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 #include <sys/select.h>
  28
  29 #include "para.h"
  30 #include "error.h"
  31 #include "list.h"
  32 #include "ggo.h"
  33 #include "string.h"
  34 #include "sched.h"
  35 #include "filter.h"
  36 #include "bitstream.h"
  37 #include "imdct.h"
  38 #include "wma.h"
  39 #include "wmadata.h"
  40
  41
  42 /* size of blocks */
  43 #define BLOCK_MIN_BITS 7
  44 #define BLOCK_MAX_BITS 11
  45 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  46
  47 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  48
  49 /* XXX: find exact max size */
  50 #define HIGH_BAND_MAX_SIZE 16
  51
  52 /* XXX: is it a suitable value ? */
  53 #define MAX_CODED_SUPERFRAME_SIZE 16384
  54
  55 #define MAX_CHANNELS 2
  56
  57 #define NOISE_TAB_SIZE 8192
  58
  59 #define LSP_POW_BITS 7
  60
  61 struct private_wmadec_data {
  62         struct asf_header_info ahi;
  63         struct getbit_context gb;
  64         int use_bit_reservoir;
  65         int use_variable_block_len;
  66         int use_exp_vlc;        ///< exponent coding: 0 = lsp, 1 = vlc + delta
  67         int use_noise_coding;   ///< true if perceptual noise is added
  68         int byte_offset_bits;
  69         struct vlc exp_vlc;
  70         int exponent_sizes[BLOCK_NB_SIZES];
  71         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  72         int high_band_start[BLOCK_NB_SIZES];    ///< index of first coef in high band
  73         int coefs_start;        ///< first coded coef
  74         int coefs_end[BLOCK_NB_SIZES];  ///< max number of coded coefficients
  75         int exponent_high_sizes[BLOCK_NB_SIZES];
  76         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  77         struct vlc hgain_vlc;
  78
  79         /* coded values in high bands */
  80         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  81         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  82
  83         /* there are two possible tables for spectral coefficients */
  84         struct vlc coef_vlc[2];
  85         uint16_t *run_table[2];
  86         uint16_t *level_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 #define SINE_WINDOW(x) float sine_ ## x[x] __aligned(16)
 135
 136 SINE_WINDOW(128);
 137 SINE_WINDOW(256);
 138 SINE_WINDOW(512);
 139 SINE_WINDOW(1024);
 140 SINE_WINDOW(2048);
 141 SINE_WINDOW(4096);
 142
 143 static float *sine_windows[6] = {
 144         sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
 145 };
 146
 147 /* Generate a sine window. */
 148 static void sine_window_init(float *window, int n)
 149 {
 150         int i;
 151
 152         for (i = 0; i < n; i++)
 153                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 154 }
 155
 156 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 157 {
 158         int i;
 159
 160         for (i = 0; i < pwd->nb_block_sizes; i++)
 161                 imdct_end(pwd->mdct_ctx[i]);
 162         if (pwd->use_exp_vlc)
 163                 free_vlc(&pwd->exp_vlc);
 164         if (pwd->use_noise_coding)
 165                 free_vlc(&pwd->hgain_vlc);
 166         for (i = 0; i < 2; i++) {
 167                 free_vlc(&pwd->coef_vlc[i]);
 168                 free(pwd->run_table[i]);
 169                 free(pwd->level_table[i]);
 170         }
 171 }
 172
 173 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 174                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 175 {
 176         int n = vlc_table->n;
 177         const uint8_t *table_bits = vlc_table->huffbits;
 178         const uint32_t *table_codes = vlc_table->huffcodes;
 179         const uint16_t *levels_table = vlc_table->levels;
 180         uint16_t *run_table, *level_table;
 181         int i, l, j, k, level;
 182
 183         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 184
 185         run_table = para_malloc(n * sizeof(uint16_t));
 186         level_table = para_malloc(n * sizeof(uint16_t));
 187         i = 2;
 188         level = 1;
 189         k = 0;
 190         while (i < n) {
 191                 l = levels_table[k++];
 192                 for (j = 0; j < l; j++) {
 193                         run_table[i] = j;
 194                         level_table[i] = level;
 195                         i++;
 196                 }
 197                 level++;
 198         }
 199         *prun_table = run_table;
 200         *plevel_table = level_table;
 201 }
 202
 203 /* compute the scale factor band sizes for each MDCT block size */
 204 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 205         float high_freq)
 206 {
 207         struct asf_header_info *ahi = &pwd->ahi;
 208         int a, b, pos, lpos, k, block_len, i, j, n;
 209         const uint8_t *table;
 210
 211         pwd->coefs_start = 0;
 212         for (k = 0; k < pwd->nb_block_sizes; k++) {
 213                 block_len = pwd->frame_len >> k;
 214
 215                 table = NULL;
 216                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 217                 if (a < 3) {
 218                         if (ahi->sample_rate >= 44100)
 219                                 table = exponent_band_44100[a];
 220                         else if (ahi->sample_rate >= 32000)
 221                                 table = exponent_band_32000[a];
 222                         else if (ahi->sample_rate >= 22050)
 223                                 table = exponent_band_22050[a];
 224                 }
 225                 if (table) {
 226                         n = *table++;
 227                         for (i = 0; i < n; i++)
 228                                 pwd->exponent_bands[k][i] = table[i];
 229                         pwd->exponent_sizes[k] = n;
 230                 } else {
 231                         j = 0;
 232                         lpos = 0;
 233                         for (i = 0; i < 25; i++) {
 234                                 a = wma_critical_freqs[i];
 235                                 b = ahi->sample_rate;
 236                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 237                                 pos <<= 2;
 238                                 if (pos > block_len)
 239                                         pos = block_len;
 240                                 if (pos > lpos)
 241                                         pwd->exponent_bands[k][j++] = pos - lpos;
 242                                 if (pos >= block_len)
 243                                         break;
 244                                 lpos = pos;
 245                         }
 246                         pwd->exponent_sizes[k] = j;
 247                 }
 248
 249                 /* max number of coefs */
 250                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 251                 /* high freq computation */
 252                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 253                         / ahi->sample_rate + 0.5);
 254                 n = pwd->exponent_sizes[k];
 255                 j = 0;
 256                 pos = 0;
 257                 for (i = 0; i < n; i++) {
 258                         int start, end;
 259                         start = pos;
 260                         pos += pwd->exponent_bands[k][i];
 261                         end = pos;
 262                         if (start < pwd->high_band_start[k])
 263                                 start = pwd->high_band_start[k];
 264                         if (end > pwd->coefs_end[k])
 265                                 end = pwd->coefs_end[k];
 266                         if (end > start)
 267                                 pwd->exponent_high_bands[k][j++] = end - start;
 268                 }
 269                 pwd->exponent_high_sizes[k] = j;
 270         }
 271 }
 272
 273 static int wma_init(struct private_wmadec_data *pwd)
 274 {
 275         int i;
 276         float bps1, high_freq;
 277         volatile float bps;
 278         int sample_rate1;
 279         int coef_vlc_table;
 280         struct asf_header_info *ahi = &pwd->ahi;
 281         int flags2 = ahi->flags2;
 282
 283         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 284                 || ahi->channels <= 0 || ahi->channels > 8
 285                 || ahi->bit_rate <= 0)
 286                 return -E_WMA_BAD_PARAMS;
 287
 288         /* compute MDCT block size */
 289         if (ahi->sample_rate <= 16000) {
 290                 pwd->frame_len_bits = 9;
 291         } else if (ahi->sample_rate <= 22050) {
 292                 pwd->frame_len_bits = 10;
 293         } else {
 294                 pwd->frame_len_bits = 11;
 295         }
 296         pwd->frame_len = 1 << pwd->frame_len_bits;
 297         if (pwd->use_variable_block_len) {
 298                 int nb_max, nb;
 299                 nb = ((flags2 >> 3) & 3) + 1;
 300                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 301                         nb += 2;
 302                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 303                 if (nb > nb_max)
 304                         nb = nb_max;
 305                 pwd->nb_block_sizes = nb + 1;
 306         } else
 307                 pwd->nb_block_sizes = 1;
 308
 309         /* init rate dependent parameters */
 310         pwd->use_noise_coding = 1;
 311         high_freq = ahi->sample_rate * 0.5;
 312
 313         /* wma2 rates are normalized */
 314         sample_rate1 = ahi->sample_rate;
 315         if (sample_rate1 >= 44100)
 316                 sample_rate1 = 44100;
 317         else if (sample_rate1 >= 22050)
 318                 sample_rate1 = 22050;
 319         else if (sample_rate1 >= 16000)
 320                 sample_rate1 = 16000;
 321         else if (sample_rate1 >= 11025)
 322                 sample_rate1 = 11025;
 323         else if (sample_rate1 >= 8000)
 324                 sample_rate1 = 8000;
 325
 326         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 327         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 328         /*
 329          * Compute high frequency value and choose if noise coding should be
 330          * activated.
 331          */
 332         bps1 = bps;
 333         if (ahi->channels == 2)
 334                 bps1 = bps * 1.6;
 335         if (sample_rate1 == 44100) {
 336                 if (bps1 >= 0.61)
 337                         pwd->use_noise_coding = 0;
 338                 else
 339                         high_freq = high_freq * 0.4;
 340         } else if (sample_rate1 == 22050) {
 341                 if (bps1 >= 1.16)
 342                         pwd->use_noise_coding = 0;
 343                 else if (bps1 >= 0.72)
 344                         high_freq = high_freq * 0.7;
 345                 else
 346                         high_freq = high_freq * 0.6;
 347         } else if (sample_rate1 == 16000) {
 348                 if (bps > 0.5)
 349                         high_freq = high_freq * 0.5;
 350                 else
 351                         high_freq = high_freq * 0.3;
 352         } else if (sample_rate1 == 11025) {
 353                 high_freq = high_freq * 0.7;
 354         } else if (sample_rate1 == 8000) {
 355                 if (bps <= 0.625) {
 356                         high_freq = high_freq * 0.5;
 357                 } else if (bps > 0.75) {
 358                         pwd->use_noise_coding = 0;
 359                 } else {
 360                         high_freq = high_freq * 0.65;
 361                 }
 362         } else {
 363                 if (bps >= 0.8) {
 364                         high_freq = high_freq * 0.75;
 365                 } else if (bps >= 0.6) {
 366                         high_freq = high_freq * 0.6;
 367                 } else {
 368                         high_freq = high_freq * 0.5;
 369                 }
 370         }
 371         PARA_INFO_LOG("channels=%d sample_rate=%d "
 372                 "bitrate=%d block_align=%d\n",
 373                 ahi->channels, ahi->sample_rate,
 374                 ahi->bit_rate, ahi->block_align);
 375         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 376                 "high_freq=%f bitoffset=%d\n",
 377                 pwd->frame_len, bps, bps1,
 378                 high_freq, pwd->byte_offset_bits);
 379         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 380                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 381
 382         compute_scale_factor_band_sizes(pwd, high_freq);
 383         /* init MDCT windows : simple sinus window */
 384         for (i = 0; i < pwd->nb_block_sizes; i++) {
 385                 int n;
 386                 n = 1 << (pwd->frame_len_bits - i);
 387                 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
 388                 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
 389         }
 390
 391         pwd->reset_block_lengths = 1;
 392
 393         if (pwd->use_noise_coding) {
 394                 /* init the noise generator */
 395                 if (pwd->use_exp_vlc)
 396                         pwd->noise_mult = 0.02;
 397                 else
 398                         pwd->noise_mult = 0.04;
 399
 400                 {
 401                         unsigned int seed;
 402                         float norm;
 403                         seed = 1;
 404                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 405                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 406                                 seed = seed * 314159 + 1;
 407                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 408                         }
 409                 }
 410         }
 411
 412         /* choose the VLC tables for the coefficients */
 413         coef_vlc_table = 2;
 414         if (ahi->sample_rate >= 32000) {
 415                 if (bps1 < 0.72)
 416                         coef_vlc_table = 0;
 417                 else if (bps1 < 1.16)
 418                         coef_vlc_table = 1;
 419         }
 420         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 421         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 422         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 423                 pwd->coef_vlcs[0]);
 424         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 425                 pwd->coef_vlcs[1]);
 426         return 0;
 427 }
 428
 429 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 430 {
 431         float wdel, a, b;
 432         int i, e, m;
 433
 434         wdel = M_PI / frame_len;
 435         for (i = 0; i < frame_len; i++)
 436                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 437
 438         /* tables for x^-0.25 computation */
 439         for (i = 0; i < 256; i++) {
 440                 e = i - 126;
 441                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 442         }
 443
 444         /* These two tables are needed to avoid two operations in pow_m1_4. */
 445         b = 1.0;
 446         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 447                 m = (1 << LSP_POW_BITS) + i;
 448                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 449                 a = pow(a, -0.25);
 450                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 451                 pwd->lsp_pow_m_table2[i] = b - a;
 452                 b = a;
 453         }
 454 }
 455
 456 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 457 {
 458         struct private_wmadec_data *pwd;
 459         int ret, i;
 460
 461         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 462         pwd = para_calloc(sizeof(*pwd));
 463         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 464         if (ret <= 0) {
 465                 free(pwd);
 466                 return ret;
 467         }
 468
 469         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 470         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 471         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 472
 473         ret = wma_init(pwd);
 474         if (ret < 0)
 475                 return ret;
 476         /* init MDCT */
 477         for (i = 0; i < pwd->nb_block_sizes; i++) {
 478                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 479                 if (ret < 0)
 480                         return ret;
 481         }
 482         if (pwd->use_noise_coding) {
 483                 PARA_INFO_LOG("using noise coding\n");
 484                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 485                         sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
 486                         wma_hgain_huffcodes, 2);
 487         }
 488
 489         if (pwd->use_exp_vlc) {
 490                 PARA_INFO_LOG("using exp_vlc\n");
 491                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 492                 sizeof(wma_scale_huffbits), wma_scale_huffbits,
 493                 wma_scale_huffcodes, 4);
 494         } else {
 495                 PARA_INFO_LOG("using curve\n");
 496                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 497         }
 498         *result = pwd;
 499         return pwd->ahi.header_len;
 500 }
 501
 502 /**
 503  * compute x^-0.25 with an exponent and mantissa table. We use linear
 504  * interpolation to reduce the mantissa table size at a small speed
 505  * expense (linear interpolation approximately doubles the number of
 506  * bits of precision).
 507  */
 508 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 509 {
 510         union {
 511                 float f;
 512                 unsigned int v;
 513         } u, t;
 514         unsigned int e, m;
 515         float a, b;
 516
 517         u.f = x;
 518         e = u.v >> 23;
 519         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 520         /* build interpolation scale: 1 <= t < 2. */
 521         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 522         a = pwd->lsp_pow_m_table1[m];
 523         b = pwd->lsp_pow_m_table2[m];
 524         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 525 }
 526
 527 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 528                 float *out, float *val_max_ptr, int n, float *lsp)
 529 {
 530         int i, j;
 531         float p, q, w, v, val_max;
 532
 533         val_max = 0;
 534         for (i = 0; i < n; i++) {
 535                 p = 0.5f;
 536                 q = 0.5f;
 537                 w = pwd->lsp_cos_table[i];
 538                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 539                         q *= w - lsp[j - 1];
 540                         p *= w - lsp[j];
 541                 }
 542                 p *= p * (2.0f - w);
 543                 q *= q * (2.0f + w);
 544                 v = p + q;
 545                 v = pow_m1_4(pwd, v);
 546                 if (v > val_max)
 547                         val_max = v;
 548                 out[i] = v;
 549         }
 550         *val_max_ptr = val_max;
 551 }
 552
 553 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 554 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 555 {
 556         float lsp_coefs[NB_LSP_COEFS];
 557         int val, i;
 558
 559         for (i = 0; i < NB_LSP_COEFS; i++) {
 560                 if (i == 0 || i >= 8)
 561                         val = get_bits(&pwd->gb, 3);
 562                 else
 563                         val = get_bits(&pwd->gb, 4);
 564                 lsp_coefs[i] = wma_lsp_codebook[i][val];
 565         }
 566
 567         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 568                 pwd->block_len, lsp_coefs);
 569 }
 570
 571 /* Decode exponents coded with VLC codes. */
 572 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 573 {
 574         int last_exp, n, code;
 575         const uint16_t *ptr, *band_ptr;
 576         float v, *q, max_scale, *q_end;
 577
 578         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 579         ptr = band_ptr;
 580         q = pwd->exponents[ch];
 581         q_end = q + pwd->block_len;
 582         max_scale = 0;
 583         last_exp = 36;
 584
 585         while (q < q_end) {
 586                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 587                 if (code < 0)
 588                         return -1;
 589                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 590                 last_exp += code - 60;
 591                 /* XXX: use a table */
 592                 v = pow(10, last_exp * (1.0 / 16.0));
 593                 if (v > max_scale)
 594                         max_scale = v;
 595                 n = *ptr++;
 596                 do {
 597                         *q++ = v;
 598                 } while (--n);
 599         }
 600         pwd->max_exponent[ch] = max_scale;
 601         return 0;
 602 }
 603
 604 /* compute src0 * src1 + src2 */
 605 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 606                 const float *src2, int len)
 607 {
 608         int i;
 609
 610         for (i = 0; i < len; i++)
 611                 dst[i] = src0[i] * src1[i] + src2[i];
 612 }
 613
 614 static inline void vector_mult_reverse(float *dst, const float *src0,
 615                 const float *src1, int len)
 616 {
 617         int i;
 618
 619         src1 += len - 1;
 620         for (i = 0; i < len; i++)
 621                 dst[i] = src0[i] * src1[-i];
 622 }
 623
 624 /**
 625  * Apply MDCT window and add into output.
 626  *
 627  * We ensure that when the windows overlap their squared sum
 628  * is always 1 (MDCT reconstruction rule).
 629  */
 630 static void wma_window(struct private_wmadec_data *pwd, float *out)
 631 {
 632         float *in = pwd->output;
 633         int block_len, bsize, n;
 634
 635         /* left part */
 636         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 637                 block_len = pwd->block_len;
 638                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 639                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 640         } else {
 641                 block_len = 1 << pwd->prev_block_len_bits;
 642                 n = (pwd->block_len - block_len) / 2;
 643                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 644                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 645                         block_len);
 646                 memcpy(out + n + block_len, in + n + block_len,
 647                         n * sizeof(float));
 648         }
 649         out += pwd->block_len;
 650         in += pwd->block_len;
 651         /* right part */
 652         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 653                 block_len = pwd->block_len;
 654                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 655                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 656         } else {
 657                 block_len = 1 << pwd->next_block_len_bits;
 658                 n = (pwd->block_len - block_len) / 2;
 659                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 660                 memcpy(out, in, n * sizeof(float));
 661                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 662                         block_len);
 663                 memset(out + n + block_len, 0, n * sizeof(float));
 664         }
 665 }
 666
 667 static int wma_total_gain_to_bits(int total_gain)
 668 {
 669         if (total_gain < 15)
 670                 return 13;
 671         else if (total_gain < 32)
 672                 return 12;
 673         else if (total_gain < 40)
 674                 return 11;
 675         else if (total_gain < 45)
 676                 return 10;
 677         else
 678                 return 9;
 679 }
 680
 681 static int compute_high_band_values(struct private_wmadec_data *pwd,
 682                 int bsize, int nb_coefs[MAX_CHANNELS])
 683 {
 684         int ch;
 685
 686         if (!pwd->use_noise_coding)
 687                 return 0;
 688         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 689                 int i, m, a;
 690                 if (!pwd->channel_coded[ch])
 691                         continue;
 692                 m = pwd->exponent_high_sizes[bsize];
 693                 for (i = 0; i < m; i++) {
 694                         a = get_bit(&pwd->gb);
 695                         pwd->high_band_coded[ch][i] = a;
 696                         if (!a)
 697                                 continue;
 698                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 699                 }
 700         }
 701         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 702                 int i, n, val;
 703                 if (!pwd->channel_coded[ch])
 704                         continue;
 705                 n = pwd->exponent_high_sizes[bsize];
 706                 val = (int)0x80000000;
 707                 for (i = 0; i < n; i++) {
 708                         if (!pwd->high_band_coded[ch][i])
 709                                 continue;
 710                         if (val == (int)0x80000000)
 711                                 val = get_bits(&pwd->gb, 7) - 19;
 712                         else {
 713                                 int code = get_vlc(&pwd->gb,
 714                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 715                                         HGAINMAX);
 716                                 if (code < 0)
 717                                         return -1;
 718                                 val += code - 18;
 719                         }
 720                         pwd->high_band_values[ch][i] = val;
 721                 }
 722         }
 723         return 1;
 724 }
 725
 726 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 727                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 728 {
 729         int ch;
 730         float mdct_norm = 1.0 / (pwd->block_len / 2);
 731
 732         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 733                 int16_t *coefs1;
 734                 float *coefs, *exponents, mult, mult1, noise;
 735                 int i, j, n, n1, last_high_band, esize;
 736                 float exp_power[HIGH_BAND_MAX_SIZE];
 737
 738                 if (!pwd->channel_coded[ch])
 739                         continue;
 740                 coefs1 = pwd->coefs1[ch];
 741                 exponents = pwd->exponents[ch];
 742                 esize = pwd->exponents_bsize[ch];
 743                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 744                 mult *= mdct_norm;
 745                 coefs = pwd->coefs[ch];
 746                 if (!pwd->use_noise_coding) {
 747                         /* XXX: optimize more */
 748                         for (i = 0; i < pwd->coefs_start; i++)
 749                                 *coefs++ = 0.0;
 750                         n = nb_coefs[ch];
 751                         for (i = 0; i < n; i++) {
 752                                 *coefs++ =
 753                                     coefs1[i] *
 754                                     exponents[i << bsize >> esize] *
 755                                     mult;
 756                         }
 757                         n = pwd->block_len - pwd->coefs_end[bsize];
 758                         for (i = 0; i < n; i++)
 759                                 *coefs++ = 0.0;
 760                         continue;
 761                 }
 762                 mult1 = mult;
 763                 /* very low freqs : noise */
 764                 for (i = 0; i < pwd->coefs_start; i++) {
 765                         *coefs++ =
 766                             pwd->noise_table[pwd->noise_index] *
 767                             exponents[i << bsize >> esize] *
 768                             mult1;
 769                         pwd->noise_index =
 770                             (pwd->noise_index +
 771                              1) & (NOISE_TAB_SIZE - 1);
 772                 }
 773
 774                 n1 = pwd->exponent_high_sizes[bsize];
 775
 776                 /* compute power of high bands */
 777                 exponents = pwd->exponents[ch] +
 778                     (pwd->high_band_start[bsize] << bsize);
 779                 last_high_band = 0;     /* avoid warning */
 780                 for (j = 0; j < n1; j++) {
 781                         n = pwd->exponent_high_bands[pwd->
 782                                                    frame_len_bits
 783                                                    -
 784                                                    pwd->
 785                                                    block_len_bits]
 786                             [j];
 787                         if (pwd->high_band_coded[ch][j]) {
 788                                 float e2, val;
 789                                 e2 = 0;
 790                                 for (i = 0; i < n; i++) {
 791                                         val = exponents[i << bsize
 792                                                       >> esize];
 793                                         e2 += val * val;
 794                                 }
 795                                 exp_power[j] = e2 / n;
 796                                 last_high_band = j;
 797                         }
 798                         exponents += n << bsize;
 799                 }
 800
 801                 /* main freqs and high freqs */
 802                 exponents =
 803                     pwd->exponents[ch] +
 804                     (pwd->coefs_start << bsize);
 805                 for (j = -1; j < n1; j++) {
 806                         if (j < 0) {
 807                                 n = pwd->high_band_start[bsize] -
 808                                     pwd->coefs_start;
 809                         } else {
 810                                 n = pwd->exponent_high_bands[pwd->
 811                                                            frame_len_bits
 812                                                            -
 813                                                            pwd->
 814                                                            block_len_bits]
 815                                     [j];
 816                         }
 817                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 818                                 /* use noise with specified power */
 819                                 mult1 =
 820                                     sqrt(exp_power[j] /
 821                                          exp_power
 822                                          [last_high_band]);
 823                                 /* XXX: use a table */
 824                                 mult1 =
 825                                     mult1 * pow(10,
 826                                                 pwd->
 827                                                 high_band_values
 828                                                 [ch][j] * 0.05);
 829                                 mult1 =
 830                                     mult1 /
 831                                     (pwd->max_exponent[ch] *
 832                                      pwd->noise_mult);
 833                                 mult1 *= mdct_norm;
 834                                 for (i = 0; i < n; i++) {
 835                                         noise =
 836                                             pwd->noise_table[pwd->
 837                                                            noise_index];
 838                                         pwd->noise_index =
 839                                             (pwd->noise_index +
 840                                              1) &
 841                                             (NOISE_TAB_SIZE -
 842                                              1);
 843                                         *coefs++ =
 844                                             noise *
 845                                             exponents[i << bsize
 846                                                       >> esize]
 847                                             * mult1;
 848                                 }
 849                                 exponents += n << bsize;
 850                         } else {
 851                                 /* coded values + small noise */
 852                                 for (i = 0; i < n; i++) {
 853                                         noise =
 854                                             pwd->noise_table[pwd->
 855                                                            noise_index];
 856                                         pwd->noise_index =
 857                                             (pwd->noise_index +
 858                                              1) &
 859                                             (NOISE_TAB_SIZE -
 860                                              1);
 861                                         *coefs++ =
 862                                             ((*coefs1++) +
 863                                              noise) *
 864                                             exponents[i << bsize
 865                                                       >> esize]
 866                                             * mult;
 867                                 }
 868                                 exponents += n << bsize;
 869                         }
 870                 }
 871
 872                 /* very high freqs : noise */
 873                 n = pwd->block_len - pwd->coefs_end[bsize];
 874                 mult1 =
 875                     mult * exponents[((-1 << bsize)) >> esize];
 876                 for (i = 0; i < n; i++) {
 877                         *coefs++ =
 878                             pwd->noise_table[pwd->noise_index] *
 879                             mult1;
 880                         pwd->noise_index =
 881                             (pwd->noise_index +
 882                              1) & (NOISE_TAB_SIZE - 1);
 883                 }
 884         }
 885 }
 886
 887 /**
 888  * @return 0 if OK. 1 if last block of frame. return -1 if
 889  * unrecorrable error.
 890  */
 891 static int wma_decode_block(struct private_wmadec_data *pwd)
 892 {
 893         int n, v, ch, code, bsize;
 894         int coef_nb_bits, total_gain;
 895         int nb_coefs[MAX_CHANNELS];
 896
 897         /* compute current block length */
 898         if (pwd->use_variable_block_len) {
 899                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 900
 901                 if (pwd->reset_block_lengths) {
 902                         pwd->reset_block_lengths = 0;
 903                         v = get_bits(&pwd->gb, n);
 904                         if (v >= pwd->nb_block_sizes)
 905                                 return -1;
 906                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 907                         v = get_bits(&pwd->gb, n);
 908                         if (v >= pwd->nb_block_sizes)
 909                                 return -1;
 910                         pwd->block_len_bits = pwd->frame_len_bits - v;
 911                 } else {
 912                         /* update block lengths */
 913                         pwd->prev_block_len_bits = pwd->block_len_bits;
 914                         pwd->block_len_bits = pwd->next_block_len_bits;
 915                 }
 916                 v = get_bits(&pwd->gb, n);
 917                 if (v >= pwd->nb_block_sizes)
 918                         return -1;
 919                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 920         } else {
 921                 /* fixed block len */
 922                 pwd->next_block_len_bits = pwd->frame_len_bits;
 923                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 924                 pwd->block_len_bits = pwd->frame_len_bits;
 925         }
 926
 927         /* now check if the block length is coherent with the frame length */
 928         pwd->block_len = 1 << pwd->block_len_bits;
 929         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 930                 return -E_INCOHERENT_BLOCK_LEN;
 931
 932         if (pwd->ahi.channels == 2)
 933                 pwd->ms_stereo = get_bit(&pwd->gb);
 934         v = 0;
 935         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 936                 int a = get_bit(&pwd->gb);
 937                 pwd->channel_coded[ch] = a;
 938                 v |= a;
 939         }
 940
 941         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 942
 943         /* if no channel coded, no need to go further */
 944         /* XXX: fix potential framing problems */
 945         if (!v)
 946                 goto next;
 947
 948         /* read total gain and extract corresponding number of bits for
 949            coef escape coding */
 950         total_gain = 1;
 951         for (;;) {
 952                 int a = get_bits(&pwd->gb, 7);
 953                 total_gain += a;
 954                 if (a != 127)
 955                         break;
 956         }
 957
 958         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 959
 960         /* compute number of coefficients */
 961         n = pwd->coefs_end[bsize] - pwd->coefs_start;
 962         for (ch = 0; ch < pwd->ahi.channels; ch++)
 963                 nb_coefs[ch] = n;
 964
 965         if (compute_high_band_values(pwd, bsize, nb_coefs) < 0)
 966                 return -1;
 967
 968         /* exponents can be reused in short blocks. */
 969         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 970                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 971                         if (pwd->channel_coded[ch]) {
 972                                 if (pwd->use_exp_vlc) {
 973                                         if (decode_exp_vlc(pwd, ch) < 0)
 974                                                 return -1;
 975                                 } else {
 976                                         decode_exp_lsp(pwd, ch);
 977                                 }
 978                                 pwd->exponents_bsize[ch] = bsize;
 979                         }
 980                 }
 981         }
 982
 983         /* parse spectral coefficients : just RLE encoding */
 984         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 985                 struct vlc *coef_vlc;
 986                 int level, run, tindex;
 987                 int16_t *ptr, *eptr;
 988                 const uint16_t *level_table, *run_table;
 989
 990                 if (!pwd->channel_coded[ch])
 991                         continue;
 992                 /*
 993                  * special VLC tables are used for ms stereo because there is
 994                  * potentially less energy there
 995                  */
 996                 tindex = (ch == 1 && pwd->ms_stereo);
 997                 coef_vlc = &pwd->coef_vlc[tindex];
 998                 run_table = pwd->run_table[tindex];
 999                 level_table = pwd->level_table[tindex];
1000                 /* XXX: optimize */
1001                 ptr = &pwd->coefs1[ch][0];
1002                 eptr = ptr + nb_coefs[ch];
1003                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
1004                 for (;;) {
1005                         code = get_vlc(&pwd->gb, coef_vlc->table,
1006                                 VLCBITS, VLCMAX);
1007                         if (code < 0)
1008                                 return -1;
1009                         if (code == 1) /* EOB */
1010                                 break;
1011                         if (code == 0) { /* escape */
1012                                 level = get_bits(&pwd->gb, coef_nb_bits);
1013                                 /* reading block_len_bits would be better */
1014                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
1015                         } else { /* normal code */
1016                                 run = run_table[code];
1017                                 level = level_table[code];
1018                         }
1019                         if (!get_bit(&pwd->gb))
1020                                 level = -level;
1021                         ptr += run;
1022                         if (ptr >= eptr) {
1023                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
1024                                 break;
1025                         }
1026                         *ptr++ = level;
1027                         if (ptr >= eptr) /* EOB can be omitted */
1028                                 break;
1029                 }
1030         }
1031
1032         compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
1033
1034         if (pwd->ms_stereo && pwd->channel_coded[1]) {
1035                 float a, b;
1036                 int i;
1037
1038                 /*
1039                  * Nominal case for ms stereo: we do it before mdct.
1040                  *
1041                  * No need to optimize this case because it should almost never
1042                  * happen.
1043                  */
1044                 if (!pwd->channel_coded[0]) {
1045                         PARA_NOTICE_LOG("rare ms-stereo\n");
1046                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1047                         pwd->channel_coded[0] = 1;
1048                 }
1049                 for (i = 0; i < pwd->block_len; i++) {
1050                         a = pwd->coefs[0][i];
1051                         b = pwd->coefs[1][i];
1052                         pwd->coefs[0][i] = a + b;
1053                         pwd->coefs[1][i] = a - b;
1054                 }
1055         }
1056
1057 next:
1058         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1059                 int n4, index;
1060
1061                 n = pwd->block_len;
1062                 n4 = pwd->block_len / 2;
1063                 if (pwd->channel_coded[ch])
1064                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1065                 else if (!(pwd->ms_stereo && ch == 1))
1066                         memset(pwd->output, 0, sizeof(pwd->output));
1067
1068                 /* multiply by the window and add in the frame */
1069                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1070                 wma_window(pwd, &pwd->frame_out[ch][index]);
1071         }
1072
1073         /* update block number */
1074         pwd->block_pos += pwd->block_len;
1075         if (pwd->block_pos >= pwd->frame_len)
1076                 return 1;
1077         else
1078                 return 0;
1079 }
1080
1081 /*
1082  * Clip a signed integer value into the -32768,32767 range.
1083  *
1084  * \param a The value to clip.
1085  *
1086  * \return The clipped value.
1087  */
1088 static inline int16_t av_clip_int16(int a)
1089 {
1090         if ((a + 32768) & ~65535)
1091                 return (a >> 31) ^ 32767;
1092         else
1093                 return a;
1094 }
1095
1096 /* Decode a frame of frame_len samples. */
1097 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1098 {
1099         int ret, i, n, ch, incr;
1100         int16_t *ptr;
1101         float *iptr;
1102
1103         /* read each block */
1104         pwd->block_pos = 0;
1105         for (;;) {
1106                 ret = wma_decode_block(pwd);
1107                 if (ret < 0)
1108                         return -1;
1109                 if (ret)
1110                         break;
1111         }
1112
1113         /* convert frame to integer */
1114         n = pwd->frame_len;
1115         incr = pwd->ahi.channels;
1116         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1117                 ptr = samples + ch;
1118                 iptr = pwd->frame_out[ch];
1119
1120                 for (i = 0; i < n; i++) {
1121                         *ptr = av_clip_int16(lrintf(*iptr++));
1122                         ptr += incr;
1123                 }
1124                 /* prepare for next block */
1125                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1126                         pwd->frame_len * sizeof(float));
1127         }
1128         return 0;
1129 }
1130
1131 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1132                 int *data_size, const uint8_t *buf, int buf_size)
1133 {
1134         int ret;
1135         int16_t *samples;
1136         static int frame_count;
1137
1138         if (buf_size == 0) {
1139                 pwd->last_superframe_len = 0;
1140                 return 0;
1141         }
1142         if (buf_size < pwd->ahi.block_align)
1143                 return 0;
1144         buf_size = pwd->ahi.block_align;
1145         samples = data;
1146         init_get_bits(&pwd->gb, buf, buf_size);
1147         if (pwd->use_bit_reservoir) {
1148                 int i, nb_frames, bit_offset, pos, len;
1149                 uint8_t *q;
1150
1151                 /* read super frame header */
1152                 skip_bits(&pwd->gb, 4); /* super frame index */
1153                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1154                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1155                 ret = -E_WMA_OUTPUT_SPACE;
1156                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1157                                 * sizeof(int16_t) > *data_size)
1158                         goto fail;
1159
1160                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1161
1162                 if (pwd->last_superframe_len > 0) {
1163                         /* add bit_offset bits to last frame */
1164                         ret = -E_WMA_BAD_SUPERFRAME;
1165                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1166                                         MAX_CODED_SUPERFRAME_SIZE)
1167                                 goto fail;
1168                         q = pwd->last_superframe + pwd->last_superframe_len;
1169                         len = bit_offset;
1170                         while (len > 7) {
1171                                 *q++ = get_bits(&pwd->gb, 8);
1172                                 len -= 8;
1173                         }
1174                         if (len > 0)
1175                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1176
1177                         /* XXX: bit_offset bits into last frame */
1178                         init_get_bits(&pwd->gb, pwd->last_superframe,
1179                                 MAX_CODED_SUPERFRAME_SIZE);
1180                         /* skip unused bits */
1181                         if (pwd->last_bitoffset > 0)
1182                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1183                         /*
1184                          * This frame is stored in the last superframe and in
1185                          * the current one.
1186                          */
1187                         ret = -E_WMA_DECODE;
1188                         if (wma_decode_frame(pwd, samples) < 0)
1189                                 goto fail;
1190                         frame_count++;
1191                         samples += pwd->ahi.channels * pwd->frame_len;
1192                 }
1193
1194                 /* read each frame starting from bit_offset */
1195                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1196                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1197                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1198                 len = pos & 7;
1199                 if (len > 0)
1200                         skip_bits(&pwd->gb, len);
1201
1202                 pwd->reset_block_lengths = 1;
1203                 for (i = 0; i < nb_frames; i++) {
1204                         ret = -E_WMA_DECODE;
1205                         if (wma_decode_frame(pwd, samples) < 0)
1206                                 goto fail;
1207                         frame_count++;
1208                         samples += pwd->ahi.channels * pwd->frame_len;
1209                 }
1210
1211                 /* we copy the end of the frame in the last frame buffer */
1212                 pos = get_bits_count(&pwd->gb) +
1213                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1214                 pwd->last_bitoffset = pos & 7;
1215                 pos >>= 3;
1216                 len = buf_size - pos;
1217                 ret = -E_WMA_BAD_SUPERFRAME;
1218                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1219                         goto fail;
1220                 pwd->last_superframe_len = len;
1221                 memcpy(pwd->last_superframe, buf + pos, len);
1222         } else {
1223                 PARA_DEBUG_LOG("not using bit reservoir\n");
1224                 ret = -E_WMA_OUTPUT_SPACE;
1225                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1226                         goto fail;
1227                 /* single frame decode */
1228                 ret = -E_WMA_DECODE;
1229                 if (wma_decode_frame(pwd, samples) < 0)
1230                         goto fail;
1231                 frame_count++;
1232                 samples += pwd->ahi.channels * pwd->frame_len;
1233         }
1234         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1235                 "outbytes: %zd, eaten: %d\n",
1236                 frame_count, pwd->frame_len, pwd->block_len,
1237                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1238         *data_size = (int8_t *)samples - (int8_t *)data;
1239         return pwd->ahi.block_align;
1240 fail:
1241         /* reset the bit reservoir on errors */
1242         pwd->last_superframe_len = 0;
1243         return ret;
1244 }
1245
1246 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1247                 struct filter_node *fn)
1248 {
1249         int ret, out_size = fn->bufsize - fn->loaded;
1250         struct private_wmadec_data *pwd = fn->private_data;
1251
1252         if (out_size < 128 * 1024)
1253                 return 0;
1254         if (len <= WMA_FRAME_SKIP)
1255                 return 0;
1256         if (!pwd) {
1257                 ret = wma_decode_init(inbuffer, len, &pwd);
1258                 if (ret <= 0)
1259                         return ret;
1260                 fn->private_data = pwd;
1261                 fn->fc->channels = pwd->ahi.channels;
1262                 fn->fc->samplerate = pwd->ahi.sample_rate;
1263                 return pwd->ahi.header_len;
1264         }
1265         /* skip 31 bytes */
1266         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1267                 return 0;
1268         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1269                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1270                 len - WMA_FRAME_SKIP);
1271         if (ret < 0)
1272                 return ret;
1273         fn->loaded += out_size;
1274         return ret + WMA_FRAME_SKIP;
1275 }
1276
1277 static void wmadec_close(struct filter_node *fn)
1278 {
1279         struct private_wmadec_data *pwd = fn->private_data;
1280
1281         if (!pwd)
1282                 return;
1283         wmadec_cleanup(pwd);
1284         free(fn->buf);
1285         fn->buf = NULL;
1286         free(fn->private_data);
1287         fn->private_data = NULL;
1288 }
1289
1290 static void wmadec_open(struct filter_node *fn)
1291 {
1292         fn->bufsize = 1024 * 1024;
1293         fn->buf = para_malloc(fn->bufsize);
1294         fn->private_data = NULL;
1295         fn->loaded = 0;
1296 }
1297
1298 /**
1299  * The init function of the wma decoder.
1300  *
1301  * \param f Its fields are filled in by the function.
1302  */
1303 void wmadec_filter_init(struct filter *f)
1304 {
1305         f->open = wmadec_open;
1306         f->close = wmadec_close;
1307         f->convert = wmadec_convert;
1308 }