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 ff_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 *ff_sine_windows[6] = {
 144         ff_sine_128, ff_sine_256, ff_sine_512, ff_sine_1024,
 145         ff_sine_2048, ff_sine_4096
 146 };
 147
 148 /* Generate a sine window. */
 149 static void sine_window_init(float *window, int n)
 150 {
 151         int i;
 152
 153         for (i = 0; i < n; i++)
 154                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 155 }
 156
 157 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 158 {
 159         int i;
 160
 161         for (i = 0; i < pwd->nb_block_sizes; i++)
 162                 imdct_end(pwd->mdct_ctx[i]);
 163         if (pwd->use_exp_vlc)
 164                 free_vlc(&pwd->exp_vlc);
 165         if (pwd->use_noise_coding)
 166                 free_vlc(&pwd->hgain_vlc);
 167         for (i = 0; i < 2; i++) {
 168                 free_vlc(&pwd->coef_vlc[i]);
 169                 free(pwd->run_table[i]);
 170                 free(pwd->level_table[i]);
 171         }
 172 }
 173
 174 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 175                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 176 {
 177         int n = vlc_table->n;
 178         const uint8_t *table_bits = vlc_table->huffbits;
 179         const uint32_t *table_codes = vlc_table->huffcodes;
 180         const uint16_t *levels_table = vlc_table->levels;
 181         uint16_t *run_table, *level_table;
 182         int i, l, j, k, level;
 183
 184         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 185
 186         run_table = para_malloc(n * sizeof(uint16_t));
 187         level_table = para_malloc(n * sizeof(uint16_t));
 188         i = 2;
 189         level = 1;
 190         k = 0;
 191         while (i < n) {
 192                 l = levels_table[k++];
 193                 for (j = 0; j < l; j++) {
 194                         run_table[i] = j;
 195                         level_table[i] = level;
 196                         i++;
 197                 }
 198                 level++;
 199         }
 200         *prun_table = run_table;
 201         *plevel_table = level_table;
 202 }
 203
 204 /* compute the scale factor band sizes for each MDCT block size */
 205 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 206         float high_freq)
 207 {
 208         struct asf_header_info *ahi = &pwd->ahi;
 209         int a, b, pos, lpos, k, block_len, i, j, n;
 210         const uint8_t *table;
 211
 212         pwd->coefs_start = 0;
 213         for (k = 0; k < pwd->nb_block_sizes; k++) {
 214                 block_len = pwd->frame_len >> k;
 215
 216                 table = NULL;
 217                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 218                 if (a < 3) {
 219                         if (ahi->sample_rate >= 44100)
 220                                 table = exponent_band_44100[a];
 221                         else if (ahi->sample_rate >= 32000)
 222                                 table = exponent_band_32000[a];
 223                         else if (ahi->sample_rate >= 22050)
 224                                 table = exponent_band_22050[a];
 225                 }
 226                 if (table) {
 227                         n = *table++;
 228                         for (i = 0; i < n; i++)
 229                                 pwd->exponent_bands[k][i] = table[i];
 230                         pwd->exponent_sizes[k] = n;
 231                 } else {
 232                         j = 0;
 233                         lpos = 0;
 234                         for (i = 0; i < 25; i++) {
 235                                 a = wma_critical_freqs[i];
 236                                 b = ahi->sample_rate;
 237                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 238                                 pos <<= 2;
 239                                 if (pos > block_len)
 240                                         pos = block_len;
 241                                 if (pos > lpos)
 242                                         pwd->exponent_bands[k][j++] = pos - lpos;
 243                                 if (pos >= block_len)
 244                                         break;
 245                                 lpos = pos;
 246                         }
 247                         pwd->exponent_sizes[k] = j;
 248                 }
 249
 250                 /* max number of coefs */
 251                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 252                 /* high freq computation */
 253                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 254                         / ahi->sample_rate + 0.5);
 255                 n = pwd->exponent_sizes[k];
 256                 j = 0;
 257                 pos = 0;
 258                 for (i = 0; i < n; i++) {
 259                         int start, end;
 260                         start = pos;
 261                         pos += pwd->exponent_bands[k][i];
 262                         end = pos;
 263                         if (start < pwd->high_band_start[k])
 264                                 start = pwd->high_band_start[k];
 265                         if (end > pwd->coefs_end[k])
 266                                 end = pwd->coefs_end[k];
 267                         if (end > start)
 268                                 pwd->exponent_high_bands[k][j++] = end - start;
 269                 }
 270                 pwd->exponent_high_sizes[k] = j;
 271         }
 272 }
 273
 274 static int wma_init(struct private_wmadec_data *pwd)
 275 {
 276         int i;
 277         float bps1, high_freq;
 278         volatile float bps;
 279         int sample_rate1;
 280         int coef_vlc_table;
 281         struct asf_header_info *ahi = &pwd->ahi;
 282         int flags2 = ahi->flags2;
 283
 284         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 285                 || ahi->channels <= 0 || ahi->channels > 8
 286                 || ahi->bit_rate <= 0)
 287                 return -E_WMA_BAD_PARAMS;
 288
 289         /* compute MDCT block size */
 290         if (ahi->sample_rate <= 16000) {
 291                 pwd->frame_len_bits = 9;
 292         } else if (ahi->sample_rate <= 22050) {
 293                 pwd->frame_len_bits = 10;
 294         } else {
 295                 pwd->frame_len_bits = 11;
 296         }
 297         pwd->frame_len = 1 << pwd->frame_len_bits;
 298         if (pwd->use_variable_block_len) {
 299                 int nb_max, nb;
 300                 nb = ((flags2 >> 3) & 3) + 1;
 301                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 302                         nb += 2;
 303                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 304                 if (nb > nb_max)
 305                         nb = nb_max;
 306                 pwd->nb_block_sizes = nb + 1;
 307         } else
 308                 pwd->nb_block_sizes = 1;
 309
 310         /* init rate dependent parameters */
 311         pwd->use_noise_coding = 1;
 312         high_freq = ahi->sample_rate * 0.5;
 313
 314         /* wma2 rates are normalized */
 315         sample_rate1 = ahi->sample_rate;
 316         if (sample_rate1 >= 44100)
 317                 sample_rate1 = 44100;
 318         else if (sample_rate1 >= 22050)
 319                 sample_rate1 = 22050;
 320         else if (sample_rate1 >= 16000)
 321                 sample_rate1 = 16000;
 322         else if (sample_rate1 >= 11025)
 323                 sample_rate1 = 11025;
 324         else if (sample_rate1 >= 8000)
 325                 sample_rate1 = 8000;
 326
 327         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 328         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 329         /*
 330          * Compute high frequency value and choose if noise coding should be
 331          * activated.
 332          */
 333         bps1 = bps;
 334         if (ahi->channels == 2)
 335                 bps1 = bps * 1.6;
 336         if (sample_rate1 == 44100) {
 337                 if (bps1 >= 0.61)
 338                         pwd->use_noise_coding = 0;
 339                 else
 340                         high_freq = high_freq * 0.4;
 341         } else if (sample_rate1 == 22050) {
 342                 if (bps1 >= 1.16)
 343                         pwd->use_noise_coding = 0;
 344                 else if (bps1 >= 0.72)
 345                         high_freq = high_freq * 0.7;
 346                 else
 347                         high_freq = high_freq * 0.6;
 348         } else if (sample_rate1 == 16000) {
 349                 if (bps > 0.5)
 350                         high_freq = high_freq * 0.5;
 351                 else
 352                         high_freq = high_freq * 0.3;
 353         } else if (sample_rate1 == 11025) {
 354                 high_freq = high_freq * 0.7;
 355         } else if (sample_rate1 == 8000) {
 356                 if (bps <= 0.625) {
 357                         high_freq = high_freq * 0.5;
 358                 } else if (bps > 0.75) {
 359                         pwd->use_noise_coding = 0;
 360                 } else {
 361                         high_freq = high_freq * 0.65;
 362                 }
 363         } else {
 364                 if (bps >= 0.8) {
 365                         high_freq = high_freq * 0.75;
 366                 } else if (bps >= 0.6) {
 367                         high_freq = high_freq * 0.6;
 368                 } else {
 369                         high_freq = high_freq * 0.5;
 370                 }
 371         }
 372         PARA_INFO_LOG("channels=%d sample_rate=%d "
 373                 "bitrate=%d block_align=%d\n",
 374                 ahi->channels, ahi->sample_rate,
 375                 ahi->bit_rate, ahi->block_align);
 376         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 377                 "high_freq=%f bitoffset=%d\n",
 378                 pwd->frame_len, bps, bps1,
 379                 high_freq, pwd->byte_offset_bits);
 380         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 381                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 382
 383         compute_scale_factor_band_sizes(pwd, high_freq);
 384         /* init MDCT windows : simple sinus window */
 385         for (i = 0; i < pwd->nb_block_sizes; i++) {
 386                 int n;
 387                 n = 1 << (pwd->frame_len_bits - i);
 388                 sine_window_init(ff_sine_windows[pwd->frame_len_bits - i - 7], n);
 389                 pwd->windows[i] = ff_sine_windows[pwd->frame_len_bits - i - 7];
 390         }
 391
 392         pwd->reset_block_lengths = 1;
 393
 394         if (pwd->use_noise_coding) {
 395                 /* init the noise generator */
 396                 if (pwd->use_exp_vlc)
 397                         pwd->noise_mult = 0.02;
 398                 else
 399                         pwd->noise_mult = 0.04;
 400
 401                 {
 402                         unsigned int seed;
 403                         float norm;
 404                         seed = 1;
 405                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 406                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 407                                 seed = seed * 314159 + 1;
 408                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 409                         }
 410                 }
 411         }
 412
 413         /* choose the VLC tables for the coefficients */
 414         coef_vlc_table = 2;
 415         if (ahi->sample_rate >= 32000) {
 416                 if (bps1 < 0.72)
 417                         coef_vlc_table = 0;
 418                 else if (bps1 < 1.16)
 419                         coef_vlc_table = 1;
 420         }
 421         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 422         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 423         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 424                 pwd->coef_vlcs[0]);
 425         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 426                 pwd->coef_vlcs[1]);
 427         return 0;
 428 }
 429
 430 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 431 {
 432         float wdel, a, b;
 433         int i, e, m;
 434
 435         wdel = M_PI / frame_len;
 436         for (i = 0; i < frame_len; i++)
 437                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 438
 439         /* tables for x^-0.25 computation */
 440         for (i = 0; i < 256; i++) {
 441                 e = i - 126;
 442                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 443         }
 444
 445         /* These two tables are needed to avoid two operations in pow_m1_4. */
 446         b = 1.0;
 447         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 448                 m = (1 << LSP_POW_BITS) + i;
 449                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 450                 a = pow(a, -0.25);
 451                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 452                 pwd->lsp_pow_m_table2[i] = b - a;
 453                 b = a;
 454         }
 455 }
 456
 457 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 458 {
 459         struct private_wmadec_data *pwd;
 460         int ret, i;
 461
 462         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 463         pwd = para_calloc(sizeof(*pwd));
 464         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 465         if (ret <= 0) {
 466                 free(pwd);
 467                 return ret;
 468         }
 469
 470         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 471         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 472         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 473
 474         ret = wma_init(pwd);
 475         if (ret < 0)
 476                 return ret;
 477         /* init MDCT */
 478         for (i = 0; i < pwd->nb_block_sizes; i++) {
 479                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 480                 if (ret < 0)
 481                         return ret;
 482         }
 483         if (pwd->use_noise_coding) {
 484                 PARA_INFO_LOG("using noise coding\n");
 485                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 486                         sizeof(ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 487                         ff_wma_hgain_huffcodes, 2);
 488         }
 489
 490         if (pwd->use_exp_vlc) {
 491                 PARA_INFO_LOG("using exp_vlc\n");
 492                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 493                 sizeof(ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 494                 ff_wma_scale_huffcodes, 4);
 495         } else {
 496                 PARA_INFO_LOG("using curve\n");
 497                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 498         }
 499         *result = pwd;
 500         return pwd->ahi.header_len;
 501 }
 502
 503 /**
 504  * compute x^-0.25 with an exponent and mantissa table. We use linear
 505  * interpolation to reduce the mantissa table size at a small speed
 506  * expense (linear interpolation approximately doubles the number of
 507  * bits of precision).
 508  */
 509 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 510 {
 511         union {
 512                 float f;
 513                 unsigned int v;
 514         } u, t;
 515         unsigned int e, m;
 516         float a, b;
 517
 518         u.f = x;
 519         e = u.v >> 23;
 520         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 521         /* build interpolation scale: 1 <= t < 2. */
 522         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 523         a = pwd->lsp_pow_m_table1[m];
 524         b = pwd->lsp_pow_m_table2[m];
 525         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 526 }
 527
 528 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 529                 float *out, float *val_max_ptr, int n, float *lsp)
 530 {
 531         int i, j;
 532         float p, q, w, v, val_max;
 533
 534         val_max = 0;
 535         for (i = 0; i < n; i++) {
 536                 p = 0.5f;
 537                 q = 0.5f;
 538                 w = pwd->lsp_cos_table[i];
 539                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 540                         q *= w - lsp[j - 1];
 541                         p *= w - lsp[j];
 542                 }
 543                 p *= p * (2.0f - w);
 544                 q *= q * (2.0f + w);
 545                 v = p + q;
 546                 v = pow_m1_4(pwd, v);
 547                 if (v > val_max)
 548                         val_max = v;
 549                 out[i] = v;
 550         }
 551         *val_max_ptr = val_max;
 552 }
 553
 554 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 555 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 556 {
 557         float lsp_coefs[NB_LSP_COEFS];
 558         int val, i;
 559
 560         for (i = 0; i < NB_LSP_COEFS; i++) {
 561                 if (i == 0 || i >= 8)
 562                         val = get_bits(&pwd->gb, 3);
 563                 else
 564                         val = get_bits(&pwd->gb, 4);
 565                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 566         }
 567
 568         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 569                 pwd->block_len, lsp_coefs);
 570 }
 571
 572 /* Decode exponents coded with VLC codes. */
 573 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 574 {
 575         int last_exp, n, code;
 576         const uint16_t *ptr, *band_ptr;
 577         float v, *q, max_scale, *q_end;
 578
 579         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 580         ptr = band_ptr;
 581         q = pwd->exponents[ch];
 582         q_end = q + pwd->block_len;
 583         max_scale = 0;
 584         last_exp = 36;
 585
 586         while (q < q_end) {
 587                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 588                 if (code < 0)
 589                         return -1;
 590                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 591                 last_exp += code - 60;
 592                 /* XXX: use a table */
 593                 v = pow(10, last_exp * (1.0 / 16.0));
 594                 if (v > max_scale)
 595                         max_scale = v;
 596                 n = *ptr++;
 597                 do {
 598                         *q++ = v;
 599                 } while (--n);
 600         }
 601         pwd->max_exponent[ch] = max_scale;
 602         return 0;
 603 }
 604
 605 /* compute src0 * src1 + src2 */
 606 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 607                 const float *src2, int len)
 608 {
 609         int i;
 610
 611         for (i = 0; i < len; i++)
 612                 dst[i] = src0[i] * src1[i] + src2[i];
 613 }
 614
 615 static inline void vector_mult_reverse(float *dst, const float *src0,
 616                 const float *src1, int len)
 617 {
 618         int i;
 619
 620         src1 += len - 1;
 621         for (i = 0; i < len; i++)
 622                 dst[i] = src0[i] * src1[-i];
 623 }
 624
 625 /**
 626  * Apply MDCT window and add into output.
 627  *
 628  * We ensure that when the windows overlap their squared sum
 629  * is always 1 (MDCT reconstruction rule).
 630  */
 631 static void wma_window(struct private_wmadec_data *pwd, float *out)
 632 {
 633         float *in = pwd->output;
 634         int block_len, bsize, n;
 635
 636         /* left part */
 637         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 638                 block_len = pwd->block_len;
 639                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 640                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 641         } else {
 642                 block_len = 1 << pwd->prev_block_len_bits;
 643                 n = (pwd->block_len - block_len) / 2;
 644                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 645                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 646                         block_len);
 647                 memcpy(out + n + block_len, in + n + block_len,
 648                         n * sizeof(float));
 649         }
 650         out += pwd->block_len;
 651         in += pwd->block_len;
 652         /* right part */
 653         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 654                 block_len = pwd->block_len;
 655                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 656                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 657         } else {
 658                 block_len = 1 << pwd->next_block_len_bits;
 659                 n = (pwd->block_len - block_len) / 2;
 660                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 661                 memcpy(out, in, n * sizeof(float));
 662                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 663                         block_len);
 664                 memset(out + n + block_len, 0, n * sizeof(float));
 665         }
 666 }
 667
 668 static int wma_total_gain_to_bits(int total_gain)
 669 {
 670         if (total_gain < 15)
 671                 return 13;
 672         else if (total_gain < 32)
 673                 return 12;
 674         else if (total_gain < 40)
 675                 return 11;
 676         else if (total_gain < 45)
 677                 return 10;
 678         else
 679                 return 9;
 680 }
 681
 682 /**
 683  * @return 0 if OK. 1 if last block of frame. return -1 if
 684  * unrecorrable error.
 685  */
 686 static int wma_decode_block(struct private_wmadec_data *pwd)
 687 {
 688         int n, v, ch, code, bsize;
 689         int coef_nb_bits, total_gain;
 690         int nb_coefs[MAX_CHANNELS];
 691         float mdct_norm;
 692
 693         /* compute current block length */
 694         if (pwd->use_variable_block_len) {
 695                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 696
 697                 if (pwd->reset_block_lengths) {
 698                         pwd->reset_block_lengths = 0;
 699                         v = get_bits(&pwd->gb, n);
 700                         if (v >= pwd->nb_block_sizes)
 701                                 return -1;
 702                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 703                         v = get_bits(&pwd->gb, n);
 704                         if (v >= pwd->nb_block_sizes)
 705                                 return -1;
 706                         pwd->block_len_bits = pwd->frame_len_bits - v;
 707                 } else {
 708                         /* update block lengths */
 709                         pwd->prev_block_len_bits = pwd->block_len_bits;
 710                         pwd->block_len_bits = pwd->next_block_len_bits;
 711                 }
 712                 v = get_bits(&pwd->gb, n);
 713                 if (v >= pwd->nb_block_sizes)
 714                         return -1;
 715                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 716         } else {
 717                 /* fixed block len */
 718                 pwd->next_block_len_bits = pwd->frame_len_bits;
 719                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 720                 pwd->block_len_bits = pwd->frame_len_bits;
 721         }
 722
 723         /* now check if the block length is coherent with the frame length */
 724         pwd->block_len = 1 << pwd->block_len_bits;
 725         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 726                 return -E_INCOHERENT_BLOCK_LEN;
 727
 728         if (pwd->ahi.channels == 2)
 729                 pwd->ms_stereo = get_bit(&pwd->gb);
 730         v = 0;
 731         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 732                 int a = get_bit(&pwd->gb);
 733                 pwd->channel_coded[ch] = a;
 734                 v |= a;
 735         }
 736
 737         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 738
 739         /* if no channel coded, no need to go further */
 740         /* XXX: fix potential framing problems */
 741         if (!v)
 742                 goto next;
 743
 744         /* read total gain and extract corresponding number of bits for
 745            coef escape coding */
 746         total_gain = 1;
 747         for (;;) {
 748                 int a = get_bits(&pwd->gb, 7);
 749                 total_gain += a;
 750                 if (a != 127)
 751                         break;
 752         }
 753
 754         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 755
 756         /* compute number of coefficients */
 757         n = pwd->coefs_end[bsize] - pwd->coefs_start;
 758         for (ch = 0; ch < pwd->ahi.channels; ch++)
 759                 nb_coefs[ch] = n;
 760
 761         /* complex coding */
 762         if (pwd->use_noise_coding) {
 763                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 764                         if (pwd->channel_coded[ch]) {
 765                                 int i, m, a;
 766                                 m = pwd->exponent_high_sizes[bsize];
 767                                 for (i = 0; i < m; i++) {
 768                                         a = get_bit(&pwd->gb);
 769                                         pwd->high_band_coded[ch][i] = a;
 770                                         /* if noise coding, the coefficients are not transmitted */
 771                                         if (a)
 772                                                 nb_coefs[ch] -=
 773                                                     pwd->
 774                                                     exponent_high_bands[bsize]
 775                                                     [i];
 776                                 }
 777                         }
 778                 }
 779                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 780                         if (pwd->channel_coded[ch]) {
 781                                 int i, val;
 782
 783                                 n = pwd->exponent_high_sizes[bsize];
 784                                 val = (int) 0x80000000;
 785                                 for (i = 0; i < n; i++) {
 786                                         if (pwd->high_band_coded[ch][i]) {
 787                                                 if (val == (int) 0x80000000) {
 788                                                         val =
 789                                                             get_bits(&pwd->gb,
 790                                                                      7) - 19;
 791                                                 } else {
 792                                                         code =
 793                                                             get_vlc(&pwd->gb,
 794                                                                      pwd->
 795                                                                      hgain_vlc.
 796                                                                      table,
 797                                                                      HGAINVLCBITS,
 798                                                                      HGAINMAX);
 799                                                         if (code < 0)
 800                                                                 return -1;
 801                                                         val += code - 18;
 802                                                 }
 803                                                 pwd->high_band_values[ch][i] =
 804                                                     val;
 805                                         }
 806                                 }
 807                         }
 808                 }
 809         }
 810
 811         /* exponents can be reused in short blocks. */
 812         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 813                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 814                         if (pwd->channel_coded[ch]) {
 815                                 if (pwd->use_exp_vlc) {
 816                                         if (decode_exp_vlc(pwd, ch) < 0)
 817                                                 return -1;
 818                                 } else {
 819                                         decode_exp_lsp(pwd, ch);
 820                                 }
 821                                 pwd->exponents_bsize[ch] = bsize;
 822                         }
 823                 }
 824         }
 825
 826         /* parse spectral coefficients : just RLE encoding */
 827         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 828                 struct vlc *coef_vlc;
 829                 int level, run, tindex;
 830                 int16_t *ptr, *eptr;
 831                 const uint16_t *level_table, *run_table;
 832
 833                 if (!pwd->channel_coded[ch])
 834                         continue;
 835                 /*
 836                  * special VLC tables are used for ms stereo because there is
 837                  * potentially less energy there
 838                  */
 839                 tindex = (ch == 1 && pwd->ms_stereo);
 840                 coef_vlc = &pwd->coef_vlc[tindex];
 841                 run_table = pwd->run_table[tindex];
 842                 level_table = pwd->level_table[tindex];
 843                 /* XXX: optimize */
 844                 ptr = &pwd->coefs1[ch][0];
 845                 eptr = ptr + nb_coefs[ch];
 846                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 847                 for (;;) {
 848                         code = get_vlc(&pwd->gb, coef_vlc->table,
 849                                 VLCBITS, VLCMAX);
 850                         if (code < 0)
 851                                 return -1;
 852                         if (code == 1) /* EOB */
 853                                 break;
 854                         if (code == 0) { /* escape */
 855                                 level = get_bits(&pwd->gb, coef_nb_bits);
 856                                 /* reading block_len_bits would be better */
 857                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 858                         } else { /* normal code */
 859                                 run = run_table[code];
 860                                 level = level_table[code];
 861                         }
 862                         if (!get_bit(&pwd->gb))
 863                                 level = -level;
 864                         ptr += run;
 865                         if (ptr >= eptr) {
 866                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 867                                 break;
 868                         }
 869                         *ptr++ = level;
 870                         if (ptr >= eptr) /* EOB can be omitted */
 871                                 break;
 872                 }
 873         }
 874
 875         /* normalize */
 876         {
 877                 int n4 = pwd->block_len / 2;
 878                 mdct_norm = 1.0 / (float) n4;
 879         }
 880
 881         /* finally compute the MDCT coefficients */
 882         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 883                 if (pwd->channel_coded[ch]) {
 884                         int16_t *coefs1;
 885                         float *coefs, *exponents, mult, mult1, noise;
 886                         int i, j, n1, last_high_band, esize;
 887                         float exp_power[HIGH_BAND_MAX_SIZE];
 888
 889                         coefs1 = pwd->coefs1[ch];
 890                         exponents = pwd->exponents[ch];
 891                         esize = pwd->exponents_bsize[ch];
 892                         mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 893                         mult *= mdct_norm;
 894                         coefs = pwd->coefs[ch];
 895                         if (pwd->use_noise_coding) {
 896                                 mult1 = mult;
 897                                 /* very low freqs : noise */
 898                                 for (i = 0; i < pwd->coefs_start; i++) {
 899                                         *coefs++ =
 900                                             pwd->noise_table[pwd->noise_index] *
 901                                             exponents[i << bsize >> esize] *
 902                                             mult1;
 903                                         pwd->noise_index =
 904                                             (pwd->noise_index +
 905                                              1) & (NOISE_TAB_SIZE - 1);
 906                                 }
 907
 908                                 n1 = pwd->exponent_high_sizes[bsize];
 909
 910                                 /* compute power of high bands */
 911                                 exponents = pwd->exponents[ch] +
 912                                     (pwd->high_band_start[bsize] << bsize);
 913                                 last_high_band = 0;     /* avoid warning */
 914                                 for (j = 0; j < n1; j++) {
 915                                         n = pwd->exponent_high_bands[pwd->
 916                                                                    frame_len_bits
 917                                                                    -
 918                                                                    pwd->
 919                                                                    block_len_bits]
 920                                             [j];
 921                                         if (pwd->high_band_coded[ch][j]) {
 922                                                 float e2, val;
 923                                                 e2 = 0;
 924                                                 for (i = 0; i < n; i++) {
 925                                                         val = exponents[i << bsize
 926                                                                       >> esize];
 927                                                         e2 += val * val;
 928                                                 }
 929                                                 exp_power[j] = e2 / n;
 930                                                 last_high_band = j;
 931                                         }
 932                                         exponents += n << bsize;
 933                                 }
 934
 935                                 /* main freqs and high freqs */
 936                                 exponents =
 937                                     pwd->exponents[ch] +
 938                                     (pwd->coefs_start << bsize);
 939                                 for (j = -1; j < n1; j++) {
 940                                         if (j < 0) {
 941                                                 n = pwd->high_band_start[bsize] -
 942                                                     pwd->coefs_start;
 943                                         } else {
 944                                                 n = pwd->exponent_high_bands[pwd->
 945                                                                            frame_len_bits
 946                                                                            -
 947                                                                            pwd->
 948                                                                            block_len_bits]
 949                                                     [j];
 950                                         }
 951                                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 952                                                 /* use noise with specified power */
 953                                                 mult1 =
 954                                                     sqrt(exp_power[j] /
 955                                                          exp_power
 956                                                          [last_high_band]);
 957                                                 /* XXX: use a table */
 958                                                 mult1 =
 959                                                     mult1 * pow(10,
 960                                                                 pwd->
 961                                                                 high_band_values
 962                                                                 [ch][j] * 0.05);
 963                                                 mult1 =
 964                                                     mult1 /
 965                                                     (pwd->max_exponent[ch] *
 966                                                      pwd->noise_mult);
 967                                                 mult1 *= mdct_norm;
 968                                                 for (i = 0; i < n; i++) {
 969                                                         noise =
 970                                                             pwd->noise_table[pwd->
 971                                                                            noise_index];
 972                                                         pwd->noise_index =
 973                                                             (pwd->noise_index +
 974                                                              1) &
 975                                                             (NOISE_TAB_SIZE -
 976                                                              1);
 977                                                         *coefs++ =
 978                                                             noise *
 979                                                             exponents[i << bsize
 980                                                                       >> esize]
 981                                                             * mult1;
 982                                                 }
 983                                                 exponents += n << bsize;
 984                                         } else {
 985                                                 /* coded values + small noise */
 986                                                 for (i = 0; i < n; i++) {
 987                                                         noise =
 988                                                             pwd->noise_table[pwd->
 989                                                                            noise_index];
 990                                                         pwd->noise_index =
 991                                                             (pwd->noise_index +
 992                                                              1) &
 993                                                             (NOISE_TAB_SIZE -
 994                                                              1);
 995                                                         *coefs++ =
 996                                                             ((*coefs1++) +
 997                                                              noise) *
 998                                                             exponents[i << bsize
 999                                                                       >> esize]
1000                                                             * mult;
1001                                                 }
1002                                                 exponents += n << bsize;
1003                                         }
1004                                 }
1005
1006                                 /* very high freqs : noise */
1007                                 n = pwd->block_len - pwd->coefs_end[bsize];
1008                                 mult1 =
1009                                     mult * exponents[((-1 << bsize)) >> esize];
1010                                 for (i = 0; i < n; i++) {
1011                                         *coefs++ =
1012                                             pwd->noise_table[pwd->noise_index] *
1013                                             mult1;
1014                                         pwd->noise_index =
1015                                             (pwd->noise_index +
1016                                              1) & (NOISE_TAB_SIZE - 1);
1017                                 }
1018                         } else {
1019                                 /* XXX: optimize more */
1020                                 for (i = 0; i < pwd->coefs_start; i++)
1021                                         *coefs++ = 0.0;
1022                                 n = nb_coefs[ch];
1023                                 for (i = 0; i < n; i++) {
1024                                         *coefs++ =
1025                                             coefs1[i] *
1026                                             exponents[i << bsize >> esize] *
1027                                             mult;
1028                                 }
1029                                 n = pwd->block_len - pwd->coefs_end[bsize];
1030                                 for (i = 0; i < n; i++)
1031                                         *coefs++ = 0.0;
1032                         }
1033                 }
1034         }
1035
1036         if (pwd->ms_stereo && pwd->channel_coded[1]) {
1037                 float a, b;
1038                 int i;
1039
1040                 /*
1041                  * Nominal case for ms stereo: we do it before mdct.
1042                  *
1043                  * No need to optimize this case because it should almost never
1044                  * happen.
1045                  */
1046                 if (!pwd->channel_coded[0]) {
1047                         PARA_NOTICE_LOG("rare ms-stereo\n");
1048                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
1049                         pwd->channel_coded[0] = 1;
1050                 }
1051                 for (i = 0; i < pwd->block_len; i++) {
1052                         a = pwd->coefs[0][i];
1053                         b = pwd->coefs[1][i];
1054                         pwd->coefs[0][i] = a + b;
1055                         pwd->coefs[1][i] = a - b;
1056                 }
1057         }
1058
1059 next:
1060         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1061                 int n4, index;
1062
1063                 n = pwd->block_len;
1064                 n4 = pwd->block_len / 2;
1065                 if (pwd->channel_coded[ch])
1066                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1067                 else if (!(pwd->ms_stereo && ch == 1))
1068                         memset(pwd->output, 0, sizeof(pwd->output));
1069
1070                 /* multiply by the window and add in the frame */
1071                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1072                 wma_window(pwd, &pwd->frame_out[ch][index]);
1073         }
1074
1075         /* update block number */
1076         pwd->block_pos += pwd->block_len;
1077         if (pwd->block_pos >= pwd->frame_len)
1078                 return 1;
1079         else
1080                 return 0;
1081 }
1082
1083 /*
1084  * Clip a signed integer value into the -32768,32767 range.
1085  *
1086  * \param a The value to clip.
1087  *
1088  * \return The clipped value.
1089  */
1090 static inline int16_t av_clip_int16(int a)
1091 {
1092         if ((a + 32768) & ~65535)
1093                 return (a >> 31) ^ 32767;
1094         else
1095                 return a;
1096 }
1097
1098 /* Decode a frame of frame_len samples. */
1099 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1100 {
1101         int ret, i, n, ch, incr;
1102         int16_t *ptr;
1103         float *iptr;
1104
1105         /* read each block */
1106         pwd->block_pos = 0;
1107         for (;;) {
1108                 ret = wma_decode_block(pwd);
1109                 if (ret < 0)
1110                         return -1;
1111                 if (ret)
1112                         break;
1113         }
1114
1115         /* convert frame to integer */
1116         n = pwd->frame_len;
1117         incr = pwd->ahi.channels;
1118         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1119                 ptr = samples + ch;
1120                 iptr = pwd->frame_out[ch];
1121
1122                 for (i = 0; i < n; i++) {
1123                         *ptr = av_clip_int16(lrintf(*iptr++));
1124                         ptr += incr;
1125                 }
1126                 /* prepare for next block */
1127                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1128                         pwd->frame_len * sizeof(float));
1129         }
1130         return 0;
1131 }
1132
1133 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1134                 int *data_size, const uint8_t *buf, int buf_size)
1135 {
1136         int ret;
1137         int16_t *samples;
1138         static int frame_count;
1139
1140         if (buf_size == 0) {
1141                 pwd->last_superframe_len = 0;
1142                 return 0;
1143         }
1144         if (buf_size < pwd->ahi.block_align)
1145                 return 0;
1146         buf_size = pwd->ahi.block_align;
1147         samples = data;
1148         init_get_bits(&pwd->gb, buf, buf_size);
1149         if (pwd->use_bit_reservoir) {
1150                 int i, nb_frames, bit_offset, pos, len;
1151                 uint8_t *q;
1152
1153                 /* read super frame header */
1154                 skip_bits(&pwd->gb, 4); /* super frame index */
1155                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1156                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1157                 ret = -E_WMA_OUTPUT_SPACE;
1158                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1159                                 * sizeof(int16_t) > *data_size)
1160                         goto fail;
1161
1162                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1163
1164                 if (pwd->last_superframe_len > 0) {
1165                         /* add bit_offset bits to last frame */
1166                         ret = -E_WMA_BAD_SUPERFRAME;
1167                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1168                                         MAX_CODED_SUPERFRAME_SIZE)
1169                                 goto fail;
1170                         q = pwd->last_superframe + pwd->last_superframe_len;
1171                         len = bit_offset;
1172                         while (len > 7) {
1173                                 *q++ = get_bits(&pwd->gb, 8);
1174                                 len -= 8;
1175                         }
1176                         if (len > 0)
1177                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1178
1179                         /* XXX: bit_offset bits into last frame */
1180                         init_get_bits(&pwd->gb, pwd->last_superframe,
1181                                 MAX_CODED_SUPERFRAME_SIZE);
1182                         /* skip unused bits */
1183                         if (pwd->last_bitoffset > 0)
1184                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1185                         /*
1186                          * This frame is stored in the last superframe and in
1187                          * the current one.
1188                          */
1189                         ret = -E_WMA_DECODE;
1190                         if (wma_decode_frame(pwd, samples) < 0)
1191                                 goto fail;
1192                         frame_count++;
1193                         samples += pwd->ahi.channels * pwd->frame_len;
1194                 }
1195
1196                 /* read each frame starting from bit_offset */
1197                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1198                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1199                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1200                 len = pos & 7;
1201                 if (len > 0)
1202                         skip_bits(&pwd->gb, len);
1203
1204                 pwd->reset_block_lengths = 1;
1205                 for (i = 0; i < nb_frames; i++) {
1206                         ret = -E_WMA_DECODE;
1207                         if (wma_decode_frame(pwd, samples) < 0)
1208                                 goto fail;
1209                         frame_count++;
1210                         samples += pwd->ahi.channels * pwd->frame_len;
1211                 }
1212
1213                 /* we copy the end of the frame in the last frame buffer */
1214                 pos = get_bits_count(&pwd->gb) +
1215                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1216                 pwd->last_bitoffset = pos & 7;
1217                 pos >>= 3;
1218                 len = buf_size - pos;
1219                 ret = -E_WMA_BAD_SUPERFRAME;
1220                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1221                         goto fail;
1222                 pwd->last_superframe_len = len;
1223                 memcpy(pwd->last_superframe, buf + pos, len);
1224         } else {
1225                 PARA_DEBUG_LOG("not using bit reservoir\n");
1226                 ret = -E_WMA_OUTPUT_SPACE;
1227                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1228                         goto fail;
1229                 /* single frame decode */
1230                 ret = -E_WMA_DECODE;
1231                 if (wma_decode_frame(pwd, samples) < 0)
1232                         goto fail;
1233                 frame_count++;
1234                 samples += pwd->ahi.channels * pwd->frame_len;
1235         }
1236         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1237                 "outbytes: %zd, eaten: %d\n",
1238                 frame_count, pwd->frame_len, pwd->block_len,
1239                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1240         *data_size = (int8_t *)samples - (int8_t *)data;
1241         return pwd->ahi.block_align;
1242 fail:
1243         /* reset the bit reservoir on errors */
1244         pwd->last_superframe_len = 0;
1245         return ret;
1246 }
1247
1248 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1249                 struct filter_node *fn)
1250 {
1251         int ret, out_size = fn->bufsize - fn->loaded;
1252         struct private_wmadec_data *pwd = fn->private_data;
1253
1254         if (out_size < 128 * 1024)
1255                 return 0;
1256         if (len <= WMA_FRAME_SKIP)
1257                 return 0;
1258         if (!pwd) {
1259                 ret = wma_decode_init(inbuffer, len, &pwd);
1260                 if (ret <= 0)
1261                         return ret;
1262                 fn->private_data = pwd;
1263                 fn->fc->channels = pwd->ahi.channels;
1264                 fn->fc->samplerate = pwd->ahi.sample_rate;
1265                 return pwd->ahi.header_len;
1266         }
1267         /* skip 31 bytes */
1268         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1269                 return 0;
1270         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1271                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1272                 len - WMA_FRAME_SKIP);
1273         if (ret < 0)
1274                 return ret;
1275         fn->loaded += out_size;
1276         return ret + WMA_FRAME_SKIP;
1277 }
1278
1279 static void wmadec_close(struct filter_node *fn)
1280 {
1281         struct private_wmadec_data *pwd = fn->private_data;
1282
1283         if (!pwd)
1284                 return;
1285         wmadec_cleanup(pwd);
1286         free(fn->buf);
1287         fn->buf = NULL;
1288         free(fn->private_data);
1289         fn->private_data = NULL;
1290 }
1291
1292 static void wmadec_open(struct filter_node *fn)
1293 {
1294         fn->bufsize = 1024 * 1024;
1295         fn->buf = para_malloc(fn->bufsize);
1296         fn->private_data = NULL;
1297         fn->loaded = 0;
1298 }
1299
1300 /**
1301  * The init function of the wma decoder.
1302  *
1303  * \param f Its fields are filled in by the function.
1304  */
1305 void wmadec_filter_init(struct filter *f)
1306 {
1307         f->open = wmadec_open;
1308         f->close = wmadec_close;
1309         f->convert = wmadec_convert;
1310 }