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 <math.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <math.h>
  26 #include <string.h>
  27 #include <regex.h>
  28
  29 #include "para.h"
  30 #include "error.h"
  31 #include "list.h"
  32 #include "ggo.h"
  33 #include "string.h"
  34 #include "sched.h"
  35 #include "filter.h"
  36 #include "bitstream.h"
  37 #include "imdct.h"
  38 #include "wma.h"
  39 #include "wmadata.h"
  40
  41
  42 /* size of blocks */
  43 #define BLOCK_MIN_BITS 7
  44 #define BLOCK_MAX_BITS 11
  45 #define BLOCK_MAX_SIZE (1 << BLOCK_MAX_BITS)
  46
  47 #define BLOCK_NB_SIZES (BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1)
  48
  49 /* XXX: find exact max size */
  50 #define HIGH_BAND_MAX_SIZE 16
  51
  52 /* XXX: is it a suitable value ? */
  53 #define MAX_CODED_SUPERFRAME_SIZE 16384
  54
  55 #define MAX_CHANNELS 2
  56
  57 #define NOISE_TAB_SIZE 8192
  58
  59 #define LSP_POW_BITS 7
  60
  61 struct private_wmadec_data {
  62         struct asf_header_info ahi;
  63         struct getbit_context gb;
  64         int use_bit_reservoir;
  65         int use_variable_block_len;
  66         int use_exp_vlc;        ///< exponent coding: 0 = lsp, 1 = vlc + delta
  67         int use_noise_coding;   ///< true if perceptual noise is added
  68         int byte_offset_bits;
  69         struct vlc exp_vlc;
  70         int exponent_sizes[BLOCK_NB_SIZES];
  71         uint16_t exponent_bands[BLOCK_NB_SIZES][25];
  72         int high_band_start[BLOCK_NB_SIZES];    ///< index of first coef in high band
  73         int coefs_start;        ///< first coded coef
  74         int coefs_end[BLOCK_NB_SIZES];  ///< max number of coded coefficients
  75         int exponent_high_sizes[BLOCK_NB_SIZES];
  76         int exponent_high_bands[BLOCK_NB_SIZES][HIGH_BAND_MAX_SIZE];
  77         struct vlc hgain_vlc;
  78
  79         /* coded values in high bands */
  80         int high_band_coded[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  81         int high_band_values[MAX_CHANNELS][HIGH_BAND_MAX_SIZE];
  82
  83         /* there are two possible tables for spectral coefficients */
  84         struct vlc coef_vlc[2];
  85         uint16_t *run_table[2];
  86         uint16_t *level_table[2];
  87         uint16_t *int_table[2];
  88         const struct coef_vlc_table *coef_vlcs[2];
  89         /* frame info */
  90         int frame_len;          ///< frame length in samples
  91         int frame_len_bits;     ///< frame_len = 1 << frame_len_bits
  92         int nb_block_sizes;     ///< number of block sizes
  93         /* block info */
  94         int reset_block_lengths;
  95         int block_len_bits;     ///< log2 of current block length
  96         int next_block_len_bits;        ///< log2 of next block length
  97         int prev_block_len_bits;        ///< log2 of prev block length
  98         int block_len;          ///< block length in samples
  99         int block_pos;          ///< current position in frame
 100         uint8_t ms_stereo;      ///< true if mid/side stereo mode
 101         uint8_t channel_coded[MAX_CHANNELS];    ///< true if channel is coded
 102         int exponents_bsize[MAX_CHANNELS];      ///< log2 ratio frame/exp. length
 103         float exponents[MAX_CHANNELS][BLOCK_MAX_SIZE];
 104         float max_exponent[MAX_CHANNELS];
 105         int16_t coefs1[MAX_CHANNELS][BLOCK_MAX_SIZE];
 106         float coefs[MAX_CHANNELS][BLOCK_MAX_SIZE];
 107         float output[BLOCK_MAX_SIZE * 2];
 108         struct mdct_context *mdct_ctx[BLOCK_NB_SIZES];
 109         float *windows[BLOCK_NB_SIZES];
 110         /* output buffer for one frame and the last for IMDCT windowing */
 111         float frame_out[MAX_CHANNELS][BLOCK_MAX_SIZE * 2];
 112         /* last frame info */
 113         uint8_t last_superframe[MAX_CODED_SUPERFRAME_SIZE + 4]; /* padding added */
 114         int last_bitoffset;
 115         int last_superframe_len;
 116         float noise_table[NOISE_TAB_SIZE];
 117         int noise_index;
 118         float noise_mult;       /* XXX: suppress that and integrate it in the noise array */
 119         /* lsp_to_curve tables */
 120         float lsp_cos_table[BLOCK_MAX_SIZE];
 121         float lsp_pow_e_table[256];
 122         float lsp_pow_m_table1[(1 << LSP_POW_BITS)];
 123         float lsp_pow_m_table2[(1 << LSP_POW_BITS)];
 124 };
 125
 126 #define EXPVLCBITS 8
 127 #define EXPMAX ((19+EXPVLCBITS-1)/EXPVLCBITS)
 128
 129 #define HGAINVLCBITS 9
 130 #define HGAINMAX ((13+HGAINVLCBITS-1)/HGAINVLCBITS)
 131
 132 #define VLCBITS 9
 133 #define VLCMAX ((22+VLCBITS-1)/VLCBITS)
 134
 135 static int wmadec_cleanup(struct private_wmadec_data *s)
 136 {
 137         int i;
 138
 139         for (i = 0; i < s->nb_block_sizes; i++)
 140                 imdct_end(s->mdct_ctx[i]);
 141
 142         if (s->use_exp_vlc)
 143                 free_vlc(&s->exp_vlc);
 144         if (s->use_noise_coding)
 145                 free_vlc(&s->hgain_vlc);
 146         for (i = 0; i < 2; i++) {
 147                 free_vlc(&s->coef_vlc[i]);
 148                 free(s->run_table[i]);
 149                 free(s->level_table[i]);
 150                 free(s->int_table[i]);
 151         }
 152         return 0;
 153 }
 154
 155 /* XXX: use same run/length optimization as mpeg decoders */
 156 //FIXME maybe split decode / encode or pass flag
 157 static void init_coef_vlc(struct vlc *vlc, uint16_t **prun_table,
 158                 uint16_t **plevel_table, uint16_t **pint_table,
 159                 const struct coef_vlc_table *vlc_table)
 160 {
 161         int n = vlc_table->n;
 162         const uint8_t *table_bits = vlc_table->huffbits;
 163         const uint32_t *table_codes = vlc_table->huffcodes;
 164         const uint16_t *levels_table = vlc_table->levels;
 165         uint16_t *run_table, *level_table, *int_table;
 166         int i, l, j, k, level;
 167
 168         init_vlc(vlc, VLCBITS, n, table_bits, 1, 1, table_codes, 4, 4);
 169
 170         run_table = para_malloc(n * sizeof (uint16_t));
 171         level_table = para_malloc(n * sizeof (uint16_t));
 172         int_table = para_malloc(n * sizeof (uint16_t));
 173         i = 2;
 174         level = 1;
 175         k = 0;
 176         while (i < n) {
 177                 int_table[k] = i;
 178                 l = levels_table[k++];
 179                 for (j = 0; j < l; j++) {
 180                         run_table[i] = j;
 181                         level_table[i] = level;
 182                         i++;
 183                 }
 184                 level++;
 185         }
 186         *prun_table = run_table;
 187         *plevel_table = level_table;
 188         *pint_table = int_table;
 189 }
 190
 191 /* compute the scale factor band sizes for each MDCT block size */
 192 static void compute_scale_factor_band_sizes(struct private_wmadec_data *s,
 193         float high_freq)
 194 {
 195         struct asf_header_info *ahi = &s->ahi;
 196         int a, b, pos, lpos, k, block_len, i, j, n;
 197         const uint8_t *table;
 198
 199         s->coefs_start = 0;
 200         for (k = 0; k < s->nb_block_sizes; k++) {
 201                 block_len = s->frame_len >> k;
 202
 203                 table = NULL;
 204                 a = s->frame_len_bits - BLOCK_MIN_BITS - k;
 205                 if (a < 3) {
 206                         if (ahi->sample_rate >= 44100)
 207                                 table = exponent_band_44100[a];
 208                         else if (ahi->sample_rate >= 32000)
 209                                 table = exponent_band_32000[a];
 210                         else if (ahi->sample_rate >= 22050)
 211                                 table = exponent_band_22050[a];
 212                 }
 213                 if (table) {
 214                         n = *table++;
 215                         for (i = 0; i < n; i++)
 216                                 s->exponent_bands[k][i] = table[i];
 217                         s->exponent_sizes[k] = n;
 218                 } else {
 219                         j = 0;
 220                         lpos = 0;
 221                         for (i = 0; i < 25; i++) {
 222                                 a = wma_critical_freqs[i];
 223                                 b = ahi->sample_rate;
 224                                 pos = ((block_len * 2 * a) + (b << 1)) / (4 * b);
 225                                 pos <<= 2;
 226                                 if (pos > block_len)
 227                                         pos = block_len;
 228                                 if (pos > lpos)
 229                                         s->exponent_bands[k][j++] = pos - lpos;
 230                                 if (pos >= block_len)
 231                                         break;
 232                                 lpos = pos;
 233                         }
 234                         s->exponent_sizes[k] = j;
 235                 }
 236
 237                 /* max number of coefs */
 238                 s->coefs_end[k] = (s->frame_len - ((s->frame_len * 9) / 100)) >> k;
 239                 /* high freq computation */
 240                 s->high_band_start[k] = (int) ((block_len * 2 * high_freq)
 241                         / ahi->sample_rate + 0.5);
 242                 n = s->exponent_sizes[k];
 243                 j = 0;
 244                 pos = 0;
 245                 for (i = 0; i < n; i++) {
 246                         int start, end;
 247                         start = pos;
 248                         pos += s->exponent_bands[k][i];
 249                         end = pos;
 250                         if (start < s->high_band_start[k])
 251                                 start = s->high_band_start[k];
 252                         if (end > s->coefs_end[k])
 253                                 end = s->coefs_end[k];
 254                         if (end > start)
 255                                 s->exponent_high_bands[k][j++] = end - start;
 256                 }
 257                 s->exponent_high_sizes[k] = j;
 258         }
 259 }
 260
 261 static int wma_init(struct private_wmadec_data *s, int flags2, struct asf_header_info *ahi)
 262 {
 263         int i;
 264         float bps1, high_freq;
 265         volatile float bps;
 266         int sample_rate1;
 267         int coef_vlc_table;
 268
 269         if (ahi->sample_rate <= 0 || ahi->sample_rate > 50000
 270                 || ahi->channels <= 0 || ahi->channels > 8
 271                 || ahi->bit_rate <= 0)
 272                 return -E_WMA_BAD_PARAMS;
 273
 274         /* compute MDCT block size */
 275         if (ahi->sample_rate <= 16000) {
 276                 s->frame_len_bits = 9;
 277         } else if (ahi->sample_rate <= 22050) {
 278                 s->frame_len_bits = 10;
 279         } else {
 280                 s->frame_len_bits = 11;
 281         }
 282         s->frame_len = 1 << s->frame_len_bits;
 283         if (s->use_variable_block_len) {
 284                 int nb_max, nb;
 285                 nb = ((flags2 >> 3) & 3) + 1;
 286                 if ((ahi->bit_rate / ahi->channels) >= 32000)
 287                         nb += 2;
 288                 nb_max = s->frame_len_bits - BLOCK_MIN_BITS;
 289                 if (nb > nb_max)
 290                         nb = nb_max;
 291                 s->nb_block_sizes = nb + 1;
 292         } else {
 293                 s->nb_block_sizes = 1;
 294         }
 295
 296         /* init rate dependent parameters */
 297         s->use_noise_coding = 1;
 298         high_freq = ahi->sample_rate * 0.5;
 299
 300         /* wma2 rates are normalized */
 301         sample_rate1 = ahi->sample_rate;
 302         if (sample_rate1 >= 44100)
 303                 sample_rate1 = 44100;
 304         else if (sample_rate1 >= 22050)
 305                 sample_rate1 = 22050;
 306         else if (sample_rate1 >= 16000)
 307                 sample_rate1 = 16000;
 308         else if (sample_rate1 >= 11025)
 309                 sample_rate1 = 11025;
 310         else if (sample_rate1 >= 8000)
 311                 sample_rate1 = 8000;
 312
 313         bps = (float) ahi->bit_rate / (float) (ahi->channels * ahi->sample_rate);
 314         s->byte_offset_bits = wma_log2((int) (bps * s->frame_len / 8.0 + 0.5)) + 2;
 315         /*
 316          * Compute high frequency value and choose if noise coding should be
 317          * activated.
 318          */
 319         bps1 = bps;
 320         if (ahi->channels == 2)
 321                 bps1 = bps * 1.6;
 322         if (sample_rate1 == 44100) {
 323                 if (bps1 >= 0.61)
 324                         s->use_noise_coding = 0;
 325                 else
 326                         high_freq = high_freq * 0.4;
 327         } else if (sample_rate1 == 22050) {
 328                 if (bps1 >= 1.16)
 329                         s->use_noise_coding = 0;
 330                 else if (bps1 >= 0.72)
 331                         high_freq = high_freq * 0.7;
 332                 else
 333                         high_freq = high_freq * 0.6;
 334         } else if (sample_rate1 == 16000) {
 335                 if (bps > 0.5)
 336                         high_freq = high_freq * 0.5;
 337                 else
 338                         high_freq = high_freq * 0.3;
 339         } else if (sample_rate1 == 11025) {
 340                 high_freq = high_freq * 0.7;
 341         } else if (sample_rate1 == 8000) {
 342                 if (bps <= 0.625) {
 343                         high_freq = high_freq * 0.5;
 344                 } else if (bps > 0.75) {
 345                         s->use_noise_coding = 0;
 346                 } else {
 347                         high_freq = high_freq * 0.65;
 348                 }
 349         } else {
 350                 if (bps >= 0.8) {
 351                         high_freq = high_freq * 0.75;
 352                 } else if (bps >= 0.6) {
 353                         high_freq = high_freq * 0.6;
 354                 } else {
 355                         high_freq = high_freq * 0.5;
 356                 }
 357         }
 358         PARA_INFO_LOG("channels=%d sample_rate=%d "
 359                 "bitrate=%d block_align=%d\n",
 360                 ahi->channels, ahi->sample_rate,
 361                 ahi->bit_rate, ahi->block_align);
 362         PARA_INFO_LOG("frame_len=%d, bps=%f bps1=%f "
 363                 "high_freq=%f bitoffset=%d\n",
 364                 s->frame_len, bps, bps1,
 365                 high_freq, s->byte_offset_bits);
 366         PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
 367                 s->use_noise_coding, s->use_exp_vlc, s->nb_block_sizes);
 368
 369         compute_scale_factor_band_sizes(s, high_freq);
 370         /* init MDCT windows : simple sinus window */
 371         for (i = 0; i < s->nb_block_sizes; i++) {
 372                 int n;
 373                 n = 1 << (s->frame_len_bits - i);
 374                 sine_window_init(ff_sine_windows[s->frame_len_bits - i - 7], n);
 375                 s->windows[i] = ff_sine_windows[s->frame_len_bits - i - 7];
 376         }
 377
 378         s->reset_block_lengths = 1;
 379
 380         if (s->use_noise_coding) {
 381                 /* init the noise generator */
 382                 if (s->use_exp_vlc)
 383                         s->noise_mult = 0.02;
 384                 else
 385                         s->noise_mult = 0.04;
 386
 387                 {
 388                         unsigned int seed;
 389                         float norm;
 390                         seed = 1;
 391                         norm = (1.0 / (float) (1LL << 31)) * sqrt(3) * s->noise_mult;
 392                         for (i = 0; i < NOISE_TAB_SIZE; i++) {
 393                                 seed = seed * 314159 + 1;
 394                                 s->noise_table[i] = (float) ((int) seed) * norm;
 395                         }
 396                 }
 397         }
 398
 399         /* choose the VLC tables for the coefficients */
 400         coef_vlc_table = 2;
 401         if (ahi->sample_rate >= 32000) {
 402                 if (bps1 < 0.72)
 403                         coef_vlc_table = 0;
 404                 else if (bps1 < 1.16)
 405                         coef_vlc_table = 1;
 406         }
 407         s->coef_vlcs[0] = &coef_vlcs[coef_vlc_table * 2];
 408         s->coef_vlcs[1] = &coef_vlcs[coef_vlc_table * 2 + 1];
 409         init_coef_vlc(&s->coef_vlc[0], &s->run_table[0], &s->level_table[0],
 410                 &s->int_table[0], s->coef_vlcs[0]);
 411         init_coef_vlc(&s->coef_vlc[1], &s->run_table[1], &s->level_table[1],
 412                 &s->int_table[1], s->coef_vlcs[1]);
 413         return 0;
 414 }
 415
 416 static void wma_lsp_to_curve_init(struct private_wmadec_data *s, int frame_len)
 417 {
 418         float wdel, a, b;
 419         int i, e, m;
 420
 421         wdel = M_PI / frame_len;
 422         for (i = 0; i < frame_len; i++)
 423                 s->lsp_cos_table[i] = 2.0f * cos(wdel * i);
 424
 425         /* tables for x^-0.25 computation */
 426         for (i = 0; i < 256; i++) {
 427                 e = i - 126;
 428                 s->lsp_pow_e_table[i] = pow(2.0, e * -0.25);
 429         }
 430
 431         /* These two tables are needed to avoid two operations in pow_m1_4. */
 432         b = 1.0;
 433         for (i = (1 << LSP_POW_BITS) - 1; i >= 0; i--) {
 434                 m = (1 << LSP_POW_BITS) + i;
 435                 a = (float) m *(0.5 / (1 << LSP_POW_BITS));
 436                 a = pow(a, -0.25);
 437                 s->lsp_pow_m_table1[i] = 2 * a - b;
 438                 s->lsp_pow_m_table2[i] = b - a;
 439                 b = a;
 440         }
 441 }
 442
 443 static int wma_decode_init(char *initial_buf, int len, struct private_wmadec_data **result)
 444 {
 445         struct private_wmadec_data *s;
 446         int ret, i;
 447
 448         PARA_NOTICE_LOG("initial buf: %d bytes\n", len);
 449         s = para_calloc(sizeof(*s));
 450         ret = read_asf_header(initial_buf, len, &s->ahi);
 451         if (ret <= 0) {
 452                 free(s);
 453                 return ret;
 454         }
 455
 456         s->use_exp_vlc = s->ahi.flags2 & 0x0001;
 457         s->use_bit_reservoir = s->ahi.flags2 & 0x0002;
 458         s->use_variable_block_len = s->ahi.flags2 & 0x0004;
 459
 460         ret = wma_init(s, s->ahi.flags2, &s->ahi);
 461         if (ret < 0)
 462                 return ret;
 463         /* init MDCT */
 464         for (i = 0; i < s->nb_block_sizes; i++) {
 465                 ret = imdct_init(s->frame_len_bits - i + 1, 1, &s->mdct_ctx[i]);
 466                 if (ret < 0)
 467                         return ret;
 468         }
 469         if (s->use_noise_coding) {
 470                 PARA_INFO_LOG("using noise coding\n");
 471                 init_vlc(&s->hgain_vlc, HGAINVLCBITS,
 472                         sizeof (ff_wma_hgain_huffbits), ff_wma_hgain_huffbits,
 473                         1, 1, ff_wma_hgain_huffcodes, 2, 2);
 474         }
 475
 476         if (s->use_exp_vlc) {
 477                 PARA_INFO_LOG("using exp_vlc\n");
 478                 init_vlc(&s->exp_vlc, EXPVLCBITS,
 479                 sizeof (ff_wma_scale_huffbits), ff_wma_scale_huffbits,
 480                 1, 1, ff_wma_scale_huffcodes, 4, 4);
 481         } else {
 482                 PARA_INFO_LOG("using curve\n");
 483                 wma_lsp_to_curve_init(s, s->frame_len);
 484         }
 485         *result = s;
 486         return s->ahi.header_len;
 487 }
 488
 489 /**
 490  * compute x^-0.25 with an exponent and mantissa table. We use linear
 491  * interpolation to reduce the mantissa table size at a small speed
 492  * expense (linear interpolation approximately doubles the number of
 493  * bits of precision).
 494  */
 495 static inline float pow_m1_4(struct private_wmadec_data *s, float x)
 496 {
 497         union {
 498                 float f;
 499                 unsigned int v;
 500         } u, t;
 501         unsigned int e, m;
 502         float a, b;
 503
 504         u.f = x;
 505         e = u.v >> 23;
 506         m = (u.v >> (23 - LSP_POW_BITS)) & ((1 << LSP_POW_BITS) - 1);
 507         /* build interpolation scale: 1 <= t < 2. */
 508         t.v = ((u.v << LSP_POW_BITS) & ((1 << 23) - 1)) | (127 << 23);
 509         a = s->lsp_pow_m_table1[m];
 510         b = s->lsp_pow_m_table2[m];
 511         return s->lsp_pow_e_table[e] * (a + b * t.f);
 512 }
 513
 514 static void wma_lsp_to_curve(struct private_wmadec_data *s,
 515                 float *out, float *val_max_ptr, int n, float *lsp)
 516 {
 517         int i, j;
 518         float p, q, w, v, val_max;
 519
 520         val_max = 0;
 521         for (i = 0; i < n; i++) {
 522                 p = 0.5f;
 523                 q = 0.5f;
 524                 w = s->lsp_cos_table[i];
 525                 for (j = 1; j < NB_LSP_COEFS; j += 2) {
 526                         q *= w - lsp[j - 1];
 527                         p *= w - lsp[j];
 528                 }
 529                 p *= p * (2.0f - w);
 530                 q *= q * (2.0f + w);
 531                 v = p + q;
 532                 v = pow_m1_4(s, v);
 533                 if (v > val_max)
 534                         val_max = v;
 535                 out[i] = v;
 536         }
 537         *val_max_ptr = val_max;
 538 }
 539
 540 /* Decode exponents coded with LSP coefficients (same idea as Vorbis). */
 541 static void decode_exp_lsp(struct private_wmadec_data *s, int ch)
 542 {
 543         float lsp_coefs[NB_LSP_COEFS];
 544         int val, i;
 545
 546         for (i = 0; i < NB_LSP_COEFS; i++) {
 547                 if (i == 0 || i >= 8)
 548                         val = get_bits(&s->gb, 3);
 549                 else
 550                         val = get_bits(&s->gb, 4);
 551                 lsp_coefs[i] = ff_wma_lsp_codebook[i][val];
 552         }
 553
 554         wma_lsp_to_curve(s, s->exponents[ch], &s->max_exponent[ch],
 555                          s->block_len, lsp_coefs);
 556 }
 557
 558 /*
 559  * Parse a vlc code, faster then get_vlc().
 560  *
 561  * \param bits The number of bits which will be read at once, must be
 562  * identical to nb_bits in init_vlc()
 563  *
 564  * \param max_depth The number of times bits bits must be read to completely
 565  * read the longest vlc code = (max_vlc_length + bits - 1) / bits.
 566  */
 567 static int get_vlc2(struct getbit_context *s, VLC_TYPE(*table)[2],
 568                 int bits, int max_depth)
 569 {
 570         int code;
 571
 572         OPEN_READER(re, s)
 573         UPDATE_CACHE(re, s)
 574         GET_VLC(code, re, s, table, bits, max_depth)
 575         CLOSE_READER(re, s)
 576         return code;
 577 }
 578
 579 /* Decode exponents coded with VLC codes. */
 580 static int decode_exp_vlc(struct private_wmadec_data *s, int ch)
 581 {
 582         int last_exp, n, code;
 583         const uint16_t *ptr, *band_ptr;
 584         float v, *q, max_scale, *q_end;
 585
 586         band_ptr = s->exponent_bands[s->frame_len_bits - s->block_len_bits];
 587         ptr = band_ptr;
 588         q = s->exponents[ch];
 589         q_end = q + s->block_len;
 590         max_scale = 0;
 591         last_exp = 36;
 592
 593         while (q < q_end) {
 594                 code = get_vlc2(&s->gb, s->exp_vlc.table, EXPVLCBITS, EXPMAX);
 595                 if (code < 0)
 596                         return -1;
 597                 /* NOTE: this offset is the same as MPEG4 AAC ! */
 598                 last_exp += code - 60;
 599                 /* XXX: use a table */
 600                 v = pow(10, last_exp * (1.0 / 16.0));
 601                 if (v > max_scale)
 602                         max_scale = v;
 603                 n = *ptr++;
 604                 do {
 605                         *q++ = v;
 606                 } while (--n);
 607         }
 608         s->max_exponent[ch] = max_scale;
 609         return 0;
 610 }
 611
 612 static void vector_fmul_add(float *dst, const float *src0, const float *src1,
 613                 const float *src2, int src3, int len, int step)
 614 {
 615         int i;
 616         for (i = 0; i < len; i++)
 617                 dst[i * step] = src0[i] * src1[i] + src2[i] + src3;
 618 }
 619
 620 static void vector_fmul_reverse_c(float *dst, const float *src0,
 621                 const float *src1, int len)
 622 {
 623         int i;
 624         src1 += len - 1;
 625         for (i = 0; i < len; i++)
 626                 dst[i] = src0[i] * src1[-i];
 627 }
 628
 629 /**
 630  * Apply MDCT window and add into output.
 631  *
 632  * We ensure that when the windows overlap their squared sum
 633  * is always 1 (MDCT reconstruction rule).
 634  */
 635 static void wma_window(struct private_wmadec_data *s, float *out)
 636 {
 637         float *in = s->output;
 638         int block_len, bsize, n;
 639
 640         /* left part */
 641         if (s->block_len_bits <= s->prev_block_len_bits) {
 642                 block_len = s->block_len;
 643                 bsize = s->frame_len_bits - s->block_len_bits;
 644
 645                 vector_fmul_add(out, in, s->windows[bsize],
 646                                          out, 0, block_len, 1);
 647
 648         } else {
 649                 block_len = 1 << s->prev_block_len_bits;
 650                 n = (s->block_len - block_len) / 2;
 651                 bsize = s->frame_len_bits - s->prev_block_len_bits;
 652
 653                 vector_fmul_add(out + n, in + n, s->windows[bsize],
 654                                          out + n, 0, block_len, 1);
 655
 656                 memcpy(out + n + block_len, in + n + block_len,
 657                        n * sizeof (float));
 658         }
 659
 660         out += s->block_len;
 661         in += s->block_len;
 662
 663         /* right part */
 664         if (s->block_len_bits <= s->next_block_len_bits) {
 665                 block_len = s->block_len;
 666                 bsize = s->frame_len_bits - s->block_len_bits;
 667
 668                 vector_fmul_reverse_c(out, in, s->windows[bsize], block_len);
 669
 670         } else {
 671                 block_len = 1 << s->next_block_len_bits;
 672                 n = (s->block_len - block_len) / 2;
 673                 bsize = s->frame_len_bits - s->next_block_len_bits;
 674
 675                 memcpy(out, in, n * sizeof (float));
 676
 677                 vector_fmul_reverse_c(out + n, in + n, s->windows[bsize],
 678                                       block_len);
 679
 680                 memset(out + n + block_len, 0, n * sizeof (float));
 681         }
 682 }
 683
 684 static int wma_total_gain_to_bits(int total_gain)
 685 {
 686         if (total_gain < 15)
 687                 return 13;
 688         else if (total_gain < 32)
 689                 return 12;
 690         else if (total_gain < 40)
 691                 return 11;
 692         else if (total_gain < 45)
 693                 return 10;
 694         else
 695                 return 9;
 696 }
 697
 698 /**
 699  * @return 0 if OK. 1 if last block of frame. return -1 if
 700  * unrecorrable error.
 701  */
 702 static int wma_decode_block(struct private_wmadec_data *s)
 703 {
 704         int n, v, ch, code, bsize;
 705         int coef_nb_bits, total_gain;
 706         int nb_coefs[MAX_CHANNELS];
 707         float mdct_norm;
 708
 709         /* compute current block length */
 710         if (s->use_variable_block_len) {
 711                 n = wma_log2(s->nb_block_sizes - 1) + 1;
 712
 713                 if (s->reset_block_lengths) {
 714                         s->reset_block_lengths = 0;
 715                         v = get_bits(&s->gb, n);
 716                         if (v >= s->nb_block_sizes)
 717                                 return -1;
 718                         s->prev_block_len_bits = s->frame_len_bits - v;
 719                         v = get_bits(&s->gb, n);
 720                         if (v >= s->nb_block_sizes)
 721                                 return -1;
 722                         s->block_len_bits = s->frame_len_bits - v;
 723                 } else {
 724                         /* update block lengths */
 725                         s->prev_block_len_bits = s->block_len_bits;
 726                         s->block_len_bits = s->next_block_len_bits;
 727                 }
 728                 v = get_bits(&s->gb, n);
 729                 if (v >= s->nb_block_sizes)
 730                         return -1;
 731                 s->next_block_len_bits = s->frame_len_bits - v;
 732         } else {
 733                 /* fixed block len */
 734                 s->next_block_len_bits = s->frame_len_bits;
 735                 s->prev_block_len_bits = s->frame_len_bits;
 736                 s->block_len_bits = s->frame_len_bits;
 737         }
 738
 739         /* now check if the block length is coherent with the frame length */
 740         s->block_len = 1 << s->block_len_bits;
 741         if ((s->block_pos + s->block_len) > s->frame_len)
 742                 return -E_INCOHERENT_BLOCK_LEN;
 743
 744         if (s->ahi.channels == 2) {
 745                 s->ms_stereo = get_bits1(&s->gb);
 746         }
 747         v = 0;
 748         for (ch = 0; ch < s->ahi.channels; ch++) {
 749                 int a = get_bits1(&s->gb);
 750                 s->channel_coded[ch] = a;
 751                 v |= a;
 752         }
 753
 754         bsize = s->frame_len_bits - s->block_len_bits;
 755
 756         /* if no channel coded, no need to go further */
 757         /* XXX: fix potential framing problems */
 758         if (!v)
 759                 goto next;
 760
 761         /* read total gain and extract corresponding number of bits for
 762            coef escape coding */
 763         total_gain = 1;
 764         for (;;) {
 765                 int a = get_bits(&s->gb, 7);
 766                 total_gain += a;
 767                 if (a != 127)
 768                         break;
 769         }
 770
 771         coef_nb_bits = wma_total_gain_to_bits(total_gain);
 772
 773         /* compute number of coefficients */
 774         n = s->coefs_end[bsize] - s->coefs_start;
 775         for (ch = 0; ch < s->ahi.channels; ch++)
 776                 nb_coefs[ch] = n;
 777
 778         /* complex coding */
 779         if (s->use_noise_coding) {
 780
 781                 for (ch = 0; ch < s->ahi.channels; ch++) {
 782                         if (s->channel_coded[ch]) {
 783                                 int i, m, a;
 784                                 m = s->exponent_high_sizes[bsize];
 785                                 for (i = 0; i < m; i++) {
 786                                         a = get_bits1(&s->gb);
 787                                         s->high_band_coded[ch][i] = a;
 788                                         /* if noise coding, the coefficients are not transmitted */
 789                                         if (a)
 790                                                 nb_coefs[ch] -=
 791                                                     s->
 792                                                     exponent_high_bands[bsize]
 793                                                     [i];
 794                                 }
 795                         }
 796                 }
 797                 for (ch = 0; ch < s->ahi.channels; ch++) {
 798                         if (s->channel_coded[ch]) {
 799                                 int i, val;
 800
 801                                 n = s->exponent_high_sizes[bsize];
 802                                 val = (int) 0x80000000;
 803                                 for (i = 0; i < n; i++) {
 804                                         if (s->high_band_coded[ch][i]) {
 805                                                 if (val == (int) 0x80000000) {
 806                                                         val =
 807                                                             get_bits(&s->gb,
 808                                                                      7) - 19;
 809                                                 } else {
 810                                                         code =
 811                                                             get_vlc2(&s->gb,
 812                                                                      s->
 813                                                                      hgain_vlc.
 814                                                                      table,
 815                                                                      HGAINVLCBITS,
 816                                                                      HGAINMAX);
 817                                                         if (code < 0)
 818                                                                 return -1;
 819                                                         val += code - 18;
 820                                                 }
 821                                                 s->high_band_values[ch][i] =
 822                                                     val;
 823                                         }
 824                                 }
 825                         }
 826                 }
 827         }
 828
 829         /* exponents can be reused in short blocks. */
 830         if ((s->block_len_bits == s->frame_len_bits) || get_bits1(&s->gb)) {
 831                 for (ch = 0; ch < s->ahi.channels; ch++) {
 832                         if (s->channel_coded[ch]) {
 833                                 if (s->use_exp_vlc) {
 834                                         if (decode_exp_vlc(s, ch) < 0)
 835                                                 return -1;
 836                                 } else {
 837                                         decode_exp_lsp(s, ch);
 838                                 }
 839                                 s->exponents_bsize[ch] = bsize;
 840                         }
 841                 }
 842         }
 843
 844         /* parse spectral coefficients : just RLE encoding */
 845         for (ch = 0; ch < s->ahi.channels; ch++) {
 846                 if (s->channel_coded[ch]) {
 847                         struct vlc *coef_vlc;
 848                         int level, run, sign, tindex;
 849                         int16_t *ptr, *eptr;
 850                         const uint16_t *level_table, *run_table;
 851
 852                         /* special VLC tables are used for ms stereo because
 853                            there is potentially less energy there */
 854                         tindex = (ch == 1 && s->ms_stereo);
 855                         coef_vlc = &s->coef_vlc[tindex];
 856                         run_table = s->run_table[tindex];
 857                         level_table = s->level_table[tindex];
 858                         /* XXX: optimize */
 859                         ptr = &s->coefs1[ch][0];
 860                         eptr = ptr + nb_coefs[ch];
 861                         memset(ptr, 0, s->block_len * sizeof(int16_t));
 862                         for (;;) {
 863                                 code =
 864                                     get_vlc2(&s->gb, coef_vlc->table, VLCBITS,
 865                                              VLCMAX);
 866                                 if (code < 0)
 867                                         return -1;
 868                                 if (code == 1) {
 869                                         /* EOB */
 870                                         break;
 871                                 } else if (code == 0) {
 872                                         /* escape */
 873                                         level = get_bits(&s->gb, coef_nb_bits);
 874                                         /* NOTE: this is rather suboptimal. reading
 875                                            block_len_bits would be better */
 876                                         run =
 877                                             get_bits(&s->gb, s->frame_len_bits);
 878                                 } else {
 879                                         /* normal code */
 880                                         run = run_table[code];
 881                                         level = level_table[code];
 882                                 }
 883                                 sign = get_bits1(&s->gb);
 884                                 if (!sign)
 885                                         level = -level;
 886                                 ptr += run;
 887                                 if (ptr >= eptr) {
 888                                         PARA_ERROR_LOG("overflow in spectral RLE, ignoring\n");
 889                                         break;
 890                                 }
 891                                 *ptr++ = level;
 892                                 /* NOTE: EOB can be omitted */
 893                                 if (ptr >= eptr)
 894                                         break;
 895                         }
 896                 }
 897         }
 898
 899         /* normalize */
 900         {
 901                 int n4 = s->block_len / 2;
 902                 mdct_norm = 1.0 / (float) n4;
 903         }
 904
 905         /* finally compute the MDCT coefficients */
 906         for (ch = 0; ch < s->ahi.channels; ch++) {
 907                 if (s->channel_coded[ch]) {
 908                         int16_t *coefs1;
 909                         float *coefs, *exponents, mult, mult1, noise;
 910                         int i, j, n1, last_high_band, esize;
 911                         float exp_power[HIGH_BAND_MAX_SIZE];
 912
 913                         coefs1 = s->coefs1[ch];
 914                         exponents = s->exponents[ch];
 915                         esize = s->exponents_bsize[ch];
 916                         mult = pow(10, total_gain * 0.05) / s->max_exponent[ch];
 917                         mult *= mdct_norm;
 918                         coefs = s->coefs[ch];
 919                         if (s->use_noise_coding) {
 920                                 mult1 = mult;
 921                                 /* very low freqs : noise */
 922                                 for (i = 0; i < s->coefs_start; i++) {
 923                                         *coefs++ =
 924                                             s->noise_table[s->noise_index] *
 925                                             exponents[i << bsize >> esize] *
 926                                             mult1;
 927                                         s->noise_index =
 928                                             (s->noise_index +
 929                                              1) & (NOISE_TAB_SIZE - 1);
 930                                 }
 931
 932                                 n1 = s->exponent_high_sizes[bsize];
 933
 934                                 /* compute power of high bands */
 935                                 exponents = s->exponents[ch] +
 936                                     (s->high_band_start[bsize] << bsize);
 937                                 last_high_band = 0;     /* avoid warning */
 938                                 for (j = 0; j < n1; j++) {
 939                                         n = s->exponent_high_bands[s->
 940                                                                    frame_len_bits
 941                                                                    -
 942                                                                    s->
 943                                                                    block_len_bits]
 944                                             [j];
 945                                         if (s->high_band_coded[ch][j]) {
 946                                                 float e2, val;
 947                                                 e2 = 0;
 948                                                 for (i = 0; i < n; i++) {
 949                                                         val = exponents[i << bsize
 950                                                                       >> esize];
 951                                                         e2 += val * val;
 952                                                 }
 953                                                 exp_power[j] = e2 / n;
 954                                                 last_high_band = j;
 955                                         }
 956                                         exponents += n << bsize;
 957                                 }
 958
 959                                 /* main freqs and high freqs */
 960                                 exponents =
 961                                     s->exponents[ch] +
 962                                     (s->coefs_start << bsize);
 963                                 for (j = -1; j < n1; j++) {
 964                                         if (j < 0) {
 965                                                 n = s->high_band_start[bsize] -
 966                                                     s->coefs_start;
 967                                         } else {
 968                                                 n = s->exponent_high_bands[s->
 969                                                                            frame_len_bits
 970                                                                            -
 971                                                                            s->
 972                                                                            block_len_bits]
 973                                                     [j];
 974                                         }
 975                                         if (j >= 0 && s->high_band_coded[ch][j]) {
 976                                                 /* use noise with specified power */
 977                                                 mult1 =
 978                                                     sqrt(exp_power[j] /
 979                                                          exp_power
 980                                                          [last_high_band]);
 981                                                 /* XXX: use a table */
 982                                                 mult1 =
 983                                                     mult1 * pow(10,
 984                                                                 s->
 985                                                                 high_band_values
 986                                                                 [ch][j] * 0.05);
 987                                                 mult1 =
 988                                                     mult1 /
 989                                                     (s->max_exponent[ch] *
 990                                                      s->noise_mult);
 991                                                 mult1 *= mdct_norm;
 992                                                 for (i = 0; i < n; i++) {
 993                                                         noise =
 994                                                             s->noise_table[s->
 995                                                                            noise_index];
 996                                                         s->noise_index =
 997                                                             (s->noise_index +
 998                                                              1) &
 999                                                             (NOISE_TAB_SIZE -
1000                                                              1);
1001                                                         *coefs++ =
1002                                                             noise *
1003                                                             exponents[i << bsize
1004                                                                       >> esize]
1005                                                             * mult1;
1006                                                 }
1007                                                 exponents += n << bsize;
1008                                         } else {
1009                                                 /* coded values + small noise */
1010                                                 for (i = 0; i < n; i++) {
1011                                                         noise =
1012                                                             s->noise_table[s->
1013                                                                            noise_index];
1014                                                         s->noise_index =
1015                                                             (s->noise_index +
1016                                                              1) &
1017                                                             (NOISE_TAB_SIZE -
1018                                                              1);
1019                                                         *coefs++ =
1020                                                             ((*coefs1++) +
1021                                                              noise) *
1022                                                             exponents[i << bsize
1023                                                                       >> esize]
1024                                                             * mult;
1025                                                 }
1026                                                 exponents += n << bsize;
1027                                         }
1028                                 }
1029
1030                                 /* very high freqs : noise */
1031                                 n = s->block_len - s->coefs_end[bsize];
1032                                 mult1 =
1033                                     mult * exponents[((-1 << bsize)) >> esize];
1034                                 for (i = 0; i < n; i++) {
1035                                         *coefs++ =
1036                                             s->noise_table[s->noise_index] *
1037                                             mult1;
1038                                         s->noise_index =
1039                                             (s->noise_index +
1040                                              1) & (NOISE_TAB_SIZE - 1);
1041                                 }
1042                         } else {
1043                                 /* XXX: optimize more */
1044                                 for (i = 0; i < s->coefs_start; i++)
1045                                         *coefs++ = 0.0;
1046                                 n = nb_coefs[ch];
1047                                 for (i = 0; i < n; i++) {
1048                                         *coefs++ =
1049                                             coefs1[i] *
1050                                             exponents[i << bsize >> esize] *
1051                                             mult;
1052                                 }
1053                                 n = s->block_len - s->coefs_end[bsize];
1054                                 for (i = 0; i < n; i++)
1055                                         *coefs++ = 0.0;
1056                         }
1057                 }
1058         }
1059
1060         if (s->ms_stereo && s->channel_coded[1]) {
1061                 float a, b;
1062                 int i;
1063
1064                 /*
1065                  * Nominal case for ms stereo: we do it before mdct.
1066                  *
1067                  * No need to optimize this case because it should almost never
1068                  * happen.
1069                  */
1070                 if (!s->channel_coded[0]) {
1071                         PARA_NOTICE_LOG("rare ms-stereo\n");
1072                         memset(s->coefs[0], 0, sizeof(float) * s->block_len);
1073                         s->channel_coded[0] = 1;
1074                 }
1075                 for (i = 0; i < s->block_len; i++) {
1076                         a = s->coefs[0][i];
1077                         b = s->coefs[1][i];
1078                         s->coefs[0][i] = a + b;
1079                         s->coefs[1][i] = a - b;
1080                 }
1081         }
1082
1083 next:
1084         for (ch = 0; ch < s->ahi.channels; ch++) {
1085                 int n4, index;
1086
1087                 n = s->block_len;
1088                 n4 = s->block_len / 2;
1089                 if (s->channel_coded[ch])
1090                         imdct(s->mdct_ctx[bsize], s->output, s->coefs[ch]);
1091                 else if (!(s->ms_stereo && ch == 1))
1092                         memset(s->output, 0, sizeof (s->output));
1093
1094                 /* multiply by the window and add in the frame */
1095                 index = (s->frame_len / 2) + s->block_pos - n4;
1096                 wma_window(s, &s->frame_out[ch][index]);
1097         }
1098
1099         /* update block number */
1100         s->block_pos += s->block_len;
1101         if (s->block_pos >= s->frame_len)
1102                 return 1;
1103         else
1104                 return 0;
1105 }
1106
1107 /*
1108  * Clip a signed integer value into the -32768,32767 range.
1109  *
1110  * \param a The value to clip.
1111  *
1112  * \return The clipped value.
1113  */
1114 static inline int16_t av_clip_int16(int a)
1115 {
1116         if ((a + 32768) & ~65535)
1117                 return (a >> 31) ^ 32767;
1118         else
1119                 return a;
1120 }
1121
1122 /* Decode a frame of frame_len samples. */
1123 static int wma_decode_frame(struct private_wmadec_data *s, int16_t * samples)
1124 {
1125         int ret, i, n, ch, incr;
1126         int16_t *ptr;
1127         float *iptr;
1128
1129         /* read each block */
1130         s->block_pos = 0;
1131         for (;;) {
1132                 ret = wma_decode_block(s);
1133                 if (ret < 0)
1134                         return -1;
1135                 if (ret)
1136                         break;
1137         }
1138
1139         /* convert frame to integer */
1140         n = s->frame_len;
1141         incr = s->ahi.channels;
1142         for (ch = 0; ch < s->ahi.channels; ch++) {
1143                 ptr = samples + ch;
1144                 iptr = s->frame_out[ch];
1145
1146                 for (i = 0; i < n; i++) {
1147                         *ptr = av_clip_int16(lrintf(*iptr++));
1148                         ptr += incr;
1149                 }
1150                 /* prepare for next block */
1151                 memmove(&s->frame_out[ch][0], &s->frame_out[ch][s->frame_len],
1152                         s->frame_len * sizeof (float));
1153         }
1154         return 0;
1155 }
1156
1157 static int wma_decode_superframe(struct private_wmadec_data *s, void *data,
1158                 int *data_size, const uint8_t *buf, int buf_size)
1159 {
1160         int ret, nb_frames, bit_offset, i, pos, len;
1161         uint8_t *q;
1162         int16_t *samples;
1163         static int frame_count;
1164
1165         if (buf_size == 0) {
1166                 s->last_superframe_len = 0;
1167                 return 0;
1168         }
1169         if (buf_size < s->ahi.block_align)
1170                 return 0;
1171         buf_size = s->ahi.block_align;
1172         samples = data;
1173         init_get_bits(&s->gb, buf, buf_size * 8);
1174         if (s->use_bit_reservoir) {
1175                 /* read super frame header */
1176                 skip_bits(&s->gb, 4);   /* super frame index */
1177                 nb_frames = get_bits(&s->gb, 4) - 1;
1178                 // PARA_DEBUG_LOG("have %d frames\n", nb_frames);
1179                 ret = -E_WMA_OUTPUT_SPACE;
1180                 if ((nb_frames + 1) * s->ahi.channels * s->frame_len
1181                                 * sizeof(int16_t) > *data_size)
1182                         goto fail;
1183
1184                 bit_offset = get_bits(&s->gb, s->byte_offset_bits + 3);
1185
1186                 if (s->last_superframe_len > 0) {
1187                         /* add bit_offset bits to last frame */
1188                         ret = -E_WMA_BAD_SUPERFRAME;
1189                         if ((s->last_superframe_len + ((bit_offset + 7) >> 3)) >
1190                                         MAX_CODED_SUPERFRAME_SIZE)
1191                                 goto fail;
1192                         q = s->last_superframe + s->last_superframe_len;
1193                         len = bit_offset;
1194                         while (len > 7) {
1195                                 *q++ = get_bits(&s->gb, 8);
1196                                 len -= 8;
1197                         }
1198                         if (len > 0) {
1199                                 *q++ = get_bits(&s->gb, len) << (8 - len);
1200                         }
1201
1202                         /* XXX: bit_offset bits into last frame */
1203                         init_get_bits(&s->gb, s->last_superframe,
1204                                 MAX_CODED_SUPERFRAME_SIZE * 8);
1205                         /* skip unused bits */
1206                         if (s->last_bitoffset > 0)
1207                                 skip_bits(&s->gb, s->last_bitoffset);
1208                         /*
1209                          * This frame is stored in the last superframe and in
1210                          * the current one.
1211                          */
1212                         ret = -E_WMA_DECODE;
1213                         if (wma_decode_frame(s, samples) < 0)
1214                                 goto fail;
1215                         frame_count++;
1216                         samples += s->ahi.channels * s->frame_len;
1217                 }
1218
1219                 /* read each frame starting from bit_offset */
1220                 pos = bit_offset + 4 + 4 + s->byte_offset_bits + 3;
1221                 init_get_bits(&s->gb, buf + (pos >> 3),
1222                         (MAX_CODED_SUPERFRAME_SIZE - (pos >> 3)) * 8);
1223                 len = pos & 7;
1224                 if (len > 0)
1225                         skip_bits(&s->gb, len);
1226
1227                 s->reset_block_lengths = 1;
1228                 for (i = 0; i < nb_frames; i++) {
1229                         ret = -E_WMA_DECODE;
1230                         if (wma_decode_frame(s, samples) < 0)
1231                                 goto fail;
1232                         frame_count++;
1233                         samples += s->ahi.channels * s->frame_len;
1234                 }
1235
1236                 /* we copy the end of the frame in the last frame buffer */
1237                 pos = get_bits_count(&s->gb) +
1238                         ((bit_offset + 4 + 4 + s->byte_offset_bits + 3) & ~7);
1239                 s->last_bitoffset = pos & 7;
1240                 pos >>= 3;
1241                 len = buf_size - pos;
1242                 ret = -E_WMA_BAD_SUPERFRAME;
1243                 if (len > MAX_CODED_SUPERFRAME_SIZE || len < 0) {
1244                         goto fail;
1245                 }
1246                 s->last_superframe_len = len;
1247                 memcpy(s->last_superframe, buf + pos, len);
1248         } else {
1249                 PARA_DEBUG_LOG("not using bit reservoir\n");
1250                 ret = -E_WMA_OUTPUT_SPACE;
1251                 if (s->ahi.channels * s->frame_len * sizeof(int16_t) > *data_size)
1252                         goto fail;
1253                 /* single frame decode */
1254                 ret = -E_WMA_DECODE;
1255                 if (wma_decode_frame(s, samples) < 0)
1256                         goto fail;
1257                 frame_count++;
1258                 samples += s->ahi.channels * s->frame_len;
1259         }
1260         PARA_DEBUG_LOG("frame_count: %d frame_len: %d, block_len: %d, "
1261                 "outbytes: %d, eaten: %d\n",
1262                 frame_count, s->frame_len, s->block_len,
1263                 (int8_t *) samples - (int8_t *) data, s->ahi.block_align);
1264         *data_size = (int8_t *)samples - (int8_t *)data;
1265         return s->ahi.block_align;
1266 fail:
1267         /* reset the bit reservoir on errors */
1268         s->last_superframe_len = 0;
1269         return ret;
1270 }
1271
1272 static ssize_t wmadec_convert(char *inbuffer, size_t len,
1273                 struct filter_node *fn)
1274 {
1275         int ret, out_size = fn->bufsize - fn->loaded;
1276         struct private_wmadec_data *pwd = fn->private_data;
1277
1278         if (out_size < 128 * 1024)
1279                 return 0;
1280         if (!pwd) {
1281                 ret = wma_decode_init(inbuffer, len, &pwd);
1282                 if (ret <= 0)
1283                         return ret;
1284                 fn->private_data = pwd;
1285                 fn->fc->channels = pwd->ahi.channels;
1286                 fn->fc->samplerate = pwd->ahi.sample_rate;
1287                 return pwd->ahi.header_len;
1288         }
1289         /* skip 31 bytes */
1290         if (len <= WMA_FRAME_SKIP + pwd->ahi.block_align)
1291                 return 0;
1292         ret = wma_decode_superframe(pwd, fn->buf + fn->loaded,
1293                 &out_size, (uint8_t *)inbuffer + WMA_FRAME_SKIP,
1294                 len - WMA_FRAME_SKIP);
1295         if (ret < 0)
1296                 return ret;
1297         fn->loaded += out_size;
1298         return ret + WMA_FRAME_SKIP;
1299 }
1300
1301 static void wmadec_close(struct filter_node *fn)
1302 {
1303         struct private_wmadec_data *pwd = fn->private_data;
1304         if (!pwd)
1305                 return;
1306         wmadec_cleanup(pwd);
1307         free(fn->buf);
1308         fn->buf = NULL;
1309         free(fn->private_data);
1310         fn->private_data = NULL;
1311 }
1312
1313 static void wmadec_open(struct filter_node *fn)
1314 {
1315         fn->bufsize = 1024 * 1024;
1316         fn->buf = para_malloc(fn->bufsize);
1317         fn->private_data = NULL;
1318         fn->loaded = 0;
1319 }
1320
1321 /**
1322  * The init function of the wma decoder.
1323  *
1324  * \param f Its fields are filled in by the function.
1325  */
1326 void wmadec_filter_init(struct filter *f)
1327 {
1328         f->open = wmadec_open;
1329         f->close = wmadec_close;
1330         f->convert = wmadec_convert;
1331 }