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