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
  28 #include "para.h"
  29 #include "error.h"
  30 #include "list.h"
  31 #include "ggo.h"
  32 #include "string.h"
  33 #include "sched.h"
  34 #include "filter.h"
  35 #include "bitstream.h"
  36 #include "imdct.h"
  37 #include "wma.h"
  38 #include "wmadata.h"
  39
  40
  41 /* size of blocks */
  42 #define BLOCK_MIN_BITS 7
  43 #define BLOCK_MAX_BITS 11
  44 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  45
  46 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  47
  48 /* XXX: find exact max size */
  49 #define HIGH_BAND_MAX_SIZE 16
  50
  51 /* XXX: is it a suitable value ? */
  52 #define MAX_CODED_SUPERFRAME_SIZE 16384
  53
  54 #define MAX_CHANNELS 2
  55
  56 #define NOISE_TAB_SIZE 8192
  57
  58 #define LSP_POW_BITS 7
  59
  60 struct private_wmadec_data {
  61         struct asf_header_info ahi;
  62         struct getbit_context gb;
  63         int use_bit_reservoir;
  64         int use_variable_block_len;
  65         int use_exp_vlc;        ///< exponent coding: 0 = lsp, 1 = vlc + delta
  66         int use_noise_coding;   ///< true if perceptual noise is added
  67         int byte_offset_bits;
  68         struct vlc exp_vlc;
  69         int exponent_sizes[BLOCK_NB_SIZES];
  70         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  71         int high_band_start[BLOCK_NB_SIZES];    ///< index of first coef in high band
  72         int coefs_start;        ///< first coded coef
  73         int coefs_end[BLOCK_NB_SIZES];  ///< max number of coded coefficients
  74         int exponent_high_sizes[BLOCK_NB_SIZES];
  75         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  76         struct vlc hgain_vlc;
  77
  78         /* coded values in high bands */
  79         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  80         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  81
  82         /* there are two possible tables for spectral coefficients */
  83         struct vlc coef_vlc[2];
  84         uint16_t *run_table[2];
  85         uint16_t *level_table[2];
  86         const struct coef_vlc_table *coef_vlcs[2];
  87         /* frame info */
  88         int frame_len;          ///< frame length in samples
  89         int frame_len_bits;     ///< frame_len = 1 << frame_len_bits
  90         int nb_block_sizes;     ///< number of block sizes
  91         /* block info */
  92         int reset_block_lengths;
  93         int block_len_bits;     ///< log2 of current block length
  94         int next_block_len_bits;        ///< log2 of next block length
  95         int prev_block_len_bits;        ///< log2 of prev block length
  96         int block_len;          ///< block length in samples
  97         int block_pos;          ///< current position in frame
  98         uint8_t ms_stereo;      ///< true if mid/side stereo mode
  99         uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
 100         int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
 101         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 102         float max_exponent[MAX_CHANNELS];
 103         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 104         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 105         float output[BLOCK_MAX_SIZE * 2];
 106         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 107         float *windows[BLOCK_NB_SIZES];
 108         /* output buffer for one frame and the last for IMDCT windowing */
 109         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 110         /* last frame info */
 111         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 112         int last_bitoffset;
 113         int last_superframe_len;
 114         float noise_table[NOISE_TAB_SIZE];
 115         int noise_index;
 116         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 117         /* lsp_to_curve tables */
 118         float lsp_cos_table[BLOCK_MAX_SIZE];
 119         float lsp_pow_e_table[256];
 120         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 121         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 122 };
 123
 124 #define EXPVLCBITS 8
 125 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
 126
 127 #define HGAINVLCBITS 9
 128 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
 129
 130 #define VLCBITS 9
 131 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
 132
 133 DECLARE_ALIGNED(16, float, ff_sine_128[128]);
 134 DECLARE_ALIGNED(16, float, ff_sine_256[256]);
 135 DECLARE_ALIGNED(16, float, ff_sine_512[512]);
 136 DECLARE_ALIGNED(16, float, ff_sine_1024[1024]);
 137 DECLARE_ALIGNED(16, float, ff_sine_2048[2048]);
 138 DECLARE_ALIGNED(16, float, ff_sine_4096[4096]);
 139
 140 static float *ff_sine_windows[6] = {
 141         ff_sine_128, ff_sine_256, ff_sine_512, ff_sine_1024,
 142         ff_sine_2048, ff_sine_4096
 143 };
 144
 145 /* Generate a sine window. */
 146 static void sine_window_init(float *window, int n)
 147 {
 148         int i;
 149
 150         for (i = 0; i < n; i++)
 151                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 152 }
 153
 154 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 155 {
 156         int i;
 157
 158         for (i = 0; i < pwd->nb_block_sizes; i++)
 159                 imdct_end(pwd->mdct_ctx[i]);
 160         if (pwd->use_exp_vlc)
 161                 free_vlc(&pwd->exp_vlc);
 162         if (pwd->use_noise_coding)
 163                 free_vlc(&pwd->hgain_vlc);
 164         for (i = 0; i < 2; i++) {
 165                 free_vlc(&pwd->coef_vlc[i]);
 166                 free(pwd->run_table[i]);
 167                 free(pwd->level_table[i]);
 168         }
 169 }
 170
 171 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 172                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 173 {
 174         int n = vlc_table->n;
 175         const uint8_t *table_bits = vlc_table->huffbits;
 176         const uint32_t *table_codes = vlc_table->huffcodes;
 177         const uint16_t *levels_table = vlc_table->levels;
 178         uint16_t *run_table, *level_table;
 179         int i, l, j, k, level;
 180
 181         PARA_ERROR_LOG("n: %d\n", n);
 182         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 183
 184         run_table = para_malloc(n * sizeof(uint16_t));
 185         level_table = para_malloc(n * sizeof(uint16_t));
 186         i = 2;
 187         level = 1;
 188         k = 0;
 189         while (i < n) {
 190                 l = levels_table[k++];
 191                 for (j = 0; j < l; j++) {
 192                         run_table[i] = j;
 193                         level_table[i] = level;
 194                         i++;
 195                 }
 196                 level++;
 197         }
 198         *prun_table = run_table;
 199         *plevel_table = level_table;
 200 }
 201
 202 /* compute the scale factor band sizes for each MDCT block size */
 203 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 204         float high_freq)
 205 {
 206         struct asf_header_info *ahi = &pwd->ahi;
 207         int a, b, pos, lpos, k, block_len, i, j, n;
 208         const uint8_t *table;
 209
 210         pwd->coefs_start = 0;
 211         for (k = 0; k < pwd->nb_block_sizes; k++) {
 212                 block_len = pwd->frame_len >> k;
 213
 214                 table = NULL;
 215                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 216                 if (a < 3) {
 217                         if (ahi->sample_rate >= 44100)
 218                                 table = exponent_band_44100[a];
 219                         else if (ahi->sample_rate >= 32000)
 220                                 table = exponent_band_32000[a];
 221                         else if (ahi->sample_rate >= 22050)
 222                                 table = exponent_band_22050[a];
 223                 }
 224                 if (table) {
 225                         n = *table++;
 226                         for (i = 0; i < n; i++)
 227                                 pwd->exponent_bands[k][i] = table[i];
 228                         pwd->exponent_sizes[k] = n;
 229                 } else {
 230                         j = 0;
 231                         lpos = 0;
 232                         for (i = 0; i < 25; i++) {
 233                                 a = wma_critical_freqs[i];
 234                                 b = ahi->sample_rate;
 235                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 236                                 pos <<= 2;
 237                                 if (pos > block_len)
 238                                         pos = block_len;
 239                                 if (pos > lpos)
 240                                         pwd->exponent_bands[k][j++] = pos - lpos;
 241                                 if (pos >= block_len)
 242                                         break;
 243                                 lpos = pos;
 244                         }
 245                         pwd->exponent_sizes[k] = j;
 246                 }
 247
 248                 /* max number of coefs */
 249                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 250                 /* high freq computation */
 251                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 252                         / ahi->sample_rate + 0.5);
 253                 n = pwd->exponent_sizes[k];
 254                 j = 0;
 255                 pos = 0;
 256                 for (i = 0; i < n; i++) {
 257                         int start, end;
 258                         start = pos;
 259                         pos += pwd->exponent_bands[k][i];
 260                         end = pos;
 261                         if (start < pwd->high_band_start[k])
 262                                 start = pwd->high_band_start[k];
 263                         if (end > pwd->coefs_end[k])
 264                                 end = pwd->coefs_end[k];
 265                         if (end > start)
 266                                 pwd->exponent_high_bands[k][j++] = end - start;
 267                 }
 268                 pwd->exponent_high_sizes[k] = j;
 269         }
 270 }
 271
 272 static int wma_init(struct private_wmadec_data *pwd)
 273 {
 274         int i;
 275         float bps1, high_freq;
 276         volatile float bps;
 277         int sample_rate1;
 278         int coef_vlc_table;
 279         struct asf_header_info *ahi = &pwd->ahi;
 280         int flags2 = ahi->flags2;
 281
 282         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 283                 || ahi->channels <= 0 || ahi->channels > 8
 284                 || ahi->bit_rate <= 0)
 285                 return -E_WMA_BAD_PARAMS;
 286
 287         /* compute MDCT block size */
 288         if (ahi->sample_rate <= 16000) {
 289                 pwd->frame_len_bits = 9;
 290         } else if (ahi->sample_rate <= 22050) {
 291                 pwd->frame_len_bits = 10;
 292         } else {
 293                 pwd->frame_len_bits = 11;
 294         }
 295         pwd->frame_len = 1 << pwd->frame_len_bits;
 296         if (pwd->use_variable_block_len) {
 297                 int nb_max, nb;
 298                 nb = ((flags2 >> 3) & 3) + 1;
 299                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 300                         nb += 2;
 301                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 302                 if (nb > nb_max)
 303                         nb = nb_max;
 304                 pwd->nb_block_sizes = nb + 1;
 305         } else
 306                 pwd->nb_block_sizes = 1;
 307
 308         /* init rate dependent parameters */
 309         pwd->use_noise_coding = 1;
 310         high_freq = ahi->sample_rate * 0.5;
 311
 312         /* wma2 rates are normalized */
 313         sample_rate1 = ahi->sample_rate;
 314         if (sample_rate1 >= 44100)
 315                 sample_rate1 = 44100;
 316         else if (sample_rate1 >= 22050)
 317                 sample_rate1 = 22050;
 318         else if (sample_rate1 >= 16000)
 319                 sample_rate1 = 16000;
 320         else if (sample_rate1 >= 11025)
 321                 sample_rate1 = 11025;
 322         else if (sample_rate1 >= 8000)
 323                 sample_rate1 = 8000;
 324
 325         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 326         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 327         /*
 328          * Compute high frequency value and choose if noise coding should be
 329          * activated.
 330          */
 331         bps1 = bps;
 332         if (ahi->channels == 2)
 333                 bps1 = bps * 1.6;
 334         if (sample_rate1 == 44100) {
 335                 if (bps1 >= 0.61)
 336                         pwd->use_noise_coding = 0;
 337                 else
 338                         high_freq = high_freq * 0.4;
 339         } else if (sample_rate1 == 22050) {
 340                 if (bps1 >= 1.16)
 341                         pwd->use_noise_coding = 0;
 342                 else if (bps1 >= 0.72)
 343                         high_freq = high_freq * 0.7;
 344                 else
 345                         high_freq = high_freq * 0.6;
 346         } else if (sample_rate1 == 16000) {
 347                 if (bps > 0.5)
 348                         high_freq = high_freq * 0.5;
 349                 else
 350                         high_freq = high_freq * 0.3;
 351         } else if (sample_rate1 == 11025) {
 352                 high_freq = high_freq * 0.7;
 353         } else if (sample_rate1 == 8000) {
 354                 if (bps <= 0.625) {
 355                         high_freq = high_freq * 0.5;
 356                 } else if (bps > 0.75) {
 357                         pwd->use_noise_coding = 0;
 358                 } else {
 359                         high_freq = high_freq * 0.65;
 360                 }
 361         } else {
 362                 if (bps >= 0.8) {
 363                         high_freq = high_freq * 0.75;
 364                 } else if (bps >= 0.6) {
 365                         high_freq = high_freq * 0.6;
 366                 } else {
 367                         high_freq = high_freq * 0.5;
 368                 }
 369         }
 370         PARA_INFO_LOG("channels=%d sample_rate=%d "
 371                 "bitrate=%d block_align=%d\n",
 372                 ahi->channels, ahi->sample_rate,
 373                 ahi->bit_rate, ahi->block_align);
 374         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 375                 "high_freq=%f bitoffset=%d\n",
 376                 pwd->frame_len, bps, bps1,
 377                 high_freq, pwd->byte_offset_bits);
 378         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 379                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 380
 381         compute_scale_factor_band_sizes(pwd, high_freq);
 382         /* init MDCT windows : simple sinus window */
 383         for (i = 0; i < pwd->nb_block_sizes; i++) {
 384                 int n;
 385                 n = 1 << (pwd->frame_len_bits - i);
 386                 sine_window_init(ff_sine_windows[pwd->frame_len_bits - i - 7], n);
 387                 pwd->windows[i] = ff_sine_windows[pwd->frame_len_bits - i - 7];
 388         }
 389
 390         pwd->reset_block_lengths = 1;
 391
 392         if (pwd->use_noise_coding) {
 393                 /* init the noise generator */
 394                 if (pwd->use_exp_vlc)
 395                         pwd->noise_mult = 0.02;
 396                 else
 397                         pwd->noise_mult = 0.04;
 398
 399                 {
 400                         unsigned int seed;
 401                         float norm;
 402                         seed = 1;
 403                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 404                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 405                                 seed = seed * 314159 + 1;
 406                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 407                         }
 408                 }
 409         }
 410
 411         /* choose the VLC tables for the coefficients */
 412         coef_vlc_table = 2;
 413         if (ahi->sample_rate >= 32000) {
 414                 if (bps1 < 0.72)
 415                         coef_vlc_table = 0;
 416                 else if (bps1 < 1.16)
 417                         coef_vlc_table = 1;
 418         }
 419         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 420         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 421         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 422                 pwd->coef_vlcs[0]);
 423         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 424                 pwd->coef_vlcs[1]);
 425         return 0;
 426 }
 427
 428 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 429 {
 430         float wdel, a, b;
 431         int i, e, m;
 432
 433         wdel = M_PI / frame_len;
 434         for (i = 0; i < frame_len; i++)
 435                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 436
 437         /* tables for x^-0.25 computation */
 438         for (i = 0; i < 256; i++) {
 439                 e = i - 126;
 440                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 441         }
 442
 443         /* These two tables are needed to avoid two operations in pow_m1_4. */
 444         b = 1.0;
 445         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 446                 m = (1 << LSP_POW_BITS) + i;
 447                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 448                 a = pow(a, -0.25);
 449                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 450                 pwd->lsp_pow_m_table2[i] = b - a;
 451                 b = a;
 452         }
 453 }
 454
 455 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 456 {
 457         struct private_wmadec_data *pwd;
 458         int ret, i;
 459
 460         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 461         pwd = para_calloc(sizeof(*pwd));
 462         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 463         if (ret <= 0) {
 464                 free(pwd);
 465                 return ret;
 466         }
 467
 468         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 469         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 470         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 471
 472         ret = wma_init(pwd);
 473         if (ret < 0)
 474                 return ret;
 475         /* init MDCT */
 476         for (i = 0; i < pwd->nb_block_sizes; i++) {
 477                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 478                 if (ret < 0)
 479                         return ret;
 480         }
 481         if (pwd->use_noise_coding) {
 482                 PARA_INFO_LOG("using noise coding\n");
 483                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 484                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 485                         ff_wma_hgain_huffcodes, 2);
 486         }
 487
 488         if (pwd->use_exp_vlc) {
 489                 PARA_INFO_LOG("using exp_vlc\n");
 490                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 491                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 492                 ff_wma_scale_huffcodes, 4);
 493         } else {
 494                 PARA_INFO_LOG("using curve\n");
 495                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 496         }
 497         *result = pwd;
 498         return pwd->ahi.header_len;
 499 }
 500
 501 /**
 502  * compute x^-0.25 with an exponent and mantissa table. We use linear
 503  * interpolation to reduce the mantissa table size at a small speed
 504  * expense (linear interpolation approximately doubles the number of
 505  * bits of precision).
 506  */
 507 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 508 {
 509         union {
 510                 float f;
 511                 unsigned int v;
 512         } u, t;
 513         unsigned int e, m;
 514         float a, b;
 515
 516         u.f = x;
 517         e = u.v >> 23;
 518         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 519         /* build interpolation scale: 1 <= t < 2. */
 520         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 521         a = pwd->lsp_pow_m_table1[m];
 522         b = pwd->lsp_pow_m_table2[m];
 523         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 524 }
 525
 526 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 527                 float *out, float *val_max_ptr, int n, float *lsp)
 528 {
 529         int i, j;
 530         float p, q, w, v, val_max;
 531
 532         val_max = 0;
 533         for (i = 0; i < n; i++) {
 534                 p = 0.5f;
 535                 q = 0.5f;
 536                 w = pwd->lsp_cos_table[i];
 537                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 538                         q *= w - lsp[j - 1];
 539                         p *= w - lsp[j];
 540                 }
 541                 p *= p * (2.0f - w);
 542                 q *= q * (2.0f + w);
 543                 v = p + q;
 544                 v = pow_m1_4(pwd, v);
 545                 if (v > val_max)
 546                         val_max = v;
 547                 out[i] = v;
 548         }
 549         *val_max_ptr = val_max;
 550 }
 551
 552 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 553 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 554 {
 555         float lsp_coefs[NB_LSP_COEFS];
 556         int val, i;
 557
 558         for (i = 0; i < NB_LSP_COEFS; i++) {
 559                 if (i == 0 || i >= 8)
 560                         val = get_bits(&pwd->gb, 3);
 561                 else
 562                         val = get_bits(&pwd->gb, 4);
 563                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 564         }
 565
 566         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 567                 pwd->block_len, lsp_coefs);
 568 }
 569
 570 /* Decode exponents coded with VLC codes. */
 571 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 572 {
 573         int last_exp, n, code;
 574         const uint16_t *ptr, *band_ptr;
 575         float v, *q, max_scale, *q_end;
 576
 577         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 578         ptr = band_ptr;
 579         q = pwd->exponents[ch];
 580         q_end = q + pwd->block_len;
 581         max_scale = 0;
 582         last_exp = 36;
 583
 584         while (q < q_end) {
 585                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 586                 if (code < 0)
 587                         return -1;
 588                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 589                 last_exp += code - 60;
 590                 /* XXX: use a table */
 591                 v = pow(10, last_exp * (1.0 / 16.0));
 592                 if (v > max_scale)
 593                         max_scale = v;
 594                 n = *ptr++;
 595                 do {
 596                         *q++ = v;
 597                 } while (--n);
 598         }
 599         pwd->max_exponent[ch] = max_scale;
 600         return 0;
 601 }
 602
 603 /* compute src0 * src1 + src2 */
 604 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 605                 const float *src2, int len)
 606 {
 607         int i;
 608
 609         for (i = 0; i < len; i++)
 610                 dst[i] = src0[i] * src1[i] + src2[i];
 611 }
 612
 613 static inline void vector_mult_reverse(float *dst, const float *src0,
 614                 const float *src1, int len)
 615 {
 616         int i;
 617
 618         src1 += len - 1;
 619         for (i = 0; i < len; i++)
 620                 dst[i] = src0[i] * src1[-i];
 621 }
 622
 623 /**
 624  * Apply MDCT window and add into output.
 625  *
 626  * We ensure that when the windows overlap their squared sum
 627  * is always 1 (MDCT reconstruction rule).
 628  */
 629 static void wma_window(struct private_wmadec_data *pwd, float *out)
 630 {
 631         float *in = pwd->output;
 632         int block_len, bsize, n;
 633
 634         /* left part */
 635         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 636                 block_len = pwd->block_len;
 637                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 638                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 639         } else {
 640                 block_len = 1 << pwd->prev_block_len_bits;
 641                 n = (pwd->block_len - block_len) / 2;
 642                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 643                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 644                         block_len);
 645                 memcpy(out + n + block_len, in + n + block_len,
 646                         n * sizeof(float));
 647         }
 648         out += pwd->block_len;
 649         in += pwd->block_len;
 650         /* right part */
 651         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 652                 block_len = pwd->block_len;
 653                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 654                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 655         } else {
 656                 block_len = 1 << pwd->next_block_len_bits;
 657                 n = (pwd->block_len - block_len) / 2;
 658                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 659                 memcpy(out, in, n * sizeof(float));
 660                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 661                         block_len);
 662                 memset(out + n + block_len, 0, n * sizeof(float));
 663         }
 664 }
 665
 666 static int wma_total_gain_to_bits(int total_gain)
 667 {
 668         if (total_gain < 15)
 669                 return 13;
 670         else if (total_gain < 32)
 671                 return 12;
 672         else if (total_gain < 40)
 673                 return 11;
 674         else if (total_gain < 45)
 675                 return 10;
 676         else
 677                 return 9;
 678 }
 679
 680 /**
 681  * @return 0 if OK. 1 if last block of frame. return -1 if
 682  * unrecorrable error.
 683  */
 684 static int wma_decode_block(struct private_wmadec_data *pwd)
 685 {
 686         int n, v, ch, code, bsize;
 687         int coef_nb_bits, total_gain;
 688         int nb_coefs[MAX_CHANNELS];
 689         float mdct_norm;
 690
 691         /* compute current block length */
 692         if (pwd->use_variable_block_len) {
 693                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 694
 695                 if (pwd->reset_block_lengths) {
 696                         pwd->reset_block_lengths = 0;
 697                         v = get_bits(&pwd->gb, n);
 698                         if (v >= pwd->nb_block_sizes)
 699                                 return -1;
 700                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 701                         v = get_bits(&pwd->gb, n);
 702                         if (v >= pwd->nb_block_sizes)
 703                                 return -1;
 704                         pwd->block_len_bits = pwd->frame_len_bits - v;
 705                 } else {
 706                         /* update block lengths */
 707                         pwd->prev_block_len_bits = pwd->block_len_bits;
 708                         pwd->block_len_bits = pwd->next_block_len_bits;
 709                 }
 710                 v = get_bits(&pwd->gb, n);
 711                 if (v >= pwd->nb_block_sizes)
 712                         return -1;
 713                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 714         } else {
 715                 /* fixed block len */
 716                 pwd->next_block_len_bits = pwd->frame_len_bits;
 717                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 718                 pwd->block_len_bits = pwd->frame_len_bits;
 719         }
 720
 721         /* now check if the block length is coherent with the frame length */
 722         pwd->block_len = 1 << pwd->block_len_bits;
 723         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 724                 return -E_INCOHERENT_BLOCK_LEN;
 725
 726         if (pwd->ahi.channels == 2)
 727                 pwd->ms_stereo = get_bit(&pwd->gb);
 728         v = 0;
 729         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 730                 int a = get_bit(&pwd->gb);
 731                 pwd->channel_coded[ch] = a;
 732                 v |= a;
 733         }
 734
 735         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 736
 737         /* if no channel coded, no need to go further */
 738         /* XXX: fix potential framing problems */
 739         if (!v)
 740                 goto next;
 741
 742         /* read total gain and extract corresponding number of bits for
 743            coef escape coding */
 744         total_gain = 1;
 745         for (;;) {
 746                 int a = get_bits(&pwd->gb, 7);
 747                 total_gain += a;
 748                 if (a != 127)
 749                         break;
 750         }
 751
 752         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 753
 754         /* compute number of coefficients */
 755         n = pwd->coefs_end[bsize] - pwd->coefs_start;
 756         for (ch = 0; ch < pwd->ahi.channels; ch++)
 757                 nb_coefs[ch] = n;
 758
 759         /* complex coding */
 760         if (pwd->use_noise_coding) {
 761                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 762                         if (pwd->channel_coded[ch]) {
 763                                 int i, m, a;
 764                                 m = pwd->exponent_high_sizes[bsize];
 765                                 for (i = 0; i < m; i++) {
 766                                         a = get_bit(&pwd->gb);
 767                                         pwd->high_band_coded[ch][i] = a;
 768                                         /* if noise coding, the coefficients are not transmitted */
 769                                         if (a)
 770                                                 nb_coefs[ch] -=
 771                                                     pwd->
 772                                                     exponent_high_bands[bsize]
 773                                                     [i];
 774                                 }
 775                         }
 776                 }
 777                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 778                         if (pwd->channel_coded[ch]) {
 779                                 int i, val;
 780
 781                                 n = pwd->exponent_high_sizes[bsize];
 782                                 val = (int) 0x80000000;
 783                                 for (i = 0; i < n; i++) {
 784                                         if (pwd->high_band_coded[ch][i]) {
 785                                                 if (val == (int) 0x80000000) {
 786                                                         val =
 787                                                             get_bits(&pwd->gb,
 788                                                                      7) - 19;
 789                                                 } else {
 790                                                         code =
 791                                                             get_vlc(&pwd->gb,
 792                                                                      pwd->
 793                                                                      hgain_vlc.
 794                                                                      table,
 795                                                                      HGAINVLCBITS,
 796                                                                      HGAINMAX);
 797                                                         if (code < 0)
 798                                                                 return -1;
 799                                                         val += code - 18;
 800                                                 }
 801                                                 pwd->high_band_values[ch][i] =
 802                                                     val;
 803                                         }
 804                                 }
 805                         }
 806                 }
 807         }
 808
 809         /* exponents can be reused in short blocks. */
 810         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 811                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 812                         if (pwd->channel_coded[ch]) {
 813                                 if (pwd->use_exp_vlc) {
 814                                         if (decode_exp_vlc(pwd, ch) < 0)
 815                                                 return -1;
 816                                 } else {
 817                                         decode_exp_lsp(pwd, ch);
 818                                 }
 819                                 pwd->exponents_bsize[ch] = bsize;
 820                         }
 821                 }
 822         }
 823
 824         /* parse spectral coefficients : just RLE encoding */
 825         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 826                 struct vlc *coef_vlc;
 827                 int level, run, tindex;
 828                 int16_t *ptr, *eptr;
 829                 const uint16_t *level_table, *run_table;
 830
 831                 if (!pwd->channel_coded[ch])
 832                         continue;
 833                 /*
 834                  * special VLC tables are used for ms stereo because there is
 835                  * potentially less energy there
 836                  */
 837                 tindex = (ch == 1 && pwd->ms_stereo);
 838                 coef_vlc = &pwd->coef_vlc[tindex];
 839                 run_table = pwd->run_table[tindex];
 840                 level_table = pwd->level_table[tindex];
 841                 /* XXX: optimize */
 842                 ptr = &pwd->coefs1[ch][0];
 843                 eptr = ptr + nb_coefs[ch];
 844                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 845                 for (;;) {
 846                         code = get_vlc(&pwd->gb, coef_vlc->table,
 847                                 VLCBITS, VLCMAX);
 848                         if (code < 0)
 849                                 return -1;
 850                         if (code == 1) /* EOB */
 851                                 break;
 852                         if (code == 0) { /* escape */
 853                                 level = get_bits(&pwd->gb, coef_nb_bits);
 854                                 /* reading block_len_bits would be better */
 855                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 856                         } else { /* normal code */
 857                                 run = run_table[code];
 858                                 level = level_table[code];
 859                         }
 860                         if (!get_bit(&pwd->gb))
 861                                 level = -level;
 862                         ptr += run;
 863                         if (ptr >= eptr) {
 864                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 865                                 break;
 866                         }
 867                         *ptr++ = level;
 868                         if (ptr >= eptr) /* EOB can be omitted */
 869                                 break;
 870                 }
 871         }
 872
 873         /* normalize */
 874         {
 875                 int n4 = pwd->block_len / 2;
 876                 mdct_norm = 1.0 / (float) n4;
 877         }
 878
 879         /* finally compute the MDCT coefficients */
 880         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 881                 if (pwd->channel_coded[ch]) {
 882                         int16_t *coefs1;
 883                         float *coefs, *exponents, mult, mult1, noise;
 884                         int i, j, n1, last_high_band, esize;
 885                         float exp_power[HIGH_BAND_MAX_SIZE];
 886
 887                         coefs1 = pwd->coefs1[ch];
 888                         exponents = pwd->exponents[ch];
 889                         esize = pwd->exponents_bsize[ch];
 890                         mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 891                         mult *= mdct_norm;
 892                         coefs = pwd->coefs[ch];
 893                         if (pwd->use_noise_coding) {
 894                                 mult1 = mult;
 895                                 /* very low freqs : noise */
 896                                 for (i = 0; i < pwd->coefs_start; i++) {
 897                                         *coefs++ =
 898                                             pwd->noise_table[pwd->noise_index] *
 899                                             exponents[i << bsize >> esize] *
 900                                             mult1;
 901                                         pwd->noise_index =
 902                                             (pwd->noise_index +
 903                                              1) & (NOISE_TAB_SIZE - 1);
 904                                 }
 905
 906                                 n1 = pwd->exponent_high_sizes[bsize];
 907
 908                                 /* compute power of high bands */
 909                                 exponents = pwd->exponents[ch] +
 910                                     (pwd->high_band_start[bsize] << bsize);
 911                                 last_high_band = 0;     /* avoid warning */
 912                                 for (j = 0; j < n1; j++) {
 913                                         n = pwd->exponent_high_bands[pwd->
 914                                                                    frame_len_bits
 915                                                                    -
 916                                                                    pwd->
 917                                                                    block_len_bits]
 918                                             [j];
 919                                         if (pwd->high_band_coded[ch][j]) {
 920                                                 float e2, val;
 921                                                 e2 = 0;
 922                                                 for (i = 0; i < n; i++) {
 923                                                         val = exponents[i << bsize
 924                                                                       >> esize];
 925                                                         e2 += val * val;
 926                                                 }
 927                                                 exp_power[j] = e2 / n;
 928                                                 last_high_band = j;
 929                                         }
 930                                         exponents += n << bsize;
 931                                 }
 932
 933                                 /* main freqs and high freqs */
 934                                 exponents =
 935                                     pwd->exponents[ch] +
 936                                     (pwd->coefs_start << bsize);
 937                                 for (j = -1; j < n1; j++) {
 938                                         if (j < 0) {
 939                                                 n = pwd->high_band_start[bsize] -
 940                                                     pwd->coefs_start;
 941                                         } else {
 942                                                 n = pwd->exponent_high_bands[pwd->
 943                                                                            frame_len_bits
 944                                                                            -
 945                                                                            pwd->
 946                                                                            block_len_bits]
 947                                                     [j];
 948                                         }
 949                                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 950                                                 /* use noise with specified power */
 951                                                 mult1 =
 952                                                     sqrt(exp_power[j] /
 953                                                          exp_power
 954                                                          [last_high_band]);
 955                                                 /* XXX: use a table */
 956                                                 mult1 =
 957                                                     mult1 * pow(10,
 958                                                                 pwd->
 959                                                                 high_band_values
 960                                                                 [ch][j] * 0.05);
 961                                                 mult1 =
 962                                                     mult1 /
 963                                                     (pwd->max_exponent[ch] *
 964                                                      pwd->noise_mult);
 965                                                 mult1 *= mdct_norm;
 966                                                 for (i = 0; i < n; i++) {
 967                                                         noise =
 968                                                             pwd->noise_table[pwd->
 969                                                                            noise_index];
 970                                                         pwd->noise_index =
 971                                                             (pwd->noise_index +
 972                                                              1) &
 973                                                             (NOISE_TAB_SIZE -
 974                                                              1);
 975                                                         *coefs++ =
 976                                                             noise *
 977                                                             exponents[i << bsize
 978                                                                       >> esize]
 979                                                             * mult1;
 980                                                 }
 981                                                 exponents += n << bsize;
 982                                         } else {
 983                                                 /* coded values + small noise */
 984                                                 for (i = 0; i < n; i++) {
 985                                                         noise =
 986                                                             pwd->noise_table[pwd->
 987                                                                            noise_index];
 988                                                         pwd->noise_index =
 989                                                             (pwd->noise_index +
 990                                                              1) &
 991                                                             (NOISE_TAB_SIZE -
 992                                                              1);
 993                                                         *coefs++ =
 994                                                             ((*coefs1++) +
 995                                                              noise) *
 996                                                             exponents[i << bsize
 997                                                                       >> esize]
 998                                                             * mult;
 999                                                 }
1000                                                 exponents += n << bsize;
1001                                         }
1002                                 }
1003
1004                                 /* very high freqs : noise */
1005                                 n = pwd->block_len - pwd->coefs_end[bsize];
1006                                 mult1 =
1007                                     mult * exponents[((-1 << bsize)) >> esize];
1008                                 for (i = 0; i < n; i++) {
1009                                         *coefs++ =
1010                                             pwd->noise_table[pwd->noise_index] *
1011                                             mult1;
1012                                         pwd->noise_index =
1013                                             (pwd->noise_index +
1014                                              1) & (NOISE_TAB_SIZE - 1);
1015                                 }
1016                         } else {
1017                                 /* XXX: optimize more */
1018                                 for (i = 0; i < pwd->coefs_start; i++)
1019                                         *coefs++ = 0.0;
1020                                 n = nb_coefs[ch];
1021                                 for (i = 0; i < n; i++) {
1022                                         *coefs++ =
1023                                             coefs1[i] *
1024                                             exponents[i << bsize >> esize] *
1025                                             mult;
1026                                 }
1027                                 n = pwd->block_len - pwd->coefs_end[bsize];
1028                                 for (i = 0; i < n; i++)
1029                                         *coefs++ = 0.0;
1030                         }
1031                 }
1032         }
1033
1034         if (pwd->ms_stereo && pwd->channel_coded[1]) {
1035                 float a, b;
1036                 int i;
1037
1038                 /*
1039                  * Nominal case for ms stereo: we do it before mdct.
1040                  *
1041                  * No need to optimize this case because it should almost never
1042                  * happen.
1043                  */
1044                 if (!pwd->channel_coded[0]) {
1045                         PARA_NOTICE_LOG("rare ms-stereo\n");
1046                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1047                         pwd->channel_coded[0] = 1;
1048                 }
1049                 for (i = 0; i < pwd->block_len; i++) {
1050                         a = pwd->coefs[0][i];
1051                         b = pwd->coefs[1][i];
1052                         pwd->coefs[0][i] = a + b;
1053                         pwd->coefs[1][i] = a - b;
1054                 }
1055         }
1056
1057 next:
1058         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1059                 int n4, index;
1060
1061                 n = pwd->block_len;
1062                 n4 = pwd->block_len / 2;
1063                 if (pwd->channel_coded[ch])
1064                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1065                 else if (!(pwd->ms_stereo && ch == 1))
1066                         memset(pwd->output, 0, sizeof(pwd->output));
1067
1068                 /* multiply by the window and add in the frame */
1069                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1070                 wma_window(pwd, &pwd->frame_out[ch][index]);
1071         }
1072
1073         /* update block number */
1074         pwd->block_pos += pwd->block_len;
1075         if (pwd->block_pos >= pwd->frame_len)
1076                 return 1;
1077         else
1078                 return 0;
1079 }
1080
1081 /*
1082  * Clip a signed integer value into the -32768,32767 range.
1083  *
1084  * \param a The value to clip.
1085  *
1086  * \return The clipped value.
1087  */
1088 static inline int16_t av_clip_int16(int a)
1089 {
1090         if ((a + 32768) & ~65535)
1091                 return (a >> 31) ^ 32767;
1092         else
1093                 return a;
1094 }
1095
1096 /* Decode a frame of frame_len samples. */
1097 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1098 {
1099         int ret, i, n, ch, incr;
1100         int16_t *ptr;
1101         float *iptr;
1102
1103         /* read each block */
1104         pwd->block_pos = 0;
1105         for (;;) {
1106                 ret = wma_decode_block(pwd);
1107                 if (ret < 0)
1108                         return -1;
1109                 if (ret)
1110                         break;
1111         }
1112
1113         /* convert frame to integer */
1114         n = pwd->frame_len;
1115         incr = pwd->ahi.channels;
1116         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1117                 ptr = samples + ch;
1118                 iptr = pwd->frame_out[ch];
1119
1120                 for (i = 0; i < n; i++) {
1121                         *ptr = av_clip_int16(lrintf(*iptr++));
1122                         ptr += incr;
1123                 }
1124                 /* prepare for next block */
1125                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1126                         pwd->frame_len * sizeof(float));
1127         }
1128         return 0;
1129 }
1130
1131 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1132                 int *data_size, const uint8_t *buf, int buf_size)
1133 {
1134         int ret;
1135         int16_t *samples;
1136         static int frame_count;
1137
1138         if (buf_size == 0) {
1139                 pwd->last_superframe_len = 0;
1140                 return 0;
1141         }
1142         if (buf_size < pwd->ahi.block_align)
1143                 return 0;
1144         buf_size = pwd->ahi.block_align;
1145         samples = data;
1146         init_get_bits(&pwd->gb, buf, buf_size);
1147         if (pwd->use_bit_reservoir) {
1148                 int i, nb_frames, bit_offset, pos, len;
1149                 uint8_t *q;
1150
1151                 /* read super frame header */
1152                 skip_bits(&pwd->gb, 4); /* super frame index */
1153                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1154                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1155                 ret = -E_WMA_OUTPUT_SPACE;
1156                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1157                                 * sizeof(int16_t) > *data_size)
1158                         goto fail;
1159
1160                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1161
1162                 if (pwd->last_superframe_len > 0) {
1163                         /* add bit_offset bits to last frame */
1164                         ret = -E_WMA_BAD_SUPERFRAME;
1165                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1166                                         MAX_CODED_SUPERFRAME_SIZE)
1167                                 goto fail;
1168                         q = pwd->last_superframe + pwd->last_superframe_len;
1169                         len = bit_offset;
1170                         while (len > 7) {
1171                                 *q++ = get_bits(&pwd->gb, 8);
1172                                 len -= 8;
1173                         }
1174                         if (len > 0)
1175                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1176
1177                         /* XXX: bit_offset bits into last frame */
1178                         init_get_bits(&pwd->gb, pwd->last_superframe,
1179                                 MAX_CODED_SUPERFRAME_SIZE);
1180                         /* skip unused bits */
1181                         if (pwd->last_bitoffset > 0)
1182                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1183                         /*
1184                          * This frame is stored in the last superframe and in
1185                          * the current one.
1186                          */
1187                         ret = -E_WMA_DECODE;
1188                         if (wma_decode_frame(pwd, samples) < 0)
1189                                 goto fail;
1190                         frame_count++;
1191                         samples += pwd->ahi.channels * pwd->frame_len;
1192                 }
1193
1194                 /* read each frame starting from bit_offset */
1195                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1196                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1197                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1198                 len = pos & 7;
1199                 if (len > 0)
1200                         skip_bits(&pwd->gb, len);
1201
1202                 pwd->reset_block_lengths = 1;
1203                 for (i = 0; i < nb_frames; i++) {
1204                         ret = -E_WMA_DECODE;
1205                         if (wma_decode_frame(pwd, samples) < 0)
1206                                 goto fail;
1207                         frame_count++;
1208                         samples += pwd->ahi.channels * pwd->frame_len;
1209                 }
1210
1211                 /* we copy the end of the frame in the last frame buffer */
1212                 pos = get_bits_count(&pwd->gb) +
1213                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1214                 pwd->last_bitoffset = pos & 7;
1215                 pos >>= 3;
1216                 len = buf_size - pos;
1217                 ret = -E_WMA_BAD_SUPERFRAME;
1218                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1219                         goto fail;
1220                 pwd->last_superframe_len = len;
1221                 memcpy(pwd->last_superframe, buf + pos, len);
1222         } else {
1223                 PARA_DEBUG_LOG("not using bit reservoir\n");
1224                 ret = -E_WMA_OUTPUT_SPACE;
1225                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1226                         goto fail;
1227                 /* single frame decode */
1228                 ret = -E_WMA_DECODE;
1229                 if (wma_decode_frame(pwd, samples) < 0)
1230                         goto fail;
1231                 frame_count++;
1232                 samples += pwd->ahi.channels * pwd->frame_len;
1233         }
1234         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1235                 "outbytes: %d, eaten: %d\n",
1236                 frame_count, pwd->frame_len, pwd->block_len,
1237                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1238         *data_size = (int8_t *)samples - (int8_t *)data;
1239         return pwd->ahi.block_align;
1240 fail:
1241         /* reset the bit reservoir on errors */
1242         pwd->last_superframe_len = 0;
1243         return ret;
1244 }
1245
1246 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1247                 struct filter_node *fn)
1248 {
1249         int ret, out_size = fn->bufsize - fn->loaded;
1250         struct private_wmadec_data *pwd = fn->private_data;
1251
1252         if (out_size < 128 * 1024)
1253                 return 0;
1254         if (!pwd) {
1255                 ret = wma_decode_init(inbuffer, len, &pwd);
1256                 if (ret <= 0)
1257                         return ret;
1258                 fn->private_data = pwd;
1259                 fn->fc->channels = pwd->ahi.channels;
1260                 fn->fc->samplerate = pwd->ahi.sample_rate;
1261                 return pwd->ahi.header_len;
1262         }
1263         /* skip 31 bytes */
1264         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1265                 return 0;
1266         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1267                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1268                 len - WMA_FRAME_SKIP);
1269         if (ret < 0)
1270                 return ret;
1271         fn->loaded += out_size;
1272         return ret + WMA_FRAME_SKIP;
1273 }
1274
1275 static void wmadec_close(struct filter_node *fn)
1276 {
1277         struct private_wmadec_data *pwd = fn->private_data;
1278
1279         if (!pwd)
1280                 return;
1281         wmadec_cleanup(pwd);
1282         free(fn->buf);
1283         fn->buf = NULL;
1284         free(fn->private_data);
1285         fn->private_data = NULL;
1286 }
1287
1288 static void wmadec_open(struct filter_node *fn)
1289 {
1290         fn->bufsize = 1024 * 1024;
1291         fn->buf = para_malloc(fn->bufsize);
1292         fn->private_data = NULL;
1293         fn->loaded = 0;
1294 }
1295
1296 /**
1297  * The init function of the wma decoder.
1298  *
1299  * \param f Its fields are filled in by the function.
1300  */
1301 void wmadec_filter_init(struct filter *f)
1302 {
1303         f->open = wmadec_open;
1304         f->close = wmadec_close;
1305         f->convert = wmadec_convert;
1306 }