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