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