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
 162         if (s->use_exp_vlc)
 163                 free_vlc(&s->exp_vlc);
 164         if (s->use_noise_coding)
 165                 free_vlc(&s->hgain_vlc);
 166         for (i = 0; i < 2; i++) {
 167                 free_vlc(&s->coef_vlc[i]);
 168                 free(s->run_table[i]);
 169                 free(s->level_table[i]);
 170                 free(s->int_table[i]);
 171         }
 172         return 0;
 173 }
 174
 175 /* XXX: use same run/length optimization as mpeg decoders */
 176 //FIXME maybe split decode / encode or pass flag
 177 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 178                 uint16_t **plevel_table, uint16_t **pint_table,
 179                 const struct coef_vlc_table *vlc_table)
 180 {
 181         int n = vlc_table->n;
 182         const uint8_t *table_bits = vlc_table->huffbits;
 183         const uint32_t *table_codes = vlc_table->huffcodes;
 184         const uint16_t *levels_table = vlc_table->levels;
 185         uint16_t *run_table, *level_table, *int_table;
 186         int i, l, j, k, level;
 187
 188         init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4);
 189
 190         run_table = para_malloc(n * sizeof(uint16_t));
 191         level_table = para_malloc(n * sizeof(uint16_t));
 192         int_table = para_malloc(n * sizeof(uint16_t));
 193         i = 2;
 194         level = 1;
 195         k = 0;
 196         while (i < n) {
 197                 int_table[k] = i;
 198                 l = levels_table[k++];
 199                 for (j = 0; j < l; j++) {
 200                         run_table[i] = j;
 201                         level_table[i] = level;
 202                         i++;
 203                 }
 204                 level++;
 205         }
 206         *prun_table = run_table;
 207         *plevel_table = level_table;
 208         *pint_table = int_table;
 209 }
 210
 211 /* compute the scale factor band sizes for each MDCT block size */
 212 static void compute_scale_factor_band_sizes(struct private_wmadec_data *s,
 213         float high_freq)
 214 {
 215         struct asf_header_info *ahi = &s->ahi;
 216         int a, b, pos, lpos, k, block_len, i, j, n;
 217         const uint8_t *table;
 218
 219         s->coefs_start = 0;
 220         for (k = 0; k < s->nb_block_sizes; k++) {
 221                 block_len = s->frame_len >> k;
 222
 223                 table = NULL;
 224                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 225                 if (a < 3) {
 226                         if (ahi->sample_rate >= 44100)
 227                                 table = exponent_band_44100[a];
 228                         else if (ahi->sample_rate >= 32000)
 229                                 table = exponent_band_32000[a];
 230                         else if (ahi->sample_rate >= 22050)
 231                                 table = exponent_band_22050[a];
 232                 }
 233                 if (table) {
 234                         n = *table++;
 235                         for (i = 0; i < n; i++)
 236                                 s->exponent_bands[k][i] = table[i];
 237                         s->exponent_sizes[k] = n;
 238                 } else {
 239                         j = 0;
 240                         lpos = 0;
 241                         for (i = 0; i < 25; i++) {
 242                                 a = wma_critical_freqs[i];
 243                                 b = ahi->sample_rate;
 244                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 245                                 pos <<= 2;
 246                                 if (pos > block_len)
 247                                         pos = block_len;
 248                                 if (pos > lpos)
 249                                         s->exponent_bands[k][j++] = pos - lpos;
 250                                 if (pos >= block_len)
 251                                         break;
 252                                 lpos = pos;
 253                         }
 254                         s->exponent_sizes[k] = j;
 255                 }
 256
 257                 /* max number of coefs */
 258                 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 259                 /* high freq computation */
 260                 s->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 261                         / ahi->sample_rate + 0.5);
 262                 n = s->exponent_sizes[k];
 263                 j = 0;
 264                 pos = 0;
 265                 for (i = 0; i < n; i++) {
 266                         int start, end;
 267                         start = pos;
 268                         pos += s->exponent_bands[k][i];
 269                         end = pos;
 270                         if (start < s->high_band_start[k])
 271                                 start = s->high_band_start[k];
 272                         if (end > s->coefs_end[k])
 273                                 end = s->coefs_end[k];
 274                         if (end > start)
 275                                 s->exponent_high_bands[k][j++] = end - start;
 276                 }
 277                 s->exponent_high_sizes[k] = j;
 278         }
 279 }
 280
 281 static int wma_init(struct private_wmadec_data *s, int flags2, struct asf_header_info *ahi)
 282 {
 283         int i;
 284         float bps1, high_freq;
 285         volatile float bps;
 286         int sample_rate1;
 287         int coef_vlc_table;
 288
 289         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 290                 || ahi->channels <= 0 || ahi->channels > 8
 291                 || ahi->bit_rate <= 0)
 292                 return -E_WMA_BAD_PARAMS;
 293
 294         /* compute MDCT block size */
 295         if (ahi->sample_rate <= 16000) {
 296                 s->frame_len_bits = 9;
 297         } else if (ahi->sample_rate <= 22050) {
 298                 s->frame_len_bits = 10;
 299         } else {
 300                 s->frame_len_bits = 11;
 301         }
 302         s->frame_len = 1 << s->frame_len_bits;
 303         if (s->use_variable_block_len) {
 304                 int nb_max, nb;
 305                 nb = ((flags2 >> 3) & 3) + 1;
 306                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 307                         nb += 2;
 308                 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
 309                 if (nb > nb_max)
 310                         nb = nb_max;
 311                 s->nb_block_sizes = nb + 1;
 312         } else {
 313                 s->nb_block_sizes = 1;
 314         }
 315
 316         /* init rate dependent parameters */
 317         s->use_noise_coding = 1;
 318         high_freq = ahi->sample_rate * 0.5;
 319
 320         /* wma2 rates are normalized */
 321         sample_rate1 = ahi->sample_rate;
 322         if (sample_rate1 >= 44100)
 323                 sample_rate1 = 44100;
 324         else if (sample_rate1 >= 22050)
 325                 sample_rate1 = 22050;
 326         else if (sample_rate1 >= 16000)
 327                 sample_rate1 = 16000;
 328         else if (sample_rate1 >= 11025)
 329                 sample_rate1 = 11025;
 330         else if (sample_rate1 >= 8000)
 331                 sample_rate1 = 8000;
 332
 333         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 334         s->byte_offset_bits = wma_log2((int) (bps * s->frame_len / 8.0 + 0.5)) + 2;
 335         /*
 336          * Compute high frequency value and choose if noise coding should be
 337          * activated.
 338          */
 339         bps1 = bps;
 340         if (ahi->channels == 2)
 341                 bps1 = bps * 1.6;
 342         if (sample_rate1 == 44100) {
 343                 if (bps1 >= 0.61)
 344                         s->use_noise_coding = 0;
 345                 else
 346                         high_freq = high_freq * 0.4;
 347         } else if (sample_rate1 == 22050) {
 348                 if (bps1 >= 1.16)
 349                         s->use_noise_coding = 0;
 350                 else if (bps1 >= 0.72)
 351                         high_freq = high_freq * 0.7;
 352                 else
 353                         high_freq = high_freq * 0.6;
 354         } else if (sample_rate1 == 16000) {
 355                 if (bps > 0.5)
 356                         high_freq = high_freq * 0.5;
 357                 else
 358                         high_freq = high_freq * 0.3;
 359         } else if (sample_rate1 == 11025) {
 360                 high_freq = high_freq * 0.7;
 361         } else if (sample_rate1 == 8000) {
 362                 if (bps <= 0.625) {
 363                         high_freq = high_freq * 0.5;
 364                 } else if (bps > 0.75) {
 365                         s->use_noise_coding = 0;
 366                 } else {
 367                         high_freq = high_freq * 0.65;
 368                 }
 369         } else {
 370                 if (bps >= 0.8) {
 371                         high_freq = high_freq * 0.75;
 372                 } else if (bps >= 0.6) {
 373                         high_freq = high_freq * 0.6;
 374                 } else {
 375                         high_freq = high_freq * 0.5;
 376                 }
 377         }
 378         PARA_INFO_LOG("channels=%d sample_rate=%d "
 379                 "bitrate=%d block_align=%d\n",
 380                 ahi->channels, ahi->sample_rate,
 381                 ahi->bit_rate, ahi->block_align);
 382         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 383                 "high_freq=%f bitoffset=%d\n",
 384                 s->frame_len, bps, bps1,
 385                 high_freq, s->byte_offset_bits);
 386         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 387                 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 388
 389         compute_scale_factor_band_sizes(s, high_freq);
 390         /* init MDCT windows : simple sinus window */
 391         for (i = 0; i < s->nb_block_sizes; i++) {
 392                 int n;
 393                 n = 1 << (s->frame_len_bits - i);
 394                 sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
 395                 s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
 396         }
 397
 398         s->reset_block_lengths = 1;
 399
 400         if (s->use_noise_coding) {
 401                 /* init the noise generator */
 402                 if (s->use_exp_vlc)
 403                         s->noise_mult = 0.02;
 404                 else
 405                         s->noise_mult = 0.04;
 406
 407                 {
 408                         unsigned int seed;
 409                         float norm;
 410                         seed = 1;
 411                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * s->noise_mult;
 412                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 413                                 seed = seed * 314159 + 1;
 414                                 s->noise_table[i] = (float) ((int) seed) * norm;
 415                         }
 416                 }
 417         }
 418
 419         /* choose the VLC tables for the coefficients */
 420         coef_vlc_table = 2;
 421         if (ahi->sample_rate >= 32000) {
 422                 if (bps1 < 0.72)
 423                         coef_vlc_table = 0;
 424                 else if (bps1 < 1.16)
 425                         coef_vlc_table = 1;
 426         }
 427         s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 428         s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 429         init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
 430                 &s->int_table[0], s->coef_vlcs[0]);
 431         init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
 432                 &s->int_table[1], s->coef_vlcs[1]);
 433         return 0;
 434 }
 435
 436 static void wma_lsp_to_curve_init(struct private_wmadec_data *s, int frame_len)
 437 {
 438         float wdel, a, b;
 439         int i, e, m;
 440
 441         wdel = M_PI / frame_len;
 442         for (i = 0; i < frame_len; i++)
 443                 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 444
 445         /* tables for x^-0.25 computation */
 446         for (i = 0; i < 256; i++) {
 447                 e = i - 126;
 448                 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 449         }
 450
 451         /* These two tables are needed to avoid two operations in pow_m1_4. */
 452         b = 1.0;
 453         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 454                 m = (1 << LSP_POW_BITS) + i;
 455                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 456                 a = pow(a, -0.25);
 457                 s->lsp_pow_m_table1[i] = 2 * a - b;
 458                 s->lsp_pow_m_table2[i] = b - a;
 459                 b = a;
 460         }
 461 }
 462
 463 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 464 {
 465         struct private_wmadec_data *s;
 466         int ret, i;
 467
 468         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 469         s = para_calloc(sizeof(*s));
 470         ret = read_asf_header(initial_buf, len, &s->ahi);
 471         if (ret <= 0) {
 472                 free(s);
 473                 return ret;
 474         }
 475
 476         s->use_exp_vlc = s->ahi.flags2 & 0x0001;
 477         s->use_bit_reservoir = s->ahi.flags2 & 0x0002;
 478         s->use_variable_block_len = s->ahi.flags2 & 0x0004;
 479
 480         ret = wma_init(s, s->ahi.flags2, &s->ahi);
 481         if (ret < 0)
 482                 return ret;
 483         /* init MDCT */
 484         for (i = 0; i < s->nb_block_sizes; i++) {
 485                 ret = imdct_init(s->frame_len_bits - i + 1, &s->mdct_ctx[i]);
 486                 if (ret < 0)
 487                         return ret;
 488         }
 489         if (s->use_noise_coding) {
 490                 PARA_INFO_LOG("using noise coding\n");
 491                 init_vlc(&s->hgain_vlc, HGAINVLCBITS,
 492                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 493                         1, 1, ff_wma_hgain_huffcodes, 2, 2);
 494         }
 495
 496         if (s->use_exp_vlc) {
 497                 PARA_INFO_LOG("using exp_vlc\n");
 498                 init_vlc(&s->exp_vlc, EXPVLCBITS,
 499                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 500                 1, 1, ff_wma_scale_huffcodes, 4, 4);
 501         } else {
 502                 PARA_INFO_LOG("using curve\n");
 503                 wma_lsp_to_curve_init(s, s->frame_len);
 504         }
 505         *result = s;
 506         return s->ahi.header_len;
 507 }
 508
 509 /**
 510  * compute x^-0.25 with an exponent and mantissa table. We use linear
 511  * interpolation to reduce the mantissa table size at a small speed
 512  * expense (linear interpolation approximately doubles the number of
 513  * bits of precision).
 514  */
 515 static inline float pow_m1_4(struct private_wmadec_data *s, float x)
 516 {
 517         union {
 518                 float f;
 519                 unsigned int v;
 520         } u, t;
 521         unsigned int e, m;
 522         float a, b;
 523
 524         u.f = x;
 525         e = u.v >> 23;
 526         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 527         /* build interpolation scale: 1 <= t < 2. */
 528         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 529         a = s->lsp_pow_m_table1[m];
 530         b = s->lsp_pow_m_table2[m];
 531         return s->lsp_pow_e_table[e] * (a + b * t.f);
 532 }
 533
 534 static void wma_lsp_to_curve(struct private_wmadec_data *s,
 535                 float *out, float *val_max_ptr, int n, float *lsp)
 536 {
 537         int i, j;
 538         float p, q, w, v, val_max;
 539
 540         val_max = 0;
 541         for (i = 0; i < n; i++) {
 542                 p = 0.5f;
 543                 q = 0.5f;
 544                 w = s->lsp_cos_table[i];
 545                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 546                         q *= w - lsp[j - 1];
 547                         p *= w - lsp[j];
 548                 }
 549                 p *= p * (2.0f - w);
 550                 q *= q * (2.0f + w);
 551                 v = p + q;
 552                 v = pow_m1_4(s, v);
 553                 if (v > val_max)
 554                         val_max = v;
 555                 out[i] = v;
 556         }
 557         *val_max_ptr = val_max;
 558 }
 559
 560 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 561 static void decode_exp_lsp(struct private_wmadec_data *s, int ch)
 562 {
 563         float lsp_coefs[NB_LSP_COEFS];
 564         int val, i;
 565
 566         for (i = 0; i < NB_LSP_COEFS; i++) {
 567                 if (i == 0 || i >= 8)
 568                         val = get_bits(&s->gb, 3);
 569                 else
 570                         val = get_bits(&s->gb, 4);
 571                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 572         }
 573
 574         wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
 575                          s->block_len, lsp_coefs);
 576 }
 577
 578 /*
 579  * Parse a vlc code, faster then get_vlc().
 580  *
 581  * \param bits The number of bits which will be read at once, must be
 582  * identical to nb_bits in init_vlc()
 583  *
 584  * \param max_depth The number of times bits bits must be read to completely
 585  * read the longest vlc code = (max_vlc_length + bits - 1) / bits.
 586  */
 587 static int get_vlc2(struct getbit_context *s, VLC_TYPE(*table)[2],
 588                 int bits, int max_depth)
 589 {
 590         int code;
 591
 592         OPEN_READER(re, s)
 593         UPDATE_CACHE(re, s)
 594         GET_VLC(code, re, s, table, bits, max_depth)
 595         CLOSE_READER(re, s)
 596         return code;
 597 }
 598
 599 /* Decode exponents coded with VLC codes. */
 600 static int decode_exp_vlc(struct private_wmadec_data *s, int ch)
 601 {
 602         int last_exp, n, code;
 603         const uint16_t *ptr, *band_ptr;
 604         float v, *q, max_scale, *q_end;
 605
 606         band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
 607         ptr = band_ptr;
 608         q = s->exponents[ch];
 609         q_end = q + s->block_len;
 610         max_scale = 0;
 611         last_exp = 36;
 612
 613         while (q < q_end) {
 614                 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
 615                 if (code < 0)
 616                         return -1;
 617                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 618                 last_exp += code - 60;
 619                 /* XXX: use a table */
 620                 v = pow(10, last_exp * (1.0 / 16.0));
 621                 if (v > max_scale)
 622                         max_scale = v;
 623                 n = *ptr++;
 624                 do {
 625                         *q++ = v;
 626                 } while (--n);
 627         }
 628         s->max_exponent[ch] = max_scale;
 629         return 0;
 630 }
 631
 632 static void vector_fmul_add(float *dst, const float *src0, const float *src1,
 633                 const float *src2, int len)
 634 {
 635         int i;
 636         for (i = 0; i < len; i++)
 637                 dst[i] = src0[i] * src1[i] + src2[i];
 638 }
 639
 640 static void vector_fmul_reverse_c(float *dst, const float *src0,
 641                 const float *src1, int len)
 642 {
 643         int i;
 644         src1 += len - 1;
 645         for (i = 0; i < len; i++)
 646                 dst[i] = src0[i] * src1[-i];
 647 }
 648
 649 /**
 650  * Apply MDCT window and add into output.
 651  *
 652  * We ensure that when the windows overlap their squared sum
 653  * is always 1 (MDCT reconstruction rule).
 654  */
 655 static void wma_window(struct private_wmadec_data *s, float *out)
 656 {
 657         float *in = s->output;
 658         int block_len, bsize, n;
 659
 660         /* left part */
 661         if (s->block_len_bits <= s->prev_block_len_bits) {
 662                 block_len = s->block_len;
 663                 bsize = s->frame_len_bits - s->block_len_bits;
 664
 665                 vector_fmul_add(out, in, s->windows[bsize], out, block_len);
 666
 667         } else {
 668                 block_len = 1 << s->prev_block_len_bits;
 669                 n = (s->block_len - block_len) / 2;
 670                 bsize = s->frame_len_bits - s->prev_block_len_bits;
 671
 672                 vector_fmul_add(out + n, in + n, s->windows[bsize], out + n,
 673                         block_len);
 674
 675                 memcpy(out + n + block_len, in + n + block_len,
 676                        n * sizeof(float));
 677         }
 678
 679         out += s->block_len;
 680         in += s->block_len;
 681
 682         /* right part */
 683         if (s->block_len_bits <= s->next_block_len_bits) {
 684                 block_len = s->block_len;
 685                 bsize = s->frame_len_bits - s->block_len_bits;
 686
 687                 vector_fmul_reverse_c(out, in, s->windows[bsize], block_len);
 688
 689         } else {
 690                 block_len = 1 << s->next_block_len_bits;
 691                 n = (s->block_len - block_len) / 2;
 692                 bsize = s->frame_len_bits - s->next_block_len_bits;
 693
 694                 memcpy(out, in, n * sizeof(float));
 695
 696                 vector_fmul_reverse_c(out + n, in + n, s->windows[bsize],
 697                                       block_len);
 698
 699                 memset(out + n + block_len, 0, n * sizeof(float));
 700         }
 701 }
 702
 703 static int wma_total_gain_to_bits(int total_gain)
 704 {
 705         if (total_gain < 15)
 706                 return 13;
 707         else if (total_gain < 32)
 708                 return 12;
 709         else if (total_gain < 40)
 710                 return 11;
 711         else if (total_gain < 45)
 712                 return 10;
 713         else
 714                 return 9;
 715 }
 716
 717 /**
 718  * @return 0 if OK. 1 if last block of frame. return -1 if
 719  * unrecorrable error.
 720  */
 721 static int wma_decode_block(struct private_wmadec_data *s)
 722 {
 723         int n, v, ch, code, bsize;
 724         int coef_nb_bits, total_gain;
 725         int nb_coefs[MAX_CHANNELS];
 726         float mdct_norm;
 727
 728         /* compute current block length */
 729         if (s->use_variable_block_len) {
 730                 n = wma_log2(s->nb_block_sizes - 1) + 1;
 731
 732                 if (s->reset_block_lengths) {
 733                         s->reset_block_lengths = 0;
 734                         v = get_bits(&s->gb, n);
 735                         if (v >= s->nb_block_sizes)
 736                                 return -1;
 737                         s->prev_block_len_bits = s->frame_len_bits - v;
 738                         v = get_bits(&s->gb, n);
 739                         if (v >= s->nb_block_sizes)
 740                                 return -1;
 741                         s->block_len_bits = s->frame_len_bits - v;
 742                 } else {
 743                         /* update block lengths */
 744                         s->prev_block_len_bits = s->block_len_bits;
 745                         s->block_len_bits = s->next_block_len_bits;
 746                 }
 747                 v = get_bits(&s->gb, n);
 748                 if (v >= s->nb_block_sizes)
 749                         return -1;
 750                 s->next_block_len_bits = s->frame_len_bits - v;
 751         } else {
 752                 /* fixed block len */
 753                 s->next_block_len_bits = s->frame_len_bits;
 754                 s->prev_block_len_bits = s->frame_len_bits;
 755                 s->block_len_bits = s->frame_len_bits;
 756         }
 757
 758         /* now check if the block length is coherent with the frame length */
 759         s->block_len = 1 << s->block_len_bits;
 760         if ((s->block_pos + s->block_len) > s->frame_len)
 761                 return -E_INCOHERENT_BLOCK_LEN;
 762
 763         if (s->ahi.channels == 2) {
 764                 s->ms_stereo = get_bits1(&s->gb);
 765         }
 766         v = 0;
 767         for (ch = 0; ch < s->ahi.channels; ch++) {
 768                 int a = get_bits1(&s->gb);
 769                 s->channel_coded[ch] = a;
 770                 v |= a;
 771         }
 772
 773         bsize = s->frame_len_bits - s->block_len_bits;
 774
 775         /* if no channel coded, no need to go further */
 776         /* XXX: fix potential framing problems */
 777         if (!v)
 778                 goto next;
 779
 780         /* read total gain and extract corresponding number of bits for
 781            coef escape coding */
 782         total_gain = 1;
 783         for (;;) {
 784                 int a = get_bits(&s->gb, 7);
 785                 total_gain += a;
 786                 if (a != 127)
 787                         break;
 788         }
 789
 790         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 791
 792         /* compute number of coefficients */
 793         n = s->coefs_end[bsize] - s->coefs_start;
 794         for (ch = 0; ch < s->ahi.channels; ch++)
 795                 nb_coefs[ch] = n;
 796
 797         /* complex coding */
 798         if (s->use_noise_coding) {
 799                 for (ch = 0; ch < s->ahi.channels; ch++) {
 800                         if (s->channel_coded[ch]) {
 801                                 int i, m, a;
 802                                 m = s->exponent_high_sizes[bsize];
 803                                 for (i = 0; i < m; i++) {
 804                                         a = get_bits1(&s->gb);
 805                                         s->high_band_coded[ch][i] = a;
 806                                         /* if noise coding, the coefficients are not transmitted */
 807                                         if (a)
 808                                                 nb_coefs[ch] -=
 809                                                     s->
 810                                                     exponent_high_bands[bsize]
 811                                                     [i];
 812                                 }
 813                         }
 814                 }
 815                 for (ch = 0; ch < s->ahi.channels; ch++) {
 816                         if (s->channel_coded[ch]) {
 817                                 int i, val;
 818
 819                                 n = s->exponent_high_sizes[bsize];
 820                                 val = (int) 0x80000000;
 821                                 for (i = 0; i < n; i++) {
 822                                         if (s->high_band_coded[ch][i]) {
 823                                                 if (val == (int) 0x80000000) {
 824                                                         val =
 825                                                             get_bits(&s->gb,
 826                                                                      7) - 19;
 827                                                 } else {
 828                                                         code =
 829                                                             get_vlc2(&s->gb,
 830                                                                      s->
 831                                                                      hgain_vlc.
 832                                                                      table,
 833                                                                      HGAINVLCBITS,
 834                                                                      HGAINMAX);
 835                                                         if (code < 0)
 836                                                                 return -1;
 837                                                         val += code - 18;
 838                                                 }
 839                                                 s->high_band_values[ch][i] =
 840                                                     val;
 841                                         }
 842                                 }
 843                         }
 844                 }
 845         }
 846
 847         /* exponents can be reused in short blocks. */
 848         if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {
 849                 for (ch = 0; ch < s->ahi.channels; ch++) {
 850                         if (s->channel_coded[ch]) {
 851                                 if (s->use_exp_vlc) {
 852                                         if (decode_exp_vlc(s, ch) < 0)
 853                                                 return -1;
 854                                 } else {
 855                                         decode_exp_lsp(s, ch);
 856                                 }
 857                                 s->exponents_bsize[ch] = bsize;
 858                         }
 859                 }
 860         }
 861
 862         /* parse spectral coefficients : just RLE encoding */
 863         for (ch = 0; ch < s->ahi.channels; ch++) {
 864                 if (s->channel_coded[ch]) {
 865                         struct vlc *coef_vlc;
 866                         int level, run, sign, tindex;
 867                         int16_t *ptr, *eptr;
 868                         const uint16_t *level_table, *run_table;
 869
 870                         /* special VLC tables are used for ms stereo because
 871                            there is potentially less energy there */
 872                         tindex = (ch == 1 && s->ms_stereo);
 873                         coef_vlc = &s->coef_vlc[tindex];
 874                         run_table = s->run_table[tindex];
 875                         level_table = s->level_table[tindex];
 876                         /* XXX: optimize */
 877                         ptr = &s->coefs1[ch][0];
 878                         eptr = ptr + nb_coefs[ch];
 879                         memset(ptr, 0, s->block_len * sizeof(int16_t));
 880                         for (;;) {
 881                                 code =
 882                                     get_vlc2(&s->gb, coef_vlc->table, VLCBITS,
 883                                              VLCMAX);
 884                                 if (code < 0)
 885                                         return -1;
 886                                 if (code == 1) {
 887                                         /* EOB */
 888                                         break;
 889                                 } else if (code == 0) {
 890                                         /* escape */
 891                                         level = get_bits(&s->gb, coef_nb_bits);
 892                                         /* NOTE: this is rather suboptimal. reading
 893                                            block_len_bits would be better */
 894                                         run =
 895                                             get_bits(&s->gb, s->frame_len_bits);
 896                                 } else {
 897                                         /* normal code */
 898                                         run = run_table[code];
 899                                         level = level_table[code];
 900                                 }
 901                                 sign = get_bits1(&s->gb);
 902                                 if (!sign)
 903                                         level = -level;
 904                                 ptr += run;
 905                                 if (ptr >= eptr) {
 906                                         PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 907                                         break;
 908                                 }
 909                                 *ptr++ = level;
 910                                 /* NOTE: EOB can be omitted */
 911                                 if (ptr >= eptr)
 912                                         break;
 913                         }
 914                 }
 915         }
 916
 917         /* normalize */
 918         {
 919                 int n4 = s->block_len / 2;
 920                 mdct_norm = 1.0 / (float) n4;
 921         }
 922
 923         /* finally compute the MDCT coefficients */
 924         for (ch = 0; ch < s->ahi.channels; ch++) {
 925                 if (s->channel_coded[ch]) {
 926                         int16_t *coefs1;
 927                         float *coefs, *exponents, mult, mult1, noise;
 928                         int i, j, n1, last_high_band, esize;
 929                         float exp_power[HIGH_BAND_MAX_SIZE];
 930
 931                         coefs1 = s->coefs1[ch];
 932                         exponents = s->exponents[ch];
 933                         esize = s->exponents_bsize[ch];
 934                         mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
 935                         mult *= mdct_norm;
 936                         coefs = s->coefs[ch];
 937                         if (s->use_noise_coding) {
 938                                 mult1 = mult;
 939                                 /* very low freqs : noise */
 940                                 for (i = 0; i < s->coefs_start; i++) {
 941                                         *coefs++ =
 942                                             s->noise_table[s->noise_index] *
 943                                             exponents[i << bsize >> esize] *
 944                                             mult1;
 945                                         s->noise_index =
 946                                             (s->noise_index +
 947                                              1) & (NOISE_TAB_SIZE - 1);
 948                                 }
 949
 950                                 n1 = s->exponent_high_sizes[bsize];
 951
 952                                 /* compute power of high bands */
 953                                 exponents = s->exponents[ch] +
 954                                     (s->high_band_start[bsize] << bsize);
 955                                 last_high_band = 0;     /* avoid warning */
 956                                 for (j = 0; j < n1; j++) {
 957                                         n = s->exponent_high_bands[s->
 958                                                                    frame_len_bits
 959                                                                    -
 960                                                                    s->
 961                                                                    block_len_bits]
 962                                             [j];
 963                                         if (s->high_band_coded[ch][j]) {
 964                                                 float e2, val;
 965                                                 e2 = 0;
 966                                                 for (i = 0; i < n; i++) {
 967                                                         val = exponents[i << bsize
 968                                                                       >> esize];
 969                                                         e2 += val * val;
 970                                                 }
 971                                                 exp_power[j] = e2 / n;
 972                                                 last_high_band = j;
 973                                         }
 974                                         exponents += n << bsize;
 975                                 }
 976
 977                                 /* main freqs and high freqs */
 978                                 exponents =
 979                                     s->exponents[ch] +
 980                                     (s->coefs_start << bsize);
 981                                 for (j = -1; j < n1; j++) {
 982                                         if (j < 0) {
 983                                                 n = s->high_band_start[bsize] -
 984                                                     s->coefs_start;
 985                                         } else {
 986                                                 n = s->exponent_high_bands[s->
 987                                                                            frame_len_bits
 988                                                                            -
 989                                                                            s->
 990                                                                            block_len_bits]
 991                                                     [j];
 992                                         }
 993                                         if (j >= 0 && s->high_band_coded[ch][j]) {
 994                                                 /* use noise with specified power */
 995                                                 mult1 =
 996                                                     sqrt(exp_power[j] /
 997                                                          exp_power
 998                                                          [last_high_band]);
 999                                                 /* XXX: use a table */
1000                                                 mult1 =
1001                                                     mult1 * pow(10,
1002                                                                 s->
1003                                                                 high_band_values
1004                                                                 [ch][j] * 0.05);
1005                                                 mult1 =
1006                                                     mult1 /
1007                                                     (s->max_exponent[ch] *
1008                                                      s->noise_mult);
1009                                                 mult1 *= mdct_norm;
1010                                                 for (i = 0; i < n; i++) {
1011                                                         noise =
1012                                                             s->noise_table[s->
1013                                                                            noise_index];
1014                                                         s->noise_index =
1015                                                             (s->noise_index +
1016                                                              1) &
1017                                                             (NOISE_TAB_SIZE -
1018                                                              1);
1019                                                         *coefs++ =
1020                                                             noise *
1021                                                             exponents[i << bsize
1022                                                                       >> esize]
1023                                                             * mult1;
1024                                                 }
1025                                                 exponents += n << bsize;
1026                                         } else {
1027                                                 /* coded values + small noise */
1028                                                 for (i = 0; i < n; i++) {
1029                                                         noise =
1030                                                             s->noise_table[s->
1031                                                                            noise_index];
1032                                                         s->noise_index =
1033                                                             (s->noise_index +
1034                                                              1) &
1035                                                             (NOISE_TAB_SIZE -
1036                                                              1);
1037                                                         *coefs++ =
1038                                                             ((*coefs1++) +
1039                                                              noise) *
1040                                                             exponents[i << bsize
1041                                                                       >> esize]
1042                                                             * mult;
1043                                                 }
1044                                                 exponents += n << bsize;
1045                                         }
1046                                 }
1047
1048                                 /* very high freqs : noise */
1049                                 n = s->block_len - s->coefs_end[bsize];
1050                                 mult1 =
1051                                     mult * exponents[((-1 << bsize)) >> esize];
1052                                 for (i = 0; i < n; i++) {
1053                                         *coefs++ =
1054                                             s->noise_table[s->noise_index] *
1055                                             mult1;
1056                                         s->noise_index =
1057                                             (s->noise_index +
1058                                              1) & (NOISE_TAB_SIZE - 1);
1059                                 }
1060                         } else {
1061                                 /* XXX: optimize more */
1062                                 for (i = 0; i < s->coefs_start; i++)
1063                                         *coefs++ = 0.0;
1064                                 n = nb_coefs[ch];
1065                                 for (i = 0; i < n; i++) {
1066                                         *coefs++ =
1067                                             coefs1[i] *
1068                                             exponents[i << bsize >> esize] *
1069                                             mult;
1070                                 }
1071                                 n = s->block_len - s->coefs_end[bsize];
1072                                 for (i = 0; i < n; i++)
1073                                         *coefs++ = 0.0;
1074                         }
1075                 }
1076         }
1077
1078         if (s->ms_stereo && s->channel_coded[1]) {
1079                 float a, b;
1080                 int i;
1081
1082                 /*
1083                  * Nominal case for ms stereo: we do it before mdct.
1084                  *
1085                  * No need to optimize this case because it should almost never
1086                  * happen.
1087                  */
1088                 if (!s->channel_coded[0]) {
1089                         PARA_NOTICE_LOG("rare ms-stereo\n");
1090                         memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1091                         s->channel_coded[0] = 1;
1092                 }
1093                 for (i = 0; i < s->block_len; i++) {
1094                         a = s->coefs[0][i];
1095                         b = s->coefs[1][i];
1096                         s->coefs[0][i] = a + b;
1097                         s->coefs[1][i] = a - b;
1098                 }
1099         }
1100
1101 next:
1102         for (ch = 0; ch < s->ahi.channels; ch++) {
1103                 int n4, index;
1104
1105                 n = s->block_len;
1106                 n4 = s->block_len / 2;
1107                 if (s->channel_coded[ch])
1108                         imdct(s->mdct_ctx[bsize], s->output, s->coefs[ch]);
1109                 else if (!(s->ms_stereo && ch == 1))
1110                         memset(s->output, 0, sizeof(s->output));
1111
1112                 /* multiply by the window and add in the frame */
1113                 index = (s->frame_len / 2) + s->block_pos - n4;
1114                 wma_window(s, &s->frame_out[ch][index]);
1115         }
1116
1117         /* update block number */
1118         s->block_pos += s->block_len;
1119         if (s->block_pos >= s->frame_len)
1120                 return 1;
1121         else
1122                 return 0;
1123 }
1124
1125 /*
1126  * Clip a signed integer value into the -32768,32767 range.
1127  *
1128  * \param a The value to clip.
1129  *
1130  * \return The clipped value.
1131  */
1132 static inline int16_t av_clip_int16(int a)
1133 {
1134         if ((a + 32768) & ~65535)
1135                 return (a >> 31) ^ 32767;
1136         else
1137                 return a;
1138 }
1139
1140 /* Decode a frame of frame_len samples. */
1141 static int wma_decode_frame(struct private_wmadec_data *s, int16_t * samples)
1142 {
1143         int ret, i, n, ch, incr;
1144         int16_t *ptr;
1145         float *iptr;
1146
1147         /* read each block */
1148         s->block_pos = 0;
1149         for (;;) {
1150                 ret = wma_decode_block(s);
1151                 if (ret < 0)
1152                         return -1;
1153                 if (ret)
1154                         break;
1155         }
1156
1157         /* convert frame to integer */
1158         n = s->frame_len;
1159         incr = s->ahi.channels;
1160         for (ch = 0; ch < s->ahi.channels; ch++) {
1161                 ptr = samples + ch;
1162                 iptr = s->frame_out[ch];
1163
1164                 for (i = 0; i < n; i++) {
1165                         *ptr = av_clip_int16(lrintf(*iptr++));
1166                         ptr += incr;
1167                 }
1168                 /* prepare for next block */
1169                 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1170                         s->frame_len * sizeof(float));
1171         }
1172         return 0;
1173 }
1174
1175 static int wma_decode_superframe(struct private_wmadec_data *s, void *data,
1176                 int *data_size, const uint8_t *buf, int buf_size)
1177 {
1178         int ret, nb_frames, bit_offset, i, pos, len;
1179         uint8_t *q;
1180         int16_t *samples;
1181         static int frame_count;
1182
1183         if (buf_size == 0) {
1184                 s->last_superframe_len = 0;
1185                 return 0;
1186         }
1187         if (buf_size < s->ahi.block_align)
1188                 return 0;
1189         buf_size = s->ahi.block_align;
1190         samples = data;
1191         init_get_bits(&s->gb, buf, buf_size * 8);
1192         if (s->use_bit_reservoir) {
1193                 /* read super frame header */
1194                 skip_bits(&s->gb, 4);   /* super frame index */
1195                 nb_frames = get_bits(&s->gb, 4) - 1;
1196                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1197                 ret = -E_WMA_OUTPUT_SPACE;
1198                 if ((nb_frames + 1) * s->ahi.channels * s->frame_len
1199                                 * sizeof(int16_t) > *data_size)
1200                         goto fail;
1201
1202                 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1203
1204                 if (s->last_superframe_len > 0) {
1205                         /* add bit_offset bits to last frame */
1206                         ret = -E_WMA_BAD_SUPERFRAME;
1207                         if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1208                                         MAX_CODED_SUPERFRAME_SIZE)
1209                                 goto fail;
1210                         q = s->last_superframe + s->last_superframe_len;
1211                         len = bit_offset;
1212                         while (len > 7) {
1213                                 *q++ = get_bits(&s->gb, 8);
1214                                 len -= 8;
1215                         }
1216                         if (len > 0) {
1217                                 *q++ = get_bits(&s->gb, len) << (8 - len);
1218                         }
1219
1220                         /* XXX: bit_offset bits into last frame */
1221                         init_get_bits(&s->gb, s->last_superframe,
1222                                 MAX_CODED_SUPERFRAME_SIZE * 8);
1223                         /* skip unused bits */
1224                         if (s->last_bitoffset > 0)
1225                                 skip_bits(&s->gb, s->last_bitoffset);
1226                         /*
1227                          * This frame is stored in the last superframe and in
1228                          * the current one.
1229                          */
1230                         ret = -E_WMA_DECODE;
1231                         if (wma_decode_frame(s, samples) < 0)
1232                                 goto fail;
1233                         frame_count++;
1234                         samples += s->ahi.channels * s->frame_len;
1235                 }
1236
1237                 /* read each frame starting from bit_offset */
1238                 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1239                 init_get_bits(&s->gb, buf + (pos >> 3),
1240                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)) * 8);
1241                 len = pos & 7;
1242                 if (len > 0)
1243                         skip_bits(&s->gb, len);
1244
1245                 s->reset_block_lengths = 1;
1246                 for (i = 0; i < nb_frames; i++) {
1247                         ret = -E_WMA_DECODE;
1248                         if (wma_decode_frame(s, samples) < 0)
1249                                 goto fail;
1250                         frame_count++;
1251                         samples += s->ahi.channels * s->frame_len;
1252                 }
1253
1254                 /* we copy the end of the frame in the last frame buffer */
1255                 pos = get_bits_count(&s->gb) +
1256                         ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1257                 s->last_bitoffset = pos & 7;
1258                 pos >>= 3;
1259                 len = buf_size - pos;
1260                 ret = -E_WMA_BAD_SUPERFRAME;
1261                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1262                         goto fail;
1263                 }
1264                 s->last_superframe_len = len;
1265                 memcpy(s->last_superframe, buf + pos, len);
1266         } else {
1267                 PARA_DEBUG_LOG("not using bit reservoir\n");
1268                 ret = -E_WMA_OUTPUT_SPACE;
1269                 if (s->ahi.channels * s->frame_len * sizeof(int16_t) > *data_size)
1270                         goto fail;
1271                 /* single frame decode */
1272                 ret = -E_WMA_DECODE;
1273                 if (wma_decode_frame(s, samples) < 0)
1274                         goto fail;
1275                 frame_count++;
1276                 samples += s->ahi.channels * s->frame_len;
1277         }
1278         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1279                 "outbytes: %d, eaten: %d\n",
1280                 frame_count, s->frame_len, s->block_len,
1281                 (int8_t *) samples - (int8_t *) data, s->ahi.block_align);
1282         *data_size = (int8_t *)samples - (int8_t *)data;
1283         return s->ahi.block_align;
1284 fail:
1285         /* reset the bit reservoir on errors */
1286         s->last_superframe_len = 0;
1287         return ret;
1288 }
1289
1290 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1291                 struct filter_node *fn)
1292 {
1293         int ret, out_size = fn->bufsize - fn->loaded;
1294         struct private_wmadec_data *pwd = fn->private_data;
1295
1296         if (out_size < 128 * 1024)
1297                 return 0;
1298         if (!pwd) {
1299                 ret = wma_decode_init(inbuffer, len, &pwd);
1300                 if (ret <= 0)
1301                         return ret;
1302                 fn->private_data = pwd;
1303                 fn->fc->channels = pwd->ahi.channels;
1304                 fn->fc->samplerate = pwd->ahi.sample_rate;
1305                 return pwd->ahi.header_len;
1306         }
1307         /* skip 31 bytes */
1308         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1309                 return 0;
1310         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1311                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1312                 len - WMA_FRAME_SKIP);
1313         if (ret < 0)
1314                 return ret;
1315         fn->loaded += out_size;
1316         return ret + WMA_FRAME_SKIP;
1317 }
1318
1319 static void wmadec_close(struct filter_node *fn)
1320 {
1321         struct private_wmadec_data *pwd = fn->private_data;
1322         if (!pwd)
1323                 return;
1324         wmadec_cleanup(pwd);
1325         free(fn->buf);
1326         fn->buf = NULL;
1327         free(fn->private_data);
1328         fn->private_data = NULL;
1329 }
1330
1331 static void wmadec_open(struct filter_node *fn)
1332 {
1333         fn->bufsize = 1024 * 1024;
1334         fn->buf = para_malloc(fn->bufsize);
1335         fn->private_data = NULL;
1336         fn->loaded = 0;
1337 }
1338
1339 /**
1340  * The init function of the wma decoder.
1341  *
1342  * \param f Its fields are filled in by the function.
1343  */
1344 void wmadec_filter_init(struct filter *f)
1345 {
1346         f->open = wmadec_open;
1347         f->close = wmadec_close;
1348         f->convert = wmadec_convert;
1349 }