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