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