apps/codecs/libffmpegFLAC/decoder.c

   1 /*
   2  * FLAC (Free Lossless Audio Codec) decoder
   3  * Copyright (c) 2003 Alex Beregszaszi
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 /**
  21  * @file flac.c
  22  * FLAC (Free Lossless Audio Codec) decoder
  23  * @author Alex Beregszaszi
  24  *
  25  * For more information on the FLAC format, visit:
  26  *  http://flac.sourceforge.net/
  27  *
  28  * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
  29  * through, starting from the initial 'fLaC' signature; or by passing the
  30  * 34-byte streaminfo structure through avctx->extradata[_size] followed
  31  * by data starting with the 0xFFF8 marker.
  32  */
  33
  34 #include <inttypes.h>
  35 #include <stdbool.h>
  36 #ifndef BUILD_STANDALONE
  37 #include "codeclib.h"
  38 #endif
  39
  40 #include "bitstream.h"
  41 #include "golomb.h"
  42
  43 #include "decoder.h"
  44
  45 #if defined(CPU_COLDFIRE)
  46 #include "coldfire.h"
  47 #elif defined(CPU_ARM)
  48 #include "arm.h"
  49 #endif
  50
  51 static const int sample_rate_table[] ICONST_ATTR =
  52 { 0, 88200, 176400, 192000,
  53   8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
  54   0, 0, 0, 0 };
  55
  56 static const int sample_size_table[] ICONST_ATTR =
  57 { 0, 8, 12, 0, 16, 20, 24, 0 };
  58
  59 static const int blocksize_table[] ICONST_ATTR = {
  60      0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
  61 256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
  62 };
  63
  64 static const uint8_t table_crc8[256] ICONST_ATTR = {
  65     0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
  66     0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
  67     0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
  68     0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
  69     0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
  70     0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
  71     0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
  72     0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
  73     0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
  74     0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
  75     0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
  76     0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
  77     0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
  78     0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
  79     0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
  80     0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
  81     0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
  82     0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
  83     0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
  84     0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
  85     0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
  86     0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
  87     0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
  88     0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
  89     0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
  90     0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
  91     0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
  92     0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
  93     0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
  94     0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
  95     0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
  96     0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
  97 };
  98
  99 static int64_t get_utf8(GetBitContext *gb) ICODE_ATTR_FLAC;
 100 static int64_t get_utf8(GetBitContext *gb)
 101 {
 102     uint64_t val;
 103     int ones=0, bytes;
 104
 105     while(get_bits1(gb))
 106         ones++;
 107
 108     if     (ones==0) bytes=0;
 109     else if(ones==1) return -1;
 110     else             bytes= ones - 1;
 111
 112     val= get_bits(gb, 7-ones);
 113     while(bytes--){
 114         const int tmp = get_bits(gb, 8);
 115
 116         if((tmp>>6) != 2)
 117             return -2;
 118         val<<=6;
 119         val|= tmp&0x3F;
 120     }
 121     return val;
 122 }
 123
 124 static int get_crc8(const uint8_t *buf, int count) ICODE_ATTR_FLAC;
 125 static int get_crc8(const uint8_t *buf, int count)
 126 {
 127     int crc=0;
 128     int i;
 129
 130     for(i=0; i<count; i++){
 131         crc = table_crc8[crc ^ buf[i]];
 132     }
 133
 134     return crc;
 135 }
 136
 137 static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 138 static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order)
 139 {
 140     int i, tmp, partition, method_type, rice_order;
 141     int sample = 0, samples;
 142
 143     method_type = get_bits(&s->gb, 2);
 144     if (method_type > 1){
 145         //fprintf(stderr,"illegal residual coding method %d\n", method_type);
 146         return -3;
 147     }
 148
 149     rice_order = get_bits(&s->gb, 4);
 150
 151     samples= s->blocksize >> rice_order;
 152
 153     sample=
 154     i= pred_order;
 155     for (partition = 0; partition < (1 << rice_order); partition++)
 156     {
 157         tmp = get_bits(&s->gb, method_type == 0 ? 4 : 5);
 158         if (tmp == (method_type == 0 ? 15 : 31))
 159         {
 160             //fprintf(stderr,"fixed len partition\n");
 161             tmp = get_bits(&s->gb, 5);
 162             for (; i < samples; i++, sample++)
 163                 decoded[sample] = get_sbits(&s->gb, tmp);
 164         }
 165         else
 166         {
 167             for (; i < samples; i++, sample++){
 168                 decoded[sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
 169             }
 170         }
 171         i= 0;
 172     }
 173
 174     return 0;
 175 }
 176
 177 static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 178 static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order)
 179 {
 180     const int blocksize = s->blocksize;
 181     int a, b, c, d, i;
 182
 183     /* warm up samples */
 184     for (i = 0; i < pred_order; i++)
 185     {
 186         decoded[i] = get_sbits(&s->gb, s->curr_bps);
 187     }
 188
 189     if (decode_residuals(s, decoded, pred_order) < 0)
 190         return -4;
 191
 192     a = decoded[pred_order-1];
 193     b = a - decoded[pred_order-2];
 194     c = b - decoded[pred_order-2] + decoded[pred_order-3];
 195     d = c - decoded[pred_order-2] + 2*decoded[pred_order-3] - decoded[pred_order-4];
 196
 197     switch(pred_order)
 198     {
 199         case 0:
 200             break;
 201         case 1:
 202             for (i = pred_order; i < blocksize; i++)
 203                 decoded[i] = a += decoded[i];
 204             break;
 205         case 2:
 206             for (i = pred_order; i < blocksize; i++)
 207                 decoded[i] = a += b += decoded[i];
 208             break;
 209         case 3:
 210             for (i = pred_order; i < blocksize; i++)
 211                 decoded[i] = a += b += c += decoded[i];
 212             break;
 213         case 4:
 214             for (i = pred_order; i < blocksize; i++)
 215                 decoded[i] = a += b += c += d += decoded[i];
 216             break;
 217         default:
 218             return -5;
 219     }
 220
 221     return 0;
 222 }
 223
 224 static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 225 static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order)
 226 {
 227     int sum, i, j;
 228     int64_t wsum;
 229     int coeff_prec, qlevel;
 230     int coeffs[pred_order];
 231
 232     /* warm up samples */
 233     for (i = 0; i < pred_order; i++)
 234     {
 235         decoded[i] = get_sbits(&s->gb, s->curr_bps);
 236     }
 237
 238     coeff_prec = get_bits(&s->gb, 4) + 1;
 239     if (coeff_prec == 16)
 240     {
 241         //fprintf(stderr,"invalid coeff precision\n");
 242         return -6;
 243     }
 244     qlevel = get_sbits(&s->gb, 5);
 245     if (qlevel < 0)
 246     {
 247         //fprintf(stderr,"qlevel %d not supported, maybe buggy stream\n", qlevel);
 248         return -7;
 249     }
 250
 251     for (i = 0; i < pred_order; i++)
 252     {
 253         coeffs[i] = get_sbits(&s->gb, coeff_prec);
 254     }
 255
 256     if (decode_residuals(s, decoded, pred_order) < 0)
 257         return -8;
 258
 259     if ((s->bps + coeff_prec + av_log2(pred_order)) <= 32) {
 260         #if defined(CPU_COLDFIRE)
 261         (void)sum;
 262         lpc_decode_emac(s->blocksize - pred_order, qlevel, pred_order,
 263                         decoded + pred_order, coeffs);
 264         #elif defined(CPU_ARM)
 265         (void)sum;
 266         lpc_decode_arm(s->blocksize - pred_order, qlevel, pred_order,
 267                        decoded + pred_order, coeffs);
 268         #else
 269         for (i = pred_order; i < s->blocksize; i++)
 270         {
 271             sum = 0;
 272             for (j = 0; j < pred_order; j++)
 273                 sum += coeffs[j] * decoded[i-j-1];
 274             decoded[i] += sum >> qlevel;
 275         }
 276         #endif
 277     } else {
 278         #if defined(CPU_COLDFIRE)
 279         (void)wsum;
 280         (void)j;
 281         lpc_decode_emac_wide(s->blocksize - pred_order, qlevel, pred_order,
 282                              decoded + pred_order, coeffs);
 283         #else
 284         for (i = pred_order; i < s->blocksize; i++)
 285         {
 286             wsum = 0;
 287             for (j = 0; j < pred_order; j++)
 288                 wsum += (int64_t)coeffs[j] * (int64_t)decoded[i-j-1];
 289             decoded[i] += wsum >> qlevel;
 290         }
 291         #endif
 292     }
 293
 294     return 0;
 295 }
 296
 297 static inline int decode_subframe(FLACContext *s, int channel, int32_t* decoded)
 298 {
 299     int type, wasted = 0;
 300     int i, tmp;
 301
 302     s->curr_bps = s->bps;
 303     if(channel == 0){
 304         if(s->decorrelation == RIGHT_SIDE)
 305             s->curr_bps++;
 306     }else{
 307         if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
 308             s->curr_bps++;
 309     }
 310
 311     if (get_bits1(&s->gb))
 312     {
 313         //fprintf(stderr,"invalid subframe padding\n");
 314         return -9;
 315     }
 316     type = get_bits(&s->gb, 6);
 317 //    wasted = get_bits1(&s->gb);
 318
 319 //    if (wasted)
 320 //    {
 321 //        while (!get_bits1(&s->gb))
 322 //            wasted++;
 323 //        if (wasted)
 324 //            wasted++;
 325 //        s->curr_bps -= wasted;
 326 //    }
 327 #if 0
 328     wasted= 16 - av_log2(show_bits(&s->gb, 17));
 329     skip_bits(&s->gb, wasted+1);
 330     s->curr_bps -= wasted;
 331 #else
 332     if (get_bits1(&s->gb))
 333     {
 334         wasted = 1;
 335         while (!get_bits1(&s->gb))
 336             wasted++;
 337         s->curr_bps -= wasted;
 338         //fprintf(stderr,"%d wasted bits\n", wasted);
 339     }
 340 #endif
 341 //FIXME use av_log2 for types
 342     if (type == 0)
 343     {
 344         //fprintf(stderr,"coding type: constant\n");
 345         tmp = get_sbits(&s->gb, s->curr_bps);
 346         for (i = 0; i < s->blocksize; i++)
 347             decoded[i] = tmp;
 348     }
 349     else if (type == 1)
 350     {
 351         //fprintf(stderr,"coding type: verbatim\n");
 352         for (i = 0; i < s->blocksize; i++)
 353             decoded[i] = get_sbits(&s->gb, s->curr_bps);
 354     }
 355     else if ((type >= 8) && (type <= 12))
 356     {
 357         //fprintf(stderr,"coding type: fixed\n");
 358         if (decode_subframe_fixed(s, decoded, type & ~0x8) < 0)
 359             return -10;
 360     }
 361     else if (type >= 32)
 362     {
 363         //fprintf(stderr,"coding type: lpc\n");
 364         if (decode_subframe_lpc(s, decoded, (type & ~0x20)+1) < 0)
 365             return -11;
 366     }
 367     else
 368     {
 369         //fprintf(stderr,"Unknown coding type: %d\n",type);
 370         return -12;
 371     }
 372
 373     if (wasted)
 374     {
 375         int i;
 376         for (i = 0; i < s->blocksize; i++)
 377             decoded[i] <<= wasted;
 378     }
 379
 380     return 0;
 381 }
 382
 383 static int decode_frame(FLACContext *s,
 384                         int32_t* decoded0,
 385                         int32_t* decoded1,
 386                         void (*yield)(void)) ICODE_ATTR_FLAC;
 387 static int decode_frame(FLACContext *s,
 388                         int32_t* decoded0,
 389                         int32_t* decoded1,
 390                         void (*yield)(void))
 391 {
 392     int blocksize_code, sample_rate_code, sample_size_code, assignment, crc8;
 393     int decorrelation, bps, blocksize, samplerate;
 394     int res;
 395
 396     blocksize_code = get_bits(&s->gb, 4);
 397
 398     sample_rate_code = get_bits(&s->gb, 4);
 399
 400     assignment = get_bits(&s->gb, 4); /* channel assignment */
 401     if (assignment < 8 && s->channels == assignment+1)
 402         decorrelation = INDEPENDENT;
 403     else if (assignment >=8 && assignment < 11 && s->channels == 2)
 404         decorrelation = LEFT_SIDE + assignment - 8;
 405     else
 406     {
 407         return -13;
 408     }
 409
 410     sample_size_code = get_bits(&s->gb, 3);
 411     if(sample_size_code == 0)
 412         bps= s->bps;
 413     else if((sample_size_code != 3) && (sample_size_code != 7))
 414         bps = sample_size_table[sample_size_code];
 415     else
 416     {
 417         return -14;
 418     }
 419
 420     if (get_bits1(&s->gb))
 421     {
 422         return -15;
 423     }
 424
 425     /* Get the samplenumber of the first sample in this block */
 426     s->samplenumber=get_utf8(&s->gb);
 427
 428     /* samplenumber actually contains the frame number for streams
 429        with a constant block size - so we multiply by blocksize to
 430        get the actual sample number */
 431     if (s->min_blocksize == s->max_blocksize) {
 432         s->samplenumber*=s->min_blocksize;
 433     }
 434
 435 #if 0
 436     if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
 437         (s->min_blocksize != s->max_blocksize)){
 438     }else{
 439     }
 440 #endif
 441
 442     if (blocksize_code == 0)
 443         blocksize = s->min_blocksize;
 444     else if (blocksize_code == 6)
 445         blocksize = get_bits(&s->gb, 8)+1;
 446     else if (blocksize_code == 7)
 447         blocksize = get_bits(&s->gb, 16)+1;
 448     else
 449         blocksize = blocksize_table[blocksize_code];
 450
 451     if(blocksize > s->max_blocksize){
 452         return -16;
 453     }
 454
 455     if (sample_rate_code == 0){
 456         samplerate= s->samplerate;
 457     }else if ((sample_rate_code < 12))
 458         samplerate = sample_rate_table[sample_rate_code];
 459     else if (sample_rate_code == 12)
 460         samplerate = get_bits(&s->gb, 8) * 1000;
 461     else if (sample_rate_code == 13)
 462         samplerate = get_bits(&s->gb, 16);
 463     else if (sample_rate_code == 14)
 464         samplerate = get_bits(&s->gb, 16) * 10;
 465     else{
 466         return -17;
 467     }
 468
 469     skip_bits(&s->gb, 8);
 470     crc8= get_crc8(s->gb.buffer, get_bits_count(&s->gb)/8);
 471     if(crc8){
 472         return -18;
 473     }
 474
 475     s->blocksize    = blocksize;
 476     s->samplerate   = samplerate;
 477     s->bps          = bps;
 478     s->decorrelation= decorrelation;
 479
 480     yield();
 481     /* subframes */
 482     if ((res=decode_subframe(s, 0, decoded0)) < 0)
 483         return res-100;
 484
 485     yield();
 486
 487     if (s->channels==2) {
 488       if ((res=decode_subframe(s, 1, decoded1)) < 0)
 489           return res-200;
 490     }
 491
 492     yield();
 493     align_get_bits(&s->gb);
 494
 495     /* frame footer */
 496     skip_bits(&s->gb, 16); /* data crc */
 497
 498     return 0;
 499 }
 500
 501 int flac_decode_frame(FLACContext *s,
 502                              int32_t* decoded0,
 503                              int32_t* decoded1,
 504                              uint8_t *buf, int buf_size,
 505                              void (*yield)(void))
 506 {
 507     int tmp;
 508     int i;
 509     int framesize;
 510     int scale;
 511
 512     init_get_bits(&s->gb, buf, buf_size*8);
 513
 514     tmp = get_bits(&s->gb, 16);
 515     if ((tmp & 0xFFFE) != 0xFFF8){
 516         return -41;
 517     }
 518
 519     if ((framesize=decode_frame(s,decoded0,decoded1,yield)) < 0){
 520        s->bitstream_size=0;
 521        s->bitstream_index=0;
 522        return framesize;
 523     }
 524
 525     yield();
 526
 527     scale=FLAC_OUTPUT_DEPTH-s->bps;
 528     switch(s->decorrelation)
 529     {
 530         case INDEPENDENT:
 531             if (s->channels==1) {;
 532                 for (i = 0; i < s->blocksize; i++)
 533                 {
 534                     decoded0[i] = decoded0[i] << scale;
 535                 }
 536             } else {
 537                 for (i = 0; i < s->blocksize; i++)
 538                 {
 539                     decoded0[i] = decoded0[i] << scale;
 540                     decoded1[i] = decoded1[i] << scale;
 541                 }
 542             }
 543             break;
 544         case LEFT_SIDE:
 545             //assert(s->channels == 2);
 546             for (i = 0; i < s->blocksize; i++)
 547             {
 548                 decoded1[i] = (decoded0[i] - decoded1[i]) << scale;
 549                 decoded0[i] = decoded0[i] << scale;
 550             }
 551             break;
 552         case RIGHT_SIDE:
 553             //assert(s->channels == 2);
 554             for (i = 0; i < s->blocksize; i++)
 555             {
 556                 decoded0[i] = (decoded0[i] + decoded1[i]) << scale;
 557                 decoded1[i] = decoded1[i] << scale;
 558             }
 559             break;
 560         case MID_SIDE:
 561             //assert(s->channels == 2);
 562             for (i = 0; i < s->blocksize; i++)
 563             {
 564                 int mid, side;
 565                 mid = decoded0[i];
 566                 side = decoded1[i];
 567
 568 #if 1 //needs to be checked but IMHO it should be binary identical
 569                 mid -= side>>1;
 570                 decoded0[i] = (mid + side) << scale;
 571                 decoded1[i] = mid << scale;
 572 #else
 573
 574                 mid <<= 1;
 575                 if (side & 1)
 576                     mid++;
 577                 decoded0[i] = ((mid + side) >> 1) << scale;
 578                 decoded1[i] = ((mid - side) >> 1) << scale;
 579 #endif
 580             }
 581             break;
 582     }
 583
 584     s->framesize = (get_bits_count(&s->gb)+7)>>3;
 585
 586     return 0;
 587 }