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         pwd->frame_len = 1 << pwd->frame_len_bits;
 300         if (pwd->use_variable_block_len) {
 301                 int nb_max, nb;
 302                 nb = ((flags2 >> 3) & 3) + 1;
 303                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 304                         nb += 2;
 305                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 306                 if (nb > nb_max)
 307                         nb = nb_max;
 308                 pwd->nb_block_sizes = nb + 1;
 309         } else
 310                 pwd->nb_block_sizes = 1;
 311
 312         /* init rate dependent parameters */
 313         pwd->use_noise_coding = 1;
 314         high_freq = ahi->sample_rate * 0.5;
 315
 316         /* wma2 rates are normalized */
 317         sample_rate1 = ahi->sample_rate;
 318         if (sample_rate1 >= 44100)
 319                 sample_rate1 = 44100;
 320         else if (sample_rate1 >= 22050)
 321                 sample_rate1 = 22050;
 322         else if (sample_rate1 >= 16000)
 323                 sample_rate1 = 16000;
 324         else if (sample_rate1 >= 11025)
 325                 sample_rate1 = 11025;
 326         else if (sample_rate1 >= 8000)
 327                 sample_rate1 = 8000;
 328
 329         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 330         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 331         /*
 332          * Compute high frequency value and choose if noise coding should be
 333          * activated.
 334          */
 335         bps1 = bps;
 336         if (ahi->channels == 2)
 337                 bps1 = bps * 1.6;
 338         if (sample_rate1 == 44100) {
 339                 if (bps1 >= 0.61)
 340                         pwd->use_noise_coding = 0;
 341                 else
 342                         high_freq = high_freq * 0.4;
 343         } else if (sample_rate1 == 22050) {
 344                 if (bps1 >= 1.16)
 345                         pwd->use_noise_coding = 0;
 346                 else if (bps1 >= 0.72)
 347                         high_freq = high_freq * 0.7;
 348                 else
 349                         high_freq = high_freq * 0.6;
 350         } else if (sample_rate1 == 16000) {
 351                 if (bps > 0.5)
 352                         high_freq = high_freq * 0.5;
 353                 else
 354                         high_freq = high_freq * 0.3;
 355         } else if (sample_rate1 == 11025)
 356                 high_freq = high_freq * 0.7;
 357         else if (sample_rate1 == 8000) {
 358                 if (bps <= 0.625)
 359                         high_freq = high_freq * 0.5;
 360                 else if (bps > 0.75)
 361                         pwd->use_noise_coding = 0;
 362                 else
 363                         high_freq = high_freq * 0.65;
 364         } else {
 365                 if (bps >= 0.8)
 366                         high_freq = high_freq * 0.75;
 367                 else if (bps >= 0.6)
 368                         high_freq = high_freq * 0.6;
 369                 else
 370                         high_freq = high_freq * 0.5;
 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(sine_windows[pwd->frame_len_bits - i - 7], n);
 389                 pwd->windows[i] = 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(wma_hgain_huffbits), wma_hgain_huffbits,
 487                         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(wma_scale_huffbits), wma_scale_huffbits,
 494                 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] = 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 code;
 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 static int compute_high_band_values(struct private_wmadec_data *pwd,
 683                 int bsize, int nb_coefs[MAX_CHANNELS])
 684 {
 685         int ch;
 686
 687         if (!pwd->use_noise_coding)
 688                 return 0;
 689         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 690                 int i, m, a;
 691                 if (!pwd->channel_coded[ch])
 692                         continue;
 693                 m = pwd->exponent_high_sizes[bsize];
 694                 for (i = 0; i < m; i++) {
 695                         a = get_bit(&pwd->gb);
 696                         pwd->high_band_coded[ch][i] = a;
 697                         if (!a)
 698                                 continue;
 699                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 700                 }
 701         }
 702         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 703                 int i, n, val;
 704                 if (!pwd->channel_coded[ch])
 705                         continue;
 706                 n = pwd->exponent_high_sizes[bsize];
 707                 val = (int)0x80000000;
 708                 for (i = 0; i < n; i++) {
 709                         if (!pwd->high_band_coded[ch][i])
 710                                 continue;
 711                         if (val == (int)0x80000000)
 712                                 val = get_bits(&pwd->gb, 7) - 19;
 713                         else {
 714                                 int code = get_vlc(&pwd->gb,
 715                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 716                                         HGAINMAX);
 717                                 if (code < 0)
 718                                         return code;
 719                                 val += code - 18;
 720                         }
 721                         pwd->high_band_values[ch][i] = val;
 722                 }
 723         }
 724         return 1;
 725 }
 726
 727 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 728                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 729 {
 730         int ch;
 731         float mdct_norm = 1.0 / (pwd->block_len / 2);
 732
 733         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 734                 int16_t *coefs1;
 735                 float *coefs, *exponents, mult, mult1, noise;
 736                 int i, j, n, n1, last_high_band, esize;
 737                 float exp_power[HIGH_BAND_MAX_SIZE];
 738
 739                 if (!pwd->channel_coded[ch])
 740                         continue;
 741                 coefs1 = pwd->coefs1[ch];
 742                 exponents = pwd->exponents[ch];
 743                 esize = pwd->exponents_bsize[ch];
 744                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 745                 mult *= mdct_norm;
 746                 coefs = pwd->coefs[ch];
 747                 if (!pwd->use_noise_coding) {
 748                         /* XXX: optimize more */
 749                         n = nb_coefs[ch];
 750                         for (i = 0; i < n; i++)
 751                                 *coefs++ = coefs1[i] *
 752                                         exponents[i << bsize >> esize] * mult;
 753                         n = pwd->block_len - pwd->coefs_end[bsize];
 754                         for (i = 0; i < n; i++)
 755                                 *coefs++ = 0.0;
 756                         continue;
 757                 }
 758                 mult1 = mult;
 759                 n1 = pwd->exponent_high_sizes[bsize];
 760                 /* compute power of high bands */
 761                 exponents = pwd->exponents[ch] +
 762                         (pwd->high_band_start[bsize] << bsize);
 763                 last_high_band = 0; /* avoid warning */
 764                 for (j = 0; j < n1; j++) {
 765                         n = pwd->exponent_high_bands[
 766                                 pwd->frame_len_bits - pwd->block_len_bits][j];
 767                         if (pwd->high_band_coded[ch][j]) {
 768                                 float e2, val;
 769                                 e2 = 0;
 770                                 for (i = 0; i < n; i++) {
 771                                         val = exponents[i << bsize >> esize];
 772                                         e2 += val * val;
 773                                 }
 774                                 exp_power[j] = e2 / n;
 775                                 last_high_band = j;
 776                         }
 777                         exponents += n << bsize;
 778                 }
 779                 /* main freqs and high freqs */
 780                 exponents = pwd->exponents[ch];
 781                 for (j = -1; j < n1; j++) {
 782                         if (j < 0)
 783                                 n = pwd->high_band_start[bsize];
 784                         else
 785                                 n = pwd->exponent_high_bands[pwd->frame_len_bits
 786                                         - pwd->block_len_bits][j];
 787                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 788                                 /* use noise with specified power */
 789                                 mult1 = sqrt(exp_power[j]
 790                                         / exp_power[last_high_band]);
 791                                 /* XXX: use a table */
 792                                 mult1 = mult1 * pow(10,
 793                                         pwd->high_band_values[ch][j] * 0.05);
 794                                 mult1 /= (pwd->max_exponent[ch] * pwd->noise_mult);
 795                                 mult1 *= mdct_norm;
 796                                 for (i = 0; i < n; i++) {
 797                                         noise = pwd->noise_table[pwd->noise_index];
 798                                         pwd->noise_index = (pwd->noise_index + 1)
 799                                                 & (NOISE_TAB_SIZE - 1);
 800                                         *coefs++ = noise * exponents[
 801                                                 i << bsize >> esize] * mult1;
 802                                 }
 803                                 exponents += n << bsize;
 804                         } else {
 805                                 /* coded values + small noise */
 806                                 for (i = 0; i < n; i++) {
 807                                         noise = pwd->noise_table[pwd->noise_index];
 808                                         pwd->noise_index = (pwd->noise_index + 1)
 809                                                 & (NOISE_TAB_SIZE - 1);
 810                                         *coefs++ = ((*coefs1++) + noise) *
 811                                                 exponents[i << bsize >> esize]
 812                                                 * mult;
 813                                 }
 814                                 exponents += n << bsize;
 815                         }
 816                 }
 817                 /* very high freqs: noise */
 818                 n = pwd->block_len - pwd->coefs_end[bsize];
 819                 mult1 = mult * exponents[((-1 << bsize)) >> esize];
 820                 for (i = 0; i < n; i++) {
 821                         *coefs++ = pwd->noise_table[pwd->noise_index] * mult1;
 822                         pwd->noise_index = (pwd->noise_index + 1)
 823                                 & (NOISE_TAB_SIZE - 1);
 824                 }
 825         }
 826 }
 827
 828 /**
 829  * Returns 0 if OK, 1 if last block of frame, negative on uncorrectable
 830  * errors.
 831  */
 832 static int wma_decode_block(struct private_wmadec_data *pwd)
 833 {
 834         int ret, n, v, ch, code, bsize;
 835         int coef_nb_bits, total_gain;
 836         int nb_coefs[MAX_CHANNELS];
 837
 838         /* compute current block length */
 839         if (pwd->use_variable_block_len) {
 840                 n = wma_log2(pwd->nb_block_sizes - 1) + 1;
 841
 842                 if (pwd->reset_block_lengths) {
 843                         pwd->reset_block_lengths = 0;
 844                         v = get_bits(&pwd->gb, n);
 845                         if (v >= pwd->nb_block_sizes)
 846                                 return -E_WMA_BLOCK_SIZE;
 847                         pwd->prev_block_len_bits = pwd->frame_len_bits - v;
 848                         v = get_bits(&pwd->gb, n);
 849                         if (v >= pwd->nb_block_sizes)
 850                                 return -E_WMA_BLOCK_SIZE;
 851                         pwd->block_len_bits = pwd->frame_len_bits - v;
 852                 } else {
 853                         /* update block lengths */
 854                         pwd->prev_block_len_bits = pwd->block_len_bits;
 855                         pwd->block_len_bits = pwd->next_block_len_bits;
 856                 }
 857                 v = get_bits(&pwd->gb, n);
 858                 if (v >= pwd->nb_block_sizes)
 859                         return -E_WMA_BLOCK_SIZE;
 860                 pwd->next_block_len_bits = pwd->frame_len_bits - v;
 861         } else {
 862                 /* fixed block len */
 863                 pwd->next_block_len_bits = pwd->frame_len_bits;
 864                 pwd->prev_block_len_bits = pwd->frame_len_bits;
 865                 pwd->block_len_bits = pwd->frame_len_bits;
 866         }
 867
 868         /* now check if the block length is coherent with the frame length */
 869         pwd->block_len = 1 << pwd->block_len_bits;
 870         if ((pwd->block_pos + pwd->block_len) > pwd->frame_len)
 871                 return -E_INCOHERENT_BLOCK_LEN;
 872
 873         if (pwd->ahi.channels == 2)
 874                 pwd->ms_stereo = get_bit(&pwd->gb);
 875         v = 0;
 876         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 877                 int a = get_bit(&pwd->gb);
 878                 pwd->channel_coded[ch] = a;
 879                 v |= a;
 880         }
 881
 882         bsize = pwd->frame_len_bits - pwd->block_len_bits;
 883
 884         /* if no channel coded, no need to go further */
 885         /* XXX: fix potential framing problems */
 886         if (!v)
 887                 goto next;
 888
 889         /*
 890          * Read total gain and extract corresponding number of bits for coef
 891          * escape coding.
 892          */
 893         total_gain = 1;
 894         for (;;) {
 895                 int a = get_bits(&pwd->gb, 7);
 896                 total_gain += a;
 897                 if (a != 127)
 898                         break;
 899         }
 900
 901         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 902
 903         /* compute number of coefficients */
 904         n = pwd->coefs_end[bsize];
 905         for (ch = 0; ch < pwd->ahi.channels; ch++)
 906                 nb_coefs[ch] = n;
 907
 908         ret = compute_high_band_values(pwd, bsize, nb_coefs);
 909         if (ret < 0)
 910                 return ret;
 911
 912         /* exponents can be reused in short blocks. */
 913         if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
 914                 for (ch = 0; ch < pwd->ahi.channels; ch++) {
 915                         if (pwd->channel_coded[ch]) {
 916                                 if (pwd->use_exp_vlc) {
 917                                         ret = decode_exp_vlc(pwd, ch);
 918                                         if (ret < 0)
 919                                                 return ret;
 920                                 } else
 921                                         decode_exp_lsp(pwd, ch);
 922                                 pwd->exponents_bsize[ch] = bsize;
 923                         }
 924                 }
 925         }
 926
 927         /* parse spectral coefficients : just RLE encoding */
 928         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 929                 struct vlc *coef_vlc;
 930                 int level, run, tindex;
 931                 int16_t *ptr, *eptr;
 932                 const uint16_t *level_table, *run_table;
 933
 934                 if (!pwd->channel_coded[ch])
 935                         continue;
 936                 /*
 937                  * special VLC tables are used for ms stereo because there is
 938                  * potentially less energy there
 939                  */
 940                 tindex = (ch == 1 && pwd->ms_stereo);
 941                 coef_vlc = &pwd->coef_vlc[tindex];
 942                 run_table = pwd->run_table[tindex];
 943                 level_table = pwd->level_table[tindex];
 944                 /* XXX: optimize */
 945                 ptr = &pwd->coefs1[ch][0];
 946                 eptr = ptr + nb_coefs[ch];
 947                 memset(ptr, 0, pwd->block_len * sizeof(int16_t));
 948                 for (;;) {
 949                         code = get_vlc(&pwd->gb, coef_vlc->table,
 950                                 VLCBITS, VLCMAX);
 951                         if (code < 0)
 952                                 return code;
 953                         if (code == 1) /* EOB */
 954                                 break;
 955                         if (code == 0) { /* escape */
 956                                 level = get_bits(&pwd->gb, coef_nb_bits);
 957                                 /* reading block_len_bits would be better */
 958                                 run = get_bits(&pwd->gb, pwd->frame_len_bits);
 959                         } else { /* normal code */
 960                                 run = run_table[code];
 961                                 level = level_table[code];
 962                         }
 963                         if (!get_bit(&pwd->gb))
 964                                 level = -level;
 965                         ptr += run;
 966                         if (ptr >= eptr) {
 967                                 PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 968                                 break;
 969                         }
 970                         *ptr++ = level;
 971                         if (ptr >= eptr) /* EOB can be omitted */
 972                                 break;
 973                 }
 974         }
 975         compute_mdct_coefficients(pwd, bsize, total_gain, nb_coefs);
 976         if (pwd->ms_stereo && pwd->channel_coded[1]) {
 977                 float a, b;
 978                 int i;
 979                 /*
 980                  * Nominal case for ms stereo: we do it before mdct.
 981                  *
 982                  * No need to optimize this case because it should almost never
 983                  * happen.
 984                  */
 985                 if (!pwd->channel_coded[0]) {
 986                         PARA_NOTICE_LOG("rare ms-stereo\n");
 987                         memset(pwd->coefs[0], 0, sizeof(float) * pwd->block_len);
 988                         pwd->channel_coded[0] = 1;
 989                 }
 990                 for (i = 0; i < pwd->block_len; i++) {
 991                         a = pwd->coefs[0][i];
 992                         b = pwd->coefs[1][i];
 993                         pwd->coefs[0][i] = a + b;
 994                         pwd->coefs[1][i] = a - b;
 995                 }
 996         }
 997 next:
 998         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 999                 int n4, index;
1000
1001                 n = pwd->block_len;
1002                 n4 = pwd->block_len / 2;
1003                 if (pwd->channel_coded[ch])
1004                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1005                 else if (!(pwd->ms_stereo && ch == 1))
1006                         memset(pwd->output, 0, sizeof(pwd->output));
1007
1008                 /* multiply by the window and add in the frame */
1009                 index = (pwd->frame_len / 2) + pwd->block_pos - n4;
1010                 wma_window(pwd, &pwd->frame_out[ch][index]);
1011         }
1012
1013         /* update block number */
1014         pwd->block_pos += pwd->block_len;
1015         if (pwd->block_pos >= pwd->frame_len)
1016                 return 1;
1017         else
1018                 return 0;
1019 }
1020
1021 /*
1022  * Clip a signed integer value into the -32768,32767 range.
1023  *
1024  * \param a The value to clip.
1025  *
1026  * \return The clipped value.
1027  */
1028 static inline int16_t av_clip_int16(int a)
1029 {
1030         if ((a + 32768) & ~65535)
1031                 return (a >> 31) ^ 32767;
1032         else
1033                 return a;
1034 }
1035
1036 /* Decode a frame of frame_len samples. */
1037 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1038 {
1039         int ret, i, n, ch, incr;
1040         int16_t *ptr;
1041         float *iptr;
1042
1043         /* read each block */
1044         pwd->block_pos = 0;
1045         for (;;) {
1046                 ret = wma_decode_block(pwd);
1047                 if (ret < 0)
1048                         return ret;
1049                 if (ret)
1050                         break;
1051         }
1052
1053         /* convert frame to integer */
1054         n = pwd->frame_len;
1055         incr = pwd->ahi.channels;
1056         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1057                 ptr = samples + ch;
1058                 iptr = pwd->frame_out[ch];
1059
1060                 for (i = 0; i < n; i++) {
1061                         *ptr = av_clip_int16(lrintf(*iptr++));
1062                         ptr += incr;
1063                 }
1064                 /* prepare for next block */
1065                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1066                         pwd->frame_len * sizeof(float));
1067         }
1068         return 0;
1069 }
1070
1071 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1072                 int *data_size, const uint8_t *buf, int buf_size)
1073 {
1074         int ret;
1075         int16_t *samples;
1076
1077         if (buf_size == 0) {
1078                 pwd->last_superframe_len = 0;
1079                 return 0;
1080         }
1081         if (buf_size < pwd->ahi.block_align)
1082                 return 0;
1083         buf_size = pwd->ahi.block_align;
1084         samples = data;
1085         init_get_bits(&pwd->gb, buf, buf_size);
1086         if (pwd->use_bit_reservoir) {
1087                 int i, nb_frames, bit_offset, pos, len;
1088                 uint8_t *q;
1089
1090                 /* read super frame header */
1091                 skip_bits(&pwd->gb, 4); /* super frame index */
1092                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1093                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1094                 ret = -E_WMA_OUTPUT_SPACE;
1095                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1096                                 * sizeof(int16_t) > *data_size)
1097                         goto fail;
1098
1099                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1100
1101                 if (pwd->last_superframe_len > 0) {
1102                         /* add bit_offset bits to last frame */
1103                         ret = -E_WMA_BAD_SUPERFRAME;
1104                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1105                                         MAX_CODED_SUPERFRAME_SIZE)
1106                                 goto fail;
1107                         q = pwd->last_superframe + pwd->last_superframe_len;
1108                         len = bit_offset;
1109                         while (len > 7) {
1110                                 *q++ = get_bits(&pwd->gb, 8);
1111                                 len -= 8;
1112                         }
1113                         if (len > 0)
1114                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1115
1116                         /* XXX: bit_offset bits into last frame */
1117                         init_get_bits(&pwd->gb, pwd->last_superframe,
1118                                 MAX_CODED_SUPERFRAME_SIZE);
1119                         /* skip unused bits */
1120                         if (pwd->last_bitoffset > 0)
1121                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1122                         /*
1123                          * This frame is stored in the last superframe and in
1124                          * the current one.
1125                          */
1126                         ret = wma_decode_frame(pwd, samples);
1127                         if (ret < 0)
1128                                 goto fail;
1129                         samples += pwd->ahi.channels * pwd->frame_len;
1130                 }
1131
1132                 /* read each frame starting from bit_offset */
1133                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1134                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1135                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1136                 len = pos & 7;
1137                 if (len > 0)
1138                         skip_bits(&pwd->gb, len);
1139
1140                 pwd->reset_block_lengths = 1;
1141                 for (i = 0; i < nb_frames; i++) {
1142                         ret = wma_decode_frame(pwd, samples);
1143                         if (ret < 0)
1144                                 goto fail;
1145                         samples += pwd->ahi.channels * pwd->frame_len;
1146                 }
1147
1148                 /* we copy the end of the frame in the last frame buffer */
1149                 pos = get_bits_count(&pwd->gb) +
1150                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1151                 pwd->last_bitoffset = pos & 7;
1152                 pos >>= 3;
1153                 len = buf_size - pos;
1154                 ret = -E_WMA_BAD_SUPERFRAME;
1155                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1156                         goto fail;
1157                 pwd->last_superframe_len = len;
1158                 memcpy(pwd->last_superframe, buf + pos, len);
1159         } else {
1160                 PARA_DEBUG_LOG("not using bit reservoir\n");
1161                 ret = -E_WMA_OUTPUT_SPACE;
1162                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1163                         goto fail;
1164                 /* single frame decode */
1165                 ret = wma_decode_frame(pwd, samples);
1166                 if (ret < 0)
1167                         goto fail;
1168                 samples += pwd->ahi.channels * pwd->frame_len;
1169         }
1170         PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %zd, eaten: %d\n",
1171                 pwd->frame_len, pwd->block_len,
1172                 (int8_t *) samples - (int8_t *) data, pwd->ahi.block_align);
1173         *data_size = (int8_t *)samples - (int8_t *)data;
1174         return pwd->ahi.block_align;
1175 fail:
1176         /* reset the bit reservoir on errors */
1177         pwd->last_superframe_len = 0;
1178         return ret;
1179 }
1180
1181 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1182                 struct filter_node *fn)
1183 {
1184         int ret, converted = 0;
1185         struct private_wmadec_data *pwd = fn->private_data;
1186
1187         if (len <= WMA_FRAME_SKIP)
1188                 return 0;
1189         if (!pwd) {
1190                 ret = wma_decode_init(inbuffer, len, &pwd);
1191                 if (ret <= 0)
1192                         return ret;
1193                 fn->private_data = pwd;
1194                 fn->fc->channels = pwd->ahi.channels;
1195                 fn->fc->samplerate = pwd->ahi.sample_rate;
1196                 return pwd->ahi.header_len;
1197         }
1198         for (;;) {
1199                 int out_size;
1200                 if (converted + WMA_FRAME_SKIP + pwd->ahi.block_align > len)
1201                         break;
1202                 out_size = fn->bufsize - fn->loaded;
1203                 if (out_size < 128 * 1024)
1204                         break;
1205                 ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1206                         &out_size, (uint8_t *)inbuffer + converted + WMA_FRAME_SKIP,
1207                         len - WMA_FRAME_SKIP);
1208                 if (ret < 0)
1209                         return ret;
1210                 fn->loaded += out_size;
1211                 converted += ret + WMA_FRAME_SKIP;
1212         }
1213         return converted;
1214 }
1215
1216 static void wmadec_close(struct filter_node *fn)
1217 {
1218         struct private_wmadec_data *pwd = fn->private_data;
1219
1220         if (!pwd)
1221                 return;
1222         wmadec_cleanup(pwd);
1223         free(fn->buf);
1224         fn->buf = NULL;
1225         free(fn->private_data);
1226         fn->private_data = NULL;
1227 }
1228
1229 static void wmadec_open(struct filter_node *fn)
1230 {
1231         fn->bufsize = 1024 * 1024;
1232         fn->buf = para_malloc(fn->bufsize);
1233         fn->private_data = NULL;
1234         fn->loaded = 0;
1235 }
1236
1237 /**
1238  * The init function of the wma decoder.
1239  *
1240  * \param f Its fields are filled in by the function.
1241  */
1242 void wmadec_filter_init(struct filter *f)
1243 {
1244         f->open = wmadec_open;
1245         f->close = wmadec_close;
1246         f->convert = wmadec_convert;
1247 }