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 *pwd)
 156 {
 157         int i;
 158
 159         for (i = 0; i < pwd->nb_block_sizes; i++)
 160                 imdct_end(pwd->mdct_ctx[i]);
 161         if (pwd->use_exp_vlc)
 162                 free_vlc(&pwd->exp_vlc);
 163         if (pwd->use_noise_coding)
 164                 free_vlc(&pwd->hgain_vlc);
 165         for (i = 0; i < 2; i++) {
 166                 free_vlc(&pwd->coef_vlc[i]);
 167                 free(pwd->run_table[i]);
 168                 free(pwd->level_table[i]);
 169                 free(pwd->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 *pwd,
 211         float high_freq)
 212 {
 213         struct asf_header_info *ahi = &pwd->ahi;
 214         int a, b, pos, lpos, k, block_len, i, j, n;
 215         const uint8_t *table;
 216
 217         pwd->coefs_start = 0;
 218         for (k = 0; k < pwd->nb_block_sizes; k++) {
 219                 block_len = pwd->frame_len >> k;
 220
 221                 table = NULL;
 222                 a = pwd->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                                 pwd->exponent_bands[k][i] = table[i];
 235                         pwd->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                                         pwd->exponent_bands[k][j++] = pos - lpos;
 248                                 if (pos >= block_len)
 249                                         break;
 250                                 lpos = pos;
 251                         }
 252                         pwd->exponent_sizes[k] = j;
 253                 }
 254
 255                 /* max number of coefs */
 256                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 257                 /* high freq computation */
 258                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 259                         / ahi->sample_rate + 0.5);
 260                 n = pwd->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 += pwd->exponent_bands[k][i];
 267                         end = pos;
 268                         if (start < pwd->high_band_start[k])
 269                                 start = pwd->high_band_start[k];
 270                         if (end > pwd->coefs_end[k])
 271                                 end = pwd->coefs_end[k];
 272                         if (end > start)
 273                                 pwd->exponent_high_bands[k][j++] = end - start;
 274                 }
 275                 pwd->exponent_high_sizes[k] = j;
 276         }
 277 }
 278
 279 static int wma_init(struct private_wmadec_data *pwd)
 280 {
 281         int i;
 282         float bps1, high_freq;
 283         volatile float bps;
 284         int sample_rate1;
 285         int coef_vlc_table;
 286         struct asf_header_info *ahi = &pwd->ahi;
 287         int flags2 = ahi->flags2;
 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                 pwd->frame_len_bits = 9;
 297         } else if (ahi->sample_rate <= 22050) {
 298                 pwd->frame_len_bits = 10;
 299         } else {
 300                 pwd->frame_len_bits = 11;
 301         }
 302         pwd->frame_len = 1 << pwd->frame_len_bits;
 303         if (pwd->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 = pwd->frame_len_bits - BLOCK_MIN_BITS;
 309                 if (nb > nb_max)
 310                         nb = nb_max;
 311                 pwd->nb_block_sizes = nb + 1;
 312         } else
 313                 pwd->nb_block_sizes = 1;
 314
 315         /* init rate dependent parameters */
 316         pwd->use_noise_coding = 1;
 317         high_freq = ahi->sample_rate * 0.5;
 318
 319         /* wma2 rates are normalized */
 320         sample_rate1 = ahi->sample_rate;
 321         if (sample_rate1 >= 44100)
 322                 sample_rate1 = 44100;
 323         else if (sample_rate1 >= 22050)
 324                 sample_rate1 = 22050;
 325         else if (sample_rate1 >= 16000)
 326                 sample_rate1 = 16000;
 327         else if (sample_rate1 >= 11025)
 328                 sample_rate1 = 11025;
 329         else if (sample_rate1 >= 8000)
 330                 sample_rate1 = 8000;
 331
 332         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 333         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 334         /*
 335          * Compute high frequency value and choose if noise coding should be
 336          * activated.
 337          */
 338         bps1 = bps;
 339         if (ahi->channels == 2)
 340                 bps1 = bps * 1.6;
 341         if (sample_rate1 == 44100) {
 342                 if (bps1 >= 0.61)
 343                         pwd->use_noise_coding = 0;
 344                 else
 345                         high_freq = high_freq * 0.4;
 346         } else if (sample_rate1 == 22050) {
 347                 if (bps1 >= 1.16)
 348                         pwd->use_noise_coding = 0;
 349                 else if (bps1 >= 0.72)
 350                         high_freq = high_freq * 0.7;
 351                 else
 352                         high_freq = high_freq * 0.6;
 353         } else if (sample_rate1 == 16000) {
 354                 if (bps > 0.5)
 355                         high_freq = high_freq * 0.5;
 356                 else
 357                         high_freq = high_freq * 0.3;
 358         } else if (sample_rate1 == 11025) {
 359                 high_freq = high_freq * 0.7;
 360         } else if (sample_rate1 == 8000) {
 361                 if (bps <= 0.625) {
 362                         high_freq = high_freq * 0.5;
 363                 } else if (bps > 0.75) {
 364                         pwd->use_noise_coding = 0;
 365                 } else {
 366                         high_freq = high_freq * 0.65;
 367                 }
 368         } else {
 369                 if (bps >= 0.8) {
 370                         high_freq = high_freq * 0.75;
 371                 } else if (bps >= 0.6) {
 372                         high_freq = high_freq * 0.6;
 373                 } else {
 374                         high_freq = high_freq * 0.5;
 375                 }
 376         }
 377         PARA_INFO_LOG("channels=%d sample_rate=%d "
 378                 "bitrate=%d block_align=%d\n",
 379                 ahi->channels, ahi->sample_rate,
 380                 ahi->bit_rate, ahi->block_align);
 381         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 382                 "high_freq=%f bitoffset=%d\n",
 383                 pwd->frame_len, bps, bps1,
 384                 high_freq, pwd->byte_offset_bits);
 385         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 386                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 387
 388         compute_scale_factor_band_sizes(pwd, high_freq);
 389         /* init MDCT windows : simple sinus window */
 390         for (i = 0; i < pwd->nb_block_sizes; i++) {
 391                 int n;
 392                 n = 1 << (pwd->frame_len_bits - i);
 393                 sine_window_init(ff_sine_windows[pwd->frame_len_bits - i - 7], n);
 394                 pwd->windows[i] = ff_sine_windows[pwd->frame_len_bits - i - 7];
 395         }
 396
 397         pwd->reset_block_lengths = 1;
 398
 399         if (pwd->use_noise_coding) {
 400                 /* init the noise generator */
 401                 if (pwd->use_exp_vlc)
 402                         pwd->noise_mult = 0.02;
 403                 else
 404                         pwd->noise_mult = 0.04;
 405
 406                 {
 407                         unsigned int seed;
 408                         float norm;
 409                         seed = 1;
 410                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 411                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 412                                 seed = seed * 314159 + 1;
 413                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 414                         }
 415                 }
 416         }
 417
 418         /* choose the VLC tables for the coefficients */
 419         coef_vlc_table = 2;
 420         if (ahi->sample_rate >= 32000) {
 421                 if (bps1 < 0.72)
 422                         coef_vlc_table = 0;
 423                 else if (bps1 < 1.16)
 424                         coef_vlc_table = 1;
 425         }
 426         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 427         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 428         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 429                 &pwd->int_table[0], pwd->coef_vlcs[0]);
 430         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 431                 &pwd->int_table[1], pwd->coef_vlcs[1]);
 432         return 0;
 433 }
 434
 435 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 436 {
 437         float wdel, a, b;
 438         int i, e, m;
 439
 440         wdel = M_PI / frame_len;
 441         for (i = 0; i < frame_len; i++)
 442                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 443
 444         /* tables for x^-0.25 computation */
 445         for (i = 0; i < 256; i++) {
 446                 e = i - 126;
 447                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 448         }
 449
 450         /* These two tables are needed to avoid two operations in pow_m1_4. */
 451         b = 1.0;
 452         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 453                 m = (1 << LSP_POW_BITS) + i;
 454                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 455                 a = pow(a, -0.25);
 456                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 457                 pwd->lsp_pow_m_table2[i] = b - a;
 458                 b = a;
 459         }
 460 }
 461
 462 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 463 {
 464         struct private_wmadec_data *pwd;
 465         int ret, i;
 466
 467         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 468         pwd = para_calloc(sizeof(*pwd));
 469         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 470         if (ret <= 0) {
 471                 free(pwd);
 472                 return ret;
 473         }
 474
 475         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 476         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 477         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 478
 479         ret = wma_init(pwd);
 480         if (ret < 0)
 481                 return ret;
 482         /* init MDCT */
 483         for (i = 0; i < pwd->nb_block_sizes; i++) {
 484                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 485                 if (ret < 0)
 486                         return ret;
 487         }
 488         if (pwd->use_noise_coding) {
 489                 PARA_INFO_LOG("using noise coding\n");
 490                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 491                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 492                         1, 1, ff_wma_hgain_huffcodes, 2, 2);
 493         }
 494
 495         if (pwd->use_exp_vlc) {
 496                 PARA_INFO_LOG("using exp_vlc\n");
 497                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 498                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 499                 1, 1, ff_wma_scale_huffcodes, 4, 4);
 500         } else {
 501                 PARA_INFO_LOG("using curve\n");
 502                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 503         }
 504         *result = pwd;
 505         return pwd->ahi.header_len;
 506 }
 507
 508 /**
 509  * compute x^-0.25 with an exponent and mantissa table. We use linear
 510  * interpolation to reduce the mantissa table size at a small speed
 511  * expense (linear interpolation approximately doubles the number of
 512  * bits of precision).
 513  */
 514 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 515 {
 516         union {
 517                 float f;
 518                 unsigned int v;
 519         } u, t;
 520         unsigned int e, m;
 521         float a, b;
 522
 523         u.f = x;
 524         e = u.v >> 23;
 525         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 526         /* build interpolation scale: 1 <= t < 2. */
 527         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 528         a = pwd->lsp_pow_m_table1[m];
 529         b = pwd->lsp_pow_m_table2[m];
 530         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 531 }
 532
 533 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 534                 float *out, float *val_max_ptr, int n, float *lsp)
 535 {
 536         int i, j;
 537         float p, q, w, v, val_max;
 538
 539         val_max = 0;
 540         for (i = 0; i < n; i++) {
 541                 p = 0.5f;
 542                 q = 0.5f;
 543                 w = pwd->lsp_cos_table[i];
 544                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 545                         q *= w - lsp[j - 1];
 546                         p *= w - lsp[j];
 547                 }
 548                 p *= p * (2.0f - w);
 549                 q *= q * (2.0f + w);
 550                 v = p + q;
 551                 v = pow_m1_4(pwd, v);
 552                 if (v > val_max)
 553                         val_max = v;
 554                 out[i] = v;
 555         }
 556         *val_max_ptr = val_max;
 557 }
 558
 559 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 560 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 561 {
 562         float lsp_coefs[NB_LSP_COEFS];
 563         int val, i;
 564
 565         for (i = 0; i < NB_LSP_COEFS; i++) {
 566                 if (i == 0 || i >= 8)
 567                         val = get_bits(&pwd->gb, 3);
 568                 else
 569                         val = get_bits(&pwd->gb, 4);
 570                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 571         }
 572
 573         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 574                 pwd->block_len, lsp_coefs);
 575 }
 576
 577 /*
 578  * Parse a vlc code, faster then get_vlc().
 579  *
 580  * \param bits The number of bits which will be read at once, must be
 581  * identical to nb_bits in init_vlc()
 582  *
 583  * \param max_depth The number of times bits bits must be read to completely
 584  * read the longest vlc code = (max_vlc_length + bits - 1) / bits.
 585  */
 586 static int get_vlc2(struct getbit_context *s, VLC_TYPE(*table)[2],
 587                 int bits, int max_depth)
 588 {
 589         int code;
 590
 591         OPEN_READER(re, s)
 592         UPDATE_CACHE(re, s)
 593         GET_VLC(code, re, s, table, bits, max_depth)
 594         CLOSE_READER(re, s)
 595         return code;
 596 }
 597
 598 /* Decode exponents coded with VLC codes. */
 599 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 600 {
 601         int last_exp, n, code;
 602         const uint16_t *ptr, *band_ptr;
 603         float v, *q, max_scale, *q_end;
 604
 605         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 606         ptr = band_ptr;
 607         q = pwd->exponents[ch];
 608         q_end = q + pwd->block_len;
 609         max_scale = 0;
 610         last_exp = 36;
 611
 612         while (q < q_end) {
 613                 code = get_vlc2(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 614                 if (code < 0)
 615                         return -1;
 616                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 617                 last_exp += code - 60;
 618                 /* XXX: use a table */
 619                 v = pow(10, last_exp * (1.0 / 16.0));
 620                 if (v > max_scale)
 621                         max_scale = v;
 622                 n = *ptr++;
 623                 do {
 624                         *q++ = v;
 625                 } while (--n);
 626         }
 627         pwd->max_exponent[ch] = max_scale;
 628         return 0;
 629 }
 630
 631 /* compute src0 * src1 + src2 */
 632 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 633                 const float *src2, int len)
 634 {
 635         int i;
 636
 637         for (i = 0; i < len; i++)
 638                 dst[i] = src0[i] * src1[i] + src2[i];
 639 }
 640
 641 static inline void vector_mult_reverse(float *dst, const float *src0,
 642                 const float *src1, int len)
 643 {
 644         int i;
 645
 646         src1 += len - 1;
 647         for (i = 0; i < len; i++)
 648                 dst[i] = src0[i] * src1[-i];
 649 }
 650
 651 /**
 652  * Apply MDCT window and add into output.
 653  *
 654  * We ensure that when the windows overlap their squared sum
 655  * is always 1 (MDCT reconstruction rule).
 656  */
 657 static void wma_window(struct private_wmadec_data *pwd, float *out)
 658 {
 659         float *in = pwd->output;
 660         int block_len, bsize, n;
 661
 662         /* left part */
 663         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 664                 block_len = pwd->block_len;
 665                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 666                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 667         } else {
 668                 block_len = 1 << pwd->prev_block_len_bits;
 669                 n = (pwd->block_len - block_len) / 2;
 670                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 671                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 672                         block_len);
 673                 memcpy(out + n + block_len, in + n + block_len,
 674                         n * sizeof(float));
 675         }
 676         out += pwd->block_len;
 677         in += pwd->block_len;
 678         /* right part */
 679         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 680                 block_len = pwd->block_len;
 681                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 682                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 683         } else {
 684                 block_len = 1 << pwd->next_block_len_bits;
 685                 n = (pwd->block_len - block_len) / 2;
 686                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 687                 memcpy(out, in, n * sizeof(float));
 688                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 689                         block_len);
 690                 memset(out + n + block_len, 0, n * sizeof(float));
 691         }
 692 }
 693
 694 static int wma_total_gain_to_bits(int total_gain)
 695 {
 696         if (total_gain < 15)
 697                 return 13;
 698         else if (total_gain < 32)
 699                 return 12;
 700         else if (total_gain < 40)
 701                 return 11;
 702         else if (total_gain < 45)
 703                 return 10;
 704         else
 705                 return 9;
 706 }
 707
 708 /**
 709  * @return 0 if OK. 1 if last block of frame. return -1 if
 710  * unrecorrable error.
 711  */
 712 static int wma_decode_block(struct private_wmadec_data *pwd)
 713 {
 714         int n, v, ch, code, bsize;
 715         int coef_nb_bits, total_gain;
 716         int nb_coefs[MAX_CHANNELS];
 717         float mdct_norm;
 718
 719         /* compute current block length */
 720         if (pwd->use_variable_block_len) {
 721                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 722
 723                 if (pwd->reset_block_lengths) {
 724                         pwd->reset_block_lengths = 0;
 725                         v = get_bits(&pwd->gb, n);
 726                         if (v >= pwd->nb_block_sizes)
 727                                 return -1;
 728                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 729                         v = get_bits(&pwd->gb, n);
 730                         if (v >= pwd->nb_block_sizes)
 731                                 return -1;
 732                         pwd->block_len_bits = pwd->frame_len_bits - v;
 733                 } else {
 734                         /* update block lengths */
 735                         pwd->prev_block_len_bits = pwd->block_len_bits;
 736                         pwd->block_len_bits = pwd->next_block_len_bits;
 737                 }
 738                 v = get_bits(&pwd->gb, n);
 739                 if (v >= pwd->nb_block_sizes)
 740                         return -1;
 741                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 742         } else {
 743                 /* fixed block len */
 744                 pwd->next_block_len_bits = pwd->frame_len_bits;
 745                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 746                 pwd->block_len_bits = pwd->frame_len_bits;
 747         }
 748
 749         /* now check if the block length is coherent with the frame length */
 750         pwd->block_len = 1 << pwd->block_len_bits;
 751         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 752                 return -E_INCOHERENT_BLOCK_LEN;
 753
 754         if (pwd->ahi.channels == 2)
 755                 pwd->ms_stereo = get_bits1(&pwd->gb);
 756         v = 0;
 757         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 758                 int a = get_bits1(&pwd->gb);
 759                 pwd->channel_coded[ch] = a;
 760                 v |= a;
 761         }
 762
 763         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 764
 765         /* if no channel coded, no need to go further */
 766         /* XXX: fix potential framing problems */
 767         if (!v)
 768                 goto next;
 769
 770         /* read total gain and extract corresponding number of bits for
 771            coef escape coding */
 772         total_gain = 1;
 773         for (;;) {
 774                 int a = get_bits(&pwd->gb, 7);
 775                 total_gain += a;
 776                 if (a != 127)
 777                         break;
 778         }
 779
 780         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 781
 782         /* compute number of coefficients */
 783         n = pwd->coefs_end[bsize] - pwd->coefs_start;
 784         for (ch = 0; ch < pwd->ahi.channels; ch++)
 785                 nb_coefs[ch] = n;
 786
 787         /* complex coding */
 788         if (pwd->use_noise_coding) {
 789                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 790                         if (pwd->channel_coded[ch]) {
 791                                 int i, m, a;
 792                                 m = pwd->exponent_high_sizes[bsize];
 793                                 for (i = 0; i < m; i++) {
 794                                         a = get_bits1(&pwd->gb);
 795                                         pwd->high_band_coded[ch][i] = a;
 796                                         /* if noise coding, the coefficients are not transmitted */
 797                                         if (a)
 798                                                 nb_coefs[ch] -=
 799                                                     pwd->
 800                                                     exponent_high_bands[bsize]
 801                                                     [i];
 802                                 }
 803                         }
 804                 }
 805                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 806                         if (pwd->channel_coded[ch]) {
 807                                 int i, val;
 808
 809                                 n = pwd->exponent_high_sizes[bsize];
 810                                 val = (int) 0x80000000;
 811                                 for (i = 0; i < n; i++) {
 812                                         if (pwd->high_band_coded[ch][i]) {
 813                                                 if (val == (int) 0x80000000) {
 814                                                         val =
 815                                                             get_bits(&pwd->gb,
 816                                                                      7) - 19;
 817                                                 } else {
 818                                                         code =
 819                                                             get_vlc2(&pwd->gb,
 820                                                                      pwd->
 821                                                                      hgain_vlc.
 822                                                                      table,
 823                                                                      HGAINVLCBITS,
 824                                                                      HGAINMAX);
 825                                                         if (code < 0)
 826                                                                 return -1;
 827                                                         val += code - 18;
 828                                                 }
 829                                                 pwd->high_band_values[ch][i] =
 830                                                     val;
 831                                         }
 832                                 }
 833                         }
 834                 }
 835         }
 836
 837         /* exponents can be reused in short blocks. */
 838         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bits1(&pwd->gb)) {
 839                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 840                         if (pwd->channel_coded[ch]) {
 841                                 if (pwd->use_exp_vlc) {
 842                                         if (decode_exp_vlc(pwd, ch) < 0)
 843                                                 return -1;
 844                                 } else {
 845                                         decode_exp_lsp(pwd, ch);
 846                                 }
 847                                 pwd->exponents_bsize[ch] = bsize;
 848                         }
 849                 }
 850         }
 851
 852         /* parse spectral coefficients : just RLE encoding */
 853         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 854                 if (pwd->channel_coded[ch]) {
 855                         struct vlc *coef_vlc;
 856                         int level, run, sign, tindex;
 857                         int16_t *ptr, *eptr;
 858                         const uint16_t *level_table, *run_table;
 859
 860                         /* special VLC tables are used for ms stereo because
 861                            there is potentially less energy there */
 862                         tindex = (ch == 1 && pwd->ms_stereo);
 863                         coef_vlc = &pwd->coef_vlc[tindex];
 864                         run_table = pwd->run_table[tindex];
 865                         level_table = pwd->level_table[tindex];
 866                         /* XXX: optimize */
 867                         ptr = &pwd->coefs1[ch][0];
 868                         eptr = ptr + nb_coefs[ch];
 869                         memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 870                         for (;;) {
 871                                 code =
 872                                     get_vlc2(&pwd->gb, coef_vlc->table, VLCBITS,
 873                                              VLCMAX);
 874                                 if (code < 0)
 875                                         return -1;
 876                                 if (code == 1) {
 877                                         /* EOB */
 878                                         break;
 879                                 } else if (code == 0) {
 880                                         /* escape */
 881                                         level = get_bits(&pwd->gb, coef_nb_bits);
 882                                         /* NOTE: this is rather suboptimal. reading
 883                                            block_len_bits would be better */
 884                                         run =
 885                                             get_bits(&pwd->gb, pwd->frame_len_bits);
 886                                 } else {
 887                                         /* normal code */
 888                                         run = run_table[code];
 889                                         level = level_table[code];
 890                                 }
 891                                 sign = get_bits1(&pwd->gb);
 892                                 if (!sign)
 893                                         level = -level;
 894                                 ptr += run;
 895                                 if (ptr >= eptr) {
 896                                         PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 897                                         break;
 898                                 }
 899                                 *ptr++ = level;
 900                                 /* NOTE: EOB can be omitted */
 901                                 if (ptr >= eptr)
 902                                         break;
 903                         }
 904                 }
 905         }
 906
 907         /* normalize */
 908         {
 909                 int n4 = pwd->block_len / 2;
 910                 mdct_norm = 1.0 / (float) n4;
 911         }
 912
 913         /* finally compute the MDCT coefficients */
 914         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 915                 if (pwd->channel_coded[ch]) {
 916                         int16_t *coefs1;
 917                         float *coefs, *exponents, mult, mult1, noise;
 918                         int i, j, n1, last_high_band, esize;
 919                         float exp_power[HIGH_BAND_MAX_SIZE];
 920
 921                         coefs1 = pwd->coefs1[ch];
 922                         exponents = pwd->exponents[ch];
 923                         esize = pwd->exponents_bsize[ch];
 924                         mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 925                         mult *= mdct_norm;
 926                         coefs = pwd->coefs[ch];
 927                         if (pwd->use_noise_coding) {
 928                                 mult1 = mult;
 929                                 /* very low freqs : noise */
 930                                 for (i = 0; i < pwd->coefs_start; i++) {
 931                                         *coefs++ =
 932                                             pwd->noise_table[pwd->noise_index] *
 933                                             exponents[i << bsize >> esize] *
 934                                             mult1;
 935                                         pwd->noise_index =
 936                                             (pwd->noise_index +
 937                                              1) & (NOISE_TAB_SIZE - 1);
 938                                 }
 939
 940                                 n1 = pwd->exponent_high_sizes[bsize];
 941
 942                                 /* compute power of high bands */
 943                                 exponents = pwd->exponents[ch] +
 944                                     (pwd->high_band_start[bsize] << bsize);
 945                                 last_high_band = 0;     /* avoid warning */
 946                                 for (j = 0; j < n1; j++) {
 947                                         n = pwd->exponent_high_bands[pwd->
 948                                                                    frame_len_bits
 949                                                                    -
 950                                                                    pwd->
 951                                                                    block_len_bits]
 952                                             [j];
 953                                         if (pwd->high_band_coded[ch][j]) {
 954                                                 float e2, val;
 955                                                 e2 = 0;
 956                                                 for (i = 0; i < n; i++) {
 957                                                         val = exponents[i << bsize
 958                                                                       >> esize];
 959                                                         e2 += val * val;
 960                                                 }
 961                                                 exp_power[j] = e2 / n;
 962                                                 last_high_band = j;
 963                                         }
 964                                         exponents += n << bsize;
 965                                 }
 966
 967                                 /* main freqs and high freqs */
 968                                 exponents =
 969                                     pwd->exponents[ch] +
 970                                     (pwd->coefs_start << bsize);
 971                                 for (j = -1; j < n1; j++) {
 972                                         if (j < 0) {
 973                                                 n = pwd->high_band_start[bsize] -
 974                                                     pwd->coefs_start;
 975                                         } else {
 976                                                 n = pwd->exponent_high_bands[pwd->
 977                                                                            frame_len_bits
 978                                                                            -
 979                                                                            pwd->
 980                                                                            block_len_bits]
 981                                                     [j];
 982                                         }
 983                                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 984                                                 /* use noise with specified power */
 985                                                 mult1 =
 986                                                     sqrt(exp_power[j] /
 987                                                          exp_power
 988                                                          [last_high_band]);
 989                                                 /* XXX: use a table */
 990                                                 mult1 =
 991                                                     mult1 * pow(10,
 992                                                                 pwd->
 993                                                                 high_band_values
 994                                                                 [ch][j] * 0.05);
 995                                                 mult1 =
 996                                                     mult1 /
 997                                                     (pwd->max_exponent[ch] *
 998                                                      pwd->noise_mult);
 999                                                 mult1 *= mdct_norm;
1000                                                 for (i = 0; i < n; i++) {
1001                                                         noise =
1002                                                             pwd->noise_table[pwd->
1003                                                                            noise_index];
1004                                                         pwd->noise_index =
1005                                                             (pwd->noise_index +
1006                                                              1) &
1007                                                             (NOISE_TAB_SIZE -
1008                                                              1);
1009                                                         *coefs++ =
1010                                                             noise *
1011                                                             exponents[i << bsize
1012                                                                       >> esize]
1013                                                             * mult1;
1014                                                 }
1015                                                 exponents += n << bsize;
1016                                         } else {
1017                                                 /* coded values + small noise */
1018                                                 for (i = 0; i < n; i++) {
1019                                                         noise =
1020                                                             pwd->noise_table[pwd->
1021                                                                            noise_index];
1022                                                         pwd->noise_index =
1023                                                             (pwd->noise_index +
1024                                                              1) &
1025                                                             (NOISE_TAB_SIZE -
1026                                                              1);
1027                                                         *coefs++ =
1028                                                             ((*coefs1++) +
1029                                                              noise) *
1030                                                             exponents[i << bsize
1031                                                                       >> esize]
1032                                                             * mult;
1033                                                 }
1034                                                 exponents += n << bsize;
1035                                         }
1036                                 }
1037
1038                                 /* very high freqs : noise */
1039                                 n = pwd->block_len - pwd->coefs_end[bsize];
1040                                 mult1 =
1041                                     mult * exponents[((-1 << bsize)) >> esize];
1042                                 for (i = 0; i < n; i++) {
1043                                         *coefs++ =
1044                                             pwd->noise_table[pwd->noise_index] *
1045                                             mult1;
1046                                         pwd->noise_index =
1047                                             (pwd->noise_index +
1048                                              1) & (NOISE_TAB_SIZE - 1);
1049                                 }
1050                         } else {
1051                                 /* XXX: optimize more */
1052                                 for (i = 0; i < pwd->coefs_start; i++)
1053                                         *coefs++ = 0.0;
1054                                 n = nb_coefs[ch];
1055                                 for (i = 0; i < n; i++) {
1056                                         *coefs++ =
1057                                             coefs1[i] *
1058                                             exponents[i << bsize >> esize] *
1059                                             mult;
1060                                 }
1061                                 n = pwd->block_len - pwd->coefs_end[bsize];
1062                                 for (i = 0; i < n; i++)
1063                                         *coefs++ = 0.0;
1064                         }
1065                 }
1066         }
1067
1068         if (pwd->ms_stereo && pwd->channel_coded[1]) {
1069                 float a, b;
1070                 int i;
1071
1072                 /*
1073                  * Nominal case for ms stereo: we do it before mdct.
1074                  *
1075                  * No need to optimize this case because it should almost never
1076                  * happen.
1077                  */
1078                 if (!pwd->channel_coded[0]) {
1079                         PARA_NOTICE_LOG("rare ms-stereo\n");
1080                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1081                         pwd->channel_coded[0] = 1;
1082                 }
1083                 for (i = 0; i < pwd->block_len; i++) {
1084                         a = pwd->coefs[0][i];
1085                         b = pwd->coefs[1][i];
1086                         pwd->coefs[0][i] = a + b;
1087                         pwd->coefs[1][i] = a - b;
1088                 }
1089         }
1090
1091 next:
1092         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1093                 int n4, index;
1094
1095                 n = pwd->block_len;
1096                 n4 = pwd->block_len / 2;
1097                 if (pwd->channel_coded[ch])
1098                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1099                 else if (!(pwd->ms_stereo && ch == 1))
1100                         memset(pwd->output, 0, sizeof(pwd->output));
1101
1102                 /* multiply by the window and add in the frame */
1103                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1104                 wma_window(pwd, &pwd->frame_out[ch][index]);
1105         }
1106
1107         /* update block number */
1108         pwd->block_pos += pwd->block_len;
1109         if (pwd->block_pos >= pwd->frame_len)
1110                 return 1;
1111         else
1112                 return 0;
1113 }
1114
1115 /*
1116  * Clip a signed integer value into the -32768,32767 range.
1117  *
1118  * \param a The value to clip.
1119  *
1120  * \return The clipped value.
1121  */
1122 static inline int16_t av_clip_int16(int a)
1123 {
1124         if ((a + 32768) & ~65535)
1125                 return (a >> 31) ^ 32767;
1126         else
1127                 return a;
1128 }
1129
1130 /* Decode a frame of frame_len samples. */
1131 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1132 {
1133         int ret, i, n, ch, incr;
1134         int16_t *ptr;
1135         float *iptr;
1136
1137         /* read each block */
1138         pwd->block_pos = 0;
1139         for (;;) {
1140                 ret = wma_decode_block(pwd);
1141                 if (ret < 0)
1142                         return -1;
1143                 if (ret)
1144                         break;
1145         }
1146
1147         /* convert frame to integer */
1148         n = pwd->frame_len;
1149         incr = pwd->ahi.channels;
1150         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1151                 ptr = samples + ch;
1152                 iptr = pwd->frame_out[ch];
1153
1154                 for (i = 0; i < n; i++) {
1155                         *ptr = av_clip_int16(lrintf(*iptr++));
1156                         ptr += incr;
1157                 }
1158                 /* prepare for next block */
1159                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1160                         pwd->frame_len * sizeof(float));
1161         }
1162         return 0;
1163 }
1164
1165 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1166                 int *data_size, const uint8_t *buf, int buf_size)
1167 {
1168         int ret, nb_frames, bit_offset, i, pos, len;
1169         uint8_t *q;
1170         int16_t *samples;
1171         static int frame_count;
1172
1173         if (buf_size == 0) {
1174                 pwd->last_superframe_len = 0;
1175                 return 0;
1176         }
1177         if (buf_size < pwd->ahi.block_align)
1178                 return 0;
1179         buf_size = pwd->ahi.block_align;
1180         samples = data;
1181         init_get_bits(&pwd->gb, buf, buf_size * 8);
1182         if (pwd->use_bit_reservoir) {
1183                 /* read super frame header */
1184                 skip_bits(&pwd->gb, 4); /* super frame index */
1185                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1186                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1187                 ret = -E_WMA_OUTPUT_SPACE;
1188                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1189                                 * sizeof(int16_t) > *data_size)
1190                         goto fail;
1191
1192                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1193
1194                 if (pwd->last_superframe_len > 0) {
1195                         /* add bit_offset bits to last frame */
1196                         ret = -E_WMA_BAD_SUPERFRAME;
1197                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1198                                         MAX_CODED_SUPERFRAME_SIZE)
1199                                 goto fail;
1200                         q = pwd->last_superframe + pwd->last_superframe_len;
1201                         len = bit_offset;
1202                         while (len > 7) {
1203                                 *q++ = get_bits(&pwd->gb, 8);
1204                                 len -= 8;
1205                         }
1206                         if (len > 0)
1207                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1208
1209                         /* XXX: bit_offset bits into last frame */
1210                         init_get_bits(&pwd->gb, pwd->last_superframe,
1211                                 MAX_CODED_SUPERFRAME_SIZE * 8);
1212                         /* skip unused bits */
1213                         if (pwd->last_bitoffset > 0)
1214                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1215                         /*
1216                          * This frame is stored in the last superframe and in
1217                          * the current one.
1218                          */
1219                         ret = -E_WMA_DECODE;
1220                         if (wma_decode_frame(pwd, samples) < 0)
1221                                 goto fail;
1222                         frame_count++;
1223                         samples += pwd->ahi.channels * pwd->frame_len;
1224                 }
1225
1226                 /* read each frame starting from bit_offset */
1227                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1228                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1229                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)) * 8);
1230                 len = pos & 7;
1231                 if (len > 0)
1232                         skip_bits(&pwd->gb, len);
1233
1234                 pwd->reset_block_lengths = 1;
1235                 for (i = 0; i < nb_frames; i++) {
1236                         ret = -E_WMA_DECODE;
1237                         if (wma_decode_frame(pwd, samples) < 0)
1238                                 goto fail;
1239                         frame_count++;
1240                         samples += pwd->ahi.channels * pwd->frame_len;
1241                 }
1242
1243                 /* we copy the end of the frame in the last frame buffer */
1244                 pos = get_bits_count(&pwd->gb) +
1245                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1246                 pwd->last_bitoffset = pos & 7;
1247                 pos >>= 3;
1248                 len = buf_size - pos;
1249                 ret = -E_WMA_BAD_SUPERFRAME;
1250                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1251                         goto fail;
1252                 pwd->last_superframe_len = len;
1253                 memcpy(pwd->last_superframe, buf + pos, len);
1254         } else {
1255                 PARA_DEBUG_LOG("not using bit reservoir\n");
1256                 ret = -E_WMA_OUTPUT_SPACE;
1257                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1258                         goto fail;
1259                 /* single frame decode */
1260                 ret = -E_WMA_DECODE;
1261                 if (wma_decode_frame(pwd, samples) < 0)
1262                         goto fail;
1263                 frame_count++;
1264                 samples += pwd->ahi.channels * pwd->frame_len;
1265         }
1266         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1267                 "outbytes: %d, eaten: %d\n",
1268                 frame_count, pwd->frame_len, pwd->block_len,
1269                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1270         *data_size = (int8_t *)samples - (int8_t *)data;
1271         return pwd->ahi.block_align;
1272 fail:
1273         /* reset the bit reservoir on errors */
1274         pwd->last_superframe_len = 0;
1275         return ret;
1276 }
1277
1278 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1279                 struct filter_node *fn)
1280 {
1281         int ret, out_size = fn->bufsize - fn->loaded;
1282         struct private_wmadec_data *pwd = fn->private_data;
1283
1284         if (out_size < 128 * 1024)
1285                 return 0;
1286         if (!pwd) {
1287                 ret = wma_decode_init(inbuffer, len, &pwd);
1288                 if (ret <= 0)
1289                         return ret;
1290                 fn->private_data = pwd;
1291                 fn->fc->channels = pwd->ahi.channels;
1292                 fn->fc->samplerate = pwd->ahi.sample_rate;
1293                 return pwd->ahi.header_len;
1294         }
1295         /* skip 31 bytes */
1296         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1297                 return 0;
1298         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1299                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1300                 len - WMA_FRAME_SKIP);
1301         if (ret < 0)
1302                 return ret;
1303         fn->loaded += out_size;
1304         return ret + WMA_FRAME_SKIP;
1305 }
1306
1307 static void wmadec_close(struct filter_node *fn)
1308 {
1309         struct private_wmadec_data *pwd = fn->private_data;
1310
1311         if (!pwd)
1312                 return;
1313         wmadec_cleanup(pwd);
1314         free(fn->buf);
1315         fn->buf = NULL;
1316         free(fn->private_data);
1317         fn->private_data = NULL;
1318 }
1319
1320 static void wmadec_open(struct filter_node *fn)
1321 {
1322         fn->bufsize = 1024 * 1024;
1323         fn->buf = para_malloc(fn->bufsize);
1324         fn->private_data = NULL;
1325         fn->loaded = 0;
1326 }
1327
1328 /**
1329  * The init function of the wma decoder.
1330  *
1331  * \param f Its fields are filled in by the function.
1332  */
1333 void wmadec_filter_init(struct filter *f)
1334 {
1335         f->open = wmadec_open;
1336         f->close = wmadec_close;
1337         f->convert = wmadec_convert;
1338 }