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         /** Whether to use the bit reservoir. */
  65         int use_bit_reservoir;
  66         /** Whether to use variable block length. */
  67         int use_variable_block_len;
  68         /** Whether to use exponent coding. */
  69         int use_exp_vlc;
  70         /** Whether perceptual noise is added. */
  71         int use_noise_coding;
  72         int byte_offset_bits;
  73         struct vlc exp_vlc;
  74         int exponent_sizes[BLOCK_NB_SIZES];
  75         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  76         /** The index of the first coef in high band. */
  77         int high_band_start[BLOCK_NB_SIZES];
  78         int coefs_end[BLOCK_NB_SIZES];  ///< max number of coded coefficients
  79         int exponent_high_sizes[BLOCK_NB_SIZES];
  80         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  81         struct vlc hgain_vlc;
  82
  83         /* coded values in high bands */
  84         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  85         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  86
  87         /* there are two possible tables for spectral coefficients */
  88         struct vlc coef_vlc[2];
  89         uint16_t *run_table[2];
  90         uint16_t *level_table[2];
  91         const struct coef_vlc_table *coef_vlcs[2];
  92         /* frame info */
  93         int frame_len;          ///< frame length in samples
  94         int frame_len_bits;     ///< frame_len = 1 << frame_len_bits
  95         /** Number of block sizes. */
  96         int nb_block_sizes;
  97         /* block info */
  98         int reset_block_lengths;
  99         int block_len_bits;     ///< log2 of current block length
 100         int next_block_len_bits;        ///< log2 of next block length
 101         int prev_block_len_bits;        ///< log2 of prev block length
 102         int block_len;          ///< block length in samples
 103         int block_pos;          ///< current position in frame
 104         uint8_t ms_stereo;      ///< true if mid/side stereo mode
 105         uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
 106         int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
 107         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 108         float max_exponent[MAX_CHANNELS];
 109         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 110         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 111         float output[BLOCK_MAX_SIZE * 2];
 112         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 113         float *windows[BLOCK_NB_SIZES];
 114         /* output buffer for one frame and the last for IMDCT windowing */
 115         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 116         /* last frame info */
 117         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 118         int last_bitoffset;
 119         int last_superframe_len;
 120         float noise_table[NOISE_TAB_SIZE];
 121         int noise_index;
 122         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 123         /* lsp_to_curve tables */
 124         float lsp_cos_table[BLOCK_MAX_SIZE];
 125         float lsp_pow_e_table[256];
 126         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 127         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 128 };
 129
 130 #define EXPVLCBITS 8
 131 #define EXPMAX ((19 + EXPVLCBITS - 1) / EXPVLCBITS)
 132
 133 #define HGAINVLCBITS 9
 134 #define HGAINMAX ((13 + HGAINVLCBITS - 1) / HGAINVLCBITS)
 135
 136 #define VLCBITS 9
 137 #define VLCMAX ((22 + VLCBITS - 1) / VLCBITS)
 138
 139 #define SINE_WINDOW(x) float sine_ ## x[x] __aligned(16)
 140
 141 SINE_WINDOW(128);
 142 SINE_WINDOW(256);
 143 SINE_WINDOW(512);
 144 SINE_WINDOW(1024);
 145 SINE_WINDOW(2048);
 146 SINE_WINDOW(4096);
 147
 148 static float *sine_windows[6] = {
 149         sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
 150 };
 151
 152 /* Generate a sine window. */
 153 static void sine_window_init(float *window, int n)
 154 {
 155         int i;
 156
 157         for (i = 0; i < n; i++)
 158                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 159 }
 160
 161 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 162 {
 163         int i;
 164
 165         for (i = 0; i < pwd->nb_block_sizes; i++)
 166                 imdct_end(pwd->mdct_ctx[i]);
 167         if (pwd->use_exp_vlc)
 168                 free_vlc(&pwd->exp_vlc);
 169         if (pwd->use_noise_coding)
 170                 free_vlc(&pwd->hgain_vlc);
 171         for (i = 0; i < 2; i++) {
 172                 free_vlc(&pwd->coef_vlc[i]);
 173                 free(pwd->run_table[i]);
 174                 free(pwd->level_table[i]);
 175         }
 176 }
 177
 178 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 179                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 180 {
 181         int n = vlc_table->n;
 182         const uint8_t *table_bits = vlc_table->huffbits;
 183         const uint32_t *table_codes = vlc_table->huffcodes;
 184         const uint16_t *levels_table = vlc_table->levels;
 185         uint16_t *run_table, *level_table;
 186         int i, l, j, k, level;
 187
 188         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 189
 190         run_table = para_malloc(n * sizeof(uint16_t));
 191         level_table = para_malloc(n * sizeof(uint16_t));
 192         i = 2;
 193         level = 1;
 194         k = 0;
 195         while (i < n) {
 196                 l = levels_table[k++];
 197                 for (j = 0; j < l; j++) {
 198                         run_table[i] = j;
 199                         level_table[i] = level;
 200                         i++;
 201                 }
 202                 level++;
 203         }
 204         *prun_table = run_table;
 205         *plevel_table = level_table;
 206 }
 207
 208 /* compute the scale factor band sizes for each MDCT block size */
 209 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 210         float high_freq)
 211 {
 212         struct asf_header_info *ahi = &pwd->ahi;
 213         int a, b, pos, lpos, k, block_len, i, j, n;
 214         const uint8_t *table;
 215
 216         for (k = 0; k < pwd->nb_block_sizes; k++) {
 217                 block_len = pwd->frame_len >> k;
 218
 219                 table = NULL;
 220                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 221                 if (a < 3) {
 222                         if (ahi->sample_rate >= 44100)
 223                                 table = exponent_band_44100[a];
 224                         else if (ahi->sample_rate >= 32000)
 225                                 table = exponent_band_32000[a];
 226                         else if (ahi->sample_rate >= 22050)
 227                                 table = exponent_band_22050[a];
 228                 }
 229                 if (table) {
 230                         n = *table++;
 231                         for (i = 0; i < n; i++)
 232                                 pwd->exponent_bands[k][i] = table[i];
 233                         pwd->exponent_sizes[k] = n;
 234                 } else {
 235                         j = 0;
 236                         lpos = 0;
 237                         for (i = 0; i < 25; i++) {
 238                                 a = wma_critical_freqs[i];
 239                                 b = ahi->sample_rate;
 240                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 241                                 pos <<= 2;
 242                                 if (pos > block_len)
 243                                         pos = block_len;
 244                                 if (pos > lpos)
 245                                         pwd->exponent_bands[k][j++] = pos - lpos;
 246                                 if (pos >= block_len)
 247                                         break;
 248                                 lpos = pos;
 249                         }
 250                         pwd->exponent_sizes[k] = j;
 251                 }
 252
 253                 /* max number of coefs */
 254                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 255                 /* high freq computation */
 256                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 257                         / ahi->sample_rate + 0.5);
 258                 n = pwd->exponent_sizes[k];
 259                 j = 0;
 260                 pos = 0;
 261                 for (i = 0; i < n; i++) {
 262                         int start, end;
 263                         start = pos;
 264                         pos += pwd->exponent_bands[k][i];
 265                         end = pos;
 266                         if (start < pwd->high_band_start[k])
 267                                 start = pwd->high_band_start[k];
 268                         if (end > pwd->coefs_end[k])
 269                                 end = pwd->coefs_end[k];
 270                         if (end > start)
 271                                 pwd->exponent_high_bands[k][j++] = end - start;
 272                 }
 273                 pwd->exponent_high_sizes[k] = j;
 274         }
 275 }
 276
 277 static int wma_init(struct private_wmadec_data *pwd)
 278 {
 279         int i;
 280         float bps1, high_freq;
 281         volatile float bps;
 282         int sample_rate1;
 283         int coef_vlc_table;
 284         struct asf_header_info *ahi = &pwd->ahi;
 285         int flags2 = ahi->flags2;
 286
 287         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 288                 || ahi->channels <= 0 || ahi->channels > 8
 289                 || ahi->bit_rate <= 0)
 290                 return -E_WMA_BAD_PARAMS;
 291
 292         /* compute MDCT block size */
 293         if (ahi->sample_rate <= 16000) {
 294                 pwd->frame_len_bits = 9;
 295         } else if (ahi->sample_rate <= 22050) {
 296                 pwd->frame_len_bits = 10;
 297         } else {
 298                 pwd->frame_len_bits = 11;
 299         }
 300         pwd->frame_len = 1 << pwd->frame_len_bits;
 301         if (pwd->use_variable_block_len) {
 302                 int nb_max, nb;
 303                 nb = ((flags2 >> 3) & 3) + 1;
 304                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 305                         nb += 2;
 306                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 307                 if (nb > nb_max)
 308                         nb = nb_max;
 309                 pwd->nb_block_sizes = nb + 1;
 310         } else
 311                 pwd->nb_block_sizes = 1;
 312
 313         /* init rate dependent parameters */
 314         pwd->use_noise_coding = 1;
 315         high_freq = ahi->sample_rate * 0.5;
 316
 317         /* wma2 rates are normalized */
 318         sample_rate1 = ahi->sample_rate;
 319         if (sample_rate1 >= 44100)
 320                 sample_rate1 = 44100;
 321         else if (sample_rate1 >= 22050)
 322                 sample_rate1 = 22050;
 323         else if (sample_rate1 >= 16000)
 324                 sample_rate1 = 16000;
 325         else if (sample_rate1 >= 11025)
 326                 sample_rate1 = 11025;
 327         else if (sample_rate1 >= 8000)
 328                 sample_rate1 = 8000;
 329
 330         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 331         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 332         /*
 333          * Compute high frequency value and choose if noise coding should be
 334          * activated.
 335          */
 336         bps1 = bps;
 337         if (ahi->channels == 2)
 338                 bps1 = bps * 1.6;
 339         if (sample_rate1 == 44100) {
 340                 if (bps1 >= 0.61)
 341                         pwd->use_noise_coding = 0;
 342                 else
 343                         high_freq = high_freq * 0.4;
 344         } else if (sample_rate1 == 22050) {
 345                 if (bps1 >= 1.16)
 346                         pwd->use_noise_coding = 0;
 347                 else if (bps1 >= 0.72)
 348                         high_freq = high_freq * 0.7;
 349                 else
 350                         high_freq = high_freq * 0.6;
 351         } else if (sample_rate1 == 16000) {
 352                 if (bps > 0.5)
 353                         high_freq = high_freq * 0.5;
 354                 else
 355                         high_freq = high_freq * 0.3;
 356         } else if (sample_rate1 == 11025) {
 357                 high_freq = high_freq * 0.7;
 358         } else if (sample_rate1 == 8000) {
 359                 if (bps <= 0.625) {
 360                         high_freq = high_freq * 0.5;
 361                 } else if (bps > 0.75) {
 362                         pwd->use_noise_coding = 0;
 363                 } else {
 364                         high_freq = high_freq * 0.65;
 365                 }
 366         } else {
 367                 if (bps >= 0.8) {
 368                         high_freq = high_freq * 0.75;
 369                 } else if (bps >= 0.6) {
 370                         high_freq = high_freq * 0.6;
 371                 } else {
 372                         high_freq = high_freq * 0.5;
 373                 }
 374         }
 375         PARA_INFO_LOG("channels=%d sample_rate=%d "
 376                 "bitrate=%d block_align=%d\n",
 377                 ahi->channels, ahi->sample_rate,
 378                 ahi->bit_rate, ahi->block_align);
 379         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 380                 "high_freq=%f bitoffset=%d\n",
 381                 pwd->frame_len, bps, bps1,
 382                 high_freq, pwd->byte_offset_bits);
 383         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 384                 pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
 385
 386         compute_scale_factor_band_sizes(pwd, high_freq);
 387         /* init MDCT windows : simple sinus window */
 388         for (i = 0; i < pwd->nb_block_sizes; i++) {
 389                 int n;
 390                 n = 1 << (pwd->frame_len_bits - i);
 391                 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
 392                 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
 393         }
 394
 395         pwd->reset_block_lengths = 1;
 396
 397         if (pwd->use_noise_coding) {
 398                 /* init the noise generator */
 399                 if (pwd->use_exp_vlc)
 400                         pwd->noise_mult = 0.02;
 401                 else
 402                         pwd->noise_mult = 0.04;
 403
 404                 {
 405                         unsigned int seed;
 406                         float norm;
 407                         seed = 1;
 408                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 409                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 410                                 seed = seed * 314159 + 1;
 411                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 412                         }
 413                 }
 414         }
 415
 416         /* choose the VLC tables for the coefficients */
 417         coef_vlc_table = 2;
 418         if (ahi->sample_rate >= 32000) {
 419                 if (bps1 < 0.72)
 420                         coef_vlc_table = 0;
 421                 else if (bps1 < 1.16)
 422                         coef_vlc_table = 1;
 423         }
 424         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 425         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 426         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 427                 pwd->coef_vlcs[0]);
 428         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 429                 pwd->coef_vlcs[1]);
 430         return 0;
 431 }
 432
 433 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 434 {
 435         float wdel, a, b;
 436         int i, e, m;
 437
 438         wdel = M_PI / frame_len;
 439         for (i = 0; i < frame_len; i++)
 440                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 441
 442         /* tables for x^-0.25 computation */
 443         for (i = 0; i < 256; i++) {
 444                 e = i - 126;
 445                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 446         }
 447
 448         /* These two tables are needed to avoid two operations in pow_m1_4. */
 449         b = 1.0;
 450         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 451                 m = (1 << LSP_POW_BITS) + i;
 452                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 453                 a = pow(a, -0.25);
 454                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 455                 pwd->lsp_pow_m_table2[i] = b - a;
 456                 b = a;
 457         }
 458 }
 459
 460 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 461 {
 462         struct private_wmadec_data *pwd;
 463         int ret, i;
 464
 465         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 466         pwd = para_calloc(sizeof(*pwd));
 467         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 468         if (ret <= 0) {
 469                 free(pwd);
 470                 return ret;
 471         }
 472
 473         pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
 474         pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
 475         pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
 476
 477         ret = wma_init(pwd);
 478         if (ret < 0)
 479                 return ret;
 480         /* init MDCT */
 481         for (i = 0; i < pwd->nb_block_sizes; i++) {
 482                 ret = imdct_init(pwd->frame_len_bits - i + 1, &pwd->mdct_ctx[i]);
 483                 if (ret < 0)
 484                         return ret;
 485         }
 486         if (pwd->use_noise_coding) {
 487                 PARA_INFO_LOG("using noise coding\n");
 488                 init_vlc(&pwd->hgain_vlc, HGAINVLCBITS,
 489                         sizeof(wma_hgain_huffbits), wma_hgain_huffbits,
 490                         wma_hgain_huffcodes, 2);
 491         }
 492
 493         if (pwd->use_exp_vlc) {
 494                 PARA_INFO_LOG("using exp_vlc\n");
 495                 init_vlc(&pwd->exp_vlc, EXPVLCBITS,
 496                 sizeof(wma_scale_huffbits), wma_scale_huffbits,
 497                 wma_scale_huffcodes, 4);
 498         } else {
 499                 PARA_INFO_LOG("using curve\n");
 500                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 501         }
 502         *result = pwd;
 503         return pwd->ahi.header_len;
 504 }
 505
 506 /**
 507  * compute x^-0.25 with an exponent and mantissa table. We use linear
 508  * interpolation to reduce the mantissa table size at a small speed
 509  * expense (linear interpolation approximately doubles the number of
 510  * bits of precision).
 511  */
 512 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 513 {
 514         union {
 515                 float f;
 516                 unsigned int v;
 517         } u, t;
 518         unsigned int e, m;
 519         float a, b;
 520
 521         u.f = x;
 522         e = u.v >> 23;
 523         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 524         /* build interpolation scale: 1 <= t < 2. */
 525         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 526         a = pwd->lsp_pow_m_table1[m];
 527         b = pwd->lsp_pow_m_table2[m];
 528         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 529 }
 530
 531 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 532                 float *out, float *val_max_ptr, int n, float *lsp)
 533 {
 534         int i, j;
 535         float p, q, w, v, val_max;
 536
 537         val_max = 0;
 538         for (i = 0; i < n; i++) {
 539                 p = 0.5f;
 540                 q = 0.5f;
 541                 w = pwd->lsp_cos_table[i];
 542                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 543                         q *= w - lsp[j - 1];
 544                         p *= w - lsp[j];
 545                 }
 546                 p *= p * (2.0f - w);
 547                 q *= q * (2.0f + w);
 548                 v = p + q;
 549                 v = pow_m1_4(pwd, v);
 550                 if (v > val_max)
 551                         val_max = v;
 552                 out[i] = v;
 553         }
 554         *val_max_ptr = val_max;
 555 }
 556
 557 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 558 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 559 {
 560         float lsp_coefs[NB_LSP_COEFS];
 561         int val, i;
 562
 563         for (i = 0; i < NB_LSP_COEFS; i++) {
 564                 if (i == 0 || i >= 8)
 565                         val = get_bits(&pwd->gb, 3);
 566                 else
 567                         val = get_bits(&pwd->gb, 4);
 568                 lsp_coefs[i] = wma_lsp_codebook[i][val];
 569         }
 570
 571         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 572                 pwd->block_len, lsp_coefs);
 573 }
 574
 575 /* Decode exponents coded with VLC codes. */
 576 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 577 {
 578         int last_exp, n, code;
 579         const uint16_t *ptr, *band_ptr;
 580         float v, *q, max_scale, *q_end;
 581
 582         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 583         ptr = band_ptr;
 584         q = pwd->exponents[ch];
 585         q_end = q + pwd->block_len;
 586         max_scale = 0;
 587         last_exp = 36;
 588
 589         while (q < q_end) {
 590                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 591                 if (code < 0)
 592                         return code;
 593                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 594                 last_exp += code - 60;
 595                 /* XXX: use a table */
 596                 v = pow(10, last_exp * (1.0 / 16.0));
 597                 if (v > max_scale)
 598                         max_scale = v;
 599                 n = *ptr++;
 600                 do {
 601                         *q++ = v;
 602                 } while (--n);
 603         }
 604         pwd->max_exponent[ch] = max_scale;
 605         return 0;
 606 }
 607
 608 /* compute src0 * src1 + src2 */
 609 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 610                 const float *src2, int len)
 611 {
 612         int i;
 613
 614         for (i = 0; i < len; i++)
 615                 dst[i] = src0[i] * src1[i] + src2[i];
 616 }
 617
 618 static inline void vector_mult_reverse(float *dst, const float *src0,
 619                 const float *src1, int len)
 620 {
 621         int i;
 622
 623         src1 += len - 1;
 624         for (i = 0; i < len; i++)
 625                 dst[i] = src0[i] * src1[-i];
 626 }
 627
 628 /**
 629  * Apply MDCT window and add into output.
 630  *
 631  * We ensure that when the windows overlap their squared sum
 632  * is always 1 (MDCT reconstruction rule).
 633  */
 634 static void wma_window(struct private_wmadec_data *pwd, float *out)
 635 {
 636         float *in = pwd->output;
 637         int block_len, bsize, n;
 638
 639         /* left part */
 640         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 641                 block_len = pwd->block_len;
 642                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 643                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 644         } else {
 645                 block_len = 1 << pwd->prev_block_len_bits;
 646                 n = (pwd->block_len - block_len) / 2;
 647                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 648                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 649                         block_len);
 650                 memcpy(out + n + block_len, in + n + block_len,
 651                         n * sizeof(float));
 652         }
 653         out += pwd->block_len;
 654         in += pwd->block_len;
 655         /* right part */
 656         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 657                 block_len = pwd->block_len;
 658                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 659                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 660         } else {
 661                 block_len = 1 << pwd->next_block_len_bits;
 662                 n = (pwd->block_len - block_len) / 2;
 663                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 664                 memcpy(out, in, n * sizeof(float));
 665                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 666                         block_len);
 667                 memset(out + n + block_len, 0, n * sizeof(float));
 668         }
 669 }
 670
 671 static int wma_total_gain_to_bits(int total_gain)
 672 {
 673         if (total_gain < 15)
 674                 return 13;
 675         else if (total_gain < 32)
 676                 return 12;
 677         else if (total_gain < 40)
 678                 return 11;
 679         else if (total_gain < 45)
 680                 return 10;
 681         else
 682                 return 9;
 683 }
 684
 685 static int compute_high_band_values(struct private_wmadec_data *pwd,
 686                 int bsize, int nb_coefs[MAX_CHANNELS])
 687 {
 688         int ch;
 689
 690         if (!pwd->use_noise_coding)
 691                 return 0;
 692         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 693                 int i, m, a;
 694                 if (!pwd->channel_coded[ch])
 695                         continue;
 696                 m = pwd->exponent_high_sizes[bsize];
 697                 for (i = 0; i < m; i++) {
 698                         a = get_bit(&pwd->gb);
 699                         pwd->high_band_coded[ch][i] = a;
 700                         if (!a)
 701                                 continue;
 702                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 703                 }
 704         }
 705         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 706                 int i, n, val;
 707                 if (!pwd->channel_coded[ch])
 708                         continue;
 709                 n = pwd->exponent_high_sizes[bsize];
 710                 val = (int)0x80000000;
 711                 for (i = 0; i < n; i++) {
 712                         if (!pwd->high_band_coded[ch][i])
 713                                 continue;
 714                         if (val == (int)0x80000000)
 715                                 val = get_bits(&pwd->gb, 7) - 19;
 716                         else {
 717                                 int code = get_vlc(&pwd->gb,
 718                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 719                                         HGAINMAX);
 720                                 if (code < 0)
 721                                         return code;
 722                                 val += code - 18;
 723                         }
 724                         pwd->high_band_values[ch][i] = val;
 725                 }
 726         }
 727         return 1;
 728 }
 729
 730 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 731                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 732 {
 733         int ch;
 734         float mdct_norm = 1.0 / (pwd->block_len / 2);
 735
 736         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 737                 int16_t *coefs1;
 738                 float *coefs, *exponents, mult, mult1, noise;
 739                 int i, j, n, n1, last_high_band, esize;
 740                 float exp_power[HIGH_BAND_MAX_SIZE];
 741
 742                 if (!pwd->channel_coded[ch])
 743                         continue;
 744                 coefs1 = pwd->coefs1[ch];
 745                 exponents = pwd->exponents[ch];
 746                 esize = pwd->exponents_bsize[ch];
 747                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 748                 mult *= mdct_norm;
 749                 coefs = pwd->coefs[ch];
 750                 if (!pwd->use_noise_coding) {
 751                         /* XXX: optimize more */
 752                         n = nb_coefs[ch];
 753                         for (i = 0; i < n; i++)
 754                                 *coefs++ = coefs1[i] *
 755                                         exponents[i << bsize >> esize] * mult;
 756                         n = pwd->block_len - pwd->coefs_end[bsize];
 757                         for (i = 0; i < n; i++)
 758                                 *coefs++ = 0.0;
 759                         continue;
 760                 }
 761                 mult1 = mult;
 762                 n1 = pwd->exponent_high_sizes[bsize];
 763                 /* compute power of high bands */
 764                 exponents = pwd->exponents[ch] +
 765                         (pwd->high_band_start[bsize] << bsize);
 766                 last_high_band = 0; /* avoid warning */
 767                 for (j = 0; j < n1; j++) {
 768                         n = pwd->exponent_high_bands[
 769                                 pwd->frame_len_bits - pwd->block_len_bits][j];
 770                         if (pwd->high_band_coded[ch][j]) {
 771                                 float e2, val;
 772                                 e2 = 0;
 773                                 for (i = 0; i < n; i++) {
 774                                         val = exponents[i << bsize >> esize];
 775                                         e2 += val * val;
 776                                 }
 777                                 exp_power[j] = e2 / n;
 778                                 last_high_band = j;
 779                         }
 780                         exponents += n << bsize;
 781                 }
 782                 /* main freqs and high freqs */
 783                 exponents = pwd->exponents[ch];
 784                 for (j = -1; j < n1; j++) {
 785                         if (j < 0)
 786                                 n = pwd->high_band_start[bsize];
 787                         else
 788                                 n = pwd->exponent_high_bands[pwd->frame_len_bits
 789                                         - pwd->block_len_bits][j];
 790                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 791                                 /* use noise with specified power */
 792                                 mult1 = sqrt(exp_power[j]
 793                                         / exp_power[last_high_band]);
 794                                 /* XXX: use a table */
 795                                 mult1 = mult1 * pow(10,
 796                                         pwd->high_band_values[ch][j] * 0.05);
 797                                 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
 798                                 mult1 *= mdct_norm;
 799                                 for (i = 0; i < n; i++) {
 800                                         noise = pwd->noise_table[pwd->noise_index];
 801                                         pwd->noise_index = (pwd->noise_index + 1)
 802                                                 & (NOISE_TAB_SIZE - 1);
 803                                         *coefs++ = noise * exponents[
 804                                                 i << bsize >> esize] * mult1;
 805                                 }
 806                                 exponents += n << bsize;
 807                         } else {
 808                                 /* coded values + small noise */
 809                                 for (i = 0; i < n; i++) {
 810                                         noise = pwd->noise_table[pwd->noise_index];
 811                                         pwd->noise_index = (pwd->noise_index + 1)
 812                                                 & (NOISE_TAB_SIZE - 1);
 813                                         *coefs++ = ((*coefs1++) + noise) *
 814                                                 exponents[i << bsize >> esize]
 815                                                 * mult;
 816                                 }
 817                                 exponents += n << bsize;
 818                         }
 819                 }
 820                 /* very high freqs: noise */
 821                 n = pwd->block_len - pwd->coefs_end[bsize];
 822                 mult1 = mult * exponents[((-1 << bsize)) >> esize];
 823                 for (i = 0; i < n; i++) {
 824                         *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
 825                         pwd->noise_index = (pwd->noise_index + 1)
 826                                 & (NOISE_TAB_SIZE - 1);
 827                 }
 828         }
 829 }
 830
 831 /**
 832  * Returns 0 if OK, 1 if last block of frame, negative on uncorrectable
 833  * errors.
 834  */
 835 static int wma_decode_block(struct private_wmadec_data *pwd)
 836 {
 837         int ret, n, v, ch, code, bsize;
 838         int coef_nb_bits, total_gain;
 839         int nb_coefs[MAX_CHANNELS];
 840
 841         /* compute current block length */
 842         if (pwd->use_variable_block_len) {
 843                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 844
 845                 if (pwd->reset_block_lengths) {
 846                         pwd->reset_block_lengths = 0;
 847                         v = get_bits(&pwd->gb, n);
 848                         if (v >= pwd->nb_block_sizes)
 849                                 return -E_WMA_BLOCK_SIZE;
 850                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 851                         v = get_bits(&pwd->gb, n);
 852                         if (v >= pwd->nb_block_sizes)
 853                                 return -E_WMA_BLOCK_SIZE;
 854                         pwd->block_len_bits = pwd->frame_len_bits - v;
 855                 } else {
 856                         /* update block lengths */
 857                         pwd->prev_block_len_bits = pwd->block_len_bits;
 858                         pwd->block_len_bits = pwd->next_block_len_bits;
 859                 }
 860                 v = get_bits(&pwd->gb, n);
 861                 if (v >= pwd->nb_block_sizes)
 862                         return -E_WMA_BLOCK_SIZE;
 863                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 864         } else {
 865                 /* fixed block len */
 866                 pwd->next_block_len_bits = pwd->frame_len_bits;
 867                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 868                 pwd->block_len_bits = pwd->frame_len_bits;
 869         }
 870
 871         /* now check if the block length is coherent with the frame length */
 872         pwd->block_len = 1 << pwd->block_len_bits;
 873         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 874                 return -E_INCOHERENT_BLOCK_LEN;
 875
 876         if (pwd->ahi.channels == 2)
 877                 pwd->ms_stereo = get_bit(&pwd->gb);
 878         v = 0;
 879         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 880                 int a = get_bit(&pwd->gb);
 881                 pwd->channel_coded[ch] = a;
 882                 v |= a;
 883         }
 884
 885         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 886
 887         /* if no channel coded, no need to go further */
 888         /* XXX: fix potential framing problems */
 889         if (!v)
 890                 goto next;
 891
 892         /*
 893          * Read total gain and extract corresponding number of bits for coef
 894          * escape coding.
 895          */
 896         total_gain = 1;
 897         for (;;) {
 898                 int a = get_bits(&pwd->gb, 7);
 899                 total_gain += a;
 900                 if (a != 127)
 901                         break;
 902         }
 903
 904         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 905
 906         /* compute number of coefficients */
 907         n = pwd->coefs_end[bsize];
 908         for (ch = 0; ch < pwd->ahi.channels; ch++)
 909                 nb_coefs[ch] = n;
 910
 911         ret = compute_high_band_values(pwd, bsize, nb_coefs);
 912         if (ret < 0)
 913                 return ret;
 914
 915         /* exponents can be reused in short blocks. */
 916         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 917                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 918                         if (pwd->channel_coded[ch]) {
 919                                 if (pwd->use_exp_vlc) {
 920                                         ret = decode_exp_vlc(pwd, ch);
 921                                         if (ret < 0)
 922                                                 return ret;
 923                                 } else
 924                                         decode_exp_lsp(pwd, ch);
 925                                 pwd->exponents_bsize[ch] = bsize;
 926                         }
 927                 }
 928         }
 929
 930         /* parse spectral coefficients : just RLE encoding */
 931         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 932                 struct vlc *coef_vlc;
 933                 int level, run, tindex;
 934                 int16_t *ptr, *eptr;
 935                 const uint16_t *level_table, *run_table;
 936
 937                 if (!pwd->channel_coded[ch])
 938                         continue;
 939                 /*
 940                  * special VLC tables are used for ms stereo because there is
 941                  * potentially less energy there
 942                  */
 943                 tindex = (ch == 1 && pwd->ms_stereo);
 944                 coef_vlc = &pwd->coef_vlc[tindex];
 945                 run_table = pwd->run_table[tindex];
 946                 level_table = pwd->level_table[tindex];
 947                 /* XXX: optimize */
 948                 ptr = &pwd->coefs1[ch][0];
 949                 eptr = ptr + nb_coefs[ch];
 950                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 951                 for (;;) {
 952                         code = get_vlc(&pwd->gb, coef_vlc->table,
 953                                 VLCBITS, VLCMAX);
 954                         if (code < 0)
 955                                 return code;
 956                         if (code == 1) /* EOB */
 957                                 break;
 958                         if (code == 0) { /* escape */
 959                                 level = get_bits(&pwd->gb, coef_nb_bits);
 960                                 /* reading block_len_bits would be better */
 961                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 962                         } else { /* normal code */
 963                                 run = run_table[code];
 964                                 level = level_table[code];
 965                         }
 966                         if (!get_bit(&pwd->gb))
 967                                 level = -level;
 968                         ptr += run;
 969                         if (ptr >= eptr) {
 970                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 971                                 break;
 972                         }
 973                         *ptr++ = level;
 974                         if (ptr >= eptr) /* EOB can be omitted */
 975                                 break;
 976                 }
 977         }
 978         compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
 979         if (pwd->ms_stereo && pwd->channel_coded[1]) {
 980                 float a, b;
 981                 int i;
 982                 /*
 983                  * Nominal case for ms stereo: we do it before mdct.
 984                  *
 985                  * No need to optimize this case because it should almost never
 986                  * happen.
 987                  */
 988                 if (!pwd->channel_coded[0]) {
 989                         PARA_NOTICE_LOG("rare ms-stereo\n");
 990                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
 991                         pwd->channel_coded[0] = 1;
 992                 }
 993                 for (i = 0; i < pwd->block_len; i++) {
 994                         a = pwd->coefs[0][i];
 995                         b = pwd->coefs[1][i];
 996                         pwd->coefs[0][i] = a + b;
 997                         pwd->coefs[1][i] = a - b;
 998                 }
 999         }
1000 next:
1001         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1002                 int n4, index;
1003
1004                 n = pwd->block_len;
1005                 n4 = pwd->block_len / 2;
1006                 if (pwd->channel_coded[ch])
1007                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1008                 else if (!(pwd->ms_stereo && ch == 1))
1009                         memset(pwd->output, 0, sizeof(pwd->output));
1010
1011                 /* multiply by the window and add in the frame */
1012                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1013                 wma_window(pwd, &pwd->frame_out[ch][index]);
1014         }
1015
1016         /* update block number */
1017         pwd->block_pos += pwd->block_len;
1018         if (pwd->block_pos >= pwd->frame_len)
1019                 return 1;
1020         else
1021                 return 0;
1022 }
1023
1024 /*
1025  * Clip a signed integer value into the -32768,32767 range.
1026  *
1027  * \param a The value to clip.
1028  *
1029  * \return The clipped value.
1030  */
1031 static inline int16_t av_clip_int16(int a)
1032 {
1033         if ((a + 32768) & ~65535)
1034                 return (a >> 31) ^ 32767;
1035         else
1036                 return a;
1037 }
1038
1039 /* Decode a frame of frame_len samples. */
1040 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1041 {
1042         int ret, i, n, ch, incr;
1043         int16_t *ptr;
1044         float *iptr;
1045
1046         /* read each block */
1047         pwd->block_pos = 0;
1048         for (;;) {
1049                 ret = wma_decode_block(pwd);
1050                 if (ret < 0)
1051                         return ret;
1052                 if (ret)
1053                         break;
1054         }
1055
1056         /* convert frame to integer */
1057         n = pwd->frame_len;
1058         incr = pwd->ahi.channels;
1059         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1060                 ptr = samples + ch;
1061                 iptr = pwd->frame_out[ch];
1062
1063                 for (i = 0; i < n; i++) {
1064                         *ptr = av_clip_int16(lrintf(*iptr++));
1065                         ptr += incr;
1066                 }
1067                 /* prepare for next block */
1068                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1069                         pwd->frame_len * sizeof(float));
1070         }
1071         return 0;
1072 }
1073
1074 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1075                 int *data_size, const uint8_t *buf, int buf_size)
1076 {
1077         int ret;
1078         int16_t *samples;
1079
1080         if (buf_size == 0) {
1081                 pwd->last_superframe_len = 0;
1082                 return 0;
1083         }
1084         if (buf_size < pwd->ahi.block_align)
1085                 return 0;
1086         buf_size = pwd->ahi.block_align;
1087         samples = data;
1088         init_get_bits(&pwd->gb, buf, buf_size);
1089         if (pwd->use_bit_reservoir) {
1090                 int i, nb_frames, bit_offset, pos, len;
1091                 uint8_t *q;
1092
1093                 /* read super frame header */
1094                 skip_bits(&pwd->gb, 4); /* super frame index */
1095                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1096                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1097                 ret = -E_WMA_OUTPUT_SPACE;
1098                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1099                                 * sizeof(int16_t) > *data_size)
1100                         goto fail;
1101
1102                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1103
1104                 if (pwd->last_superframe_len > 0) {
1105                         /* add bit_offset bits to last frame */
1106                         ret = -E_WMA_BAD_SUPERFRAME;
1107                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1108                                         MAX_CODED_SUPERFRAME_SIZE)
1109                                 goto fail;
1110                         q = pwd->last_superframe + pwd->last_superframe_len;
1111                         len = bit_offset;
1112                         while (len > 7) {
1113                                 *q++ = get_bits(&pwd->gb, 8);
1114                                 len -= 8;
1115                         }
1116                         if (len > 0)
1117                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1118
1119                         /* XXX: bit_offset bits into last frame */
1120                         init_get_bits(&pwd->gb, pwd->last_superframe,
1121                                 MAX_CODED_SUPERFRAME_SIZE);
1122                         /* skip unused bits */
1123                         if (pwd->last_bitoffset > 0)
1124                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1125                         /*
1126                          * This frame is stored in the last superframe and in
1127                          * the current one.
1128                          */
1129                         ret = wma_decode_frame(pwd, samples);
1130                         if (ret < 0)
1131                                 goto fail;
1132                         samples += pwd->ahi.channels * pwd->frame_len;
1133                 }
1134
1135                 /* read each frame starting from bit_offset */
1136                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1137                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1138                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1139                 len = pos & 7;
1140                 if (len > 0)
1141                         skip_bits(&pwd->gb, len);
1142
1143                 pwd->reset_block_lengths = 1;
1144                 for (i = 0; i < nb_frames; i++) {
1145                         ret = wma_decode_frame(pwd, samples);
1146                         if (ret < 0)
1147                                 goto fail;
1148                         samples += pwd->ahi.channels * pwd->frame_len;
1149                 }
1150
1151                 /* we copy the end of the frame in the last frame buffer */
1152                 pos = get_bits_count(&pwd->gb) +
1153                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1154                 pwd->last_bitoffset = pos & 7;
1155                 pos >>= 3;
1156                 len = buf_size - pos;
1157                 ret = -E_WMA_BAD_SUPERFRAME;
1158                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1159                         goto fail;
1160                 pwd->last_superframe_len = len;
1161                 memcpy(pwd->last_superframe, buf + pos, len);
1162         } else {
1163                 PARA_DEBUG_LOG("not using bit reservoir\n");
1164                 ret = -E_WMA_OUTPUT_SPACE;
1165                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1166                         goto fail;
1167                 /* single frame decode */
1168                 ret = wma_decode_frame(pwd, samples);
1169                 if (ret < 0)
1170                         goto fail;
1171                 samples += pwd->ahi.channels * pwd->frame_len;
1172         }
1173         PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %zd, eaten: %d\n",
1174                 pwd->frame_len, pwd->block_len,
1175                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1176         *data_size = (int8_t *)samples - (int8_t *)data;
1177         return pwd->ahi.block_align;
1178 fail:
1179         /* reset the bit reservoir on errors */
1180         pwd->last_superframe_len = 0;
1181         return ret;
1182 }
1183
1184 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1185                 struct filter_node *fn)
1186 {
1187         int ret, converted = 0;
1188         struct private_wmadec_data *pwd = fn->private_data;
1189
1190         if (len <= WMA_FRAME_SKIP)
1191                 return 0;
1192         if (!pwd) {
1193                 ret = wma_decode_init(inbuffer, len, &pwd);
1194                 if (ret <= 0)
1195                         return ret;
1196                 fn->private_data = pwd;
1197                 fn->fc->channels = pwd->ahi.channels;
1198                 fn->fc->samplerate = pwd->ahi.sample_rate;
1199                 return pwd->ahi.header_len;
1200         }
1201         for (;;) {
1202                 int out_size;
1203                 if (converted + WMA_FRAME_SKIP + pwd->ahi.block_align > len)
1204                         break;
1205                 out_size = fn->bufsize - fn->loaded;
1206                 if (out_size < 128 * 1024)
1207                         break;
1208                 ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1209                         &out_size, (uint8_t *)inbuffer + converted + WMA_FRAME_SKIP,
1210                         len - WMA_FRAME_SKIP);
1211                 if (ret < 0)
1212                         return ret;
1213                 fn->loaded += out_size;
1214                 converted += ret + WMA_FRAME_SKIP;
1215         }
1216         return converted;
1217 }
1218
1219 static void wmadec_close(struct filter_node *fn)
1220 {
1221         struct private_wmadec_data *pwd = fn->private_data;
1222
1223         if (!pwd)
1224                 return;
1225         wmadec_cleanup(pwd);
1226         free(fn->buf);
1227         fn->buf = NULL;
1228         free(fn->private_data);
1229         fn->private_data = NULL;
1230 }
1231
1232 static void wmadec_open(struct filter_node *fn)
1233 {
1234         fn->bufsize = 1024 * 1024;
1235         fn->buf = para_malloc(fn->bufsize);
1236         fn->private_data = NULL;
1237         fn->loaded = 0;
1238 }
1239
1240 /**
1241  * The init function of the wma decoder.
1242  *
1243  * \param f Its fields are filled in by the function.
1244  */
1245 void wmadec_filter_init(struct filter *f)
1246 {
1247         f->open = wmadec_open;
1248         f->close = wmadec_close;
1249         f->convert = wmadec_convert;
1250 }