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         uint16_t *int_table[2];
  87         const struct coef_vlc_table *coef_vlcs[2];
  88         /* frame info */
  89         int frame_len;          ///< frame length in samples
  90         int frame_len_bits;     ///< frame_len = 1 << frame_len_bits
  91         int nb_block_sizes;     ///< number of block sizes
  92         /* block info */
  93         int reset_block_lengths;
  94         int block_len_bits;     ///< log2 of current block length
  95         int next_block_len_bits;        ///< log2 of next block length
  96         int prev_block_len_bits;        ///< log2 of prev block length
  97         int block_len;          ///< block length in samples
  98         int block_pos;          ///< current position in frame
  99         uint8_t ms_stereo;      ///< true if mid/side stereo mode
 100         uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
 101         int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
 102         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 103         float max_exponent[MAX_CHANNELS];
 104         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 105         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 106         float output[BLOCK_MAX_SIZE * 2];
 107         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 108         float *windows[BLOCK_NB_SIZES];
 109         /* output buffer for one frame and the last for IMDCT windowing */
 110         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 111         /* last frame info */
 112         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 113         int last_bitoffset;
 114         int last_superframe_len;
 115         float noise_table[NOISE_TAB_SIZE];
 116         int noise_index;
 117         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 118         /* lsp_to_curve tables */
 119         float lsp_cos_table[BLOCK_MAX_SIZE];
 120         float lsp_pow_e_table[256];
 121         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 122         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 123 };
 124
 125 #define EXPVLCBITS 8
 126 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
 127
 128 #define HGAINVLCBITS 9
 129 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
 130
 131 #define VLCBITS 9
 132 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
 133
 134 DECLARE_ALIGNED(16, float, ff_sine_128[128]);
 135 DECLARE_ALIGNED(16, float, ff_sine_256[256]);
 136 DECLARE_ALIGNED(16, float, ff_sine_512[512]);
 137 DECLARE_ALIGNED(16, float, ff_sine_1024[1024]);
 138 DECLARE_ALIGNED(16, float, ff_sine_2048[2048]);
 139 DECLARE_ALIGNED(16, float, ff_sine_4096[4096]);
 140
 141 static float *ff_sine_windows[6] = {
 142         ff_sine_128, ff_sine_256, ff_sine_512, ff_sine_1024,
 143         ff_sine_2048, ff_sine_4096
 144 };
 145
 146 /* Generate a sine window. */
 147 static void sine_window_init(float *window, int n)
 148 {
 149         int i;
 150
 151         for (i = 0; i < n; i++)
 152                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 153 }
 154
 155 static int wmadec_cleanup(struct private_wmadec_data *s)
 156 {
 157         int i;
 158
 159         for (i = 0; i < s->nb_block_sizes; i++)
 160                 imdct_end(s->mdct_ctx[i]);
 161         if (s->use_exp_vlc)
 162                 free_vlc(&s->exp_vlc);
 163         if (s->use_noise_coding)
 164                 free_vlc(&s->hgain_vlc);
 165         for (i = 0; i < 2; i++) {
 166                 free_vlc(&s->coef_vlc[i]);
 167                 free(s->run_table[i]);
 168                 free(s->level_table[i]);
 169                 free(s->int_table[i]);
 170         }
 171         return 0;
 172 }
 173
 174 /* XXX: use same run/length optimization as mpeg decoders */
 175 //FIXME maybe split decode / encode or pass flag
 176 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 177                 uint16_t **plevel_table, uint16_t **pint_table,
 178                 const struct coef_vlc_table *vlc_table)
 179 {
 180         int n = vlc_table->n;
 181         const uint8_t *table_bits = vlc_table->huffbits;
 182         const uint32_t *table_codes = vlc_table->huffcodes;
 183         const uint16_t *levels_table = vlc_table->levels;
 184         uint16_t *run_table, *level_table, *int_table;
 185         int i, l, j, k, level;
 186
 187         init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4);
 188
 189         run_table = para_malloc(n * sizeof(uint16_t));
 190         level_table = para_malloc(n * sizeof(uint16_t));
 191         int_table = para_malloc(n * sizeof(uint16_t));
 192         i = 2;
 193         level = 1;
 194         k = 0;
 195         while (i < n) {
 196                 int_table[k] = i;
 197                 l = levels_table[k++];
 198                 for (j = 0; j < l; j++) {
 199                         run_table[i] = j;
 200                         level_table[i] = level;
 201                         i++;
 202                 }
 203                 level++;
 204         }
 205         *prun_table = run_table;
 206         *plevel_table = level_table;
 207         *pint_table = int_table;
 208 }
 209
 210 /* compute the scale factor band sizes for each MDCT block size */
 211 static void compute_scale_factor_band_sizes(struct private_wmadec_data *s,
 212         float high_freq)
 213 {
 214         struct asf_header_info *ahi = &s->ahi;
 215         int a, b, pos, lpos, k, block_len, i, j, n;
 216         const uint8_t *table;
 217
 218         s->coefs_start = 0;
 219         for (k = 0; k < s->nb_block_sizes; k++) {
 220                 block_len = s->frame_len >> k;
 221
 222                 table = NULL;
 223                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 224                 if (a < 3) {
 225                         if (ahi->sample_rate >= 44100)
 226                                 table = exponent_band_44100[a];
 227                         else if (ahi->sample_rate >= 32000)
 228                                 table = exponent_band_32000[a];
 229                         else if (ahi->sample_rate >= 22050)
 230                                 table = exponent_band_22050[a];
 231                 }
 232                 if (table) {
 233                         n = *table++;
 234                         for (i = 0; i < n; i++)
 235                                 s->exponent_bands[k][i] = table[i];
 236                         s->exponent_sizes[k] = n;
 237                 } else {
 238                         j = 0;
 239                         lpos = 0;
 240                         for (i = 0; i < 25; i++) {
 241                                 a = wma_critical_freqs[i];
 242                                 b = ahi->sample_rate;
 243                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 244                                 pos <<= 2;
 245                                 if (pos > block_len)
 246                                         pos = block_len;
 247                                 if (pos > lpos)
 248                                         s->exponent_bands[k][j++] = pos - lpos;
 249                                 if (pos >= block_len)
 250                                         break;
 251                                 lpos = pos;
 252                         }
 253                         s->exponent_sizes[k] = j;
 254                 }
 255
 256                 /* max number of coefs */
 257                 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 258                 /* high freq computation */
 259                 s->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 260                         / ahi->sample_rate + 0.5);
 261                 n = s->exponent_sizes[k];
 262                 j = 0;
 263                 pos = 0;
 264                 for (i = 0; i < n; i++) {
 265                         int start, end;
 266                         start = pos;
 267                         pos += s->exponent_bands[k][i];
 268                         end = pos;
 269                         if (start < s->high_band_start[k])
 270                                 start = s->high_band_start[k];
 271                         if (end > s->coefs_end[k])
 272                                 end = s->coefs_end[k];
 273                         if (end > start)
 274                                 s->exponent_high_bands[k][j++] = end - start;
 275                 }
 276                 s->exponent_high_sizes[k] = j;
 277         }
 278 }
 279
 280 static int wma_init(struct private_wmadec_data *s, int flags2, struct asf_header_info *ahi)
 281 {
 282         int i;
 283         float bps1, high_freq;
 284         volatile float bps;
 285         int sample_rate1;
 286         int coef_vlc_table;
 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                 s->frame_len_bits = 9;
 296         } else if (ahi->sample_rate <= 22050) {
 297                 s->frame_len_bits = 10;
 298         } else {
 299                 s->frame_len_bits = 11;
 300         }
 301         s->frame_len = 1 << s->frame_len_bits;
 302         if (s->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 = s->frame_len_bits - BLOCK_MIN_BITS;
 308                 if (nb > nb_max)
 309                         nb = nb_max;
 310                 s->nb_block_sizes = nb + 1;
 311         } else
 312                 s->nb_block_sizes = 1;
 313
 314         /* init rate dependent parameters */
 315         s->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         s->byte_offset_bits = wma_log2((int) (bps * s->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                         s->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                         s->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                         s->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                 s->frame_len, bps, bps1,
 383                 high_freq, s->byte_offset_bits);
 384         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 385                 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 386
 387         compute_scale_factor_band_sizes(s, high_freq);
 388         /* init MDCT windows : simple sinus window */
 389         for (i = 0; i < s->nb_block_sizes; i++) {
 390                 int n;
 391                 n = 1 << (s->frame_len_bits - i);
 392                 sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
 393                 s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
 394         }
 395
 396         s->reset_block_lengths = 1;
 397
 398         if (s->use_noise_coding) {
 399                 /* init the noise generator */
 400                 if (s->use_exp_vlc)
 401                         s->noise_mult = 0.02;
 402                 else
 403                         s->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) * s->noise_mult;
 410                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 411                                 seed = seed * 314159 + 1;
 412                                 s->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         s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 426         s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 427         init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
 428                 &s->int_table[0], s->coef_vlcs[0]);
 429         init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
 430                 &s->int_table[1], s->coef_vlcs[1]);
 431         return 0;
 432 }
 433
 434 static void wma_lsp_to_curve_init(struct private_wmadec_data *s, 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                 s->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                 s->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                 s->lsp_pow_m_table1[i] = 2 * a - b;
 456                 s->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 *s;
 464         int ret, i;
 465
 466         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 467         s = para_calloc(sizeof(*s));
 468         ret = read_asf_header(initial_buf, len, &s->ahi);
 469         if (ret <= 0) {
 470                 free(s);
 471                 return ret;
 472         }
 473
 474         s->use_exp_vlc = s->ahi.flags2 & 0x0001;
 475         s->use_bit_reservoir = s->ahi.flags2 & 0x0002;
 476         s->use_variable_block_len = s->ahi.flags2 & 0x0004;
 477
 478         ret = wma_init(s, s->ahi.flags2, &s->ahi);
 479         if (ret < 0)
 480                 return ret;
 481         /* init MDCT */
 482         for (i = 0; i < s->nb_block_sizes; i++) {
 483                 ret = imdct_init(s->frame_len_bits - i + 1, &s->mdct_ctx[i]);
 484                 if (ret < 0)
 485                         return ret;
 486         }
 487         if (s->use_noise_coding) {
 488                 PARA_INFO_LOG("using noise coding\n");
 489                 init_vlc(&s->hgain_vlc, HGAINVLCBITS,
 490                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 491                         1, 1, ff_wma_hgain_huffcodes, 2, 2);
 492         }
 493
 494         if (s->use_exp_vlc) {
 495                 PARA_INFO_LOG("using exp_vlc\n");
 496                 init_vlc(&s->exp_vlc, EXPVLCBITS,
 497                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 498                 1, 1, ff_wma_scale_huffcodes, 4, 4);
 499         } else {
 500                 PARA_INFO_LOG("using curve\n");
 501                 wma_lsp_to_curve_init(s, s->frame_len);
 502         }
 503         *result = s;
 504         return s->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 *s, 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 = s->lsp_pow_m_table1[m];
 528         b = s->lsp_pow_m_table2[m];
 529         return s->lsp_pow_e_table[e] * (a + b * t.f);
 530 }
 531
 532 static void wma_lsp_to_curve(struct private_wmadec_data *s,
 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 = s->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(s, 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 *s, 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(&s->gb, 3);
 567                 else
 568                         val = get_bits(&s->gb, 4);
 569                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 570         }
 571
 572         wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
 573                          s->block_len, lsp_coefs);
 574 }
 575
 576 /*
 577  * Parse a vlc code, faster then get_vlc().
 578  *
 579  * \param bits The number of bits which will be read at once, must be
 580  * identical to nb_bits in init_vlc()
 581  *
 582  * \param max_depth The number of times bits bits must be read to completely
 583  * read the longest vlc code = (max_vlc_length + bits - 1) / bits.
 584  */
 585 static int get_vlc2(struct getbit_context *s, VLC_TYPE(*table)[2],
 586                 int bits, int max_depth)
 587 {
 588         int code;
 589
 590         OPEN_READER(re, s)
 591         UPDATE_CACHE(re, s)
 592         GET_VLC(code, re, s, table, bits, max_depth)
 593         CLOSE_READER(re, s)
 594         return code;
 595 }
 596
 597 /* Decode exponents coded with VLC codes. */
 598 static int decode_exp_vlc(struct private_wmadec_data *s, int ch)
 599 {
 600         int last_exp, n, code;
 601         const uint16_t *ptr, *band_ptr;
 602         float v, *q, max_scale, *q_end;
 603
 604         band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
 605         ptr = band_ptr;
 606         q = s->exponents[ch];
 607         q_end = q + s->block_len;
 608         max_scale = 0;
 609         last_exp = 36;
 610
 611         while (q < q_end) {
 612                 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
 613                 if (code < 0)
 614                         return -1;
 615                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 616                 last_exp += code - 60;
 617                 /* XXX: use a table */
 618                 v = pow(10, last_exp * (1.0 / 16.0));
 619                 if (v > max_scale)
 620                         max_scale = v;
 621                 n = *ptr++;
 622                 do {
 623                         *q++ = v;
 624                 } while (--n);
 625         }
 626         s->max_exponent[ch] = max_scale;
 627         return 0;
 628 }
 629
 630 /* compute src0 * src1 + src2 */
 631 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 632                 const float *src2, int len)
 633 {
 634         int i;
 635
 636         for (i = 0; i < len; i++)
 637                 dst[i] = src0[i] * src1[i] + src2[i];
 638 }
 639
 640 static inline void vector_mult_reverse(float *dst, const float *src0,
 641                 const float *src1, int len)
 642 {
 643         int i;
 644
 645         src1 += len - 1;
 646         for (i = 0; i < len; i++)
 647                 dst[i] = src0[i] * src1[-i];
 648 }
 649
 650 /**
 651  * Apply MDCT window and add into output.
 652  *
 653  * We ensure that when the windows overlap their squared sum
 654  * is always 1 (MDCT reconstruction rule).
 655  */
 656 static void wma_window(struct private_wmadec_data *s, float *out)
 657 {
 658         float *in = s->output;
 659         int block_len, bsize, n;
 660
 661         /* left part */
 662         if (s->block_len_bits <= s->prev_block_len_bits) {
 663                 block_len = s->block_len;
 664                 bsize = s->frame_len_bits - s->block_len_bits;
 665                 vector_mult_add(out, in, s->windows[bsize], out, block_len);
 666         } else {
 667                 block_len = 1 << s->prev_block_len_bits;
 668                 n = (s->block_len - block_len) / 2;
 669                 bsize = s->frame_len_bits - s->prev_block_len_bits;
 670                 vector_mult_add(out + n, in + n, s->windows[bsize], out + n,
 671                         block_len);
 672                 memcpy(out + n + block_len, in + n + block_len,
 673                         n * sizeof(float));
 674         }
 675         out += s->block_len;
 676         in += s->block_len;
 677         /* right part */
 678         if (s->block_len_bits <= s->next_block_len_bits) {
 679                 block_len = s->block_len;
 680                 bsize = s->frame_len_bits - s->block_len_bits;
 681                 vector_mult_reverse(out, in, s->windows[bsize], block_len);
 682         } else {
 683                 block_len = 1 << s->next_block_len_bits;
 684                 n = (s->block_len - block_len) / 2;
 685                 bsize = s->frame_len_bits - s->next_block_len_bits;
 686                 memcpy(out, in, n * sizeof(float));
 687                 vector_mult_reverse(out + n, in + n, s->windows[bsize],
 688                         block_len);
 689                 memset(out + n + block_len, 0, n * sizeof(float));
 690         }
 691 }
 692
 693 static int wma_total_gain_to_bits(int total_gain)
 694 {
 695         if (total_gain < 15)
 696                 return 13;
 697         else if (total_gain < 32)
 698                 return 12;
 699         else if (total_gain < 40)
 700                 return 11;
 701         else if (total_gain < 45)
 702                 return 10;
 703         else
 704                 return 9;
 705 }
 706
 707 /**
 708  * @return 0 if OK. 1 if last block of frame. return -1 if
 709  * unrecorrable error.
 710  */
 711 static int wma_decode_block(struct private_wmadec_data *s)
 712 {
 713         int n, v, ch, code, bsize;
 714         int coef_nb_bits, total_gain;
 715         int nb_coefs[MAX_CHANNELS];
 716         float mdct_norm;
 717
 718         /* compute current block length */
 719         if (s->use_variable_block_len) {
 720                 n = wma_log2(s->nb_block_sizes - 1) + 1;
 721
 722                 if (s->reset_block_lengths) {
 723                         s->reset_block_lengths = 0;
 724                         v = get_bits(&s->gb, n);
 725                         if (v >= s->nb_block_sizes)
 726                                 return -1;
 727                         s->prev_block_len_bits = s->frame_len_bits - v;
 728                         v = get_bits(&s->gb, n);
 729                         if (v >= s->nb_block_sizes)
 730                                 return -1;
 731                         s->block_len_bits = s->frame_len_bits - v;
 732                 } else {
 733                         /* update block lengths */
 734                         s->prev_block_len_bits = s->block_len_bits;
 735                         s->block_len_bits = s->next_block_len_bits;
 736                 }
 737                 v = get_bits(&s->gb, n);
 738                 if (v >= s->nb_block_sizes)
 739                         return -1;
 740                 s->next_block_len_bits = s->frame_len_bits - v;
 741         } else {
 742                 /* fixed block len */
 743                 s->next_block_len_bits = s->frame_len_bits;
 744                 s->prev_block_len_bits = s->frame_len_bits;
 745                 s->block_len_bits = s->frame_len_bits;
 746         }
 747
 748         /* now check if the block length is coherent with the frame length */
 749         s->block_len = 1 << s->block_len_bits;
 750         if ((s->block_pos + s->block_len) > s->frame_len)
 751                 return -E_INCOHERENT_BLOCK_LEN;
 752
 753         if (s->ahi.channels == 2)
 754                 s->ms_stereo = get_bits1(&s->gb);
 755         v = 0;
 756         for (ch = 0; ch < s->ahi.channels; ch++) {
 757                 int a = get_bits1(&s->gb);
 758                 s->channel_coded[ch] = a;
 759                 v |= a;
 760         }
 761
 762         bsize = s->frame_len_bits - s->block_len_bits;
 763
 764         /* if no channel coded, no need to go further */
 765         /* XXX: fix potential framing problems */
 766         if (!v)
 767                 goto next;
 768
 769         /* read total gain and extract corresponding number of bits for
 770            coef escape coding */
 771         total_gain = 1;
 772         for (;;) {
 773                 int a = get_bits(&s->gb, 7);
 774                 total_gain += a;
 775                 if (a != 127)
 776                         break;
 777         }
 778
 779         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 780
 781         /* compute number of coefficients */
 782         n = s->coefs_end[bsize] - s->coefs_start;
 783         for (ch = 0; ch < s->ahi.channels; ch++)
 784                 nb_coefs[ch] = n;
 785
 786         /* complex coding */
 787         if (s->use_noise_coding) {
 788                 for (ch = 0; ch < s->ahi.channels; ch++) {
 789                         if (s->channel_coded[ch]) {
 790                                 int i, m, a;
 791                                 m = s->exponent_high_sizes[bsize];
 792                                 for (i = 0; i < m; i++) {
 793                                         a = get_bits1(&s->gb);
 794                                         s->high_band_coded[ch][i] = a;
 795                                         /* if noise coding, the coefficients are not transmitted */
 796                                         if (a)
 797                                                 nb_coefs[ch] -=
 798                                                     s->
 799                                                     exponent_high_bands[bsize]
 800                                                     [i];
 801                                 }
 802                         }
 803                 }
 804                 for (ch = 0; ch < s->ahi.channels; ch++) {
 805                         if (s->channel_coded[ch]) {
 806                                 int i, val;
 807
 808                                 n = s->exponent_high_sizes[bsize];
 809                                 val = (int) 0x80000000;
 810                                 for (i = 0; i < n; i++) {
 811                                         if (s->high_band_coded[ch][i]) {
 812                                                 if (val == (int) 0x80000000) {
 813                                                         val =
 814                                                             get_bits(&s->gb,
 815                                                                      7) - 19;
 816                                                 } else {
 817                                                         code =
 818                                                             get_vlc2(&s->gb,
 819                                                                      s->
 820                                                                      hgain_vlc.
 821                                                                      table,
 822                                                                      HGAINVLCBITS,
 823                                                                      HGAINMAX);
 824                                                         if (code < 0)
 825                                                                 return -1;
 826                                                         val += code - 18;
 827                                                 }
 828                                                 s->high_band_values[ch][i] =
 829                                                     val;
 830                                         }
 831                                 }
 832                         }
 833                 }
 834         }
 835
 836         /* exponents can be reused in short blocks. */
 837         if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {
 838                 for (ch = 0; ch < s->ahi.channels; ch++) {
 839                         if (s->channel_coded[ch]) {
 840                                 if (s->use_exp_vlc) {
 841                                         if (decode_exp_vlc(s, ch) < 0)
 842                                                 return -1;
 843                                 } else {
 844                                         decode_exp_lsp(s, ch);
 845                                 }
 846                                 s->exponents_bsize[ch] = bsize;
 847                         }
 848                 }
 849         }
 850
 851         /* parse spectral coefficients : just RLE encoding */
 852         for (ch = 0; ch < s->ahi.channels; ch++) {
 853                 if (s->channel_coded[ch]) {
 854                         struct vlc *coef_vlc;
 855                         int level, run, sign, tindex;
 856                         int16_t *ptr, *eptr;
 857                         const uint16_t *level_table, *run_table;
 858
 859                         /* special VLC tables are used for ms stereo because
 860                            there is potentially less energy there */
 861                         tindex = (ch == 1 && s->ms_stereo);
 862                         coef_vlc = &s->coef_vlc[tindex];
 863                         run_table = s->run_table[tindex];
 864                         level_table = s->level_table[tindex];
 865                         /* XXX: optimize */
 866                         ptr = &s->coefs1[ch][0];
 867                         eptr = ptr + nb_coefs[ch];
 868                         memset(ptr, 0, s->block_len * sizeof(int16_t));
 869                         for (;;) {
 870                                 code =
 871                                     get_vlc2(&s->gb, coef_vlc->table, VLCBITS,
 872                                              VLCMAX);
 873                                 if (code < 0)
 874                                         return -1;
 875                                 if (code == 1) {
 876                                         /* EOB */
 877                                         break;
 878                                 } else if (code == 0) {
 879                                         /* escape */
 880                                         level = get_bits(&s->gb, coef_nb_bits);
 881                                         /* NOTE: this is rather suboptimal. reading
 882                                            block_len_bits would be better */
 883                                         run =
 884                                             get_bits(&s->gb, s->frame_len_bits);
 885                                 } else {
 886                                         /* normal code */
 887                                         run = run_table[code];
 888                                         level = level_table[code];
 889                                 }
 890                                 sign = get_bits1(&s->gb);
 891                                 if (!sign)
 892                                         level = -level;
 893                                 ptr += run;
 894                                 if (ptr >= eptr) {
 895                                         PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 896                                         break;
 897                                 }
 898                                 *ptr++ = level;
 899                                 /* NOTE: EOB can be omitted */
 900                                 if (ptr >= eptr)
 901                                         break;
 902                         }
 903                 }
 904         }
 905
 906         /* normalize */
 907         {
 908                 int n4 = s->block_len / 2;
 909                 mdct_norm = 1.0 / (float) n4;
 910         }
 911
 912         /* finally compute the MDCT coefficients */
 913         for (ch = 0; ch < s->ahi.channels; ch++) {
 914                 if (s->channel_coded[ch]) {
 915                         int16_t *coefs1;
 916                         float *coefs, *exponents, mult, mult1, noise;
 917                         int i, j, n1, last_high_band, esize;
 918                         float exp_power[HIGH_BAND_MAX_SIZE];
 919
 920                         coefs1 = s->coefs1[ch];
 921                         exponents = s->exponents[ch];
 922                         esize = s->exponents_bsize[ch];
 923                         mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
 924                         mult *= mdct_norm;
 925                         coefs = s->coefs[ch];
 926                         if (s->use_noise_coding) {
 927                                 mult1 = mult;
 928                                 /* very low freqs : noise */
 929                                 for (i = 0; i < s->coefs_start; i++) {
 930                                         *coefs++ =
 931                                             s->noise_table[s->noise_index] *
 932                                             exponents[i << bsize >> esize] *
 933                                             mult1;
 934                                         s->noise_index =
 935                                             (s->noise_index +
 936                                              1) & (NOISE_TAB_SIZE - 1);
 937                                 }
 938
 939                                 n1 = s->exponent_high_sizes[bsize];
 940
 941                                 /* compute power of high bands */
 942                                 exponents = s->exponents[ch] +
 943                                     (s->high_band_start[bsize] << bsize);
 944                                 last_high_band = 0;     /* avoid warning */
 945                                 for (j = 0; j < n1; j++) {
 946                                         n = s->exponent_high_bands[s->
 947                                                                    frame_len_bits
 948                                                                    -
 949                                                                    s->
 950                                                                    block_len_bits]
 951                                             [j];
 952                                         if (s->high_band_coded[ch][j]) {
 953                                                 float e2, val;
 954                                                 e2 = 0;
 955                                                 for (i = 0; i < n; i++) {
 956                                                         val = exponents[i << bsize
 957                                                                       >> esize];
 958                                                         e2 += val * val;
 959                                                 }
 960                                                 exp_power[j] = e2 / n;
 961                                                 last_high_band = j;
 962                                         }
 963                                         exponents += n << bsize;
 964                                 }
 965
 966                                 /* main freqs and high freqs */
 967                                 exponents =
 968                                     s->exponents[ch] +
 969                                     (s->coefs_start << bsize);
 970                                 for (j = -1; j < n1; j++) {
 971                                         if (j < 0) {
 972                                                 n = s->high_band_start[bsize] -
 973                                                     s->coefs_start;
 974                                         } else {
 975                                                 n = s->exponent_high_bands[s->
 976                                                                            frame_len_bits
 977                                                                            -
 978                                                                            s->
 979                                                                            block_len_bits]
 980                                                     [j];
 981                                         }
 982                                         if (j >= 0 && s->high_band_coded[ch][j]) {
 983                                                 /* use noise with specified power */
 984                                                 mult1 =
 985                                                     sqrt(exp_power[j] /
 986                                                          exp_power
 987                                                          [last_high_band]);
 988                                                 /* XXX: use a table */
 989                                                 mult1 =
 990                                                     mult1 * pow(10,
 991                                                                 s->
 992                                                                 high_band_values
 993                                                                 [ch][j] * 0.05);
 994                                                 mult1 =
 995                                                     mult1 /
 996                                                     (s->max_exponent[ch] *
 997                                                      s->noise_mult);
 998                                                 mult1 *= mdct_norm;
 999                                                 for (i = 0; i < n; i++) {
1000                                                         noise =
1001                                                             s->noise_table[s->
1002                                                                            noise_index];
1003                                                         s->noise_index =
1004                                                             (s->noise_index +
1005                                                              1) &
1006                                                             (NOISE_TAB_SIZE -
1007                                                              1);
1008                                                         *coefs++ =
1009                                                             noise *
1010                                                             exponents[i << bsize
1011                                                                       >> esize]
1012                                                             * mult1;
1013                                                 }
1014                                                 exponents += n << bsize;
1015                                         } else {
1016                                                 /* coded values + small noise */
1017                                                 for (i = 0; i < n; i++) {
1018                                                         noise =
1019                                                             s->noise_table[s->
1020                                                                            noise_index];
1021                                                         s->noise_index =
1022                                                             (s->noise_index +
1023                                                              1) &
1024                                                             (NOISE_TAB_SIZE -
1025                                                              1);
1026                                                         *coefs++ =
1027                                                             ((*coefs1++) +
1028                                                              noise) *
1029                                                             exponents[i << bsize
1030                                                                       >> esize]
1031                                                             * mult;
1032                                                 }
1033                                                 exponents += n << bsize;
1034                                         }
1035                                 }
1036
1037                                 /* very high freqs : noise */
1038                                 n = s->block_len - s->coefs_end[bsize];
1039                                 mult1 =
1040                                     mult * exponents[((-1 << bsize)) >> esize];
1041                                 for (i = 0; i < n; i++) {
1042                                         *coefs++ =
1043                                             s->noise_table[s->noise_index] *
1044                                             mult1;
1045                                         s->noise_index =
1046                                             (s->noise_index +
1047                                              1) & (NOISE_TAB_SIZE - 1);
1048                                 }
1049                         } else {
1050                                 /* XXX: optimize more */
1051                                 for (i = 0; i < s->coefs_start; i++)
1052                                         *coefs++ = 0.0;
1053                                 n = nb_coefs[ch];
1054                                 for (i = 0; i < n; i++) {
1055                                         *coefs++ =
1056                                             coefs1[i] *
1057                                             exponents[i << bsize >> esize] *
1058                                             mult;
1059                                 }
1060                                 n = s->block_len - s->coefs_end[bsize];
1061                                 for (i = 0; i < n; i++)
1062                                         *coefs++ = 0.0;
1063                         }
1064                 }
1065         }
1066
1067         if (s->ms_stereo && s->channel_coded[1]) {
1068                 float a, b;
1069                 int i;
1070
1071                 /*
1072                  * Nominal case for ms stereo: we do it before mdct.
1073                  *
1074                  * No need to optimize this case because it should almost never
1075                  * happen.
1076                  */
1077                 if (!s->channel_coded[0]) {
1078                         PARA_NOTICE_LOG("rare ms-stereo\n");
1079                         memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1080                         s->channel_coded[0] = 1;
1081                 }
1082                 for (i = 0; i < s->block_len; i++) {
1083                         a = s->coefs[0][i];
1084                         b = s->coefs[1][i];
1085                         s->coefs[0][i] = a + b;
1086                         s->coefs[1][i] = a - b;
1087                 }
1088         }
1089
1090 next:
1091         for (ch = 0; ch < s->ahi.channels; ch++) {
1092                 int n4, index;
1093
1094                 n = s->block_len;
1095                 n4 = s->block_len / 2;
1096                 if (s->channel_coded[ch])
1097                         imdct(s->mdct_ctx[bsize], s->output, s->coefs[ch]);
1098                 else if (!(s->ms_stereo && ch == 1))
1099                         memset(s->output, 0, sizeof(s->output));
1100
1101                 /* multiply by the window and add in the frame */
1102                 index = (s->frame_len / 2) + s->block_pos - n4;
1103                 wma_window(s, &s->frame_out[ch][index]);
1104         }
1105
1106         /* update block number */
1107         s->block_pos += s->block_len;
1108         if (s->block_pos >= s->frame_len)
1109                 return 1;
1110         else
1111                 return 0;
1112 }
1113
1114 /*
1115  * Clip a signed integer value into the -32768,32767 range.
1116  *
1117  * \param a The value to clip.
1118  *
1119  * \return The clipped value.
1120  */
1121 static inline int16_t av_clip_int16(int a)
1122 {
1123         if ((a + 32768) & ~65535)
1124                 return (a >> 31) ^ 32767;
1125         else
1126                 return a;
1127 }
1128
1129 /* Decode a frame of frame_len samples. */
1130 static int wma_decode_frame(struct private_wmadec_data *s, int16_t *samples)
1131 {
1132         int ret, i, n, ch, incr;
1133         int16_t *ptr;
1134         float *iptr;
1135
1136         /* read each block */
1137         s->block_pos = 0;
1138         for (;;) {
1139                 ret = wma_decode_block(s);
1140                 if (ret < 0)
1141                         return -1;
1142                 if (ret)
1143                         break;
1144         }
1145
1146         /* convert frame to integer */
1147         n = s->frame_len;
1148         incr = s->ahi.channels;
1149         for (ch = 0; ch < s->ahi.channels; ch++) {
1150                 ptr = samples + ch;
1151                 iptr = s->frame_out[ch];
1152
1153                 for (i = 0; i < n; i++) {
1154                         *ptr = av_clip_int16(lrintf(*iptr++));
1155                         ptr += incr;
1156                 }
1157                 /* prepare for next block */
1158                 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1159                         s->frame_len * sizeof(float));
1160         }
1161         return 0;
1162 }
1163
1164 static int wma_decode_superframe(struct private_wmadec_data *s, void *data,
1165                 int *data_size, const uint8_t *buf, int buf_size)
1166 {
1167         int ret, nb_frames, bit_offset, i, pos, len;
1168         uint8_t *q;
1169         int16_t *samples;
1170         static int frame_count;
1171
1172         if (buf_size == 0) {
1173                 s->last_superframe_len = 0;
1174                 return 0;
1175         }
1176         if (buf_size < s->ahi.block_align)
1177                 return 0;
1178         buf_size = s->ahi.block_align;
1179         samples = data;
1180         init_get_bits(&s->gb, buf, buf_size * 8);
1181         if (s->use_bit_reservoir) {
1182                 /* read super frame header */
1183                 skip_bits(&s->gb, 4);   /* super frame index */
1184                 nb_frames = get_bits(&s->gb, 4) - 1;
1185                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1186                 ret = -E_WMA_OUTPUT_SPACE;
1187                 if ((nb_frames + 1) * s->ahi.channels * s->frame_len
1188                                 * sizeof(int16_t) > *data_size)
1189                         goto fail;
1190
1191                 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1192
1193                 if (s->last_superframe_len > 0) {
1194                         /* add bit_offset bits to last frame */
1195                         ret = -E_WMA_BAD_SUPERFRAME;
1196                         if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1197                                         MAX_CODED_SUPERFRAME_SIZE)
1198                                 goto fail;
1199                         q = s->last_superframe + s->last_superframe_len;
1200                         len = bit_offset;
1201                         while (len > 7) {
1202                                 *q++ = get_bits(&s->gb, 8);
1203                                 len -= 8;
1204                         }
1205                         if (len > 0)
1206                                 *q++ = get_bits(&s->gb, len) << (8 - len);
1207
1208                         /* XXX: bit_offset bits into last frame */
1209                         init_get_bits(&s->gb, s->last_superframe,
1210                                 MAX_CODED_SUPERFRAME_SIZE * 8);
1211                         /* skip unused bits */
1212                         if (s->last_bitoffset > 0)
1213                                 skip_bits(&s->gb, s->last_bitoffset);
1214                         /*
1215                          * This frame is stored in the last superframe and in
1216                          * the current one.
1217                          */
1218                         ret = -E_WMA_DECODE;
1219                         if (wma_decode_frame(s, samples) < 0)
1220                                 goto fail;
1221                         frame_count++;
1222                         samples += s->ahi.channels * s->frame_len;
1223                 }
1224
1225                 /* read each frame starting from bit_offset */
1226                 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1227                 init_get_bits(&s->gb, buf + (pos >> 3),
1228                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)) * 8);
1229                 len = pos & 7;
1230                 if (len > 0)
1231                         skip_bits(&s->gb, len);
1232
1233                 s->reset_block_lengths = 1;
1234                 for (i = 0; i < nb_frames; i++) {
1235                         ret = -E_WMA_DECODE;
1236                         if (wma_decode_frame(s, samples) < 0)
1237                                 goto fail;
1238                         frame_count++;
1239                         samples += s->ahi.channels * s->frame_len;
1240                 }
1241
1242                 /* we copy the end of the frame in the last frame buffer */
1243                 pos = get_bits_count(&s->gb) +
1244                         ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1245                 s->last_bitoffset = pos & 7;
1246                 pos >>= 3;
1247                 len = buf_size - pos;
1248                 ret = -E_WMA_BAD_SUPERFRAME;
1249                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1250                         goto fail;
1251                 s->last_superframe_len = len;
1252                 memcpy(s->last_superframe, buf + pos, len);
1253         } else {
1254                 PARA_DEBUG_LOG("not using bit reservoir\n");
1255                 ret = -E_WMA_OUTPUT_SPACE;
1256                 if (s->ahi.channels * s->frame_len * sizeof(int16_t) > *data_size)
1257                         goto fail;
1258                 /* single frame decode */
1259                 ret = -E_WMA_DECODE;
1260                 if (wma_decode_frame(s, samples) < 0)
1261                         goto fail;
1262                 frame_count++;
1263                 samples += s->ahi.channels * s->frame_len;
1264         }
1265         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1266                 "outbytes: %d, eaten: %d\n",
1267                 frame_count, s->frame_len, s->block_len,
1268                 (int8_t *) samples - (int8_t *) data, s->ahi.block_align);
1269         *data_size = (int8_t *)samples - (int8_t *)data;
1270         return s->ahi.block_align;
1271 fail:
1272         /* reset the bit reservoir on errors */
1273         s->last_superframe_len = 0;
1274         return ret;
1275 }
1276
1277 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1278                 struct filter_node *fn)
1279 {
1280         int ret, out_size = fn->bufsize - fn->loaded;
1281         struct private_wmadec_data *pwd = fn->private_data;
1282
1283         if (out_size < 128 * 1024)
1284                 return 0;
1285         if (!pwd) {
1286                 ret = wma_decode_init(inbuffer, len, &pwd);
1287                 if (ret <= 0)
1288                         return ret;
1289                 fn->private_data = pwd;
1290                 fn->fc->channels = pwd->ahi.channels;
1291                 fn->fc->samplerate = pwd->ahi.sample_rate;
1292                 return pwd->ahi.header_len;
1293         }
1294         /* skip 31 bytes */
1295         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1296                 return 0;
1297         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1298                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1299                 len - WMA_FRAME_SKIP);
1300         if (ret < 0)
1301                 return ret;
1302         fn->loaded += out_size;
1303         return ret + WMA_FRAME_SKIP;
1304 }
1305
1306 static void wmadec_close(struct filter_node *fn)
1307 {
1308         struct private_wmadec_data *pwd = fn->private_data;
1309
1310         if (!pwd)
1311                 return;
1312         wmadec_cleanup(pwd);
1313         free(fn->buf);
1314         fn->buf = NULL;
1315         free(fn->private_data);
1316         fn->private_data = NULL;
1317 }
1318
1319 static void wmadec_open(struct filter_node *fn)
1320 {
1321         fn->bufsize = 1024 * 1024;
1322         fn->buf = para_malloc(fn->bufsize);
1323         fn->private_data = NULL;
1324         fn->loaded = 0;
1325 }
1326
1327 /**
1328  * The init function of the wma decoder.
1329  *
1330  * \param f Its fields are filled in by the function.
1331  */
1332 void wmadec_filter_init(struct filter *f)
1333 {
1334         f->open = wmadec_open;
1335         f->close = wmadec_close;
1336         f->convert = wmadec_convert;
1337 }