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