wmadec_filter.c

   1 /*
   2  * WMA compatible decoder
   3  *
   4  * Extracted 2009 from the mplayer source code 2009-02-10.
   5  *
   6  * Copyright (c) 2002 The FFmpeg Project
   7  *
   8  * Licensed under the GNU Lesser General Public License.
   9  * For licencing details see COPYING.LIB.
  10  */
  11
  12 /** \file wmadec_filter.c paraslash's WMA decoder. */
  13
  14 /*
  15  * This decoder handles Microsoft Windows Media Audio data version 2.
  16  */
  17
  18 #define _XOPEN_SOURCE 600
  19
  20 #include <sys/time.h>
  21 #include <inttypes.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <math.h>
  25 #include <string.h>
  26 #include <regex.h>
  27 #include <sys/select.h>
  28
  29 #include "para.h"
  30 #include "error.h"
  31 #include "list.h"
  32 #include "ggo.h"
  33 #include "string.h"
  34 #include "sched.h"
  35 #include "buffer_tree.h"
  36 #include "filter.h"
  37 #include "bitstream.h"
  38 #include "imdct.h"
  39 #include "wma.h"
  40 #include "wmadata.h"
  41
  42
  43 /* size of blocks */
  44 #define BLOCK_MIN_BITS 7
  45 #define BLOCK_MAX_BITS 11
  46 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  47
  48 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  49
  50 /* XXX: find exact max size */
  51 #define HIGH_BAND_MAX_SIZE 16
  52
  53 /* XXX: is it a suitable value ? */
  54 #define MAX_CODED_SUPERFRAME_SIZE 16384
  55
  56 #define MAX_CHANNELS 2
  57
  58 #define NOISE_TAB_SIZE 8192
  59
  60 #define LSP_POW_BITS 7
  61
  62 struct private_wmadec_data {
  63         /** Information contained in the audio file header. */
  64         struct asf_header_info ahi;
  65         struct getbit_context gb;
  66         /** Whether to use the bit reservoir. */
  67         int use_bit_reservoir;
  68         /** Whether to use variable block length. */
  69         int use_variable_block_len;
  70         /** Whether to use exponent coding. */
  71         int use_exp_vlc;
  72         /** Whether perceptual noise is added. */
  73         int use_noise_coding;
  74         /** Depends on number of the bits per second and the frame length. */
  75         int byte_offset_bits;
  76         /** Only used if use_exp_vlc is true. */
  77         struct vlc exp_vlc;
  78         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  79         /** The index of the first coef in high band. */
  80         int high_band_start[BLOCK_NB_SIZES];
  81         /** Maximal number of coded coefficients. */
  82         int coefs_end[BLOCK_NB_SIZES];
  83         int exponent_high_sizes[BLOCK_NB_SIZES];
  84         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  85         struct vlc hgain_vlc;
  86
  87         /* coded values in high bands */
  88         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  89         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  90
  91         /* there are two possible tables for spectral coefficients */
  92         struct vlc coef_vlc[2];
  93         uint16_t *run_table[2];
  94         uint16_t *level_table[2];
  95         const struct coef_vlc_table *coef_vlcs[2];
  96         /** Frame length in samples. */
  97         int frame_len;
  98         /** log2 of frame_len. */
  99         int frame_len_bits;
 100         /** Number of block sizes. */
 101         int nb_block_sizes;
 102         /* block info */
 103         int reset_block_lengths;
 104         /** log2 of current block length. */
 105         int block_len_bits;
 106         /** log2 of next block length. */
 107         int next_block_len_bits;
 108         /** log2 of previous block length. */
 109         int prev_block_len_bits;
 110         /** Block length in samples. */
 111         int block_len;
 112         /** Current position in frame. */
 113         int block_pos;
 114         /** True if mid/side stereo mode. */
 115         uint8_t ms_stereo;
 116         /** True if channel is coded. */
 117         uint8_t channel_coded[MAX_CHANNELS];
 118         /** log2 ratio frame/exp. length. */
 119         int exponents_bsize[MAX_CHANNELS];
 120
 121         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 122         float max_exponent[MAX_CHANNELS];
 123         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 124         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 125         float output[BLOCK_MAX_SIZE * 2];
 126         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 127         float *windows[BLOCK_NB_SIZES];
 128         /** Output buffer for one frame and the last for IMDCT windowing. */
 129         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 130         /** Last frame info. */
 131         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 132         int last_bitoffset;
 133         int last_superframe_len;
 134         float noise_table[NOISE_TAB_SIZE];
 135         int noise_index;
 136         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 137         /* lsp_to_curve tables */
 138         float lsp_cos_table[BLOCK_MAX_SIZE];
 139         float lsp_pow_e_table[256];
 140         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 141         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 142 };
 143
 144 #define EXPVLCBITS 8
 145 #define EXPMAX DIV_ROUND_UP(19, EXPVLCBITS)
 146
 147 #define HGAINVLCBITS 9
 148 #define HGAINMAX DIV_ROUND_UP(13, HGAINVLCBITS)
 149
 150 #define VLCBITS 9
 151 #define VLCMAX DIV_ROUND_UP(22, VLCBITS)
 152
 153 #define SINE_WINDOW(x) static float sine_ ## x[x] __a_aligned(16)
 154
 155 SINE_WINDOW(128);
 156 SINE_WINDOW(256);
 157 SINE_WINDOW(512);
 158 SINE_WINDOW(1024);
 159 SINE_WINDOW(2048);
 160 SINE_WINDOW(4096);
 161
 162 static float *sine_windows[6] = {
 163         sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
 164 };
 165
 166 /* Generate a sine window. */
 167 static void sine_window_init(float *window, int n)
 168 {
 169         int i;
 170
 171         for (i = 0; i < n; i++)
 172                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 173 }
 174
 175 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 176 {
 177         int i;
 178
 179         for (i = 0; i < pwd->nb_block_sizes; i++)
 180                 imdct_end(pwd->mdct_ctx[i]);
 181         if (pwd->use_exp_vlc)
 182                 free_vlc(&pwd->exp_vlc);
 183         if (pwd->use_noise_coding)
 184                 free_vlc(&pwd->hgain_vlc);
 185         for (i = 0; i < 2; i++) {
 186                 free_vlc(&pwd->coef_vlc[i]);
 187                 free(pwd->run_table[i]);
 188                 free(pwd->level_table[i]);
 189         }
 190 }
 191
 192 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 193                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 194 {
 195         int n = vlc_table->n;
 196         const uint8_t *table_bits = vlc_table->huffbits;
 197         const uint32_t *table_codes = vlc_table->huffcodes;
 198         const uint16_t *levels_table = vlc_table->levels;
 199         uint16_t *run_table, *level_table;
 200         int i, l, j, k, level;
 201
 202         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 203
 204         run_table = para_malloc(n * sizeof(uint16_t));
 205         level_table = para_malloc(n * sizeof(uint16_t));
 206         i = 2;
 207         level = 1;
 208         k = 0;
 209         while (i < n) {
 210                 l = levels_table[k++];
 211                 for (j = 0; j < l; j++) {
 212                         run_table[i] = j;
 213                         level_table[i] = level;
 214                         i++;
 215                 }
 216                 level++;
 217         }
 218         *prun_table = run_table;
 219         *plevel_table = level_table;
 220 }
 221
 222 /* compute the scale factor band sizes for each MDCT block size */
 223 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 224         float high_freq)
 225 {
 226         struct asf_header_info *ahi = &pwd->ahi;
 227         int a, b, pos, lpos, k, block_len, i, j, n;
 228         const uint8_t *table;
 229
 230         for (k = 0; k < pwd->nb_block_sizes; k++) {
 231                 int exponent_size;
 232
 233                 block_len = pwd->frame_len >> k;
 234                 table = NULL;
 235                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 236                 if (a < 3) {
 237                         if (ahi->sample_rate >= 44100)
 238                                 table = exponent_band_44100[a];
 239                         else if (ahi->sample_rate >= 32000)
 240                                 table = exponent_band_32000[a];
 241                         else if (ahi->sample_rate >= 22050)
 242                                 table = exponent_band_22050[a];
 243                 }
 244                 if (table) {
 245                         n = *table++;
 246                         for (i = 0; i < n; i++)
 247                                 pwd->exponent_bands[k][i] = table[i];
 248                         exponent_size = n;
 249                 } else {
 250                         j = 0;
 251                         lpos = 0;
 252                         for (i = 0; i < 25; i++) {
 253                                 a = wma_critical_freqs[i];
 254                                 b = ahi->sample_rate;
 255                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 256                                 pos <<= 2;
 257                                 if (pos > block_len)
 258                                         pos = block_len;
 259                                 if (pos > lpos)
 260                                         pwd->exponent_bands[k][j++] = pos - lpos;
 261                                 if (pos >= block_len)
 262                                         break;
 263                                 lpos = pos;
 264                         }
 265                         exponent_size = j;
 266                 }
 267
 268                 /* max number of coefs */
 269                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 270                 /* high freq computation */
 271                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 272                         / ahi->sample_rate + 0.5);
 273                 n = exponent_size;
 274                 j = 0;
 275                 pos = 0;
 276                 for (i = 0; i < n; i++) {
 277                         int start, end;
 278                         start = pos;
 279                         pos += pwd->exponent_bands[k][i];
 280                         end = pos;
 281                         if (start < pwd->high_band_start[k])
 282                                 start = pwd->high_band_start[k];
 283                         if (end > pwd->coefs_end[k])
 284                                 end = pwd->coefs_end[k];
 285                         if (end > start)
 286                                 pwd->exponent_high_bands[k][j++] = end - start;
 287                 }
 288                 pwd->exponent_high_sizes[k] = j;
 289         }
 290 }
 291
 292 static int wma_init(struct private_wmadec_data *pwd)
 293 {
 294         int i;
 295         float bps1, high_freq;
 296         volatile float bps;
 297         int sample_rate1;
 298         int coef_vlc_table;
 299         struct asf_header_info *ahi = &pwd->ahi;
 300         int flags2 = ahi->flags2;
 301
 302         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 303                 || ahi->channels <= 0 || ahi->channels > 8
 304                 || ahi->bit_rate <= 0)
 305                 return -E_WMA_BAD_PARAMS;
 306
 307         /* compute MDCT block size */
 308         if (ahi->sample_rate <= 16000)
 309                 pwd->frame_len_bits = 9;
 310         else if (ahi->sample_rate <= 22050)
 311                 pwd->frame_len_bits = 10;
 312         else
 313                 pwd->frame_len_bits = 11;
 314         pwd->frame_len = 1 << pwd->frame_len_bits;
 315         if (pwd->use_variable_block_len) {
 316                 int nb_max, nb;
 317                 nb = ((flags2 >> 3) & 3) + 1;
 318                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 319                         nb += 2;
 320                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 321                 if (nb > nb_max)
 322                         nb = nb_max;
 323                 pwd->nb_block_sizes = nb + 1;
 324         } else
 325                 pwd->nb_block_sizes = 1;
 326
 327         /* init rate dependent parameters */
 328         pwd->use_noise_coding = 1;
 329         high_freq = ahi->sample_rate * 0.5;
 330
 331         /* wma2 rates are normalized */
 332         sample_rate1 = ahi->sample_rate;
 333         if (sample_rate1 >= 44100)
 334                 sample_rate1 = 44100;
 335         else if (sample_rate1 >= 22050)
 336                 sample_rate1 = 22050;
 337         else if (sample_rate1 >= 16000)
 338                 sample_rate1 = 16000;
 339         else if (sample_rate1 >= 11025)
 340                 sample_rate1 = 11025;
 341         else if (sample_rate1 >= 8000)
 342                 sample_rate1 = 8000;
 343
 344         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 345         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 346         /*
 347          * Compute high frequency value and choose if noise coding should be
 348          * activated.
 349          */
 350         bps1 = bps;
 351         if (ahi->channels == 2)
 352                 bps1 = bps * 1.6;
 353         if (sample_rate1 == 44100) {
 354                 if (bps1 >= 0.61)
 355                         pwd->use_noise_coding = 0;
 356                 else
 357                         high_freq = high_freq * 0.4;
 358         } else if (sample_rate1 == 22050) {
 359                 if (bps1 >= 1.16)
 360                         pwd->use_noise_coding = 0;
 361                 else if (bps1 >= 0.72)
 362                         high_freq = high_freq * 0.7;
 363                 else
 364                         high_freq = high_freq * 0.6;
 365         } else if (sample_rate1 == 16000) {
 366                 if (bps > 0.5)
 367                         high_freq = high_freq * 0.5;
 368                 else
 369                         high_freq = high_freq * 0.3;
 370         } else if (sample_rate1 == 11025)
 371                 high_freq = high_freq * 0.7;
 372         else if (sample_rate1 == 8000) {
 373                 if (bps <= 0.625)
 374                         high_freq = high_freq * 0.5;
 375                 else if (bps > 0.75)
 376                         pwd->use_noise_coding = 0;
 377                 else
 378                         high_freq = high_freq * 0.65;
 379         } else {
 380                 if (bps >= 0.8)
 381                         high_freq = high_freq * 0.75;
 382                 else if (bps >= 0.6)
 383                         high_freq = high_freq * 0.6;
 384                 else
 385                         high_freq = high_freq * 0.5;
 386         }
 387         PARA_INFO_LOG("channels=%d sample_rate=%d "
 388                 "bitrate=%d block_align=%d\n",
 389                 ahi->channels, ahi->sample_rate,
 390                 ahi->bit_rate, ahi->block_align);
 391         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 392                 "high_freq=%f bitoffset=%d\n",
 393                 pwd->frame_len, bps, bps1,
 394                 high_freq, pwd->byte_offset_bits);
 395         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 396                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 397
 398         compute_scale_factor_band_sizes(pwd, high_freq);
 399         /* init MDCT windows : simple sinus window */
 400         for (i = 0; i < pwd->nb_block_sizes; i++) {
 401                 int n;
 402                 n = 1 << (pwd->frame_len_bits - i);
 403                 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
 404                 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
 405         }
 406
 407         pwd->reset_block_lengths = 1;
 408
 409         if (pwd->use_noise_coding) {
 410                 /* init the noise generator */
 411                 if (pwd->use_exp_vlc)
 412                         pwd->noise_mult = 0.02;
 413                 else
 414                         pwd->noise_mult = 0.04;
 415
 416                 {
 417                         unsigned int seed;
 418                         float norm;
 419                         seed = 1;
 420                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 421                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 422                                 seed = seed * 314159 + 1;
 423                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 424                         }
 425                 }
 426         }
 427
 428         /* choose the VLC tables for the coefficients */
 429         coef_vlc_table = 2;
 430         if (ahi->sample_rate >= 32000) {
 431                 if (bps1 < 0.72)
 432                         coef_vlc_table = 0;
 433                 else if (bps1 < 1.16)
 434                         coef_vlc_table = 1;
 435         }
 436         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 437         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 438         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 439                 pwd->coef_vlcs[0]);
 440         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 441                 pwd->coef_vlcs[1]);
 442         return 0;
 443 }
 444
 445 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 446 {
 447         float wdel, a, b;
 448         int i, e, m;
 449
 450         wdel = M_PI / frame_len;
 451         for (i = 0; i < frame_len; i++)
 452                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 453
 454         /* tables for x^-0.25 computation */
 455         for (i = 0; i < 256; i++) {
 456                 e = i - 126;
 457                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 458         }
 459
 460         /* These two tables are needed to avoid two operations in pow_m1_4. */
 461         b = 1.0;
 462         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 463                 m = (1 << LSP_POW_BITS) + i;
 464                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 465                 a = pow(a, -0.25);
 466                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 467                 pwd->lsp_pow_m_table2[i] = b - a;
 468                 b = a;
 469         }
 470 }
 471
 472 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 473 {
 474         struct private_wmadec_data *pwd;
 475         int ret, i;
 476
 477         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 478         pwd = para_calloc(sizeof(*pwd));
 479         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 480         if (ret <= 0) {
 481                 free(pwd);
 482                 return ret;
 483         }
 484
 485         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 486         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 487         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 488
 489         ret = wma_init(pwd);
 490         if (ret < 0)
 491                 return ret;
 492         /* init MDCT */
 493         for (i = 0; i < pwd->nb_block_sizes; i++) {
 494                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 495                 if (ret < 0)
 496                         return ret;
 497         }
 498         if (pwd->use_noise_coding) {
 499                 PARA_INFO_LOG("using noise coding\n");
 500                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 501                         sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
 502                         wma_hgain_huffcodes, 2);
 503         }
 504
 505         if (pwd->use_exp_vlc) {
 506                 PARA_INFO_LOG("using exp_vlc\n");
 507                 init_vlc(&pwd->exp_vlc, EXPVLCBITS, sizeof(wma_scale_huffbits),
 508                         wma_scale_huffbits, wma_scale_huffcodes, 4);
 509         } else {
 510                 PARA_INFO_LOG("using curve\n");
 511                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 512         }
 513         *result = pwd;
 514         return pwd->ahi.header_len;
 515 }
 516
 517 /**
 518  * compute x^-0.25 with an exponent and mantissa table. We use linear
 519  * interpolation to reduce the mantissa table size at a small speed
 520  * expense (linear interpolation approximately doubles the number of
 521  * bits of precision).
 522  */
 523 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 524 {
 525         union {
 526                 float f;
 527                 unsigned int v;
 528         } u, t;
 529         unsigned int e, m;
 530         float a, b;
 531
 532         u.f = x;
 533         e = u.v >> 23;
 534         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 535         /* build interpolation scale: 1 <= t < 2. */
 536         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 537         a = pwd->lsp_pow_m_table1[m];
 538         b = pwd->lsp_pow_m_table2[m];
 539         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 540 }
 541
 542 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 543                 float *out, float *val_max_ptr, int n, float *lsp)
 544 {
 545         int i, j;
 546         float p, q, w, v, val_max;
 547
 548         val_max = 0;
 549         for (i = 0; i < n; i++) {
 550                 p = 0.5f;
 551                 q = 0.5f;
 552                 w = pwd->lsp_cos_table[i];
 553                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 554                         q *= w - lsp[j - 1];
 555                         p *= w - lsp[j];
 556                 }
 557                 p *= p * (2.0f - w);
 558                 q *= q * (2.0f + w);
 559                 v = p + q;
 560                 v = pow_m1_4(pwd, v);
 561                 if (v > val_max)
 562                         val_max = v;
 563                 out[i] = v;
 564         }
 565         *val_max_ptr = val_max;
 566 }
 567
 568 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 569 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 570 {
 571         float lsp_coefs[NB_LSP_COEFS];
 572         int val, i;
 573
 574         for (i = 0; i < NB_LSP_COEFS; i++) {
 575                 if (i == 0 || i >= 8)
 576                         val = get_bits(&pwd->gb, 3);
 577                 else
 578                         val = get_bits(&pwd->gb, 4);
 579                 lsp_coefs[i] = wma_lsp_codebook[i][val];
 580         }
 581
 582         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 583                 pwd->block_len, lsp_coefs);
 584 }
 585
 586 /* Decode exponents coded with VLC codes. */
 587 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 588 {
 589         int last_exp, n, code;
 590         const uint16_t *ptr, *band_ptr;
 591         float v, *q, max_scale, *q_end;
 592
 593         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 594         ptr = band_ptr;
 595         q = pwd->exponents[ch];
 596         q_end = q + pwd->block_len;
 597         max_scale = 0;
 598         last_exp = 36;
 599
 600         while (q < q_end) {
 601                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 602                 if (code < 0)
 603                         return code;
 604                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 605                 last_exp += code - 60;
 606                 /* XXX: use a table */
 607                 v = pow(10, last_exp * (1.0 / 16.0));
 608                 if (v > max_scale)
 609                         max_scale = v;
 610                 n = *ptr++;
 611                 do {
 612                         *q++ = v;
 613                 } while (--n);
 614         }
 615         pwd->max_exponent[ch] = max_scale;
 616         return 0;
 617 }
 618
 619 /* compute src0 * src1 + src2 */
 620 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 621                 const float *src2, int len)
 622 {
 623         int i;
 624
 625         for (i = 0; i < len; i++)
 626                 dst[i] = src0[i] * src1[i] + src2[i];
 627 }
 628
 629 static inline void vector_mult_reverse(float *dst, const float *src0,
 630                 const float *src1, int len)
 631 {
 632         int i;
 633
 634         src1 += len - 1;
 635         for (i = 0; i < len; i++)
 636                 dst[i] = src0[i] * src1[-i];
 637 }
 638
 639 /**
 640  * Apply MDCT window and add into output.
 641  *
 642  * We ensure that when the windows overlap their squared sum
 643  * is always 1 (MDCT reconstruction rule).
 644  */
 645 static void wma_window(struct private_wmadec_data *pwd, float *out)
 646 {
 647         float *in = pwd->output;
 648         int block_len, bsize, n;
 649
 650         /* left part */
 651         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 652                 block_len = pwd->block_len;
 653                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 654                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 655         } else {
 656                 block_len = 1 << pwd->prev_block_len_bits;
 657                 n = (pwd->block_len - block_len) / 2;
 658                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 659                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 660                         block_len);
 661                 memcpy(out + n + block_len, in + n + block_len,
 662                         n * sizeof(float));
 663         }
 664         out += pwd->block_len;
 665         in += pwd->block_len;
 666         /* right part */
 667         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 668                 block_len = pwd->block_len;
 669                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 670                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 671         } else {
 672                 block_len = 1 << pwd->next_block_len_bits;
 673                 n = (pwd->block_len - block_len) / 2;
 674                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 675                 memcpy(out, in, n * sizeof(float));
 676                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 677                         block_len);
 678                 memset(out + n + block_len, 0, n * sizeof(float));
 679         }
 680 }
 681
 682 static int wma_total_gain_to_bits(int total_gain)
 683 {
 684         if (total_gain < 15)
 685                 return 13;
 686         else if (total_gain < 32)
 687                 return 12;
 688         else if (total_gain < 40)
 689                 return 11;
 690         else if (total_gain < 45)
 691                 return 10;
 692         else
 693                 return 9;
 694 }
 695
 696 static int compute_high_band_values(struct private_wmadec_data *pwd,
 697                 int bsize, int nb_coefs[MAX_CHANNELS])
 698 {
 699         int ch;
 700
 701         if (!pwd->use_noise_coding)
 702                 return 0;
 703         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 704                 int i, m, a;
 705                 if (!pwd->channel_coded[ch])
 706                         continue;
 707                 m = pwd->exponent_high_sizes[bsize];
 708                 for (i = 0; i < m; i++) {
 709                         a = get_bit(&pwd->gb);
 710                         pwd->high_band_coded[ch][i] = a;
 711                         if (!a)
 712                                 continue;
 713                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 714                 }
 715         }
 716         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 717                 int i, n, val;
 718                 if (!pwd->channel_coded[ch])
 719                         continue;
 720                 n = pwd->exponent_high_sizes[bsize];
 721                 val = (int)0x80000000;
 722                 for (i = 0; i < n; i++) {
 723                         if (!pwd->high_band_coded[ch][i])
 724                                 continue;
 725                         if (val == (int)0x80000000)
 726                                 val = get_bits(&pwd->gb, 7) - 19;
 727                         else {
 728                                 int code = get_vlc(&pwd->gb,
 729                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 730                                         HGAINMAX);
 731                                 if (code < 0)
 732                                         return code;
 733                                 val += code - 18;
 734                         }
 735                         pwd->high_band_values[ch][i] = val;
 736                 }
 737         }
 738         return 1;
 739 }
 740
 741 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 742                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 743 {
 744         int ch;
 745         float mdct_norm = 1.0 / (pwd->block_len / 2);
 746
 747         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 748                 int16_t *coefs1;
 749                 float *coefs, *exponents, mult, mult1, noise;
 750                 int i, j, n, n1, last_high_band, esize;
 751                 float exp_power[HIGH_BAND_MAX_SIZE];
 752
 753                 if (!pwd->channel_coded[ch])
 754                         continue;
 755                 coefs1 = pwd->coefs1[ch];
 756                 exponents = pwd->exponents[ch];
 757                 esize = pwd->exponents_bsize[ch];
 758                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 759                 mult *= mdct_norm;
 760                 coefs = pwd->coefs[ch];
 761                 if (!pwd->use_noise_coding) {
 762                         /* XXX: optimize more */
 763                         n = nb_coefs[ch];
 764                         for (i = 0; i < n; i++)
 765                                 *coefs++ = coefs1[i] *
 766                                         exponents[i << bsize >> esize] * mult;
 767                         n = pwd->block_len - pwd->coefs_end[bsize];
 768                         for (i = 0; i < n; i++)
 769                                 *coefs++ = 0.0;
 770                         continue;
 771                 }
 772                 n1 = pwd->exponent_high_sizes[bsize];
 773                 /* compute power of high bands */
 774                 exponents = pwd->exponents[ch] +
 775                         (pwd->high_band_start[bsize] << bsize);
 776                 last_high_band = 0; /* avoid warning */
 777                 for (j = 0; j < n1; j++) {
 778                         n = pwd->exponent_high_bands[
 779                                 pwd->frame_len_bits - pwd->block_len_bits][j];
 780                         if (pwd->high_band_coded[ch][j]) {
 781                                 float e2, val;
 782                                 e2 = 0;
 783                                 for (i = 0; i < n; i++) {
 784                                         val = exponents[i << bsize >> esize];
 785                                         e2 += val * val;
 786                                 }
 787                                 exp_power[j] = e2 / n;
 788                                 last_high_band = j;
 789                         }
 790                         exponents += n << bsize;
 791                 }
 792                 /* main freqs and high freqs */
 793                 exponents = pwd->exponents[ch];
 794                 for (j = -1; j < n1; j++) {
 795                         if (j < 0)
 796                                 n = pwd->high_band_start[bsize];
 797                         else
 798                                 n = pwd->exponent_high_bands[pwd->frame_len_bits
 799                                         - pwd->block_len_bits][j];
 800                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 801                                 /* use noise with specified power */
 802                                 mult1 = sqrt(exp_power[j]
 803                                         / exp_power[last_high_band]);
 804                                 /* XXX: use a table */
 805                                 mult1 *= pow(10, pwd->high_band_values[ch][j] * 0.05);
 806                                 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
 807                                 mult1 *= mdct_norm;
 808                                 for (i = 0; i < n; i++) {
 809                                         noise = pwd->noise_table[pwd->noise_index];
 810                                         pwd->noise_index = (pwd->noise_index + 1)
 811                                                 & (NOISE_TAB_SIZE - 1);
 812                                         *coefs++ = noise * exponents[
 813                                                 i << bsize >> esize] * mult1;
 814                                 }
 815                                 exponents += n << bsize;
 816                         } else {
 817                                 /* coded values + small noise */
 818                                 for (i = 0; i < n; i++) {
 819                                         noise = pwd->noise_table[pwd->noise_index];
 820                                         pwd->noise_index = (pwd->noise_index + 1)
 821                                                 & (NOISE_TAB_SIZE - 1);
 822                                         *coefs++ = ((*coefs1++) + noise) *
 823                                                 exponents[i << bsize >> esize]
 824                                                 * mult;
 825                                 }
 826                                 exponents += n << bsize;
 827                         }
 828                 }
 829                 /* very high freqs: noise */
 830                 n = pwd->block_len - pwd->coefs_end[bsize];
 831                 mult1 = mult * exponents[((-1 << bsize)) >> esize];
 832                 for (i = 0; i < n; i++) {
 833                         *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
 834                         pwd->noise_index = (pwd->noise_index + 1)
 835                                 & (NOISE_TAB_SIZE - 1);
 836                 }
 837         }
 838 }
 839
 840 /**
 841  * Returns 0 if OK, 1 if last block of frame, negative on uncorrectable
 842  * errors.
 843  */
 844 static int wma_decode_block(struct private_wmadec_data *pwd)
 845 {
 846         int ret, n, v, ch, code, bsize;
 847         int coef_nb_bits, total_gain;
 848         int nb_coefs[MAX_CHANNELS];
 849
 850         /* compute current block length */
 851         if (pwd->use_variable_block_len) {
 852                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 853
 854                 if (pwd->reset_block_lengths) {
 855                         pwd->reset_block_lengths = 0;
 856                         v = get_bits(&pwd->gb, n);
 857                         if (v >= pwd->nb_block_sizes)
 858                                 return -E_WMA_BLOCK_SIZE;
 859                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 860                         v = get_bits(&pwd->gb, n);
 861                         if (v >= pwd->nb_block_sizes)
 862                                 return -E_WMA_BLOCK_SIZE;
 863                         pwd->block_len_bits = pwd->frame_len_bits - v;
 864                 } else {
 865                         /* update block lengths */
 866                         pwd->prev_block_len_bits = pwd->block_len_bits;
 867                         pwd->block_len_bits = pwd->next_block_len_bits;
 868                 }
 869                 v = get_bits(&pwd->gb, n);
 870                 if (v >= pwd->nb_block_sizes)
 871                         return -E_WMA_BLOCK_SIZE;
 872                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 873         } else {
 874                 /* fixed block len */
 875                 pwd->next_block_len_bits = pwd->frame_len_bits;
 876                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 877                 pwd->block_len_bits = pwd->frame_len_bits;
 878         }
 879
 880         /* now check if the block length is coherent with the frame length */
 881         pwd->block_len = 1 << pwd->block_len_bits;
 882         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 883                 return -E_INCOHERENT_BLOCK_LEN;
 884
 885         if (pwd->ahi.channels == 2)
 886                 pwd->ms_stereo = get_bit(&pwd->gb);
 887         v = 0;
 888         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 889                 int a = get_bit(&pwd->gb);
 890                 pwd->channel_coded[ch] = a;
 891                 v |= a;
 892         }
 893
 894         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 895
 896         /* if no channel coded, no need to go further */
 897         /* XXX: fix potential framing problems */
 898         if (!v)
 899                 goto next;
 900
 901         /*
 902          * Read total gain and extract corresponding number of bits for coef
 903          * escape coding.
 904          */
 905         total_gain = 1;
 906         for (;;) {
 907                 int a = get_bits(&pwd->gb, 7);
 908                 total_gain += a;
 909                 if (a != 127)
 910                         break;
 911         }
 912
 913         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 914
 915         /* compute number of coefficients */
 916         n = pwd->coefs_end[bsize];
 917         for (ch = 0; ch < pwd->ahi.channels; ch++)
 918                 nb_coefs[ch] = n;
 919
 920         ret = compute_high_band_values(pwd, bsize, nb_coefs);
 921         if (ret < 0)
 922                 return ret;
 923
 924         /* exponents can be reused in short blocks. */
 925         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 926                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 927                         if (pwd->channel_coded[ch]) {
 928                                 if (pwd->use_exp_vlc) {
 929                                         ret = decode_exp_vlc(pwd, ch);
 930                                         if (ret < 0)
 931                                                 return ret;
 932                                 } else
 933                                         decode_exp_lsp(pwd, ch);
 934                                 pwd->exponents_bsize[ch] = bsize;
 935                         }
 936                 }
 937         }
 938
 939         /* parse spectral coefficients : just RLE encoding */
 940         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 941                 struct vlc *coef_vlc;
 942                 int level, run, tindex;
 943                 int16_t *ptr, *eptr;
 944                 const uint16_t *level_table, *run_table;
 945
 946                 if (!pwd->channel_coded[ch])
 947                         continue;
 948                 /*
 949                  * special VLC tables are used for ms stereo because there is
 950                  * potentially less energy there
 951                  */
 952                 tindex = (ch == 1 && pwd->ms_stereo);
 953                 coef_vlc = &pwd->coef_vlc[tindex];
 954                 run_table = pwd->run_table[tindex];
 955                 level_table = pwd->level_table[tindex];
 956                 /* XXX: optimize */
 957                 ptr = &pwd->coefs1[ch][0];
 958                 eptr = ptr + nb_coefs[ch];
 959                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 960                 for (;;) {
 961                         code = get_vlc(&pwd->gb, coef_vlc->table,
 962                                 VLCBITS, VLCMAX);
 963                         if (code < 0)
 964                                 return code;
 965                         if (code == 1) /* EOB */
 966                                 break;
 967                         if (code == 0) { /* escape */
 968                                 level = get_bits(&pwd->gb, coef_nb_bits);
 969                                 /* reading block_len_bits would be better */
 970                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 971                         } else { /* normal code */
 972                                 run = run_table[code];
 973                                 level = level_table[code];
 974                         }
 975                         if (!get_bit(&pwd->gb))
 976                                 level = -level;
 977                         ptr += run;
 978                         if (ptr >= eptr) {
 979                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 980                                 break;
 981                         }
 982                         *ptr++ = level;
 983                         if (ptr >= eptr) /* EOB can be omitted */
 984                                 break;
 985                 }
 986         }
 987         compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
 988         if (pwd->ms_stereo && pwd->channel_coded[1]) {
 989                 float a, b;
 990                 int i;
 991                 /*
 992                  * Nominal case for ms stereo: we do it before mdct.
 993                  *
 994                  * No need to optimize this case because it should almost never
 995                  * happen.
 996                  */
 997                 if (!pwd->channel_coded[0]) {
 998                         PARA_NOTICE_LOG("rare ms-stereo\n");
 999                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1000                         pwd->channel_coded[0] = 1;
1001                 }
1002                 for (i = 0; i < pwd->block_len; i++) {
1003                         a = pwd->coefs[0][i];
1004                         b = pwd->coefs[1][i];
1005                         pwd->coefs[0][i] = a + b;
1006                         pwd->coefs[1][i] = a - b;
1007                 }
1008         }
1009 next:
1010         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1011                 int n4, idx;
1012
1013                 n4 = pwd->block_len / 2;
1014                 if (pwd->channel_coded[ch])
1015                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1016                 else if (!(pwd->ms_stereo && ch == 1))
1017                         memset(pwd->output, 0, sizeof(pwd->output));
1018
1019                 /* multiply by the window and add in the frame */
1020                 idx = (pwd->frame_len / 2) + pwd->block_pos - n4;
1021                 wma_window(pwd, &pwd->frame_out[ch][idx]);
1022         }
1023
1024         /* update block number */
1025         pwd->block_pos += pwd->block_len;
1026         if (pwd->block_pos >= pwd->frame_len)
1027                 return 1;
1028         else
1029                 return 0;
1030 }
1031
1032 /*
1033  * Clip a signed integer value into the -32768,32767 range.
1034  *
1035  * \param a The value to clip.
1036  *
1037  * \return The clipped value.
1038  */
1039 static inline int16_t av_clip_int16(int a)
1040 {
1041         if ((a + 32768) & ~65535)
1042                 return (a >> 31) ^ 32767;
1043         else
1044                 return a;
1045 }
1046
1047 /* Decode a frame of frame_len samples. */
1048 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1049 {
1050         int ret, i, n, ch, incr;
1051         int16_t *ptr;
1052         float *iptr;
1053
1054         /* read each block */
1055         pwd->block_pos = 0;
1056         for (;;) {
1057                 ret = wma_decode_block(pwd);
1058                 if (ret < 0)
1059                         return ret;
1060                 if (ret)
1061                         break;
1062         }
1063
1064         /* convert frame to integer */
1065         n = pwd->frame_len;
1066         incr = pwd->ahi.channels;
1067         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1068                 ptr = samples + ch;
1069                 iptr = pwd->frame_out[ch];
1070
1071                 for (i = 0; i < n; i++) {
1072                         *ptr = av_clip_int16(lrintf(*iptr++));
1073                         ptr += incr;
1074                 }
1075                 /* prepare for next block */
1076                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1077                         pwd->frame_len * sizeof(float));
1078         }
1079         return 0;
1080 }
1081
1082 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1083                 int *data_size, const uint8_t *buf, int buf_size)
1084 {
1085         int ret;
1086         int16_t *samples;
1087
1088         if (buf_size == 0) {
1089                 pwd->last_superframe_len = 0;
1090                 return 0;
1091         }
1092         if (buf_size < pwd->ahi.block_align)
1093                 return 0;
1094         buf_size = pwd->ahi.block_align;
1095         samples = data;
1096         init_get_bits(&pwd->gb, buf, buf_size);
1097         if (pwd->use_bit_reservoir) {
1098                 int i, nb_frames, bit_offset, pos, len;
1099                 uint8_t *q;
1100
1101                 /* read super frame header */
1102                 skip_bits(&pwd->gb, 4); /* super frame index */
1103                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1104                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1105                 ret = -E_WMA_OUTPUT_SPACE;
1106                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1107                                 * sizeof(int16_t) > *data_size)
1108                         goto fail;
1109
1110                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1111
1112                 if (pwd->last_superframe_len > 0) {
1113                         /* add bit_offset bits to last frame */
1114                         ret = -E_WMA_BAD_SUPERFRAME;
1115                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1116                                         MAX_CODED_SUPERFRAME_SIZE)
1117                                 goto fail;
1118                         q = pwd->last_superframe + pwd->last_superframe_len;
1119                         len = bit_offset;
1120                         while (len > 7) {
1121                                 *q++ = get_bits(&pwd->gb, 8);
1122                                 len -= 8;
1123                         }
1124                         if (len > 0)
1125                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1126
1127                         /* XXX: bit_offset bits into last frame */
1128                         init_get_bits(&pwd->gb, pwd->last_superframe,
1129                                 MAX_CODED_SUPERFRAME_SIZE);
1130                         /* skip unused bits */
1131                         if (pwd->last_bitoffset > 0)
1132                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1133                         /*
1134                          * This frame is stored in the last superframe and in
1135                          * the current one.
1136                          */
1137                         ret = wma_decode_frame(pwd, samples);
1138                         if (ret < 0)
1139                                 goto fail;
1140                         samples += pwd->ahi.channels * pwd->frame_len;
1141                 }
1142
1143                 /* read each frame starting from bit_offset */
1144                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1145                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1146                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1147                 len = pos & 7;
1148                 if (len > 0)
1149                         skip_bits(&pwd->gb, len);
1150
1151                 pwd->reset_block_lengths = 1;
1152                 for (i = 0; i < nb_frames; i++) {
1153                         ret = wma_decode_frame(pwd, samples);
1154                         if (ret < 0)
1155                                 goto fail;
1156                         samples += pwd->ahi.channels * pwd->frame_len;
1157                 }
1158
1159                 /* we copy the end of the frame in the last frame buffer */
1160                 pos = get_bits_count(&pwd->gb) +
1161                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1162                 pwd->last_bitoffset = pos & 7;
1163                 pos >>= 3;
1164                 len = buf_size - pos;
1165                 ret = -E_WMA_BAD_SUPERFRAME;
1166                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1167                         goto fail;
1168                 pwd->last_superframe_len = len;
1169                 memcpy(pwd->last_superframe, buf + pos, len);
1170         } else {
1171                 PARA_DEBUG_LOG("not using bit reservoir\n");
1172                 ret = -E_WMA_OUTPUT_SPACE;
1173                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1174                         goto fail;
1175                 /* single frame decode */
1176                 ret = wma_decode_frame(pwd, samples);
1177                 if (ret < 0)
1178                         goto fail;
1179                 samples += pwd->ahi.channels * pwd->frame_len;
1180         }
1181         PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %d, eaten: %d\n",
1182                 pwd->frame_len, pwd->block_len,
1183                 (int)((int8_t *)samples - (int8_t *)data), pwd->ahi.block_align);
1184         *data_size = (int8_t *)samples - (int8_t *)data;
1185         return pwd->ahi.block_align;
1186 fail:
1187         /* reset the bit reservoir on errors */
1188         pwd->last_superframe_len = 0;
1189         return ret;
1190 }
1191
1192 static void wmadec_close(struct filter_node *fn)
1193 {
1194         struct private_wmadec_data *pwd = fn->private_data;
1195
1196         if (!pwd)
1197                 return;
1198         wmadec_cleanup(pwd);
1199         free(fn->private_data);
1200         fn->private_data = NULL;
1201 }
1202
1203 static int wmadec_execute(struct btr_node *btrn, const char *cmd, char **result)
1204 {
1205         struct filter_node *fn = btr_context(btrn);
1206         struct private_wmadec_data *pwd = fn->private_data;
1207
1208         return decoder_execute(cmd, pwd->ahi.sample_rate, pwd->ahi.channels,
1209                 result);
1210 }
1211
1212 #define WMA_OUTPUT_BUFFER_SIZE (128 * 1024)
1213
1214 static void wmadec_post_select(__a_unused struct sched *s, struct task *t)
1215 {
1216         struct filter_node *fn = container_of(t, struct filter_node, task);
1217         int ret, converted, out_size;
1218         struct private_wmadec_data *pwd = fn->private_data;
1219         struct btr_node *btrn = fn->btrn;
1220         size_t len;
1221         char *in, *out;
1222
1223 next_buffer:
1224         converted = 0;
1225         t->error = 0;
1226         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
1227         if (ret < 0)
1228                 goto err;
1229         if (ret == 0)
1230                 return;
1231         btr_merge(btrn, fn->min_iqs);
1232         len = btr_next_buffer(btrn, (char **)&in);
1233         ret = -E_WMADEC_EOF;
1234         if (len < fn->min_iqs)
1235                 goto err;
1236         if (!pwd) {
1237                 ret = wma_decode_init(in, len, &pwd);
1238                 if (ret < 0)
1239                         goto err;
1240                 if (ret == 0) {
1241                         fn->min_iqs += 4096;
1242                         goto next_buffer;
1243                 }
1244                 fn->min_iqs = 2 * (WMA_FRAME_SKIP + pwd->ahi.block_align);
1245                 fn->private_data = pwd;
1246                 converted = pwd->ahi.header_len;
1247                 goto success;
1248         }
1249         fn->min_iqs = WMA_FRAME_SKIP + pwd->ahi.block_align;
1250         if (fn->min_iqs > len)
1251                 goto success;
1252         out_size = WMA_OUTPUT_BUFFER_SIZE;
1253         out = para_malloc(out_size);
1254         ret = wma_decode_superframe(pwd, out, &out_size,
1255                 (uint8_t *)in + WMA_FRAME_SKIP, len - WMA_FRAME_SKIP);
1256         if (ret < 0) {
1257                 free(out);
1258                 goto err;
1259         }
1260         out = para_realloc(out, out_size);
1261         if (out_size > 0)
1262                 btr_add_output(out, out_size, btrn);
1263         converted += ret + WMA_FRAME_SKIP;
1264 success:
1265         btr_consume(btrn, converted);
1266         return;
1267 err:
1268         assert(ret < 0);
1269         t->error = ret;
1270         btr_remove_node(&fn->btrn);
1271 }
1272
1273 static void wmadec_open(struct filter_node *fn)
1274 {
1275         fn->private_data = NULL;
1276         fn->min_iqs = 4096;
1277 }
1278
1279 /**
1280  * The init function of the wma decoder.
1281  *
1282  * \param f Its fields are filled in by the function.
1283  */
1284 void wmadec_filter_init(struct filter *f)
1285 {
1286         f->open = wmadec_open;
1287         f->close = wmadec_close;
1288         f->execute = wmadec_execute;
1289         f->pre_select = generic_filter_pre_select;
1290         f->post_select = wmadec_post_select;
1291 }