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 #include <sys/select.h>
  28
  29 #include "para.h"
  30 #include "error.h"
  31 #include "list.h"
  32 #include "ggo.h"
  33 #include "string.h"
  34 #include "sched.h"
  35 #include "buffer_tree.h"
  36 #include "filter.h"
  37 #include "bitstream.h"
  38 #include "imdct.h"
  39 #include "wma.h"
  40 #include "wmadata.h"
  41
  42
  43 /* size of blocks */
  44 #define BLOCK_MIN_BITS 7
  45 #define BLOCK_MAX_BITS 11
  46 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  47
  48 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  49
  50 /* XXX: find exact max size */
  51 #define HIGH_BAND_MAX_SIZE 16
  52
  53 /* XXX: is it a suitable value ? */
  54 #define MAX_CODED_SUPERFRAME_SIZE 16384
  55
  56 #define MAX_CHANNELS 2
  57
  58 #define NOISE_TAB_SIZE 8192
  59
  60 #define LSP_POW_BITS 7
  61
  62 struct private_wmadec_data {
  63         /** Information contained in the audio file header. */
  64         struct asf_header_info ahi;
  65         struct getbit_context gb;
  66         /** Whether to use the bit reservoir. */
  67         int use_bit_reservoir;
  68         /** Whether to use variable block length. */
  69         int use_variable_block_len;
  70         /** Whether to use exponent coding. */
  71         int use_exp_vlc;
  72         /** Whether perceptual noise is added. */
  73         int use_noise_coding;
  74         /** Depends on number of the bits per second and the frame length. */
  75         int byte_offset_bits;
  76         /** Only used if use_exp_vlc is true. */
  77         struct vlc exp_vlc;
  78         int exponent_sizes[BLOCK_NB_SIZES];
  79         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  80         /** The index of the first coef in high band. */
  81         int high_band_start[BLOCK_NB_SIZES];
  82         /** Maximal number of coded coefficients. */
  83         int coefs_end[BLOCK_NB_SIZES];
  84         int exponent_high_sizes[BLOCK_NB_SIZES];
  85         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  86         struct vlc hgain_vlc;
  87
  88         /* coded values in high bands */
  89         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  90         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  91
  92         /* there are two possible tables for spectral coefficients */
  93         struct vlc coef_vlc[2];
  94         uint16_t *run_table[2];
  95         uint16_t *level_table[2];
  96         const struct coef_vlc_table *coef_vlcs[2];
  97         /** Frame length in samples. */
  98         int frame_len;
  99         /** log2 of frame_len. */
 100         int frame_len_bits;
 101         /** Number of block sizes. */
 102         int nb_block_sizes;
 103         /* block info */
 104         int reset_block_lengths;
 105         /** log2 of current block length. */
 106         int block_len_bits;
 107         /** log2 of next block length. */
 108         int next_block_len_bits;
 109         /** log2 of previous block length. */
 110         int prev_block_len_bits;
 111         /** Block length in samples. */
 112         int block_len;
 113         /** Current position in frame. */
 114         int block_pos;
 115         /** True if mid/side stereo mode. */
 116         uint8_t ms_stereo;
 117         /** True if channel is coded. */
 118         uint8_t channel_coded[MAX_CHANNELS];
 119         /** log2 ratio frame/exp. length. */
 120         int exponents_bsize[MAX_CHANNELS];
 121
 122         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 123         float max_exponent[MAX_CHANNELS];
 124         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 125         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 126         float output[BLOCK_MAX_SIZE * 2];
 127         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 128         float *windows[BLOCK_NB_SIZES];
 129         /** Output buffer for one frame and the last for IMDCT windowing. */
 130         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 131         /** Last frame info. */
 132         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 133         int last_bitoffset;
 134         int last_superframe_len;
 135         float noise_table[NOISE_TAB_SIZE];
 136         int noise_index;
 137         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 138         /* lsp_to_curve tables */
 139         float lsp_cos_table[BLOCK_MAX_SIZE];
 140         float lsp_pow_e_table[256];
 141         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 142         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 143 };
 144
 145 #define EXPVLCBITS 8
 146 #define EXPMAX DIV_ROUND_UP(19, EXPVLCBITS)
 147
 148 #define HGAINVLCBITS 9
 149 #define HGAINMAX DIV_ROUND_UP(13, HGAINVLCBITS)
 150
 151 #define VLCBITS 9
 152 #define VLCMAX DIV_ROUND_UP(22, VLCBITS)
 153
 154 #define SINE_WINDOW(x) static float sine_ ## x[x] __a_aligned(16)
 155
 156 SINE_WINDOW(128);
 157 SINE_WINDOW(256);
 158 SINE_WINDOW(512);
 159 SINE_WINDOW(1024);
 160 SINE_WINDOW(2048);
 161 SINE_WINDOW(4096);
 162
 163 static float *sine_windows[6] = {
 164         sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
 165 };
 166
 167 /* Generate a sine window. */
 168 static void sine_window_init(float *window, int n)
 169 {
 170         int i;
 171
 172         for (i = 0; i < n; i++)
 173                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 174 }
 175
 176 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 177 {
 178         int i;
 179
 180         for (i = 0; i < pwd->nb_block_sizes; i++)
 181                 imdct_end(pwd->mdct_ctx[i]);
 182         if (pwd->use_exp_vlc)
 183                 free_vlc(&pwd->exp_vlc);
 184         if (pwd->use_noise_coding)
 185                 free_vlc(&pwd->hgain_vlc);
 186         for (i = 0; i < 2; i++) {
 187                 free_vlc(&pwd->coef_vlc[i]);
 188                 free(pwd->run_table[i]);
 189                 free(pwd->level_table[i]);
 190         }
 191 }
 192
 193 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 194                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 195 {
 196         int n = vlc_table->n;
 197         const uint8_t *table_bits = vlc_table->huffbits;
 198         const uint32_t *table_codes = vlc_table->huffcodes;
 199         const uint16_t *levels_table = vlc_table->levels;
 200         uint16_t *run_table, *level_table;
 201         int i, l, j, k, level;
 202
 203         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 204
 205         run_table = para_malloc(n * sizeof(uint16_t));
 206         level_table = para_malloc(n * sizeof(uint16_t));
 207         i = 2;
 208         level = 1;
 209         k = 0;
 210         while (i < n) {
 211                 l = levels_table[k++];
 212                 for (j = 0; j < l; j++) {
 213                         run_table[i] = j;
 214                         level_table[i] = level;
 215                         i++;
 216                 }
 217                 level++;
 218         }
 219         *prun_table = run_table;
 220         *plevel_table = level_table;
 221 }
 222
 223 /* compute the scale factor band sizes for each MDCT block size */
 224 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 225         float high_freq)
 226 {
 227         struct asf_header_info *ahi = &pwd->ahi;
 228         int a, b, pos, lpos, k, block_len, i, j, n;
 229         const uint8_t *table;
 230
 231         for (k = 0; k < pwd->nb_block_sizes; k++) {
 232                 block_len = pwd->frame_len >> k;
 233
 234                 table = NULL;
 235                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 236                 if (a < 3) {
 237                         if (ahi->sample_rate >= 44100)
 238                                 table = exponent_band_44100[a];
 239                         else if (ahi->sample_rate >= 32000)
 240                                 table = exponent_band_32000[a];
 241                         else if (ahi->sample_rate >= 22050)
 242                                 table = exponent_band_22050[a];
 243                 }
 244                 if (table) {
 245                         n = *table++;
 246                         for (i = 0; i < n; i++)
 247                                 pwd->exponent_bands[k][i] = table[i];
 248                         pwd->exponent_sizes[k] = n;
 249                 } else {
 250                         j = 0;
 251                         lpos = 0;
 252                         for (i = 0; i < 25; i++) {
 253                                 a = wma_critical_freqs[i];
 254                                 b = ahi->sample_rate;
 255                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 256                                 pos <<= 2;
 257                                 if (pos > block_len)
 258                                         pos = block_len;
 259                                 if (pos > lpos)
 260                                         pwd->exponent_bands[k][j++] = pos - lpos;
 261                                 if (pos >= block_len)
 262                                         break;
 263                                 lpos = pos;
 264                         }
 265                         pwd->exponent_sizes[k] = j;
 266                 }
 267
 268                 /* max number of coefs */
 269                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 270                 /* high freq computation */
 271                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 272                         / ahi->sample_rate + 0.5);
 273                 n = pwd->exponent_sizes[k];
 274                 j = 0;
 275                 pos = 0;
 276                 for (i = 0; i < n; i++) {
 277                         int start, end;
 278                         start = pos;
 279                         pos += pwd->exponent_bands[k][i];
 280                         end = pos;
 281                         if (start < pwd->high_band_start[k])
 282                                 start = pwd->high_band_start[k];
 283                         if (end > pwd->coefs_end[k])
 284                                 end = pwd->coefs_end[k];
 285                         if (end > start)
 286                                 pwd->exponent_high_bands[k][j++] = end - start;
 287                 }
 288                 pwd->exponent_high_sizes[k] = j;
 289         }
 290 }
 291
 292 static int wma_init(struct private_wmadec_data *pwd)
 293 {
 294         int i;
 295         float bps1, high_freq;
 296         volatile float bps;
 297         int sample_rate1;
 298         int coef_vlc_table;
 299         struct asf_header_info *ahi = &pwd->ahi;
 300         int flags2 = ahi->flags2;
 301
 302         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 303                 || ahi->channels <= 0 || ahi->channels > 8
 304                 || ahi->bit_rate <= 0)
 305                 return -E_WMA_BAD_PARAMS;
 306
 307         /* compute MDCT block size */
 308         if (ahi->sample_rate <= 16000)
 309                 pwd->frame_len_bits = 9;
 310         else if (ahi->sample_rate <= 22050)
 311                 pwd->frame_len_bits = 10;
 312         else
 313                 pwd->frame_len_bits = 11;
 314         pwd->frame_len = 1 << pwd->frame_len_bits;
 315         if (pwd->use_variable_block_len) {
 316                 int nb_max, nb;
 317                 nb = ((flags2 >> 3) & 3) + 1;
 318                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 319                         nb += 2;
 320                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 321                 if (nb > nb_max)
 322                         nb = nb_max;
 323                 pwd->nb_block_sizes = nb + 1;
 324         } else
 325                 pwd->nb_block_sizes = 1;
 326
 327         /* init rate dependent parameters */
 328         pwd->use_noise_coding = 1;
 329         high_freq = ahi->sample_rate * 0.5;
 330
 331         /* wma2 rates are normalized */
 332         sample_rate1 = ahi->sample_rate;
 333         if (sample_rate1 >= 44100)
 334                 sample_rate1 = 44100;
 335         else if (sample_rate1 >= 22050)
 336                 sample_rate1 = 22050;
 337         else if (sample_rate1 >= 16000)
 338                 sample_rate1 = 16000;
 339         else if (sample_rate1 >= 11025)
 340                 sample_rate1 = 11025;
 341         else if (sample_rate1 >= 8000)
 342                 sample_rate1 = 8000;
 343
 344         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 345         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 346         /*
 347          * Compute high frequency value and choose if noise coding should be
 348          * activated.
 349          */
 350         bps1 = bps;
 351         if (ahi->channels == 2)
 352                 bps1 = bps * 1.6;
 353         if (sample_rate1 == 44100) {
 354                 if (bps1 >= 0.61)
 355                         pwd->use_noise_coding = 0;
 356                 else
 357                         high_freq = high_freq * 0.4;
 358         } else if (sample_rate1 == 22050) {
 359                 if (bps1 >= 1.16)
 360                         pwd->use_noise_coding = 0;
 361                 else if (bps1 >= 0.72)
 362                         high_freq = high_freq * 0.7;
 363                 else
 364                         high_freq = high_freq * 0.6;
 365         } else if (sample_rate1 == 16000) {
 366                 if (bps > 0.5)
 367                         high_freq = high_freq * 0.5;
 368                 else
 369                         high_freq = high_freq * 0.3;
 370         } else if (sample_rate1 == 11025)
 371                 high_freq = high_freq * 0.7;
 372         else if (sample_rate1 == 8000) {
 373                 if (bps <= 0.625)
 374                         high_freq = high_freq * 0.5;
 375                 else if (bps > 0.75)
 376                         pwd->use_noise_coding = 0;
 377                 else
 378                         high_freq = high_freq * 0.65;
 379         } else {
 380                 if (bps >= 0.8)
 381                         high_freq = high_freq * 0.75;
 382                 else if (bps >= 0.6)
 383                         high_freq = high_freq * 0.6;
 384                 else
 385                         high_freq = high_freq * 0.5;
 386         }
 387         PARA_INFO_LOG("channels=%d sample_rate=%d "
 388                 "bitrate=%d block_align=%d\n",
 389                 ahi->channels, ahi->sample_rate,
 390                 ahi->bit_rate, ahi->block_align);
 391         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 392                 "high_freq=%f bitoffset=%d\n",
 393                 pwd->frame_len, bps, bps1,
 394                 high_freq, pwd->byte_offset_bits);
 395         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 396                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 397
 398         compute_scale_factor_band_sizes(pwd, high_freq);
 399         /* init MDCT windows : simple sinus window */
 400         for (i = 0; i < pwd->nb_block_sizes; i++) {
 401                 int n;
 402                 n = 1 << (pwd->frame_len_bits - i);
 403                 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
 404                 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
 405         }
 406
 407         pwd->reset_block_lengths = 1;
 408
 409         if (pwd->use_noise_coding) {
 410                 /* init the noise generator */
 411                 if (pwd->use_exp_vlc)
 412                         pwd->noise_mult = 0.02;
 413                 else
 414                         pwd->noise_mult = 0.04;
 415
 416                 {
 417                         unsigned int seed;
 418                         float norm;
 419                         seed = 1;
 420                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 421                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 422                                 seed = seed * 314159 + 1;
 423                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 424                         }
 425                 }
 426         }
 427
 428         /* choose the VLC tables for the coefficients */
 429         coef_vlc_table = 2;
 430         if (ahi->sample_rate >= 32000) {
 431                 if (bps1 < 0.72)
 432                         coef_vlc_table = 0;
 433                 else if (bps1 < 1.16)
 434                         coef_vlc_table = 1;
 435         }
 436         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 437         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 438         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 439                 pwd->coef_vlcs[0]);
 440         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 441                 pwd->coef_vlcs[1]);
 442         return 0;
 443 }
 444
 445 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 446 {
 447         float wdel, a, b;
 448         int i, e, m;
 449
 450         wdel = M_PI / frame_len;
 451         for (i = 0; i < frame_len; i++)
 452                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 453
 454         /* tables for x^-0.25 computation */
 455         for (i = 0; i < 256; i++) {
 456                 e = i - 126;
 457                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 458         }
 459
 460         /* These two tables are needed to avoid two operations in pow_m1_4. */
 461         b = 1.0;
 462         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 463                 m = (1 << LSP_POW_BITS) + i;
 464                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 465                 a = pow(a, -0.25);
 466                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 467                 pwd->lsp_pow_m_table2[i] = b - a;
 468                 b = a;
 469         }
 470 }
 471
 472 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 473 {
 474         struct private_wmadec_data *pwd;
 475         int ret, i;
 476
 477         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 478         pwd = para_calloc(sizeof(*pwd));
 479         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 480         if (ret <= 0) {
 481                 free(pwd);
 482                 return ret;
 483         }
 484
 485         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 486         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 487         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 488
 489         ret = wma_init(pwd);
 490         if (ret < 0)
 491                 return ret;
 492         /* init MDCT */
 493         for (i = 0; i < pwd->nb_block_sizes; i++) {
 494                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 495                 if (ret < 0)
 496                         return ret;
 497         }
 498         if (pwd->use_noise_coding) {
 499                 PARA_INFO_LOG("using noise coding\n");
 500                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 501                         sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
 502                         wma_hgain_huffcodes, 2);
 503         }
 504
 505         if (pwd->use_exp_vlc) {
 506                 PARA_INFO_LOG("using exp_vlc\n");
 507                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 508                 sizeof(wma_scale_huffbits), wma_scale_huffbits,
 509                 wma_scale_huffcodes, 4);
 510         } else {
 511                 PARA_INFO_LOG("using curve\n");
 512                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 513         }
 514         *result = pwd;
 515         return pwd->ahi.header_len;
 516 }
 517
 518 /**
 519  * compute x^-0.25 with an exponent and mantissa table. We use linear
 520  * interpolation to reduce the mantissa table size at a small speed
 521  * expense (linear interpolation approximately doubles the number of
 522  * bits of precision).
 523  */
 524 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 525 {
 526         union {
 527                 float f;
 528                 unsigned int v;
 529         } u, t;
 530         unsigned int e, m;
 531         float a, b;
 532
 533         u.f = x;
 534         e = u.v >> 23;
 535         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 536         /* build interpolation scale: 1 <= t < 2. */
 537         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 538         a = pwd->lsp_pow_m_table1[m];
 539         b = pwd->lsp_pow_m_table2[m];
 540         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 541 }
 542
 543 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 544                 float *out, float *val_max_ptr, int n, float *lsp)
 545 {
 546         int i, j;
 547         float p, q, w, v, val_max;
 548
 549         val_max = 0;
 550         for (i = 0; i < n; i++) {
 551                 p = 0.5f;
 552                 q = 0.5f;
 553                 w = pwd->lsp_cos_table[i];
 554                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 555                         q *= w - lsp[j - 1];
 556                         p *= w - lsp[j];
 557                 }
 558                 p *= p * (2.0f - w);
 559                 q *= q * (2.0f + w);
 560                 v = p + q;
 561                 v = pow_m1_4(pwd, v);
 562                 if (v > val_max)
 563                         val_max = v;
 564                 out[i] = v;
 565         }
 566         *val_max_ptr = val_max;
 567 }
 568
 569 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 570 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 571 {
 572         float lsp_coefs[NB_LSP_COEFS];
 573         int val, i;
 574
 575         for (i = 0; i < NB_LSP_COEFS; i++) {
 576                 if (i == 0 || i >= 8)
 577                         val = get_bits(&pwd->gb, 3);
 578                 else
 579                         val = get_bits(&pwd->gb, 4);
 580                 lsp_coefs[i] = wma_lsp_codebook[i][val];
 581         }
 582
 583         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 584                 pwd->block_len, lsp_coefs);
 585 }
 586
 587 /* Decode exponents coded with VLC codes. */
 588 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 589 {
 590         int last_exp, n, code;
 591         const uint16_t *ptr, *band_ptr;
 592         float v, *q, max_scale, *q_end;
 593
 594         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 595         ptr = band_ptr;
 596         q = pwd->exponents[ch];
 597         q_end = q + pwd->block_len;
 598         max_scale = 0;
 599         last_exp = 36;
 600
 601         while (q < q_end) {
 602                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 603                 if (code < 0)
 604                         return code;
 605                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 606                 last_exp += code - 60;
 607                 /* XXX: use a table */
 608                 v = pow(10, last_exp * (1.0 / 16.0));
 609                 if (v > max_scale)
 610                         max_scale = v;
 611                 n = *ptr++;
 612                 do {
 613                         *q++ = v;
 614                 } while (--n);
 615         }
 616         pwd->max_exponent[ch] = max_scale;
 617         return 0;
 618 }
 619
 620 /* compute src0 * src1 + src2 */
 621 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 622                 const float *src2, int len)
 623 {
 624         int i;
 625
 626         for (i = 0; i < len; i++)
 627                 dst[i] = src0[i] * src1[i] + src2[i];
 628 }
 629
 630 static inline void vector_mult_reverse(float *dst, const float *src0,
 631                 const float *src1, int len)
 632 {
 633         int i;
 634
 635         src1 += len - 1;
 636         for (i = 0; i < len; i++)
 637                 dst[i] = src0[i] * src1[-i];
 638 }
 639
 640 /**
 641  * Apply MDCT window and add into output.
 642  *
 643  * We ensure that when the windows overlap their squared sum
 644  * is always 1 (MDCT reconstruction rule).
 645  */
 646 static void wma_window(struct private_wmadec_data *pwd, float *out)
 647 {
 648         float *in = pwd->output;
 649         int block_len, bsize, n;
 650
 651         /* left part */
 652         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 653                 block_len = pwd->block_len;
 654                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 655                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 656         } else {
 657                 block_len = 1 << pwd->prev_block_len_bits;
 658                 n = (pwd->block_len - block_len) / 2;
 659                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 660                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 661                         block_len);
 662                 memcpy(out + n + block_len, in + n + block_len,
 663                         n * sizeof(float));
 664         }
 665         out += pwd->block_len;
 666         in += pwd->block_len;
 667         /* right part */
 668         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 669                 block_len = pwd->block_len;
 670                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 671                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 672         } else {
 673                 block_len = 1 << pwd->next_block_len_bits;
 674                 n = (pwd->block_len - block_len) / 2;
 675                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 676                 memcpy(out, in, n * sizeof(float));
 677                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 678                         block_len);
 679                 memset(out + n + block_len, 0, n * sizeof(float));
 680         }
 681 }
 682
 683 static int wma_total_gain_to_bits(int total_gain)
 684 {
 685         if (total_gain < 15)
 686                 return 13;
 687         else if (total_gain < 32)
 688                 return 12;
 689         else if (total_gain < 40)
 690                 return 11;
 691         else if (total_gain < 45)
 692                 return 10;
 693         else
 694                 return 9;
 695 }
 696
 697 static int compute_high_band_values(struct private_wmadec_data *pwd,
 698                 int bsize, int nb_coefs[MAX_CHANNELS])
 699 {
 700         int ch;
 701
 702         if (!pwd->use_noise_coding)
 703                 return 0;
 704         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 705                 int i, m, a;
 706                 if (!pwd->channel_coded[ch])
 707                         continue;
 708                 m = pwd->exponent_high_sizes[bsize];
 709                 for (i = 0; i < m; i++) {
 710                         a = get_bit(&pwd->gb);
 711                         pwd->high_band_coded[ch][i] = a;
 712                         if (!a)
 713                                 continue;
 714                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 715                 }
 716         }
 717         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 718                 int i, n, val;
 719                 if (!pwd->channel_coded[ch])
 720                         continue;
 721                 n = pwd->exponent_high_sizes[bsize];
 722                 val = (int)0x80000000;
 723                 for (i = 0; i < n; i++) {
 724                         if (!pwd->high_band_coded[ch][i])
 725                                 continue;
 726                         if (val == (int)0x80000000)
 727                                 val = get_bits(&pwd->gb, 7) - 19;
 728                         else {
 729                                 int code = get_vlc(&pwd->gb,
 730                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 731                                         HGAINMAX);
 732                                 if (code < 0)
 733                                         return code;
 734                                 val += code - 18;
 735                         }
 736                         pwd->high_band_values[ch][i] = val;
 737                 }
 738         }
 739         return 1;
 740 }
 741
 742 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 743                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 744 {
 745         int ch;
 746         float mdct_norm = 1.0 / (pwd->block_len / 2);
 747
 748         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 749                 int16_t *coefs1;
 750                 float *coefs, *exponents, mult, mult1, noise;
 751                 int i, j, n, n1, last_high_band, esize;
 752                 float exp_power[HIGH_BAND_MAX_SIZE];
 753
 754                 if (!pwd->channel_coded[ch])
 755                         continue;
 756                 coefs1 = pwd->coefs1[ch];
 757                 exponents = pwd->exponents[ch];
 758                 esize = pwd->exponents_bsize[ch];
 759                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 760                 mult *= mdct_norm;
 761                 coefs = pwd->coefs[ch];
 762                 if (!pwd->use_noise_coding) {
 763                         /* XXX: optimize more */
 764                         n = nb_coefs[ch];
 765                         for (i = 0; i < n; i++)
 766                                 *coefs++ = coefs1[i] *
 767                                         exponents[i << bsize >> esize] * mult;
 768                         n = pwd->block_len - pwd->coefs_end[bsize];
 769                         for (i = 0; i < n; i++)
 770                                 *coefs++ = 0.0;
 771                         continue;
 772                 }
 773                 n1 = pwd->exponent_high_sizes[bsize];
 774                 /* compute power of high bands */
 775                 exponents = pwd->exponents[ch] +
 776                         (pwd->high_band_start[bsize] << bsize);
 777                 last_high_band = 0; /* avoid warning */
 778                 for (j = 0; j < n1; j++) {
 779                         n = pwd->exponent_high_bands[
 780                                 pwd->frame_len_bits - pwd->block_len_bits][j];
 781                         if (pwd->high_band_coded[ch][j]) {
 782                                 float e2, val;
 783                                 e2 = 0;
 784                                 for (i = 0; i < n; i++) {
 785                                         val = exponents[i << bsize >> esize];
 786                                         e2 += val * val;
 787                                 }
 788                                 exp_power[j] = e2 / n;
 789                                 last_high_band = j;
 790                         }
 791                         exponents += n << bsize;
 792                 }
 793                 /* main freqs and high freqs */
 794                 exponents = pwd->exponents[ch];
 795                 for (j = -1; j < n1; j++) {
 796                         if (j < 0)
 797                                 n = pwd->high_band_start[bsize];
 798                         else
 799                                 n = pwd->exponent_high_bands[pwd->frame_len_bits
 800                                         - pwd->block_len_bits][j];
 801                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 802                                 /* use noise with specified power */
 803                                 mult1 = sqrt(exp_power[j]
 804                                         / exp_power[last_high_band]);
 805                                 /* XXX: use a table */
 806                                 mult1 *= pow(10, pwd->high_band_values[ch][j] * 0.05);
 807                                 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
 808                                 mult1 *= mdct_norm;
 809                                 for (i = 0; i < n; i++) {
 810                                         noise = pwd->noise_table[pwd->noise_index];
 811                                         pwd->noise_index = (pwd->noise_index + 1)
 812                                                 & (NOISE_TAB_SIZE - 1);
 813                                         *coefs++ = noise * exponents[
 814                                                 i << bsize >> esize] * mult1;
 815                                 }
 816                                 exponents += n << bsize;
 817                         } else {
 818                                 /* coded values + small noise */
 819                                 for (i = 0; i < n; i++) {
 820                                         noise = pwd->noise_table[pwd->noise_index];
 821                                         pwd->noise_index = (pwd->noise_index + 1)
 822                                                 & (NOISE_TAB_SIZE - 1);
 823                                         *coefs++ = ((*coefs1++) + noise) *
 824                                                 exponents[i << bsize >> esize]
 825                                                 * mult;
 826                                 }
 827                                 exponents += n << bsize;
 828                         }
 829                 }
 830                 /* very high freqs: noise */
 831                 n = pwd->block_len - pwd->coefs_end[bsize];
 832                 mult1 = mult * exponents[((-1 << bsize)) >> esize];
 833                 for (i = 0; i < n; i++) {
 834                         *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
 835                         pwd->noise_index = (pwd->noise_index + 1)
 836                                 & (NOISE_TAB_SIZE - 1);
 837                 }
 838         }
 839 }
 840
 841 /**
 842  * Returns 0 if OK, 1 if last block of frame, negative on uncorrectable
 843  * errors.
 844  */
 845 static int wma_decode_block(struct private_wmadec_data *pwd)
 846 {
 847         int ret, n, v, ch, code, bsize;
 848         int coef_nb_bits, total_gain;
 849         int nb_coefs[MAX_CHANNELS];
 850
 851         /* compute current block length */
 852         if (pwd->use_variable_block_len) {
 853                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 854
 855                 if (pwd->reset_block_lengths) {
 856                         pwd->reset_block_lengths = 0;
 857                         v = get_bits(&pwd->gb, n);
 858                         if (v >= pwd->nb_block_sizes)
 859                                 return -E_WMA_BLOCK_SIZE;
 860                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 861                         v = get_bits(&pwd->gb, n);
 862                         if (v >= pwd->nb_block_sizes)
 863                                 return -E_WMA_BLOCK_SIZE;
 864                         pwd->block_len_bits = pwd->frame_len_bits - v;
 865                 } else {
 866                         /* update block lengths */
 867                         pwd->prev_block_len_bits = pwd->block_len_bits;
 868                         pwd->block_len_bits = pwd->next_block_len_bits;
 869                 }
 870                 v = get_bits(&pwd->gb, n);
 871                 if (v >= pwd->nb_block_sizes)
 872                         return -E_WMA_BLOCK_SIZE;
 873                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 874         } else {
 875                 /* fixed block len */
 876                 pwd->next_block_len_bits = pwd->frame_len_bits;
 877                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 878                 pwd->block_len_bits = pwd->frame_len_bits;
 879         }
 880
 881         /* now check if the block length is coherent with the frame length */
 882         pwd->block_len = 1 << pwd->block_len_bits;
 883         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 884                 return -E_INCOHERENT_BLOCK_LEN;
 885
 886         if (pwd->ahi.channels == 2)
 887                 pwd->ms_stereo = get_bit(&pwd->gb);
 888         v = 0;
 889         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 890                 int a = get_bit(&pwd->gb);
 891                 pwd->channel_coded[ch] = a;
 892                 v |= a;
 893         }
 894
 895         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 896
 897         /* if no channel coded, no need to go further */
 898         /* XXX: fix potential framing problems */
 899         if (!v)
 900                 goto next;
 901
 902         /*
 903          * Read total gain and extract corresponding number of bits for coef
 904          * escape coding.
 905          */
 906         total_gain = 1;
 907         for (;;) {
 908                 int a = get_bits(&pwd->gb, 7);
 909                 total_gain += a;
 910                 if (a != 127)
 911                         break;
 912         }
 913
 914         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 915
 916         /* compute number of coefficients */
 917         n = pwd->coefs_end[bsize];
 918         for (ch = 0; ch < pwd->ahi.channels; ch++)
 919                 nb_coefs[ch] = n;
 920
 921         ret = compute_high_band_values(pwd, bsize, nb_coefs);
 922         if (ret < 0)
 923                 return ret;
 924
 925         /* exponents can be reused in short blocks. */
 926         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 927                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 928                         if (pwd->channel_coded[ch]) {
 929                                 if (pwd->use_exp_vlc) {
 930                                         ret = decode_exp_vlc(pwd, ch);
 931                                         if (ret < 0)
 932                                                 return ret;
 933                                 } else
 934                                         decode_exp_lsp(pwd, ch);
 935                                 pwd->exponents_bsize[ch] = bsize;
 936                         }
 937                 }
 938         }
 939
 940         /* parse spectral coefficients : just RLE encoding */
 941         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 942                 struct vlc *coef_vlc;
 943                 int level, run, tindex;
 944                 int16_t *ptr, *eptr;
 945                 const uint16_t *level_table, *run_table;
 946
 947                 if (!pwd->channel_coded[ch])
 948                         continue;
 949                 /*
 950                  * special VLC tables are used for ms stereo because there is
 951                  * potentially less energy there
 952                  */
 953                 tindex = (ch == 1 && pwd->ms_stereo);
 954                 coef_vlc = &pwd->coef_vlc[tindex];
 955                 run_table = pwd->run_table[tindex];
 956                 level_table = pwd->level_table[tindex];
 957                 /* XXX: optimize */
 958                 ptr = &pwd->coefs1[ch][0];
 959                 eptr = ptr + nb_coefs[ch];
 960                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 961                 for (;;) {
 962                         code = get_vlc(&pwd->gb, coef_vlc->table,
 963                                 VLCBITS, VLCMAX);
 964                         if (code < 0)
 965                                 return code;
 966                         if (code == 1) /* EOB */
 967                                 break;
 968                         if (code == 0) { /* escape */
 969                                 level = get_bits(&pwd->gb, coef_nb_bits);
 970                                 /* reading block_len_bits would be better */
 971                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 972                         } else { /* normal code */
 973                                 run = run_table[code];
 974                                 level = level_table[code];
 975                         }
 976                         if (!get_bit(&pwd->gb))
 977                                 level = -level;
 978                         ptr += run;
 979                         if (ptr >= eptr) {
 980                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 981                                 break;
 982                         }
 983                         *ptr++ = level;
 984                         if (ptr >= eptr) /* EOB can be omitted */
 985                                 break;
 986                 }
 987         }
 988         compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
 989         if (pwd->ms_stereo && pwd->channel_coded[1]) {
 990                 float a, b;
 991                 int i;
 992                 /*
 993                  * Nominal case for ms stereo: we do it before mdct.
 994                  *
 995                  * No need to optimize this case because it should almost never
 996                  * happen.
 997                  */
 998                 if (!pwd->channel_coded[0]) {
 999                         PARA_NOTICE_LOG("rare ms-stereo\n");
1000                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1001                         pwd->channel_coded[0] = 1;
1002                 }
1003                 for (i = 0; i < pwd->block_len; i++) {
1004                         a = pwd->coefs[0][i];
1005                         b = pwd->coefs[1][i];
1006                         pwd->coefs[0][i] = a + b;
1007                         pwd->coefs[1][i] = a - b;
1008                 }
1009         }
1010 next:
1011         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1012                 int n4, idx;
1013
1014                 n4 = pwd->block_len / 2;
1015                 if (pwd->channel_coded[ch])
1016                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1017                 else if (!(pwd->ms_stereo && ch == 1))
1018                         memset(pwd->output, 0, sizeof(pwd->output));
1019
1020                 /* multiply by the window and add in the frame */
1021                 idx = (pwd->frame_len / 2) + pwd->block_pos - n4;
1022                 wma_window(pwd, &pwd->frame_out[ch][idx]);
1023         }
1024
1025         /* update block number */
1026         pwd->block_pos += pwd->block_len;
1027         if (pwd->block_pos >= pwd->frame_len)
1028                 return 1;
1029         else
1030                 return 0;
1031 }
1032
1033 /*
1034  * Clip a signed integer value into the -32768,32767 range.
1035  *
1036  * \param a The value to clip.
1037  *
1038  * \return The clipped value.
1039  */
1040 static inline int16_t av_clip_int16(int a)
1041 {
1042         if ((a + 32768) & ~65535)
1043                 return (a >> 31) ^ 32767;
1044         else
1045                 return a;
1046 }
1047
1048 /* Decode a frame of frame_len samples. */
1049 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1050 {
1051         int ret, i, n, ch, incr;
1052         int16_t *ptr;
1053         float *iptr;
1054
1055         /* read each block */
1056         pwd->block_pos = 0;
1057         for (;;) {
1058                 ret = wma_decode_block(pwd);
1059                 if (ret < 0)
1060                         return ret;
1061                 if (ret)
1062                         break;
1063         }
1064
1065         /* convert frame to integer */
1066         n = pwd->frame_len;
1067         incr = pwd->ahi.channels;
1068         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1069                 ptr = samples + ch;
1070                 iptr = pwd->frame_out[ch];
1071
1072                 for (i = 0; i < n; i++) {
1073                         *ptr = av_clip_int16(lrintf(*iptr++));
1074                         ptr += incr;
1075                 }
1076                 /* prepare for next block */
1077                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1078                         pwd->frame_len * sizeof(float));
1079         }
1080         return 0;
1081 }
1082
1083 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1084                 int *data_size, const uint8_t *buf, int buf_size)
1085 {
1086         int ret;
1087         int16_t *samples;
1088
1089         if (buf_size == 0) {
1090                 pwd->last_superframe_len = 0;
1091                 return 0;
1092         }
1093         if (buf_size < pwd->ahi.block_align)
1094                 return 0;
1095         buf_size = pwd->ahi.block_align;
1096         samples = data;
1097         init_get_bits(&pwd->gb, buf, buf_size);
1098         if (pwd->use_bit_reservoir) {
1099                 int i, nb_frames, bit_offset, pos, len;
1100                 uint8_t *q;
1101
1102                 /* read super frame header */
1103                 skip_bits(&pwd->gb, 4); /* super frame index */
1104                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1105                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1106                 ret = -E_WMA_OUTPUT_SPACE;
1107                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1108                                 * sizeof(int16_t) > *data_size)
1109                         goto fail;
1110
1111                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1112
1113                 if (pwd->last_superframe_len > 0) {
1114                         /* add bit_offset bits to last frame */
1115                         ret = -E_WMA_BAD_SUPERFRAME;
1116                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1117                                         MAX_CODED_SUPERFRAME_SIZE)
1118                                 goto fail;
1119                         q = pwd->last_superframe + pwd->last_superframe_len;
1120                         len = bit_offset;
1121                         while (len > 7) {
1122                                 *q++ = get_bits(&pwd->gb, 8);
1123                                 len -= 8;
1124                         }
1125                         if (len > 0)
1126                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1127
1128                         /* XXX: bit_offset bits into last frame */
1129                         init_get_bits(&pwd->gb, pwd->last_superframe,
1130                                 MAX_CODED_SUPERFRAME_SIZE);
1131                         /* skip unused bits */
1132                         if (pwd->last_bitoffset > 0)
1133                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1134                         /*
1135                          * This frame is stored in the last superframe and in
1136                          * the current one.
1137                          */
1138                         ret = wma_decode_frame(pwd, samples);
1139                         if (ret < 0)
1140                                 goto fail;
1141                         samples += pwd->ahi.channels * pwd->frame_len;
1142                 }
1143
1144                 /* read each frame starting from bit_offset */
1145                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1146                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1147                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1148                 len = pos & 7;
1149                 if (len > 0)
1150                         skip_bits(&pwd->gb, len);
1151
1152                 pwd->reset_block_lengths = 1;
1153                 for (i = 0; i < nb_frames; i++) {
1154                         ret = wma_decode_frame(pwd, samples);
1155                         if (ret < 0)
1156                                 goto fail;
1157                         samples += pwd->ahi.channels * pwd->frame_len;
1158                 }
1159
1160                 /* we copy the end of the frame in the last frame buffer */
1161                 pos = get_bits_count(&pwd->gb) +
1162                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1163                 pwd->last_bitoffset = pos & 7;
1164                 pos >>= 3;
1165                 len = buf_size - pos;
1166                 ret = -E_WMA_BAD_SUPERFRAME;
1167                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1168                         goto fail;
1169                 pwd->last_superframe_len = len;
1170                 memcpy(pwd->last_superframe, buf + pos, len);
1171         } else {
1172                 PARA_DEBUG_LOG("not using bit reservoir\n");
1173                 ret = -E_WMA_OUTPUT_SPACE;
1174                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1175                         goto fail;
1176                 /* single frame decode */
1177                 ret = wma_decode_frame(pwd, samples);
1178                 if (ret < 0)
1179                         goto fail;
1180                 samples += pwd->ahi.channels * pwd->frame_len;
1181         }
1182         PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %d, eaten: %d\n",
1183                 pwd->frame_len, pwd->block_len,
1184                 (int)((int8_t *)samples - (int8_t *)data), pwd->ahi.block_align);
1185         *data_size = (int8_t *)samples - (int8_t *)data;
1186         return pwd->ahi.block_align;
1187 fail:
1188         /* reset the bit reservoir on errors */
1189         pwd->last_superframe_len = 0;
1190         return ret;
1191 }
1192
1193 static void wmadec_close(struct filter_node *fn)
1194 {
1195         struct private_wmadec_data *pwd = fn->private_data;
1196
1197         if (!pwd)
1198                 return;
1199         wmadec_cleanup(pwd);
1200         free(fn->private_data);
1201         fn->private_data = NULL;
1202 }
1203
1204 static int wmadec_execute(struct btr_node *btrn, const char *cmd, char **result)
1205 {
1206         struct filter_node *fn = btr_context(btrn);
1207         struct private_wmadec_data *pwd = fn->private_data;
1208
1209         return decoder_execute(cmd, pwd->ahi.sample_rate, pwd->ahi.channels,
1210                 result);
1211 }
1212
1213 #define WMA_OUTPUT_BUFFER_SIZE (128 * 1024)
1214
1215 static void wmadec_post_select(__a_unused struct sched *s, struct task *t)
1216 {
1217         struct filter_node *fn = container_of(t, struct filter_node, task);
1218         int ret, converted;
1219         struct private_wmadec_data *pwd = fn->private_data;
1220         struct btr_node *btrn = fn->btrn;
1221         size_t len;
1222         char *in;
1223
1224 next_buffer:
1225         converted = 0;
1226         t->error = 0;
1227         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
1228         if (ret < 0)
1229                 goto err;
1230         if (ret == 0)
1231                 return;
1232         btr_merge(btrn, fn->min_iqs);
1233         len = btr_next_buffer(btrn, (char **)&in);
1234         ret = -E_WMADEC_EOF;
1235         if (len < fn->min_iqs)
1236                 goto err;
1237         if (!pwd) {
1238                 ret = wma_decode_init(in, len, &pwd);
1239                 if (ret < 0)
1240                         goto err;
1241                 if (ret == 0) {
1242                         fn->min_iqs += 4096;
1243                         goto next_buffer;
1244                 }
1245                 fn->min_iqs = 2 * (WMA_FRAME_SKIP + pwd->ahi.block_align);
1246                 fn->private_data = pwd;
1247                 converted = pwd->ahi.header_len;
1248                 goto success;
1249         }
1250         fn->min_iqs = WMA_FRAME_SKIP + pwd->ahi.block_align;
1251         for (;;) {
1252                 char *out;
1253                 int out_size = WMA_OUTPUT_BUFFER_SIZE;
1254                 if (converted + fn->min_iqs > len)
1255                         break;
1256                 out = para_malloc(WMA_OUTPUT_BUFFER_SIZE);
1257                 ret = wma_decode_superframe(pwd, out,
1258                         &out_size, (uint8_t *)in + converted + WMA_FRAME_SKIP,
1259                         len - WMA_FRAME_SKIP);
1260                 if (ret < 0) {
1261                         free(out);
1262                         goto err;
1263                 }
1264                 btr_add_output(out, out_size, btrn);
1265                 converted += ret + WMA_FRAME_SKIP;
1266         }
1267 success:
1268         btr_consume(btrn, converted);
1269         return;
1270 err:
1271         assert(ret < 0);
1272         t->error = ret;
1273         btr_remove_node(btrn);
1274 }
1275
1276 static void wmadec_open(struct filter_node *fn)
1277 {
1278         fn->private_data = NULL;
1279         fn->min_iqs = 4096;
1280 }
1281
1282 /**
1283  * The init function of the wma decoder.
1284  *
1285  * \param f Its fields are filled in by the function.
1286  */
1287 void wmadec_filter_init(struct filter *f)
1288 {
1289         f->open = wmadec_open;
1290         f->close = wmadec_close;
1291         f->execute = wmadec_execute;
1292         f->pre_select = generic_filter_pre_select;
1293         f->post_select = wmadec_post_select;
1294 }