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 <math.h>
  21 #include <regex.h>
  22 #include <sys/select.h>
  23
  24 #include "para.h"
  25 #include "error.h"
  26 #include "list.h"
  27 #include "ggo.h"
  28 #include "string.h"
  29 #include "sched.h"
  30 #include "buffer_tree.h"
  31 #include "filter.h"
  32 #include "bitstream.h"
  33 #include "imdct.h"
  34 #include "wma.h"
  35 #include "wmadata.h"
  36
  37
  38 /* size of blocks */
  39 #define BLOCK_MIN_BITS 7
  40 #define BLOCK_MAX_BITS 11
  41 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  42
  43 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  44
  45 /* XXX: find exact max size */
  46 #define HIGH_BAND_MAX_SIZE 16
  47
  48 /* XXX: is it a suitable value ? */
  49 #define MAX_CODED_SUPERFRAME_SIZE 16384
  50
  51 #define MAX_CHANNELS 2
  52
  53 #define NOISE_TAB_SIZE 8192
  54
  55 #define LSP_POW_BITS 7
  56
  57 struct private_wmadec_data {
  58         /** Information contained in the audio file header. */
  59         struct asf_header_info ahi;
  60         struct getbit_context gb;
  61         /** Whether perceptual noise is added. */
  62         int use_noise_coding;
  63         /** Depends on number of the bits per second and the frame length. */
  64         int byte_offset_bits;
  65         /** Only used if ahi->use_exp_vlc is true. */
  66         struct vlc exp_vlc;
  67         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  68         /** The index of the first coef in high band. */
  69         int high_band_start[BLOCK_NB_SIZES];
  70         /** Maximal number of coded coefficients. */
  71         int coefs_end[BLOCK_NB_SIZES];
  72         int exponent_high_sizes[BLOCK_NB_SIZES];
  73         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  74         struct vlc hgain_vlc;
  75
  76         /* coded values in high bands */
  77         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  78         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  79
  80         /* there are two possible tables for spectral coefficients */
  81         struct vlc coef_vlc[2];
  82         uint16_t *run_table[2];
  83         uint16_t *level_table[2];
  84         const struct coef_vlc_table *coef_vlcs[2];
  85         /** Frame length in samples. */
  86         int frame_len;
  87         /** log2 of frame_len. */
  88         int frame_len_bits;
  89         /** Number of block sizes, one if !ahi->use_variable_block_len. */
  90         int nb_block_sizes;
  91         /* block info */
  92         int reset_block_lengths;
  93         /** log2 of current block length. */
  94         int block_len_bits;
  95         /** log2 of next block length. */
  96         int next_block_len_bits;
  97         /** log2 of previous block length. */
  98         int prev_block_len_bits;
  99         /** Block length in samples. */
 100         int block_len;
 101         /** Current position in frame. */
 102         int block_pos;
 103         /** True if mid/side stereo mode. */
 104         uint8_t ms_stereo;
 105         /** True if channel is coded. */
 106         uint8_t channel_coded[MAX_CHANNELS];
 107         /** log2 ratio frame/exp. length. */
 108         int exponents_bsize[MAX_CHANNELS];
 109
 110         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 111         float max_exponent[MAX_CHANNELS];
 112         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 113         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 114         float output[BLOCK_MAX_SIZE * 2];
 115         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 116         float *windows[BLOCK_NB_SIZES];
 117         /** Output buffer for one frame and the last for IMDCT windowing. */
 118         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 119         /** Last frame info. */
 120         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 121         int last_bitoffset;
 122         int last_superframe_len;
 123         float noise_table[NOISE_TAB_SIZE];
 124         int noise_index;
 125         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 126         /* lsp_to_curve tables */
 127         float lsp_cos_table[BLOCK_MAX_SIZE];
 128         float lsp_pow_e_table[256];
 129         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 130         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 131 };
 132
 133 #define EXPVLCBITS 8
 134 #define EXPMAX DIV_ROUND_UP(19, EXPVLCBITS)
 135
 136 #define HGAINVLCBITS 9
 137 #define HGAINMAX DIV_ROUND_UP(13, HGAINVLCBITS)
 138
 139 #define VLCBITS 9
 140 #define VLCMAX DIV_ROUND_UP(22, VLCBITS)
 141
 142 /** \cond sine_winows */
 143
 144 #define SINE_WINDOW(x) static float sine_ ## x[x] __a_aligned(16)
 145
 146 SINE_WINDOW(128);
 147 SINE_WINDOW(256);
 148 SINE_WINDOW(512);
 149 SINE_WINDOW(1024);
 150 SINE_WINDOW(2048);
 151 SINE_WINDOW(4096);
 152
 153 static float *sine_windows[6] = {
 154         sine_128, sine_256, sine_512, sine_1024, sine_2048, sine_4096
 155 };
 156 /** \endcond sine_windows */
 157
 158 /* Generate a sine window. */
 159 static void sine_window_init(float *window, int n)
 160 {
 161         int i;
 162
 163         for (i = 0; i < n; i++)
 164                 window[i] = sinf((i + 0.5) * (M_PI / (2.0 * n)));
 165 }
 166
 167 static void wmadec_cleanup(struct private_wmadec_data *pwd)
 168 {
 169         int i;
 170
 171         for (i = 0; i < pwd->nb_block_sizes; i++)
 172                 imdct_end(pwd->mdct_ctx[i]);
 173         if (pwd->ahi.use_exp_vlc)
 174                 free_vlc(&pwd->exp_vlc);
 175         if (pwd->use_noise_coding)
 176                 free_vlc(&pwd->hgain_vlc);
 177         for (i = 0; i < 2; i++) {
 178                 free_vlc(&pwd->coef_vlc[i]);
 179                 free(pwd->run_table[i]);
 180                 free(pwd->level_table[i]);
 181         }
 182 }
 183
 184 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 185                 uint16_t **plevel_table, const struct coef_vlc_table *vlc_table)
 186 {
 187         int n = vlc_table->n;
 188         const uint8_t *table_bits = vlc_table->huffbits;
 189         const uint32_t *table_codes = vlc_table->huffcodes;
 190         const uint16_t *levels_table = vlc_table->levels;
 191         uint16_t *run_table, *level_table;
 192         int i, l, j, k, level;
 193
 194         init_vlc(vlc, VLCBITS, n, table_bits, table_codes, 4);
 195
 196         run_table = para_malloc(n * sizeof(uint16_t));
 197         level_table = para_malloc(n * sizeof(uint16_t));
 198         i = 2;
 199         level = 1;
 200         k = 0;
 201         while (i < n) {
 202                 l = levels_table[k++];
 203                 for (j = 0; j < l; j++) {
 204                         run_table[i] = j;
 205                         level_table[i] = level;
 206                         i++;
 207                 }
 208                 level++;
 209         }
 210         *prun_table = run_table;
 211         *plevel_table = level_table;
 212 }
 213
 214 /* compute the scale factor band sizes for each MDCT block size */
 215 static void compute_scale_factor_band_sizes(struct private_wmadec_data *pwd,
 216         float high_freq)
 217 {
 218         struct asf_header_info *ahi = &pwd->ahi;
 219         int a, b, pos, lpos, k, block_len, i, j, n;
 220         const uint8_t *table;
 221
 222         for (k = 0; k < pwd->nb_block_sizes; k++) {
 223                 int exponent_size;
 224
 225                 block_len = pwd->frame_len >> k;
 226                 table = NULL;
 227                 a = pwd->frame_len_bits - BLOCK_MIN_BITS - k;
 228                 if (a < 3) {
 229                         if (ahi->sample_rate >= 44100)
 230                                 table = exponent_band_44100[a];
 231                         else if (ahi->sample_rate >= 32000)
 232                                 table = exponent_band_32000[a];
 233                         else if (ahi->sample_rate >= 22050)
 234                                 table = exponent_band_22050[a];
 235                 }
 236                 if (table) {
 237                         n = *table++;
 238                         for (i = 0; i < n; i++)
 239                                 pwd->exponent_bands[k][i] = table[i];
 240                         exponent_size = n;
 241                 } else {
 242                         j = 0;
 243                         lpos = 0;
 244                         for (i = 0; i < 25; i++) {
 245                                 a = wma_critical_freqs[i];
 246                                 b = ahi->sample_rate;
 247                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 248                                 pos <<= 2;
 249                                 if (pos > block_len)
 250                                         pos = block_len;
 251                                 if (pos > lpos)
 252                                         pwd->exponent_bands[k][j++] = pos - lpos;
 253                                 if (pos >= block_len)
 254                                         break;
 255                                 lpos = pos;
 256                         }
 257                         exponent_size = j;
 258                 }
 259
 260                 /* max number of coefs */
 261                 pwd->coefs_end[k] = (pwd->frame_len - ((pwd->frame_len * 9) / 100)) >> k;
 262                 /* high freq computation */
 263                 pwd->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 264                         / ahi->sample_rate + 0.5);
 265                 n = exponent_size;
 266                 j = 0;
 267                 pos = 0;
 268                 for (i = 0; i < n; i++) {
 269                         int start, end;
 270                         start = pos;
 271                         pos += pwd->exponent_bands[k][i];
 272                         end = pos;
 273                         if (start < pwd->high_band_start[k])
 274                                 start = pwd->high_band_start[k];
 275                         if (end > pwd->coefs_end[k])
 276                                 end = pwd->coefs_end[k];
 277                         if (end > start)
 278                                 pwd->exponent_high_bands[k][j++] = end - start;
 279                 }
 280                 pwd->exponent_high_sizes[k] = j;
 281         }
 282 }
 283
 284 static int wma_init(struct private_wmadec_data *pwd)
 285 {
 286         int i;
 287         float bps1, high_freq;
 288         volatile float bps;
 289         int sample_rate1;
 290         int coef_vlc_table;
 291         struct asf_header_info *ahi = &pwd->ahi;
 292         int flags2 = ahi->flags2;
 293
 294         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 295                 || ahi->channels <= 0 || ahi->channels > 8
 296                 || ahi->bit_rate <= 0)
 297                 return -E_WMA_BAD_PARAMS;
 298
 299         /* compute MDCT block size */
 300         if (ahi->sample_rate <= 16000)
 301                 pwd->frame_len_bits = 9;
 302         else if (ahi->sample_rate <= 22050)
 303                 pwd->frame_len_bits = 10;
 304         else
 305                 pwd->frame_len_bits = 11;
 306         pwd->frame_len = 1 << pwd->frame_len_bits;
 307         if (pwd->ahi.use_variable_block_len) {
 308                 int nb_max, nb;
 309                 nb = ((flags2 >> 3) & 3) + 1;
 310                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 311                         nb += 2;
 312                 nb_max = pwd->frame_len_bits - BLOCK_MIN_BITS;
 313                 if (nb > nb_max)
 314                         nb = nb_max;
 315                 pwd->nb_block_sizes = nb + 1;
 316         } else
 317                 pwd->nb_block_sizes = 1;
 318
 319         /* init rate dependent parameters */
 320         pwd->use_noise_coding = 1;
 321         high_freq = ahi->sample_rate * 0.5;
 322
 323         /* wma2 rates are normalized */
 324         sample_rate1 = ahi->sample_rate;
 325         if (sample_rate1 >= 44100)
 326                 sample_rate1 = 44100;
 327         else if (sample_rate1 >= 22050)
 328                 sample_rate1 = 22050;
 329         else if (sample_rate1 >= 16000)
 330                 sample_rate1 = 16000;
 331         else if (sample_rate1 >= 11025)
 332                 sample_rate1 = 11025;
 333         else if (sample_rate1 >= 8000)
 334                 sample_rate1 = 8000;
 335
 336         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 337         pwd->byte_offset_bits = wma_log2((int) (bps * pwd->frame_len / 8.0 + 0.5)) + 2;
 338         /*
 339          * Compute high frequency value and choose if noise coding should be
 340          * activated.
 341          */
 342         bps1 = bps;
 343         if (ahi->channels == 2)
 344                 bps1 = bps * 1.6;
 345         if (sample_rate1 == 44100) {
 346                 if (bps1 >= 0.61)
 347                         pwd->use_noise_coding = 0;
 348                 else
 349                         high_freq = high_freq * 0.4;
 350         } else if (sample_rate1 == 22050) {
 351                 if (bps1 >= 1.16)
 352                         pwd->use_noise_coding = 0;
 353                 else if (bps1 >= 0.72)
 354                         high_freq = high_freq * 0.7;
 355                 else
 356                         high_freq = high_freq * 0.6;
 357         } else if (sample_rate1 == 16000) {
 358                 if (bps > 0.5)
 359                         high_freq = high_freq * 0.5;
 360                 else
 361                         high_freq = high_freq * 0.3;
 362         } else if (sample_rate1 == 11025)
 363                 high_freq = high_freq * 0.7;
 364         else if (sample_rate1 == 8000) {
 365                 if (bps <= 0.625)
 366                         high_freq = high_freq * 0.5;
 367                 else if (bps > 0.75)
 368                         pwd->use_noise_coding = 0;
 369                 else
 370                         high_freq = high_freq * 0.65;
 371         } else {
 372                 if (bps >= 0.8)
 373                         high_freq = high_freq * 0.75;
 374                 else if (bps >= 0.6)
 375                         high_freq = high_freq * 0.6;
 376                 else
 377                         high_freq = high_freq * 0.5;
 378         }
 379         PARA_INFO_LOG("channels=%d sample_rate=%d "
 380                 "bitrate=%d block_align=%d\n",
 381                 ahi->channels, ahi->sample_rate,
 382                 ahi->bit_rate, ahi->block_align);
 383         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 384                 "high_freq=%f bitoffset=%d\n",
 385                 pwd->frame_len, bps, bps1,
 386                 high_freq, pwd->byte_offset_bits);
 387         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 388                 pwd->use_noise_coding, pwd->ahi.use_exp_vlc, pwd->nb_block_sizes);
 389
 390         compute_scale_factor_band_sizes(pwd, high_freq);
 391         /* init MDCT windows : simple sinus window */
 392         for (i = 0; i < pwd->nb_block_sizes; i++) {
 393                 int n;
 394                 n = 1 << (pwd->frame_len_bits - i);
 395                 sine_window_init(sine_windows[pwd->frame_len_bits - i - 7], n);
 396                 pwd->windows[i] = sine_windows[pwd->frame_len_bits - i - 7];
 397         }
 398
 399         pwd->reset_block_lengths = 1;
 400
 401         if (pwd->use_noise_coding) {
 402                 /* init the noise generator */
 403                 if (pwd->ahi.use_exp_vlc)
 404                         pwd->noise_mult = 0.02;
 405                 else
 406                         pwd->noise_mult = 0.04;
 407
 408                 {
 409                         unsigned int seed;
 410                         float norm;
 411                         seed = 1;
 412                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * pwd->noise_mult;
 413                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 414                                 seed = seed * 314159 + 1;
 415                                 pwd->noise_table[i] = (float) ((int) seed) * norm;
 416                         }
 417                 }
 418         }
 419
 420         /* choose the VLC tables for the coefficients */
 421         coef_vlc_table = 2;
 422         if (ahi->sample_rate >= 32000) {
 423                 if (bps1 < 0.72)
 424                         coef_vlc_table = 0;
 425                 else if (bps1 < 1.16)
 426                         coef_vlc_table = 1;
 427         }
 428         pwd->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 429         pwd->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 430         init_coef_vlc(&pwd->coef_vlc[0], &pwd->run_table[0], &pwd->level_table[0],
 431                 pwd->coef_vlcs[0]);
 432         init_coef_vlc(&pwd->coef_vlc[1], &pwd->run_table[1], &pwd->level_table[1],
 433                 pwd->coef_vlcs[1]);
 434         return 0;
 435 }
 436
 437 static void wma_lsp_to_curve_init(struct private_wmadec_data *pwd, int frame_len)
 438 {
 439         float wdel, a, b;
 440         int i, e, m;
 441
 442         wdel = M_PI / frame_len;
 443         for (i = 0; i < frame_len; i++)
 444                 pwd->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 445
 446         /* tables for x^-0.25 computation */
 447         for (i = 0; i < 256; i++) {
 448                 e = i - 126;
 449                 pwd->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 450         }
 451
 452         /* These two tables are needed to avoid two operations in pow_m1_4. */
 453         b = 1.0;
 454         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 455                 m = (1 << LSP_POW_BITS) + i;
 456                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 457                 a = pow(a, -0.25);
 458                 pwd->lsp_pow_m_table1[i] = 2 * a - b;
 459                 pwd->lsp_pow_m_table2[i] = b - a;
 460                 b = a;
 461         }
 462 }
 463
 464 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 465 {
 466         struct private_wmadec_data *pwd;
 467         int ret, i;
 468
 469         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 470         pwd = para_calloc(sizeof(*pwd));
 471         ret = read_asf_header(initial_buf, len, &pwd->ahi);
 472         if (ret <= 0) {
 473                 free(pwd);
 474                 return ret;
 475         }
 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->ahi.use_exp_vlc) {
 494                 PARA_INFO_LOG("using exp_vlc\n");
 495                 init_vlc(&pwd->exp_vlc, EXPVLCBITS, sizeof(wma_scale_huffbits),
 496                         wma_scale_huffbits, wma_scale_huffcodes, 4);
 497         } else {
 498                 PARA_INFO_LOG("using curve\n");
 499                 wma_lsp_to_curve_init(pwd, pwd->frame_len);
 500         }
 501         *result = pwd;
 502         return pwd->ahi.header_len;
 503 }
 504
 505 /**
 506  * compute x^-0.25 with an exponent and mantissa table. We use linear
 507  * interpolation to reduce the mantissa table size at a small speed
 508  * expense (linear interpolation approximately doubles the number of
 509  * bits of precision).
 510  */
 511 static inline float pow_m1_4(struct private_wmadec_data *pwd, float x)
 512 {
 513         union {
 514                 float f;
 515                 unsigned int v;
 516         } u, t;
 517         unsigned int e, m;
 518         float a, b;
 519
 520         u.f = x;
 521         e = u.v >> 23;
 522         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 523         /* build interpolation scale: 1 <= t < 2. */
 524         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 525         a = pwd->lsp_pow_m_table1[m];
 526         b = pwd->lsp_pow_m_table2[m];
 527         return pwd->lsp_pow_e_table[e] * (a + b * t.f);
 528 }
 529
 530 static void wma_lsp_to_curve(struct private_wmadec_data *pwd,
 531                 float *out, float *val_max_ptr, int n, float *lsp)
 532 {
 533         int i, j;
 534         float p, q, w, v, val_max;
 535
 536         val_max = 0;
 537         for (i = 0; i < n; i++) {
 538                 p = 0.5f;
 539                 q = 0.5f;
 540                 w = pwd->lsp_cos_table[i];
 541                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 542                         q *= w - lsp[j - 1];
 543                         p *= w - lsp[j];
 544                 }
 545                 p *= p * (2.0f - w);
 546                 q *= q * (2.0f + w);
 547                 v = p + q;
 548                 v = pow_m1_4(pwd, v);
 549                 if (v > val_max)
 550                         val_max = v;
 551                 out[i] = v;
 552         }
 553         *val_max_ptr = val_max;
 554 }
 555
 556 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 557 static void decode_exp_lsp(struct private_wmadec_data *pwd, int ch)
 558 {
 559         float lsp_coefs[NB_LSP_COEFS];
 560         int val, i;
 561
 562         for (i = 0; i < NB_LSP_COEFS; i++) {
 563                 if (i == 0 || i >= 8)
 564                         val = get_bits(&pwd->gb, 3);
 565                 else
 566                         val = get_bits(&pwd->gb, 4);
 567                 lsp_coefs[i] = wma_lsp_codebook[i][val];
 568         }
 569
 570         wma_lsp_to_curve(pwd, pwd->exponents[ch], &pwd->max_exponent[ch],
 571                 pwd->block_len, lsp_coefs);
 572 }
 573
 574 /* Decode exponents coded with VLC codes. */
 575 static int decode_exp_vlc(struct private_wmadec_data *pwd, int ch)
 576 {
 577         int last_exp, n, code;
 578         const uint16_t *ptr, *band_ptr;
 579         float v, *q, max_scale, *q_end;
 580
 581         band_ptr = pwd->exponent_bands[pwd->frame_len_bits - pwd->block_len_bits];
 582         ptr = band_ptr;
 583         q = pwd->exponents[ch];
 584         q_end = q + pwd->block_len;
 585         max_scale = 0;
 586         last_exp = 36;
 587
 588         while (q < q_end) {
 589                 code = get_vlc(&pwd->gb, pwd->exp_vlc.table, EXPVLCBITS, EXPMAX);
 590                 if (code < 0)
 591                         return code;
 592                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 593                 last_exp += code - 60;
 594                 /* XXX: use a table */
 595                 v = pow(10, last_exp * (1.0 / 16.0));
 596                 if (v > max_scale)
 597                         max_scale = v;
 598                 n = *ptr++;
 599                 do {
 600                         *q++ = v;
 601                 } while (--n);
 602         }
 603         pwd->max_exponent[ch] = max_scale;
 604         return 0;
 605 }
 606
 607 /* compute src0 * src1 + src2 */
 608 static inline void vector_mult_add(float *dst, const float *src0, const float *src1,
 609                 const float *src2, int len)
 610 {
 611         int i;
 612
 613         for (i = 0; i < len; i++)
 614                 dst[i] = src0[i] * src1[i] + src2[i];
 615 }
 616
 617 static inline void vector_mult_reverse(float *dst, const float *src0,
 618                 const float *src1, int len)
 619 {
 620         int i;
 621
 622         src1 += len - 1;
 623         for (i = 0; i < len; i++)
 624                 dst[i] = src0[i] * src1[-i];
 625 }
 626
 627 /**
 628  * Apply MDCT window and add into output.
 629  *
 630  * We ensure that when the windows overlap their squared sum
 631  * is always 1 (MDCT reconstruction rule).
 632  */
 633 static void wma_window(struct private_wmadec_data *pwd, float *out)
 634 {
 635         float *in = pwd->output;
 636         int block_len, bsize, n;
 637
 638         /* left part */
 639         if (pwd->block_len_bits <= pwd->prev_block_len_bits) {
 640                 block_len = pwd->block_len;
 641                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 642                 vector_mult_add(out, in, pwd->windows[bsize], out, block_len);
 643         } else {
 644                 block_len = 1 << pwd->prev_block_len_bits;
 645                 n = (pwd->block_len - block_len) / 2;
 646                 bsize = pwd->frame_len_bits - pwd->prev_block_len_bits;
 647                 vector_mult_add(out + n, in + n, pwd->windows[bsize], out + n,
 648                         block_len);
 649                 memcpy(out + n + block_len, in + n + block_len,
 650                         n * sizeof(float));
 651         }
 652         out += pwd->block_len;
 653         in += pwd->block_len;
 654         /* right part */
 655         if (pwd->block_len_bits <= pwd->next_block_len_bits) {
 656                 block_len = pwd->block_len;
 657                 bsize = pwd->frame_len_bits - pwd->block_len_bits;
 658                 vector_mult_reverse(out, in, pwd->windows[bsize], block_len);
 659         } else {
 660                 block_len = 1 << pwd->next_block_len_bits;
 661                 n = (pwd->block_len - block_len) / 2;
 662                 bsize = pwd->frame_len_bits - pwd->next_block_len_bits;
 663                 memcpy(out, in, n * sizeof(float));
 664                 vector_mult_reverse(out + n, in + n, pwd->windows[bsize],
 665                         block_len);
 666                 memset(out + n + block_len, 0, n * sizeof(float));
 667         }
 668 }
 669
 670 static int wma_total_gain_to_bits(int total_gain)
 671 {
 672         if (total_gain < 15)
 673                 return 13;
 674         else if (total_gain < 32)
 675                 return 12;
 676         else if (total_gain < 40)
 677                 return 11;
 678         else if (total_gain < 45)
 679                 return 10;
 680         else
 681                 return 9;
 682 }
 683
 684 static int compute_high_band_values(struct private_wmadec_data *pwd,
 685                 int bsize, int nb_coefs[MAX_CHANNELS])
 686 {
 687         int ch;
 688
 689         if (!pwd->use_noise_coding)
 690                 return 0;
 691         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 692                 int i, m, a;
 693                 if (!pwd->channel_coded[ch])
 694                         continue;
 695                 m = pwd->exponent_high_sizes[bsize];
 696                 for (i = 0; i < m; i++) {
 697                         a = get_bit(&pwd->gb);
 698                         pwd->high_band_coded[ch][i] = a;
 699                         if (!a)
 700                                 continue;
 701                         nb_coefs[ch] -= pwd->exponent_high_bands[bsize][i];
 702                 }
 703         }
 704         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 705                 int i, n, val;
 706                 if (!pwd->channel_coded[ch])
 707                         continue;
 708                 n = pwd->exponent_high_sizes[bsize];
 709                 val = (int)0x80000000;
 710                 for (i = 0; i < n; i++) {
 711                         if (!pwd->high_band_coded[ch][i])
 712                                 continue;
 713                         if (val == (int)0x80000000)
 714                                 val = get_bits(&pwd->gb, 7) - 19;
 715                         else {
 716                                 int code = get_vlc(&pwd->gb,
 717                                         pwd->hgain_vlc.table, HGAINVLCBITS,
 718                                         HGAINMAX);
 719                                 if (code < 0)
 720                                         return code;
 721                                 val += code - 18;
 722                         }
 723                         pwd->high_band_values[ch][i] = val;
 724                 }
 725         }
 726         return 1;
 727 }
 728
 729 static void compute_mdct_coefficients(struct private_wmadec_data *pwd,
 730                 int bsize, int total_gain, int nb_coefs[MAX_CHANNELS])
 731 {
 732         int ch;
 733         float mdct_norm = 1.0 / (pwd->block_len / 2);
 734
 735         for (ch = 0; ch < pwd->ahi.channels; ch++) {
 736                 int16_t *coefs1;
 737                 float *coefs, *exponents, mult, mult1, noise;
 738                 int i, j, n, n1, last_high_band, esize;
 739                 float exp_power[HIGH_BAND_MAX_SIZE];
 740
 741                 if (!pwd->channel_coded[ch])
 742                         continue;
 743                 coefs1 = pwd->coefs1[ch];
 744                 exponents = pwd->exponents[ch];
 745                 esize = pwd->exponents_bsize[ch];
 746                 mult = pow(10, total_gain * 0.05) / pwd->max_exponent[ch];
 747                 mult *= mdct_norm;
 748                 coefs = pwd->coefs[ch];
 749                 if (!pwd->use_noise_coding) {
 750                         /* XXX: optimize more */
 751                         n = nb_coefs[ch];
 752                         for (i = 0; i < n; i++)
 753                                 *coefs++ = coefs1[i] *
 754                                         exponents[i << bsize >> esize] * mult;
 755                         n = pwd->block_len - pwd->coefs_end[bsize];
 756                         for (i = 0; i < n; i++)
 757                                 *coefs++ = 0.0;
 758                         continue;
 759                 }
 760                 n1 = pwd->exponent_high_sizes[bsize];
 761                 /* compute power of high bands */
 762                 exponents = pwd->exponents[ch] +
 763                         (pwd->high_band_start[bsize] << bsize);
 764                 last_high_band = 0; /* avoid warning */
 765                 for (j = 0; j < n1; j++) {
 766                         n = pwd->exponent_high_bands[
 767                                 pwd->frame_len_bits - pwd->block_len_bits][j];
 768                         if (pwd->high_band_coded[ch][j]) {
 769                                 float e2, val;
 770                                 e2 = 0;
 771                                 for (i = 0; i < n; i++) {
 772                                         val = exponents[i << bsize >> esize];
 773                                         e2 += val * val;
 774                                 }
 775                                 exp_power[j] = e2 / n;
 776                                 last_high_band = j;
 777                         }
 778                         exponents += n << bsize;
 779                 }
 780                 /* main freqs and high freqs */
 781                 exponents = pwd->exponents[ch];
 782                 for (j = -1; j < n1; j++) {
 783                         if (j < 0)
 784                                 n = pwd->high_band_start[bsize];
 785                         else
 786                                 n = pwd->exponent_high_bands[pwd->frame_len_bits
 787                                         - pwd->block_len_bits][j];
 788                         if (j >= 0 && pwd->high_band_coded[ch][j]) {
 789                                 /* use noise with specified power */
 790                                 mult1 = sqrt(exp_power[j]
 791                                         / exp_power[last_high_band]);
 792                                 /* XXX: use a table */
 793                                 mult1 *= pow(10, 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->ahi.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->ahi.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, idx;
1000
1001                 n4 = pwd->block_len / 2;
1002                 if (pwd->channel_coded[ch])
1003                         imdct(pwd->mdct_ctx[bsize], pwd->output, pwd->coefs[ch]);
1004                 else if (!(pwd->ms_stereo && ch == 1))
1005                         memset(pwd->output, 0, sizeof(pwd->output));
1006
1007                 /* multiply by the window and add in the frame */
1008                 idx = (pwd->frame_len / 2) + pwd->block_pos - n4;
1009                 wma_window(pwd, &pwd->frame_out[ch][idx]);
1010         }
1011
1012         /* update block number */
1013         pwd->block_pos += pwd->block_len;
1014         if (pwd->block_pos >= pwd->frame_len)
1015                 return 1;
1016         else
1017                 return 0;
1018 }
1019
1020 /*
1021  * Clip a signed integer value into the -32768,32767 range.
1022  *
1023  * \param a The value to clip.
1024  *
1025  * \return The clipped value.
1026  */
1027 static inline int16_t av_clip_int16(int a)
1028 {
1029         if ((a + 32768) & ~65535)
1030                 return (a >> 31) ^ 32767;
1031         else
1032                 return a;
1033 }
1034
1035 /* Decode a frame of frame_len samples. */
1036 static int wma_decode_frame(struct private_wmadec_data *pwd, int16_t *samples)
1037 {
1038         int ret, i, n, ch, incr;
1039         int16_t *ptr;
1040         float *iptr;
1041
1042         /* read each block */
1043         pwd->block_pos = 0;
1044         for (;;) {
1045                 ret = wma_decode_block(pwd);
1046                 if (ret < 0)
1047                         return ret;
1048                 if (ret)
1049                         break;
1050         }
1051
1052         /* convert frame to integer */
1053         n = pwd->frame_len;
1054         incr = pwd->ahi.channels;
1055         for (ch = 0; ch < pwd->ahi.channels; ch++) {
1056                 ptr = samples + ch;
1057                 iptr = pwd->frame_out[ch];
1058
1059                 for (i = 0; i < n; i++) {
1060                         *ptr = av_clip_int16(lrintf(*iptr++));
1061                         ptr += incr;
1062                 }
1063                 /* prepare for next block */
1064                 memmove(&pwd->frame_out[ch][0], &pwd->frame_out[ch][pwd->frame_len],
1065                         pwd->frame_len * sizeof(float));
1066         }
1067         return 0;
1068 }
1069
1070 static int wma_decode_superframe(struct private_wmadec_data *pwd, void *data,
1071                 int *data_size, const uint8_t *buf, int buf_size)
1072 {
1073         int ret;
1074         int16_t *samples;
1075
1076         if (buf_size == 0) {
1077                 pwd->last_superframe_len = 0;
1078                 return 0;
1079         }
1080         if (buf_size < pwd->ahi.block_align)
1081                 return 0;
1082         buf_size = pwd->ahi.block_align;
1083         samples = data;
1084         init_get_bits(&pwd->gb, buf, buf_size);
1085         if (pwd->ahi.use_bit_reservoir) {
1086                 int i, nb_frames, bit_offset, pos, len;
1087                 uint8_t *q;
1088
1089                 /* read super frame header */
1090                 skip_bits(&pwd->gb, 4); /* super frame index */
1091                 nb_frames = get_bits(&pwd->gb, 4) - 1;
1092                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1093                 ret = -E_WMA_OUTPUT_SPACE;
1094                 if ((nb_frames + 1) * pwd->ahi.channels * pwd->frame_len
1095                                 * sizeof(int16_t) > *data_size)
1096                         goto fail;
1097
1098                 bit_offset = get_bits(&pwd->gb, pwd->byte_offset_bits + 3);
1099
1100                 if (pwd->last_superframe_len > 0) {
1101                         /* add bit_offset bits to last frame */
1102                         ret = -E_WMA_BAD_SUPERFRAME;
1103                         if ((pwd->last_superframe_len + ((bit_offset + 7) >> 3)) >
1104                                         MAX_CODED_SUPERFRAME_SIZE)
1105                                 goto fail;
1106                         q = pwd->last_superframe + pwd->last_superframe_len;
1107                         len = bit_offset;
1108                         while (len > 7) {
1109                                 *q++ = get_bits(&pwd->gb, 8);
1110                                 len -= 8;
1111                         }
1112                         if (len > 0)
1113                                 *q++ = get_bits(&pwd->gb, len) << (8 - len);
1114
1115                         /* XXX: bit_offset bits into last frame */
1116                         init_get_bits(&pwd->gb, pwd->last_superframe,
1117                                 MAX_CODED_SUPERFRAME_SIZE);
1118                         /* skip unused bits */
1119                         if (pwd->last_bitoffset > 0)
1120                                 skip_bits(&pwd->gb, pwd->last_bitoffset);
1121                         /*
1122                          * This frame is stored in the last superframe and in
1123                          * the current one.
1124                          */
1125                         ret = wma_decode_frame(pwd, samples);
1126                         if (ret < 0)
1127                                 goto fail;
1128                         samples += pwd->ahi.channels * pwd->frame_len;
1129                 }
1130
1131                 /* read each frame starting from bit_offset */
1132                 pos = bit_offset + 4 + 4 + pwd->byte_offset_bits + 3;
1133                 init_get_bits(&pwd->gb, buf + (pos >> 3),
1134                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)));
1135                 len = pos & 7;
1136                 if (len > 0)
1137                         skip_bits(&pwd->gb, len);
1138
1139                 pwd->reset_block_lengths = 1;
1140                 for (i = 0; i < nb_frames; i++) {
1141                         ret = wma_decode_frame(pwd, samples);
1142                         if (ret < 0)
1143                                 goto fail;
1144                         samples += pwd->ahi.channels * pwd->frame_len;
1145                 }
1146
1147                 /* we copy the end of the frame in the last frame buffer */
1148                 pos = get_bits_count(&pwd->gb) +
1149                         ((bit_offset + 4 + 4 + pwd->byte_offset_bits + 3) & ~7);
1150                 pwd->last_bitoffset = pos & 7;
1151                 pos >>= 3;
1152                 len = buf_size - pos;
1153                 ret = -E_WMA_BAD_SUPERFRAME;
1154                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0)
1155                         goto fail;
1156                 pwd->last_superframe_len = len;
1157                 memcpy(pwd->last_superframe, buf + pos, len);
1158         } else {
1159                 PARA_DEBUG_LOG("not using bit reservoir\n");
1160                 ret = -E_WMA_OUTPUT_SPACE;
1161                 if (pwd->ahi.channels * pwd->frame_len * sizeof(int16_t) > *data_size)
1162                         goto fail;
1163                 /* single frame decode */
1164                 ret = wma_decode_frame(pwd, samples);
1165                 if (ret < 0)
1166                         goto fail;
1167                 samples += pwd->ahi.channels * pwd->frame_len;
1168         }
1169         PARA_DEBUG_LOG("frame_len: %d, block_len: %d, outbytes: %d, eaten: %d\n",
1170                 pwd->frame_len, pwd->block_len,
1171                 (int)((int8_t *)samples - (int8_t *)data), pwd->ahi.block_align);
1172         *data_size = (int8_t *)samples - (int8_t *)data;
1173         return pwd->ahi.block_align;
1174 fail:
1175         /* reset the bit reservoir on errors */
1176         pwd->last_superframe_len = 0;
1177         return ret;
1178 }
1179
1180 static void wmadec_close(struct filter_node *fn)
1181 {
1182         struct private_wmadec_data *pwd = fn->private_data;
1183
1184         if (!pwd)
1185                 return;
1186         wmadec_cleanup(pwd);
1187         free(fn->private_data);
1188         fn->private_data = NULL;
1189 }
1190
1191 static int wmadec_execute(struct btr_node *btrn, const char *cmd, char **result)
1192 {
1193         struct filter_node *fn = btr_context(btrn);
1194         struct private_wmadec_data *pwd = fn->private_data;
1195
1196         return decoder_execute(cmd, pwd->ahi.sample_rate, pwd->ahi.channels,
1197                 result);
1198 }
1199
1200 #define WMA_OUTPUT_BUFFER_SIZE (128 * 1024)
1201
1202 static int wmadec_post_select(__a_unused struct sched *s, void *context)
1203 {
1204         struct filter_node *fn = context;
1205         int ret, converted, out_size;
1206         struct private_wmadec_data *pwd = fn->private_data;
1207         struct btr_node *btrn = fn->btrn;
1208         size_t len;
1209         char *in, *out;
1210
1211 next_buffer:
1212         converted = 0;
1213         ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
1214         if (ret < 0)
1215                 goto err;
1216         if (ret == 0)
1217                 return 0;
1218         btr_merge(btrn, fn->min_iqs);
1219         len = btr_next_buffer(btrn, (char **)&in);
1220         ret = -E_WMADEC_EOF;
1221         if (len < fn->min_iqs)
1222                 goto err;
1223         if (!pwd) {
1224                 ret = wma_decode_init(in, len, &pwd);
1225                 if (ret < 0)
1226                         goto err;
1227                 if (ret == 0) {
1228                         fn->min_iqs += 4096;
1229                         goto next_buffer;
1230                 }
1231                 fn->min_iqs = 2 * (WMA_FRAME_SKIP + pwd->ahi.block_align);
1232                 fn->private_data = pwd;
1233                 converted = pwd->ahi.header_len;
1234                 goto success;
1235         }
1236         fn->min_iqs = WMA_FRAME_SKIP + pwd->ahi.block_align;
1237         if (fn->min_iqs > len)
1238                 goto success;
1239         out_size = WMA_OUTPUT_BUFFER_SIZE;
1240         out = para_malloc(out_size);
1241         ret = wma_decode_superframe(pwd, out, &out_size,
1242                 (uint8_t *)in + WMA_FRAME_SKIP, len - WMA_FRAME_SKIP);
1243         if (ret < 0) {
1244                 free(out);
1245                 goto err;
1246         }
1247         out = para_realloc(out, out_size);
1248         if (out_size > 0)
1249                 btr_add_output(out, out_size, btrn);
1250         converted += ret + WMA_FRAME_SKIP;
1251 success:
1252         btr_consume(btrn, converted);
1253         return 0;
1254 err:
1255         assert(ret < 0);
1256         btr_remove_node(&fn->btrn);
1257         return ret;
1258 }
1259
1260 static void wmadec_open(struct filter_node *fn)
1261 {
1262         fn->private_data = NULL;
1263         fn->min_iqs = 4096;
1264 }
1265
1266 /**
1267  * The init function of the wma decoder.
1268  *
1269  * \param f Its fields are filled in by the function.
1270  */
1271 void wmadec_filter_init(struct filter *f)
1272 {
1273         f->open = wmadec_open;
1274         f->close = wmadec_close;
1275         f->execute = wmadec_execute;
1276         f->pre_select = generic_filter_pre_select;
1277         f->post_select = wmadec_post_select;
1278 }