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