
 861                         ptr += run;
 862                         if (ptr >= eptr) {
 863                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 864                                 break;
 865                         }
 866                         *ptr++ = level;
 867                         if (ptr >= eptr) /* EOB can be omitted */
 868                                 break;
 869                 }
 870         }
 871
 872         /* normalize */
 873         {
 874                 int n4 = pwd->block_len / 2;
 875                 mdct_norm = 1.0 / (float) n4;
 876         }
 877
 878         /* finally compute the MDCT coefficients */
 879         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 880                 if (pwd->channel_coded[ch]) {
 881                         int16_t *coefs1;
 882                         float *coefs, *exponents, mult, mult1, noise;
 883                         int i, j, n1, last_high_band, esize;
 884                         float exp_power[HIGH_BAND_MAX_SIZE];
 885
 886                         coefs1 = pwd->coefs1[ch];
 887                         exponents = pwd->exponents[ch];
 888                         esize = pwd->exponents_bsize[ch];
 889                         mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 890                         mult *= mdct_norm;
 891                         coefs = pwd->coefs[ch];
 892                         if (pwd->use_noise_coding) {
 893                                 mult1 = mult;
 894                                 /* very low freqs : noise */
 895                                 for (i = 0; i < pwd->coefs_start; i++) {
 896                                         *coefs++ =
 897                                             pwd->noise_table[pwd->noise_index] *
 898                                             exponents[i << bsize >> esize] *
 899                                             mult1;
 900                                         pwd->noise_index =
 901                                             (pwd->noise_index +
 902                                              1) & (NOISE_TAB_SIZE - 1);
 903                                 }
 904
 905                                 n1 = pwd->exponent_high_sizes[bsize];
 906
 907                                 /* compute power of high bands */
 908                                 exponents = pwd->exponents[ch] +
 909                                     (pwd->high_band_start[bsize] << bsize);
 910                                 last_high_band = 0;     /* avoid warning */
 911                                 for (j = 0; j < n1; j++) {
 912                                         n = pwd->exponent_high_bands[pwd->
 913                                                                    frame_len_bits
 914                                                                    -
 915                                                                    pwd->
 916                                                                    block_len_bits]
 917                                             [j];
 918                                         if (pwd->high_band_coded[ch][j]) {
 919                                                 float e2, val;
 920                                                 e2 = 0;
 921                                                 for (i = 0; i < n; i++) {
 922                                                         val = exponents[i << bsize
 923                                                                       >> esize];
 924                                                         e2 += val * val;
 925                                                 }
 926                                                 exp_power[j] = e2 / n;
 927                                                 last_high_band = j;
 928                                         }
 929                                         exponents += n << bsize;
 930                                 }
 931
 932                                 /* main freqs and high freqs */
 933                                 exponents =
 934                                     pwd->exponents[ch] +
 935                                     (pwd->coefs_start << bsize);
 936                                 for (j = -1; j < n1; j++) {
 937                                         if (j < 0) {
 938                                                 n = pwd->high_band_start[bsize] -
 939                                                     pwd->coefs_start;
 940                                         } else {
 941                                                 n = pwd->exponent_high_bands[pwd->
 942                                                                            frame_len_bits
 943                                                                            -
 944                                                                            pwd->
 945                                                                            block_len_bits]
 946                                                     [j];
 947                                         }
 948                                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 949                                                 /* use noise with specified power */
 950                                                 mult1 =
 951                                                     sqrt(exp_power[j] /
 952                                                          exp_power
 953                                                          [last_high_band]);
 954                                                 /* XXX: use a table */
 955                                                 mult1 =
 956                                                     mult1 * pow(10,
 957                                                                 pwd->
 958                                                                 high_band_values
 959                                                                 [ch][j] * 0.05);
 960                                                 mult1 =
 961                                                     mult1 /
 962                                                     (pwd->max_exponent[ch] *
 963                                                      pwd->noise_mult);
 964                                                 mult1 *= mdct_norm;
 965                                                 for (i = 0; i < n; i++) {
 966                                                         noise =
 967                                                             pwd->noise_table[pwd->
 968                                                                            noise_index];
 969                                                         pwd->noise_index =
 970                                                             (pwd->noise_index +
 971                                                              1) &
 972                                                             (NOISE_TAB_SIZE -
 973                                                              1);
 974                                                         *coefs++ =
 975                                                             noise *
 976                                                             exponents[i << bsize
 977                                                                       >> esize]
 978                                                             * mult1;
 979                                                 }
 980                                                 exponents += n << bsize;
 981                                         } else {
 982                                                 /* coded values + small noise */
 983                                                 for (i = 0; i < n; i++) {
 984                                                         noise =
 985                                                             pwd->noise_table[pwd->
 986                                                                            noise_index];
 987                                                         pwd->noise_index =
 988                                                             (pwd->noise_index +
 989                                                              1) &
 990                                                             (NOISE_TAB_SIZE -
 991                                                              1);
 992                                                         *coefs++ =
 993                                                             ((*coefs1++) +
 994                                                              noise) *
 995                                                             exponents[i << bsize
 996                                                                       >> esize]
 997                                                             * mult;
 998                                                 }
 999                                                 exponents += n << bsize;
1000                                         }
1001                                 }
1002
1003                                 /* very high freqs : noise */
1004                                 n = pwd->block_len - pwd->coefs_end[bsize];
1005                                 mult1 =
1006                                     mult * exponents[((-1 << bsize)) >> esize];
1007                                 for (i = 0; i < n; i++) {
1008                                         *coefs++ =
1009                                             pwd->noise_table[pwd->noise_index] *
1010                                             mult1;
1011                                         pwd->noise_index =
1012                                             (pwd->noise_index +
1013                                              1) & (NOISE_TAB_SIZE - 1);
1014                                 }
1015                         } else {
1016                                 /* XXX: optimize more */
1017                                 for (i = 0; i < pwd->coefs_start; i++)
1018                                         *coefs++ = 0.0;
1019                                 n = nb_coefs[ch];
1020                                 for (i = 0; i < n; i++) {
1021                                         *coefs++ =
1022                                             coefs1[i] *
1023                                             exponents[i << bsize >> esize] *
1024                                             mult;
1025                                 }
1026                                 n = pwd->block_len - pwd->coefs_end[bsize];
1027                                 for (i = 0; i < n; i++)
1028                                         *coefs++ = 0.0;
1029                         }
1030                 }
1031         }
1032
1033         if (pwd->ms_stereo && pwd->channel_coded[1]) {
1034                 float a, b;
1035                 int i;
1036
1037                 /*
1038                  * Nominal case for ms stereo: we do it before mdct.
1039                  *
1040                  * No need to optimize this case because it should almost never
1041                  * happen.
1042                  */
1043                 if (!pwd->channel_coded[0]) {
1044                         PARA_NOTICE_LOG("rare ms-stereo\n");
1045                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1046                         pwd->channel_coded[0] = 1;
1047                 }
1048                 for (i = 0; i < pwd->block_len; i++) {
1049                         a = pwd->coefs[0][i];
1050                         b = pwd->coefs[1][i];
1051                         pwd->coefs[0][i] = a + b;
1052                         pwd->coefs[1][i] = a - b;
1053                 }
1054         }
1055
1056 next:
1057         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1058                 int n4, index;
1059
1060                 n = pwd->block_len;
1061                 n4 = pwd->block_len / 2;
1062                 if (pwd->channel_coded[ch])
1063                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1064                 else if (!(pwd->ms_stereo && ch == 1))
1065                         memset(pwd->output, 0, sizeof(pwd->output));
1066
1067                 /* multiply by the window and add in the frame */
1068                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1069                 wma_window(pwd, &pwd->frame_out[ch][index]);
1070         }
1071
1072         /* update block number */
1073         pwd->block_pos += pwd->block_len;
1074         if (pwd->block_pos >= pwd->frame_len)
1075                 return 1;
1076         else
1077                 return 0;
1078 }
1079
1080 /*
1081  * Clip a signed integer value into the -32768,32767 range.
1082  *
1083  * \param a The value to clip.
1084  *
1085  * \return The clipped value.
1086  */
1087 static inline int16_t av_clip_int16(int a)
1088 {
1089         if ((a + 32768) & ~65535)
1090                 return (a >> 31) ^ 32767;
1091         else
1092                 return a;
1093 }
1094
1095 /* Decode a frame of frame_len samples. */
1096 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1097 {
1098         int ret, i, n, ch, incr;
1099         int16_t *ptr;
1100         float *iptr;
1101
1102         /* read each block */
1103         pwd->block_pos = 0;
1104         for (;;) {
1105                 ret = wma_decode_block(pwd);
1106                 if (ret < 0)
1107                         return -1;
1108                 if (ret)
1109                         break;
1110         }
1111
1112         /* convert frame to integer */
1113         n = pwd->frame_len;
1114         incr = pwd->ahi.channels;
1115         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1116                 ptr = samples + ch;
1117                 iptr = pwd->frame_out[ch];
1118
1119                 for (i = 0; i < n; i++) {
1120                         *ptr = av_clip_int16(lrintf(*iptr++));
1121                         ptr += incr;
1122                 }
1123                 /* prepare for next block */
1124                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1125                         pwd->frame_len * sizeof(float));
1126         }
1127         return 0;
1128 }
1129
1130 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1131                 int *data_size, const uint8_t *buf, int buf_size)
1132 {
1133         int ret;
1134         int16_t *samples;
1135         static int frame_count;
1136
1137         if (buf_size == 0) {
1138                 pwd->last_superframe_len = 0;
1139                 return 0;
1140         }
1141         if (buf_size < pwd->ahi.block_align)
1142                 return 0;
1143         buf_size = pwd->ahi.block_align;
1144         samples = data;
1145         init_get_bits(&pwd->gb, buf, buf_size);
1146         if (pwd->use_bit_reservoir) {
1147                 int i, nb_frames, bit_offset, pos, len;
1148                 uint8_t *q;
1149
1150                 /* read super frame header */
1151                 skip_bits(&pwd->gb, 4); /* super frame index */
1152                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1153                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1154                 ret = -E_WMA_OUTPUT_SPACE;
1155                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1156                                 * sizeof(int16_t) > *data_size)
1157                         goto fail;
1158
1159                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1160
1161                 if (pwd->last_superframe_len > 0) {
1162                         /* add bit_offset bits to last frame */
1163                         ret = -E_WMA_BAD_SUPERFRAME;
1164                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1165                                         MAX_CODED_SUPERFRAME_SIZE)
1166                                 goto fail;
1167                         q = pwd->last_superframe + pwd->last_superframe_len;
1168                         len = bit_offset;
1169                         while (len > 7) {
1170                                 *q++ = get_bits(&pwd->gb, 8);
1171                                 len -= 8;
1172                         }
1173                         if (len > 0)
1174                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1175
1176                         /* XXX: bit_offset bits into last frame */
1177                         init_get_bits(&pwd->gb, pwd->last_superframe,
1178                                 MAX_CODED_SUPERFRAME_SIZE);
1179                         /* skip unused bits */
1180                         if (pwd->last_bitoffset > 0)
1181                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1182                         /*
1183                          * This frame is stored in the last superframe and in
1184                          * the current one.
1185                          */
1186                         ret = -E_WMA_DECODE;
1187                         if (wma_decode_frame(pwd, samples) < 0)
1188                                 goto fail;
1189                         frame_count++;
1190                         samples += pwd->ahi.channels * pwd->frame_len;
1191                 }
1192
1193                 /* read each frame starting from bit_offset */
1194                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1195                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1196                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1197                 len = pos & 7;
1198                 if (len > 0)
1199                         skip_bits(&pwd->gb, len);
1200
1201                 pwd->reset_block_lengths = 1;
1202                 for (i = 0; i < nb_frames; i++) {
1203                         ret = -E_WMA_DECODE;
1204                         if (wma_decode_frame(pwd, samples) < 0)
1205                                 goto fail;
1206                         frame_count++;
1207                         samples += pwd->ahi.channels * pwd->frame_len;
1208                 }
1209
1210                 /* we copy the end of the frame in the last frame buffer */
1211                 pos = get_bits_count(&pwd->gb) +
1212                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1213                 pwd->last_bitoffset = pos & 7;
1214                 pos >>= 3;
1215                 len = buf_size - pos;
1216                 ret = -E_WMA_BAD_SUPERFRAME;
1217                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1218                         goto fail;
1219                 pwd->last_superframe_len = len;
1220                 memcpy(pwd->last_superframe, buf + pos, len);
1221         } else {
1222                 PARA_DEBUG_LOG("not using bit reservoir\n");
1223                 ret = -E_WMA_OUTPUT_SPACE;
1224                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1225                         goto fail;
1226                 /* single frame decode */
1227                 ret = -E_WMA_DECODE;
1228                 if (wma_decode_frame(pwd, samples) < 0)
1229                         goto fail;
1230                 frame_count++;
1231                 samples += pwd->ahi.channels * pwd->frame_len;
1232         }
1233         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1234                 "outbytes: %d, eaten: %d\n",
1235                 frame_count, pwd->frame_len, pwd->block_len,
1236                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1237         *data_size = (int8_t *)samples - (int8_t *)data;
1238         return pwd->ahi.block_align;
1239 fail:
1240         /* reset the bit reservoir on errors */
1241         pwd->last_superframe_len = 0;
1242         return ret;
1243 }
1244
1245 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1246                 struct filter_node *fn)
1247 {
1248         int ret, out_size = fn->bufsize - fn->loaded;
1249         struct private_wmadec_data *pwd = fn->private_data;
1250
1251         if (out_size < 128 * 1024)
1252                 return 0;
1253         if (!pwd) {
1254                 ret = wma_decode_init(inbuffer, len, &pwd);
1255                 if (ret <= 0)
1256                         return ret;
1257                 fn->private_data = pwd;
1258                 fn->fc->channels = pwd->ahi.channels;
1259                 fn->fc->samplerate = pwd->ahi.sample_rate;
1260                 return pwd->ahi.header_len;
1261         }
1262         /* skip 31 bytes */
1263         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1264                 return 0;
1265         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1266                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1267                 len - WMA_FRAME_SKIP);
1268         if (ret < 0)
1269                 return ret;
1270         fn->loaded += out_size;
1271         return ret + WMA_FRAME_SKIP;
1272 }
1273
1274 static void wmadec_close(struct filter_node *fn)
1275 {
1276         struct private_wmadec_data *pwd = fn->private_data;
1277
1278         if (!pwd)
1279                 return;
1280         wmadec_cleanup(pwd);
1281         free(fn->buf);
1282         fn->buf = NULL;
1283         free(fn->private_data);
1284         fn->private_data = NULL;
1285 }
1286
1287 static void wmadec_open(struct filter_node *fn)
1288 {
1289         fn->bufsize = 1024 * 1024;
1290         fn->buf = para_malloc(fn->bufsize);
1291         fn->private_data = NULL;
1292         fn->loaded = 0;
1293 }
1294
1295 /**
1296  * The init function of the wma decoder.
1297  *
1298  * \param f Its fields are filled in by the function.
1299  */
1300 void wmadec_filter_init(struct filter *f)
1301 {
1302         f->open = wmadec_open;
1303         f->close = wmadec_close;
1304         f->convert = wmadec_convert;
1305 }